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How To Write A Natural Disasters Research Report

Researching natural disasters give kids a chance to dig deeper into a topic of interest. Today I discuss the 7 steps to writing a research report.

From tsunamis to earthquakes, tornados to volcanos, landslides to avalanches, natural disasters happen. They teach us about geology and geography, weather and climate science. They are powerful and fascinating, whether they hit close to home or pop up in far away news.

Researching natural disasters give kids a chance to dig deeper into a topic of interest. They can learn about the research and report writing process and about a particular natural disaster.

Through this process, students

  • Understand that reports are used to describe
  • Use information texts to collect facts about natural disasters
  • Write a report to describe a natural disaster.

Steps to writing a research report

Like any other writing, writing a research report is a process. Students need to learn how to conduct research and then how to put their findings together in a well organized report.

  • Brainstorm topics and research questions

Start by brainstorming what you know about a topic. Then ask, what else would I like to know about this topic? This is a great group activity as one student’s idea may spark another. Students can use some of the wonderings or what else they would like to know to help focus their research.

  •  Consult informational resources

Students can use informational texts such as nonfiction books and internet resources to gather information. Students may also draw from news accounts of natural disasters or talk to eye witnesses or experts. Students should learn about choosing appropriate sources in this phase. This includes understanding primary and secondary sources, and also looking at the age of the information and who produced it.

There are several skills students need for effective note taking. They need to understand what information is relevant to their report. For example, if they are writing about how hurricanes form, lots of details about the effects of historic hurricanes aren’t relevant. They should know how to record sources so that they can go back to a source for clarification or cite the source as needed. Perhaps most important, they need to understand paraphrasing, direct quoting, and plagiarism.

  • Organize your ideas

An outline is appropriate for organizing ideas in a report. It may be a formal outline or a graphic organizer that helps get ideas in order. Once students have an outline, they can organize their notes based on the outline.

  • Use notes to write report

Using their outline and notes, students now actually draft their report, including introduction, body paragraphs, and conclusion. While students may be used to writing from beginning to end, many writers find writing the body paragraphs first and then writing the introduction and conclusion a useful process.

  • Edit report

Students can share reports with a partner or small group to get feedback on areas where ideas may need clarification or where readers might have questions. You can also use editing checklists to make sure all the pieces of the report are done, that students have checked for run-on sentences, spelling errors, punctuation, and the like.

  • Share report and reflect on learning

Students can read reports or parts of them aloud. You could host a museum of natural disasters featuring the reports. You could create a library of natural disasters for students to read at some point during the day. In addition, have students reflect on their learning.

I’ve put together a unit on writing research reports about natural disasters that takes you from brainstorming through to reflection. This series of lessons introduces students to informational texts and how to use these texts to find information about natural disasters in order to write a report. This unit contains 5 individual activities and a final project s uitable for grades 4 – 7.

You can learn more and get your Natural Disasters Report Writing pack here.

Researching natural disasters give kids a chance to dig deeper into a topic of interest. Today I discuss the 7 steps to writing a research report.

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National Academies Press: OpenBook

Facing Hazards and Disasters: Understanding Human Dimensions (2006)

Chapter: 4 research on disaster response and recovery, 4 research on disaster response and recovery.

T his chapter and the preceding one use the conceptual model presented in Chapter 1 (see Figure 1.1 ) as a guide to understanding societal response to hazards and disasters. As specified in that model, Chapter 3 discusses three sets of pre-disaster activities that have the potential to reduce disaster losses: hazard mitigation practices, emergency preparedness practices, and pre-disaster planning for post-disaster recovery. This chapter focuses on National Earthquake Hazards Reduction Program (NEHRP) contributions to social science knowledge concerning those dimensions of the model that are related to post-disaster response and recovery activities. As in Chapter 3 , discussions are organized around research findings regarding different units of analysis, including individuals, households, groups and organizations, social networks, and communities. The chapter also highlights trends, controversies, and issues that warrant further investigation. The contents of this chapter are linked to key themes discussed elsewhere in this report, including the conceptualization and measurement of societal vulnerability and resilience, the importance of taking diversity into account in understanding both response-related activities and recovery processes and outcomes, and linkages between hazard loss reduction and sustainability. Although this review centers primarily on research on natural disasters and to a lesser degree on technological disasters, research findings are also discussed in terms of their implications for understanding and managing emerging homeland security threats.

The discussions that follow seek to address several interrelated questions: What is currently known about post-disaster response and recovery,

and to what extent is that knowledge traceable to NEHRP-sponsored research activities? What gaps exist in that knowledge? What further research—both disciplinary and interdisciplinary—is needed to fill those gaps?


Emergency response encompasses a range of measures aimed at protecting life and property and coping with the social disruption that disasters produce. As noted in Chapter 3 , emergency response activities can be categorized usefully as expedient mitigation actions (e.g., clearing debris from channels when floods threaten, containing earthquake-induced fires and hazardous materials releases before they can cause additional harm) and population protection actions (e.g., warning, evacuation and other self-protective actions, search and rescue, the provision of emergency medical care and shelter; Tierney et al., 2001). Another common conceptual distinction in the literature on disaster response (Dynes et al., 1981) contrasts agent-generated demands , or the types of losses and forms of disruption that disasters create, and response-generated demands , such as the need for situation assessment, crisis communication and coordination, and response management. Paralleling preparedness measures, disaster response activities take place at various units of analysis, from individuals and households, to organizations, communities, and intergovernmental systems. This section does not attempt to deal exhaustively with the topic of emergency response activities, which is the most-studied of all phases of hazard and disaster management. Rather, it highlights key themes in the literature, with an emphasis on NEHRP-based findings that are especially relevant in light of newly recognized human-induced threats.

Public Response: Warning Response, Evacuation, and Other Self-Protective Actions

The decision processes and behaviors involved in public responses to disaster warnings are among the best-studied topics in the research literature. Over nearly three decades, NEHRP has been a major sponsor of this body of research. As noted in Chapter 3 , warning response research overlaps to some degree with more general risk communication research. For example, both literatures emphasize the importance of considering source, message, channel, and receiver effects on the warning process. While this discussion centers mainly on responses to official warning information, it should be noted that self-protective decision-making processes are also initiated in the absence of formal warnings—for example, in response to cues that people perceive as signaling impending danger and in disasters that occur without warning. Previous research suggests that the basic deci-

sion processes involved in self-protective action are similar across different types of disaster events, although the challenges posed and the problems that may develop can be agent specific.

As in other areas discussed here, empirical studies on warning response and self-protective behavior in different types of disasters and emergencies have led to the development of broadly generalizable explanatory models. One such model, the protective action decision model, developed by Perry, Lindell, and their colleagues (see, for example, Lindell and Perry, 2004), draws heavily on Turner and Killian’s (1987) emergent norm theory of collective behavior. According to that theory, groups faced with the potential need to act under conditions of uncertainty (or potential danger) engage in interaction in an attempt to develop a collective definition of the situation they face and a set of new norms that can guide their subsequent action. 1 Thus, when warnings and protective instructions are disseminated, those who receive warnings interact with one another in an effort to determine collectively whether the warning is authentic, whether it applies to them, whether they are indeed personally in danger, whether they can reduce their vulnerability through action, whether action is possible, and when they should act. These collective determinations are shaped in turn by such factors as (1) the characteristics of warning recipients , including their prior experience with the hazard in question or with similar emergencies, as well as their prior preparedness efforts; (2) situational factors , including the presence of perceptual cues signaling danger; and (3) the social contexts in which decisions are made—for example, contacts among family members, coworkers, neighborhood residents, or others present in the setting, as well as the strength of preexisting social ties. Through interaction and under the influence of these kinds of factors, individuals and groups develop new norms that serve as guidelines for action.

Conceptualizing warning response as a form of collective behavior that is guided by emergent norms brings several issues to the fore. One is that far from being automatic or governed by official orders, behavior undertaken in response to warnings is the product of interaction and deliberation among members of affected groups—activities that are typically accompanied by a search for additional confirmatory information. Circumstances that complicate the deliberation process, such as conflicting warning information that individuals and groups may receive, difficulties in getting in touch with others whose views are considered important for the decision-making process, or disagreements among group members about any aspect of the

Note that what is being discussed here are deliberations and decisions, not individual ones. Actions under conditions of uncertainty and urgency such as those that accompany disaster warnings should not be conceptualized in individualistic terms.

threat situation, invariably lead to additional efforts to communicate and confirm the information and lengthen the period between when a warning is issued and when groups actually respond.

Another implication of the emergent norm approach to protective action decision making is the recognition that groups may collectively define an emergency situation in ways that are at variance from official views. This is essentially what occurs in the shadow evacuation phenomenon, which has been documented in several emergency situations, including the Three Mile Island nuclear plant accident (Zeigler et al., 1981). While authorities may not issue a warning for a particular geographic area or group of people, or may even tell them they are safe, groups may still collectively decide that they are at risk or that the situation is fluid and confusing enough that they should take self-protective action despite official pronouncements.

The behavior of occupants of the World Trade Center during the September 11, 2001 terrorist attack illustrates the importance of collectively developed definitions. Groups of people in Tower 2 of the World Trade Center decided that they should evacuate the building after seeing and hearing about what was happening in Tower 1 and after speaking with coworkers and loved ones, even when official announcements and other building occupants indicated that they should not do so. Others decided to remain in the tower or, perhaps more accurately, they decided to delay evacuating until receiving additional information clarifying the extent to which they were in danger. Journalistic accounts suggest that decisions were shaped in part by what people could see taking place in Tower 1, conversations with others outside the towers who had additional relevant information, and directives received from those in positions of authority in tenant firms. In that highly confusing and time-constrained situation, emergent norms guiding the behavior of occupants of the second tower meant the difference between life and death when the second plane struck (NIST, 2005).

The large body of research that exists regarding decision making under threat conditions points to the need to consider a wide range of individual, group, situational, and resource-related factors that facilitate and inhibit self-protective action. Qualitatively based decision-tree models developed by Gladwin et al. (2001) demonstrate the complexity of self-protective decisions. As illustrated by their work on hurricane evacuation, a number of different factors contribute to decisions on whether or not to evacuate. Such factors range from perceptions of risk and personal safety with respect to a threatened disaster, to the extent of knowledge about specific areas at risk, to constraining factors such as the presence of pets in the home that require care, lack of a suitable place to go, counterarguments by other family members, fears of looting (shown by the literature to be unjustified; see, for example, Fischer, 1998), and fear that the evacuation process may

be more dangerous than staying home and riding out a hurricane. Warning recipients may decide that they should wait before evacuating, ultimately missing the opportunity to escape, or they may decide to shelter in-place after concluding that their homes are strong enough to resist hurricane forces despite what they are told by authorities.

In their research on Hurricane Andrew, Gladwin and Peacock describe some of the many factors that complicate the evacuation process for endangered populations (1997:54):

Except under extreme circumstances, households cannot be compelled to evacuate or to remain where they are, much less to prepare themselves for the threat. Even under extraordinary conditions many households have to be individually located and assisted or forced to comply. Segments of a population may fail to receive, ignore, or discount official requests and orders. Still others may not have the resources or wherewithal to comply. Much will depend upon the source of the information, the consistency of the message received from multiple sources, the nature of the information conveyed, as well as the household’s ability to perceive the danger, make decisions, and act accordingly. Disputes, competition, and the lack of coordination among local, state, and federal governmental agencies and between those agencies and privately controlled media can add confusion. Businesses and governmental agencies that refuse to release their employees and suspend normal activities can add still further to the confusion and noncompliance.

The normalcy bias adds other complications to the warning response process. While popular notions of crisis response behaviors seem to assume that people react automatically to messages signaling impending danger—for example, by fleeing in panic—the reality is quite different. People typically “normalize” unusual situations and persist in their everyday activities even when urged to act differently. As noted earlier, people will not act on threat information unless they perceive a personal risk to themselves. Simply knowing that a threat exists—even if that threat is described as imminent—is insufficient to motivate self-protective action. Nor can people be expected to act if warning-related guidance is not specific enough to provide them with a blueprint for what to do or if they do not believe they have the resources required to follow the guidance. One practical implication of research on warnings is that rather than being concerned about panicking the public with warning information, or about communicating too much information, authorities should instead be seeking better ways to penetrate the normalcy bias, persuade people that they should be concerned about an impending danger, provide directives that are detailed enough to follow during an emergency, and encourage pre-disaster response planning so that people have thought through what to do prior to being required to act.

Other Important Findings Regarding the Evacuation Process

As noted earlier, evacuation behavior has long been recognized as the reflection of social-level factors and collective deliberation. Decades ago, Drabek (1983) established that households constitute the basic deliberative units for evacuation decision making in community-wide disasters and that the decisions that are ultimately made tend to be consistent with pre-disaster household authority patterns. For example, gender-related concerns often enter into evacuation decision making. Women tend to be more risk-averse and more inclined to want to follow evacuation orders, while males are less inclined to do so (for an extensive discussion of gender differences in vulnerability, risk perception, and responses to disasters, see Fothergill, 1998). In arriving at decisions regarding evacuation, households take official orders into account, but they weigh those orders in light of their own priorities, other information sources, and their past experiences. Information received from media sources and from family and friends, along with confirmatory data actively sought by those at risk, generally has a greater impact on evacuation decisions than information provided by public officials (Dow and Cutter, 1998, 2000).

Recent research also suggests that family evacuation patterns are undergoing change. For example, even though families decide together to evacuate and wish to stay together, they increasingly tend to use more than one vehicle to evacuate—perhaps because they want to take more of their possessions with them, make sure their valuable vehicles are protected, or return to their homes at different times (Dow and Cutter, 2002). Other social influences also play a role. Neighborhood residents may be more willing to evacuate or, conversely, more inclined to delay the decision to evacuate if they see their neighbors doing so. Rather than becoming more vigilant, communities that are struck repeatedly by disasters such as hurricanes and floods may develop “disaster subcultures,” such as groups that see no reason to heed evacuation orders since sheltering in-place has been effective in previous events.

NEHRP-sponsored research has shown that different racial, ethnic, income, and special needs groups respond in different ways to warning information and evacuation orders, in part because of the unique characteristics of these groups, the manner in which they receive information during crises, and their varying responses to different information sources. For example, members of some minority groups tend to have large extended families, making contacting family members and deliberating on alternative courses of action a more complicated process. Lower-income groups, inner-city residents, and elderly persons are more likely to have to rely on public transportation, rather than personal vehicles, in order to evacuate. Lower-income and minority populations, who tend to have larger families, may

also be reluctant to impose on friends and relatives for shelter. Lack of financial resources may leave less-well-off segments of the population less able to afford to take time off from work when disasters threaten, to travel long distances to avoid danger, or to pay for emergency lodging. Socially isolated individuals, such as elderly persons living alone, may lack the social support that is required to carry out self-protective actions. Members of minority groups may find majority spokespersons and official institutions less credible and believable than members of the white majority, turning instead to other sources, such as their informal social networks. Those who rely on non-English-speaking mass media for news may receive less complete warning information, or may receive warnings later than those who are tuned into mainstream media sources (Aguirre et al., 1991; Perry and Lindell, 1991; Lindell and Perry, 1992, 2004; Klinenberg, 2002; for more extensive discussions, see Tierney et al., 2001).

Hurricane Katrina vividly revealed the manner in which social factors such as those discussed above influence evacuation decisions and actions. In many respects, the Katrina experience validated what social science research had already shown with respect to evacuation behavior. Those who stayed behind did so for different reasons—all of which have been discussed in past research. Some at-risk residents lacked resources, such as automobiles and financial resources that would have enabled them to escape the city. Based on their past experiences with hurricanes like Betsey and Camille, others considered themselves not at risk and decided it was not necessary to evacuate. Still others, particularly elderly residents, felt so attached to their homes that they refused to leave even when transportation was offered.

This is not to imply that evacuation-related problems stemmed solely from individual decisions. Katrina also revealed the crucial significance of evacuation planning, effective warnings, and government leadership in facilitating evacuations. Planning efforts in New Orleans were rudimentary at best, clear evacuation orders were given too late, and the hurricane rendered evacuation resources useless once the city began to flood.

With respect to other patterns of evacuation behavior when they do evacuate, most people prefer to stay with relatives or friends, rather than using public shelters. Shelter use is generally limited to people who feel they have no other options—for example, those who have no close friends and relatives to take them in and cannot afford the price of lodging. Many people avoid public shelters or elect to stay in their homes because shelters do not allow pets. Following earthquakes, some victims, particularly Latinos in the United States who have experienced or learned about highly damaging earthquakes in their countries of origin, avoid indoor shelter of all types, preferring instead to sleep outdoors (Tierney, 1988; Phillips, 1993; Simile, 1995).

Disaster warnings involving “near misses,” as well as concerns about the possible impact of elevated color-coded homeland security warnings,

raise the question of whether warnings that do not materialize can induce a “cry-wolf” effect, resulting in lowered attention to and compliance with future warnings. The disaster literature shows little support for the cry-wolf hypothesis. For example, Dow and Cutter (1998) studied South Carolina residents who had been warned of impending hurricanes that ultimately struck North Carolina. Earlier false alarms did not influence residents’ decisions on whether to evacuate; that is, there was little behavioral evidence for a cry-wolf effect. However, false alarms did result in a decrease in confidence in official warning sources, as opposed to other sources of information on which people relied in making evacuation decisions—certainly not the outcome officials would have intended. Studies also suggest that it is advisable to clarify for the public why forecasts and warnings were uncertain or incorrect. Based on an extensive review of the warning literature, Sorensen (2000:121) concluded that “[t]he likelihood of people responding to a warning is not diminished by what has come to be labeled the ‘cry-wolf’ syndrome if the basis for the false alarm is understood [emphasis added].” Along those same lines, Atwood and Major (1998) argue that if officials explain reasons for false alarms, that information can increase public awareness and make people more likely to respond to subsequent hazard advisories.


Dispelling myths about crisis-related behavior: panic and social breakdown.

Numerous individual studies and research syntheses have contrasted commonsense ideas about how people respond during crises with empirical data on actual behavior. Among the most important myths addressed in these analyses is the notion that panic and social disorganization are common responses to imminent threats and to actual disaster events (Quarantelli and Dynes, 1972; Johnson, 1987; Clarke, 2002). True panic, defined as highly individualistic flight behavior that is nonsocial in nature, undertaken without regard to social norms and relationships, is extremely rare prior to and during extreme events of all types. Panic takes place under specific conditions that are almost never present in disaster situations. Panic only occurs when individuals feel completely isolated and when both social bonds and measures to promote safety break down to such a degree that individuals feel totally on their own in seeking safety. Panic results from a breakdown in the ongoing social order—a breakdown that Clarke (2003:128) describes as having moral, network, and cognitive dimensions:

There is a moral failure, so that people pursue their self interest regardless

of rules of duty and obligation to others. There is a network failure, so that the resources that people can normally draw on in times of crisis are no longer there. There is a cognitive failure, in which someone’s understanding of how they are connected to others is cast aside.

Failures on this scale almost never occur during disasters. Panic reactions are rare in part because social bonds remain intact and extremely resilient even under conditions of severe danger (Johnson, 1987; Johnson et al., 1994; Feinberg and Johnson, 2001).

Panic persists in public and media discourses on disasters, in part because those discourses conflate a wide range of other behaviors with panic. Often, people are described as panicking because they experience feelings of intense fear, even though fright and panic are conceptually and behaviorally distinct. Another behavioral pattern that is sometimes labeled panic involves intensified rumors and information seeking, which are common patterns among publics attempting to make sense of confusing and potentially dangerous situations. Under conditions of uncertainty, people make more frequent use of both informal ties and official information sources, as they seek to collectively define threats and decide what actions to take. Such activities are a normal extension of everyday information-seeking practices (Turner, 1994). They are not indicators of panic.

The phenomenon of shadow evacuation, discussed earlier, is also frequently confused with panic. Such evacuations take place because people who are not defined by authorities as in danger nevertheless determine that they are—perhaps because they have received conflicting or confusing information or because they are geographically close to areas considered at risk (Tierney et al., 2001). Collective demands for antibiotics by those considered not at risk for anthrax, “runs” on stores to obtain self-protective items, and the so-called worried-well phenomenon are other forms of collective behavior that reflect the same sociobehavioral processes that drive shadow evacuations: emergent norms that define certain individuals and groups as in danger, even though authorities do not consider them at risk; confusion about the magnitude of the risk; a collectively defined need to act; and in some cases, an unwillingness to rely on official sources for self-protective advice. These types of behaviors, which constitute interesting subjects for research in their own right, are not examples of panic.

Research also indicates that panic and other problematic behaviors are linked in important ways to the manner in which institutions manage risk and disaster. Such behaviors are more likely to emerge when those who are in danger come to believe that crisis management measures are ineffective, suggesting that enhancing public understanding of and trust in preparedness measures and in organizations charged with managing disasters can lessen the likelihood of panic. With respect to homeland security threats, some researchers have argued that the best way to “vaccinate” the public

against the emergence of panic in situations involving weapons of mass destruction is to provide timely and accurate information about impending threats and to actively include the public in pre-crisis preparedness efforts (Glass and Shoch-Spana, 2002).

Blaming the public for panicking during emergencies serves to diffuse responsibility from professionals whose duty it is to protect the public, such as emergency managers, fire and public safety officials, and those responsible for the design, construction, and safe operation of buildings and other structures (Sime, 1999). The empirical record bears out the fact that to the extent panic does occur during emergencies, such behavior can be traced in large measure to environmental factors such as overcrowding, failure to provide adequate egress routes, and breakdowns in communications, rather than to some inherent human impulse to stampede with complete disregard for others. Any potential for panic and other problematic behaviors that may exist can, in other words, be mitigated through appropriate design, regulatory, management, and communications strategies.

As discussed elsewhere in this report, looting and violence are also exceedingly rare in disaster situations. Here again, empirical evidence of what people actually do during and following disasters contradicts what many officials and much of the public believe. Beliefs concerning looting are based not on evidence but rather on assumptions—for example, that social control breaks down during disasters and that lawlessness and violence inevitably result when the social order is disrupted. Such beliefs fail to take into account the fact that powerful norms emerge during disasters that foster prosocial behavior—so much so that lawless behavior actually declines in disaster situations. Signs erected following disasters saying, “We shoot to kill looters” are not so much evidence that looting is occurring as they are evidence that community consensus condemns looting.

The myth of disaster looting can be contrasted with the reality of looting during episodes of civil disorder such as the riots of the 1960s and the 1992 Los Angeles unrest. During episodes of civil unrest, looting is done publicly, in groups, quite often in plain sight of law enforcement officials. Taking goods and damaging businesses are the hallmarks of modern “commodity riots.” New norms also emerge during these types of crises, but unlike the prosocial norms that develop in disasters, norms governing behavior during civil unrest permit and actually encourage lawbreaking. Under these circumstances, otherwise law-abiding citizens allow themselves to take part in looting behavior (Dynes and Quarantelli, 1968; Quarantelli and Dynes, 1970).

Looting and damaging property can also become normative in situations that do not involve civil unrest—for example, in victory celebrations following sports events. Once again, in such cases, norms and traditions governing behavior in crowd celebrations encourage destructive activities

(Rosenfeld, 1997). The behavior of participants in these destructive crowd celebrations again bears no resemblance to that of disaster victims.

In the aftermath of Hurricane Katrina, social scientists had no problem understanding why episodes of looting might have been more widespread in that event than in the vast majority of U.S. disasters. Looting has occurred on a widespread basis following other disasters, although such cases have been rare. Residents of St. Croix engaged in extensive looting behavior following Hurricane Hugo, and this particular episode sheds light on why some Katrina victims might have felt justified in looting. Hurricane Hugo produced massive damage on St. Croix, and government agencies were rendered helpless. Essentially trapped on the island, residents had no idea when help would arrive. Instead, they felt entirely on their own following Hugo. The tourist-based St. Croix economy was characterized by stark social class differences, and crime and corruption had been high prior to the hurricane. Under these circumstances, looting for survival was seen as justified, and patterns of collective behavior developed that were not unlike those seen during episodes of civil unrest. Even law enforcement personnel joined in the looting (Quarantelli, 2006; Rodriguez et al., forthcoming).

Despite their similarities, the parallels between New Orleans and St. Croix should not be overstated. It is now clear that looting and violent behavior were far less common than initially reported and that rumors concerning shootings, rapes, and murders were groundless. The media employed the “looting frame” extensively while downplaying far more numerous examples of selflessness and altruism. In hindsight, it now appears that many reports involving looting and social breakdown were based on stereotyped images of poor minority community residents (Tierney et al., forthcoming).

Extensive research also indicates that despite longstanding evidence, beliefs about disaster-related looting and lawlessness remain quite common, and these beliefs can influence the behavior of both community residents and authorities. For example, those who are at risk may decide not to evacuate and instead stay in their homes to protect their property from looters (Fischer, 1998). Concern regarding looting and lawlessness may cause government officials to make highly questionable and even counterproductive decisions. Following Hurricane Katrina, for example, based largely on rumors and exaggerated media reports, rescue efforts were halted because of fears for the safety of rescue workers, and Louisiana’s governor issued a “shoot-to-kill” order to quash looting. These decisions likely resulted in additional loss of life and also interfered with citizen efforts to aid one another. Interestingly, recent historical accounts indicate that similar decisions were made following other large-scale disasters, such as the 1871 Chicago fire, the 1900 Galveston hurricane, and the 1906 San Francisco earthquake and firestorm. In all three cases, armed force was used to stop

looting, and immigrant groups and the poor were scapegoated for their putative “crimes” (Fradkin, 2005). Along with Katrina, these events caution against making decisions on the basis of mythical beliefs and rumors.

As is the case with the panic myth, attributing the causes of looting behavior to individual motivations and impulses serves to deflect attention from the ways in which institutional failures can create insurmountable problems for disaster victims. When disasters occur, communications, disaster management, and service delivery systems should remain sufficiently robust that victims will not feel isolated and afraid or conclude that needed assistance will never arrive. More to the point, victims of disasters should not be scapegoated when institutions show themselves to be entirely incapable of providing even rudimentary forms of assistance—which was exactly what occurred with respect to Hurricane Katrina.

Patterns of Collective Mobilization in Disaster-Stricken Areas: Prosocial and Helping Behavior

In contrast to the panicky and lawless behavior that is often attributed to disaster-stricken populations, public behavior during earthquakes and other major community emergencies is overwhelmingly adaptive, prosocial, and aimed at promoting the safety of others and the restoration of ongoing community life. The predominance of prosocial behavior (and, conversely, a decline in antisocial behavior) in disaster situations is one of the most longstanding and robust research findings in the disaster literature. Research conducted with NEHRP sponsorship has provided an even better understanding of the processes involved in adaptive collective mobilization during disasters.

Helping Behavior and Disaster Volunteers. Helping behavior in disasters takes various forms, ranging from spontaneous and informal efforts to provide assistance to more organized emergent group activity, and finally to more formalized organizational arrangements. With respect to spontaneously developing and informal helping networks, disaster victims are assisted first by others in the immediate vicinity and surrounding area and only later by official public safety personnel. In a discussion on search and rescue activities following earthquakes, for example, Noji observes (1997:162)

In Southern Italy in 1980, 90 percent of the survivors of an earthquake were extricated by untrained, uninjured survivors who used their bare hands and simple tools such as shovels and axes…. Following the 1976 Tangshan earthquake, about 200,000 to 300,000 entrapped people crawled out of the debris on their own and went on to rescue others…. They became the backbone of the rescue teams, and it was to their credit that more than 80 percent of those buried under the debris were rescued.

Thus, lifesaving efforts in a stricken community rely heavily on the capabilities of relatively uninjured survivors, including untrained volunteers, as well as those of local firefighters and other relevant personnel.

The spontaneous provision of assistance is facilitated by the fact that when crises occur, they take place in the context of ongoing community life and daily routines—that is, they affect not isolated individuals but rather people who are embedded in networks of social relationships. When a massive gasoline explosion destroyed a neighborhood in Guadalajara, Mexico, in 1992, for example, survivors searched for and rescued their loved ones and neighbors. Indeed, they were best suited to do so, because they were the ones who knew who lived in different households and where those individuals probably were at the time of the disaster (Aguirre et al., 1995). Similarly, crowds and gatherings of all types are typically comprised of smaller groupings—couples, families, groups of friends—that become a source of support and aid when emergencies occur.

As the emergency period following a disaster lengthens, unofficial helping behavior begins to take on a more structured form with the development of emergent groups—newly formed entities that become involved in crisis-related activities (Stallings and Quarantelli, 1985; Saunders and Kreps, 1987). Emergent groups perform many different types of activities in disasters, from sandbagging to prevent flooding, to searching for and rescuing victims and providing for other basic needs, to post-disaster cleanup and the informal provision of recovery assistance to victims. Such groupings form both because of the strength of altruistic norms that develop during disasters and because of emerging collective definitions that victims’ needs are not being met—whether official agencies share those views or not. While emergent groups are in many ways essential for the effectiveness of crisis response activities, their activities may be seen as unnecessary or even disruptive by formal crisis response agencies. In the aftermath of the attack on the World Trade Center, for example, numerous groups emerged to offer every conceivable type of assistance to victims and emergency responders. Some were incorporated into official crisis management activities, while others were labeled “rogue volunteers” by official agencies (Halford and Nolan, 2002; Kendra and Wachtendorf, 2002). 2

Disaster-related volunteering also takes place within more formalized organizational structures, both in existing organizations that mobilize in response to disasters and through organizations such as the Red Cross,

Indeed, many individuals persisted in literally demanding to be allowed to serve as volunteers, even after being repeatedly turned away. Some of those who were intent on serving as volunteers managed to talk their way into settings that were off-limits in order to offer their services.

which has a federal mandate to respond in presidentially declared disasters and relies primarily on volunteers in its provision of disaster services. Some forms of volunteering have been institutionalized in the United States through the development of the National Voluntary Organizations Active in Disaster (NVOAD) organization. NVOAD, a large federation of religious, public service, and other groups, has organizational affiliates in 49 states, the District of Columbia, Puerto Rico, and U.S. territories. National-level NVOAD affiliates include organizations such as the Salvation Army, Church World Service, Church of the Brethren Disaster Response, and dozens of others that provide disaster services. Organizations such as the Red Cross and the NVOAD federation thus provide an infrastructure that can support very extensive volunteer mobilization. That infrastructure will likely form the basis for organized volunteering in future homeland security emergencies, just as it does in major disasters.

Helping behavior is very widespread after disasters, particularly large and damaging ones. For example, NEHRP-sponsored research indicates that in the three weeks following the 1985 earthquake in Mexico City, an estimated 1.7 to 2.1 million residents of that city were involved in providing volunteer aid. Activities in which volunteers engaged after that disaster included searching for and rescuing victims trapped under rubble, donating blood and supplies, inspecting building damage, collecting funds, providing medical care and psychological counseling, and providing food and shelter to victims (Wenger and James, 1994). In other research on post-earthquake volunteering, also funded by NEHRP, O’Brien and Mileti (1992) found that more than half of the population in San Francisco and Santa Cruz counties provided assistance to their fellow victims after the 1989 Loma Prieta earthquake—help that ranged from assisting with search and rescue and debris removal activities to offering food, water, and shelter to those in need. Thus, the volunteer sector responding to disasters typically constitutes a very large proportion of the population of affected regions, as well as volunteers converging from other locations.

Social science research, much of it conducted under NEHRP auspices, highlights a number of other points regarding post-disaster helping behavior. One such insight is that helping behavior in many ways mirrors roles and responsibilities people assume during nondisaster times. For example, when people provide assistance during disasters and other emergencies, their involvement is typically consistent with gender role expectations (Wenger and James, 1994; Feinberg and Johnson, 2001). Research also indicates that mass convergence of volunteers and donations can create significant management problems and undue burdens on disaster-stricken communities. In their eagerness to provide assistance, people may “overrespond” to disaster sites, creating congestion and putting themselves and others at risk or insisting on providing resources that are in fact not needed. After disas-

ters, communities typically experience major difficulties in dealing with unwanted and unneeded donations (Neal, 1990).

Research on public behavior during disasters has major implications for homeland security policies and practices. The research literature provides support for the inclusion of the voluntary sector and community-based organizations in preparedness and response efforts. Initiatives that aim at encouraging public involvement in homeland security efforts of all types are clearly needed. The literature also provides extensive evidence that members of the public are in fact the true “first responders” in major disasters. In using that term to refer to fire, police, and other public safety organizations, current homeland security discourse fails to recognize that community residents themselves constitute the front-line responders in any major emergency

One implication of this line of research is that planning and management models that fail to recognize the role of victims and volunteers in responding to all types of extreme events will leave responders unprepared for what will actually occur during disasters—for example, that, as research consistently shows, community residents will be the first to search for victims, provide emergency aid, and transport victims to health care facilities in emergencies of all types. 3 Such plans will also fail to take advantage of the public’s crucial skills, resources, and expertise. For this reason, experts on human-induced threats such as bioterrorism stress the value of public engagement and involvement in planning for homeland security emergencies (Working Group on “Governance Dilemmas” in Bioterrorism Response, 2004).

These research findings have significant policy implications. To date, Department of Homeland Security initiatives have focused almost exclusively on providing equipment and training for uniformed responders, as opposed to community residents. Recently, however, DHS has begun placing more emphasis on its Citizen Corps component, which is designed to mobilize the skills and talents of the public when disasters strike. Public involvement in Citizen Corps and Community Emergency Response Team (CERT) activities have expanded considerably since the terrorist attacks of

In one illustrative case, nearly half of those killed in the Northridge earthquake died as a consequence of damage in one of the buildings in the Northridge Meadows apartment complex, which was located not far from the earthquake’s epicenter. Fire department personnel dispatched in vehicles to the damaged area following the earthquake mistook the structure, a three-story building that had pancaked on the first floor, for a two-story building, and they did not stop to inspect the structure or look for victims. The fact that fire personnel failed to recognize the severity of the earthquake’s impact at the Northridge Meadows location made little difference in this case, because by that time, survivors had already escaped on their own or had been rescued by their fellow tenants.

9/11—a sign that many community residents around the nation wish to play an active role in responding to future disasters. The need for community-based preparedness and response initiatives is more evident than ever follow-ing the Katrina disaster.

Organizational, Governmental, and Network Responses. The importance of observing disaster response operations while they are ongoing or as soon as possible after disaster impact has long been a hallmark of the disaster research field. The quick-response tradition in disaster research, which has been a part of the field since its inception, developed out of a recognition that data on disaster response activities are perishable and that information collected from organizations after the passage of time is likely to be distorted and incomplete (Quarantelli, 1987, 2002). NEHRP funds, provided through grant supplements, Small Grants for Exploratory Research (SGER) awards, Earthquake Engineering Research Institute (EERI) reconnaissance missions, earthquake center reconnaissance funding, and small grants such as those provided by the Natural Hazards Research and Applications Information Center, have supported the collection of perishable data and enabled social science researchers to mobilize rapidly following major earthquakes and other disasters.

NEHRP provided substantial support for the collection of data on organizational and community responses in a number of earthquake events, including the 1987 Whittier Narrows, 1989 Loma Prieta, and 1994 Northridge earthquakes (see, for example, Tierney, 1988, 1994; EERI, 1995), as well as major earthquakes outside the United States such as the 1985 Mexico City, 1986 San Salvador, and 1988 Armenia events. More recently, NEHRP funds were used to support rapid-response research on the September 11, 2001 terrorist attacks and Hurricanes Katrina and Rita. Many of those studies focused on organizational issues in both the public and private sectors. (For a compilation of NEHRP-sponsored quick-response findings on the events of September 11, see Natural Hazards Research and Applications Information Center, 2003).

In many cases, quick-response research on disaster impacts and organizational and governmental response has led to subsequent in-depth studies on response-related issues identified during the post-impact reconnaissance phase. Following major events such as Loma Prieta, Northridge, and Kobe, insights from initial reconnaissance studies have formed the basis for broader research initiatives. Recent efforts have focused on ways to better take advantage of reconnaissance opportunities and to identify topics for longer-term study. A new plan has been developed to better coordinate and integrate both reconnaissance and longer-term research activities carried out with NEHRP support. That planning activity, outlined in the report The Plan to Coordinate NEHRP Post-earthquake Investigations (Holzer et

al., 2003), encompasses both reconnaissance and more systematic research activities in the earth sciences, engineering, and social sciences.

Through both initial quick-response activities and longer-term studies, NEHRP research has added to the knowledge base on how organizations cope with crises. Studies have focused on a variety of topics. A partial list of those topics includes organizational and group activities associated with the post-disaster search and rescue process (Aguirre et al., 1995); intergovernmental coordination during the response period following major disaster events (Nigg, 1998); expected and improvised organizational forms that characterize the disaster response milieu (Kreps, 1985, 1989b); strategies used by local government organizations to enhance interorganizational coordination following disasters (Drabek, 2003); and response activities undertaken by specific types of organizations, such as those in the volunteer and nonprofit sector (Neal, 1990) and tourism-oriented enterprises (Drabek, 1994).

Focusing specifically at the interorganizational level of analysis, NEHRP research has also highlighted the significance and mix of planned and improvised networks in disaster response. It has long been recognized that post-disaster response activities involve the formation of new (or emergent) networks of organizations. Indeed, one distinguishing feature of major crisis events is the prominence and proliferation of network forms of organization during the response period. Emergent multiorganizational networks (EMON) constitute new organizational interrelationships that reflect collective efforts to manage crisis events. Such networks are typically heterogeneous, consisting of existing organizations with pre-designated crisis management responsibilities, other organizations that may not have been included in prior planning but become involved in crisis response activities because those involved believe they have some contribution to make, and emergent groups. EMONs tend to be very large in major disaster events, encompassing hundreds and even thousands of interacting entities. As crisis conditions change and additional resources converge, EMON structures evolve, new organizations join the network, and new relationships form. What is often incorrectly described as disaster-generated “chaos” is more accurately seen as the understandable confusion that results when mobilization takes place on such a massive scale and when organizations and groups that may be unfamiliar with one another attempt to communicate, negotiate, and coordinate their activities under extreme pressure. (For more detailed discussions on EMONs in disasters, including the 2001 World Trade Center attack, see Drabek, 1985, 2003; Tierney, 2003; Tierney and Trainor, 2004.)

This is not to say that response activities always go smoothly. The disaster literature, organizational after-action reports, and official investigations contain numerous examples of problems that develop as inter-

organizational and intergovernmental networks attempt to address disaster-related challenges. Such problems include the following: failure to recognize the magnitude and seriousness of an event; delayed and insufficient responses; confusion regarding authorities and responsibilities, often resulting in major “turf battles;” resource shortages and misdirection of existing resources; poor organizational, interorganizational, and public communications; failures in intergovernmental coordination; failures in leadership and vision; inequities in the provision of disaster assistance; and organizational practices and cultures that permit and even encourage risky behavior. Hurricane Katrina became a national scandal because of the sheer scale on which these organizational pathologies manifested. However, Katrina was by no means atypical. In one form or another and at varying levels of severity, such pathologies are ever-present in the landscape of disaster response (for examples, see U.S. President’s Commission on the Accident at Three Mile Island, 1979; Perrow, 1984; Shrivastava, 1987; Sagan, 1993; National Academy of Public Administration, 1993; Vaughan, 1996, 1999; Peacock et al., 1997; Klinenberg, 2002; Select Bipartisan Committee to Investigate the Preparations for and Response to Hurricane Katrina, 2006; White House, 2006).

Management Considerations in Disaster Response

U.S. disaster researchers have identified two contrasting approaches to disaster response management, commonly termed the “command-and-control” and the “emergent human resources,” or “problem-solving,” models. The command-and-control model equates preparedness and response activities with military exercises. It assumes that (1) government agencies and other responders must be prepared to take over management and control in disaster situations, both because they are uniquely qualified to do so and because members of the public will be overwhelmed and will likely engage in various types of problematic behavior, such as panic; (2) disaster response activities are best carried out through centralized direction, control, and decision making; and (3) for response activities to be effective, a single person is ideally in charge, and relations among responding entities are arranged hierarchically.

In contrast, the emergent human resources, or problem-solving, model is based on the assumption that communities and societies are resilient and resourceful and that even in areas that are very hard hit by disasters, considerable local response capacity is likely to remain. Another underlying assumption is that preparedness strategies should build on existing community institutions and support systems—for example by pre-identifying existing groups, organizations, and institutions that are capable of assuming leadership when a disaster strikes. Again, this approach argues against

highly specialized approaches that tend to result in “stovepiped” rather than well-integrated preparedness and response efforts. The model also recognizes that when a disaster occurs, responding entities must be flexible if they are to be effective and that flexibility is best achieved through a decentralized response structure that seeks to solve problems as they arise, as opposed to top-down decision making. (For more extensive discussions of these two models and their implications, see Dynes, 1993, 1994; Kreps and Bosworth, forthcoming.)

Empirical research, much of which has been carried out with NEHRP support, finds essentially no support for the command-and-control model either as a heuristic device for conceptualizing the disaster management process or as a strategy employed in actual disasters. Instead, as suggested in the discussion above on EMONs, disaster response activities in the United States correspond much more closely to the emergent resources or problem-solving model. More specifically, such responses are characterized by decentralized, rather than centralized, decision making; by collaborative relationships among organizations and levels of government, rather than hierarchical ones; and, perhaps most important, by considerable emergence—that is, the often rapid appearance of novel and unplanned-for activities, roles, groups, and relationships. Other hallmarks of disaster responses include their fluidity and hence the fast pace at which decisions must be made; the predominance of the EMON as the organizational form most involved in carrying out response activities; the wide array of improvisational strategies that are employed to deal with problems as they manifest themselves; and the importance of local knowledge and situation-specific information in gauging appropriate response strategies. (For empirical research supporting these points, see Drabek et al., 1982; Stallings and Quarantelli, 1985; Kreps, 1985, 1989b; Bosworth and Kreps, 1986; Kreps and Bosworth, 1993; Aguirre et al., 1995; Drabek and McEntire, 2002; Waugh and Sylves, 2002; Webb, 2002; Drabek, 2003; Tierney, 2003; Tierney and Trainor, 2004; Wachtendorf, 2004.)


Advancements brought about through NEHRP research include new frameworks for conceptualizing responses to extreme events. In Shared Risk: Complex Systems in Seismic Response , a NEHRP-supported comparative study of organized responses to 11 different earthquake events, Comfort argues that the major challenge facing response systems is to use information in ways that enhance organizational and interorganizational learning and develop ways of “integrating both technical and organiza-

tional components in a socio-technical system to support timely, informed collective action” (Comfort, 1999:14). Accordingly, effective responses depend on the ability of organizations to simultaneously sustain structure and allow for flexibility in the face of rapidly changing disaster conditions and unexpected demands. Response networks must also be able to accommodate processes of self-organization —that is, organized action by volunteers and emergent groups. This approach again contrasts with command-and-control notions of how major crises are managed (Comfort, 1999:263-264):

A socio-technical approach requires a shift in the conception of response systems as reactive, command-and-control driven systems to one of inquiring systems , activated by processes of inquiry, validation, and creative self-organization…. Combining technical with organizational systems appropriately enables communities to face complex events more effectively by monitoring changing conditions and adapting its performance accordingly, increasing the efficiency of its use of limited resources. It links human capacity to learn with the technical means to support that capacity in complex, dynamic environments [emphasis added].

Similarly, research stressing the importance of EMONs as the predominant organizational form during crisis response periods points to the importance of improving strategies for network management and of developing better methods to take advantage of emergent structures and activities during disasters. Planning and management approaches must, in other words, support rather than interfere with the open and dynamic qualities of disaster response activities. Indicators of improved capacity to manage emergent networks could include the diversity of organizations and community sectors involved in pre-crisis planning; plans and agreements facilitating the incorporation of the voluntary sector and emergent citizen groups into response activities; plans and tools enabling the rapid expansion of crisis communication and information-sharing networks during disasters to include new organizations; and protocols, such as mutual aid agreements, making it possible for new actors to more easily join response networks (Tierney and Trainor, 2004).

In the wake of the Katrina disaster, the need for disaster management by command-and-control-oriented entities has once again achieved prominence. For example, calls have increased for greater involvement on the part of the military in domestic disaster management. Such recommendations are not new. Giving a larger role in disaster management to the military was an idea that was considered—and rejected—following Hurricane Andrew (National Academy of Public Administration, 1993). Post-Katrina debates on needed policy and programmatic changes will likely continue to focus on how to most effectively deploy military assets while ensuring that disaster management remains the responsibility of civilian institutions.

Additional Considerations: Do Responses to Natural, Technological, and Human-Induced Events Differ?

One issue that has come to the fore with the emergence of terrorism as a major threat involves the extent to which findings from the field of disaster research can predict responses to human-induced extreme events. Although some take the position that terrorism and bioterrorism constitute such unique threats that behavioral and organizational responses in such events will differ from what has been documented for other types of extreme events, others contend that this assumption is not borne out by social science disaster research.

The preponderance of evidence seems to suggest that there is more similarity than difference in response behaviors across different types of disaster agents. Regarding the potential for panic, for example, there is no empirical evidence that panic was a problem during the influenza pandemic of 1918, among populations under attack during World War II (Janis, 1951), in catastrophic structure fires and crowd crushes (Johnson, 1987; Johnson et al., 1994; Feinberg and Johnson, 2001), or in the Chernobyl nuclear disaster (Medvedev, 1990). Nor was panic a factor in the 1993 bombing of the World Trade Center (Aguirre et al., 1998), the 1995 Tokyo subway sarin attack (Murakami, 2000), or the terrorist attacks of September 11, 2001 (NIST, 2005; National Commission on Terrorist Attacks upon the United States, 2004). The failure to find significant evidence of panic across a wide range of crisis events is a testimony to the resilience of social relationships and normative practices, even under conditions of extreme peril.

Similarly, as noted earlier, research findings on challenges related to risk communication and warning the public of impending extreme events are also quite consistent across different types of disaster events. For individuals and groups, there are invariably challenges associated with understanding what self-protective actions are required for different types of emergencies, regardless of their origin.

In all types of disasters, organizations must likewise face a common set of challenges associated with situation assessment, the management of primary and secondary impacts, communicating with one another and with the public, and dealing with response-related demands. The need for more effective communication, coordination, planning, and training transcends hazard type. Although recent government initiatives such as the National Response Plan will result in the incorporation of new organizational actors into response systems for extreme events, most of the same local-, state-, and federal-level organizations will still be involved in managing extreme events of all types, employing common management frameworks such as

the Incident Command System and now the National Incident Management System (NIMS).

Social scientific studies on disasters have long shown that general features of extreme events, such as geographic scope and scale, impact severity, and speed of onset, combined with the overall quality of pre-disaster preparedness, have a greater influence on response patterns than do the specific hazard agents that trigger response activities. Regardless of their origins, very large, near-catastrophic, and catastrophic events all place high levels of stress on response systems.

In sum, social science disaster research finds little justification for the notion that individual, group, and community responses to human-induced extreme events, including those triggered by weapons of mass terror, will differ in important ways from those that have been documented in natural and technological disasters. Instead, research highlights the importance of a variety of general factors that affect the quality and effectiveness of responses to disasters, irrespective of the hazard in question. With respect to warning the public and encouraging self-protective action, for example, warning systems must be well designed and warning messages must meet certain criteria for effectiveness, regardless of what type of warning is issued. Members of the public must receive, understand, and personalize warning information; must understand what actions they need to take in order to protect themselves; and must be able to carry out those actions, again regardless of the peril in question. Community residents must feel that they can trust their leaders and community institutions during crises of all types. For organizations, training and exercises and effective mechanisms for interorganizational communication and coordination are critical for community-wide emergencies of all types. When such criteria are not met, response-related problems can be expected regardless of whether the emergency stems from a naturally occurring event, a technological accident, or an intentional act.

Individual and group responses, as well as organizational response challenges, are thus likely to be consistent across different types of crises. At the same time, however, it is clear that there are significant variations in the behavior of responding institutions (as opposed to individuals, groups, and first responders) according to event type. In most technological disasters, along with the need to help those affected, questions of negligence and liability typically come to the fore, and efforts are made to assign blame and make responsible parties accountable. In terrorist events, damaged areas are always treated as crime scenes, and the response involves intense efforts both to care for victims and to identify and capture the perpetrators. Further, although as noted earlier, scapegoating can occur in disasters of all types, the tendency for both institutions and the public to assign blame to

particular groups may be greater in technological and terrorism-related crises than in natural disasters. 4

Finally, with respect to responses on the part of the public, even though evidence to the contrary is strong, the idea that some future homeland security emergencies could engender responses different from those observed in past natural, technological, and intentional disasters cannot be ruled out entirely. The concluding section of this chapter highlights the need for further research in this area.

Research on Disaster Recovery

Like hazards and disaster research generally, NERHRP-sponsored research has tended to focus much more on preparedness and response than on either mitigation or disaster recovery. This is especially the case with respect to long-term recovery, a topic that despite its importance has received very little emphasis in the literature. However, even though the topic has not been well studied, NEHRP-funded projects have done a great deal to advance social science understanding of disaster recovery. As discussed later in this section, they have also led to the development of decision tools and guidance that can be used to facilitate the recovery process for affected social units.

It is not an exaggeration to say that prior to NEHRP, relatively little was known about disaster recovery processes and outcomes at different levels of analysis. Researchers had concentrated to some degree on analyzing the impacts of a few earthquakes, such as the 1964 Alaska and 1971 San Fernando events, as well as earthquakes and other major disasters outside the United States. Generally speaking, however, research on recovery was quite sparse. Equally important, earlier research oversimplified the recovery process in a variety of ways. First, there was a tendency to equate recovery, which is a social process, with reconstruction, which involves restoration and replacement of the built environment. Second, there was an assumption that disasters and their impacts proceed in a temporal, stage-like fashion, with “recovery” following once “response” activities have

At the same time, consistent with positions taken elsewhere in this report, it is important to recognize that in crises of all kinds, blame and responsibility are socially constructed. For example, although triggered by a natural disaster, the levee failures during Hurricane Katrina are increasingly being defined as the result of human error. The disaster itself is also framed as resulting from catastrophic failures in decision making at all levels of government (Select Bipartisan Committee to Investigate the Preparation for and Response to Hurricane Katrina, 2006). While the connections are obviously clearer in crisis caused by willful attacks, it is now widely recognized that human agency is involved in disastrous events of all types—including not only terrorist events but also technological and natural disasters.

been concluded. 5 Earlier research also underemphasized the extent to which recovery may be experienced differently by different sectors and subpopulations within society. Some of these problems were related to the fact that at a more abstract level, earlier work had not sufficiently explored the concept of recovery itself—for example, whether recovery should be equated with a return to pre-disaster circumstances and social and economic activities, with the creation of a “new normal” that involves some degree of social transformation, or with improvements in community sustainability and long-term disaster loss reduction. Since the inception of NEHRP and in large measure because of NEHRP sponsorship, research has moved in the direction of a more nuanced understanding of recovery processes and outcomes that has not entirely resolved but at least acknowledges many of these issues.

The sections that follow discuss significant contributions to knowledge and practice that have resulted primarily from NEHRP-sponsored work. Those contributions can be seen (somewhat arbitrarily) as falling into four categories: (1) refinements in definitions and conceptions of disaster recovery, along with a critique and reformulation of stage-like models; (2) contributions to the literature on recovery processes and outcomes across different social units; (3) the development of empirically based models to estimate losses, anticipate recovery challenges, and guide decision making; and (4) efforts to link disaster recovery with broader ideas concerning long-term sustainability and environmental management.

Conceptual Clarification. Owing in large measure to NEHRP-sponsored efforts, the disaster field has moved beyond equating recovery with reconstruction or the restoration of the built environment. More usefully, research has moved in the direction of making analytic distinctions among different types of disaster impacts, recovery activities undertaken by and affecting different social units , and recovery outcomes. Although disaster impacts can be positive or negative, research generally tends to focus on various negative impacts occurring at different levels of analysis. As outlined in Chapter 3 , these impacts include effects on the physical and built environment, including residential, commercial, and infrastructure damage as well as disaster-induced damage to the environment; other property losses; deaths and injuries; impacts on social and economic activity; effects at the community level, such as impacts on community cohesiveness and urban

For example, Drabek’s (1986), which is organized according to disaster “stages,” discusses short-term recovery in a chapter entitled “Restoration” and longer-term recovery in a chapter called “Reconstruction.” Those two chapters address topics ranging from sheltering, looting, and emergent groups to mental health impacts, conflict during the recovery period, and organizational and community change.

form; and psychological, psychosocial, and political impacts. Such impacts can vary in severity and duration, as well as in the extent to which they are addressed effectively during the recovery process. An emphasis on recovery as a multidimensional concept calls attention to the fact that physical and social impacts, recovery trajectories, and short- and longer-term outcomes in chronological and social time can vary considerably across social units.

Recovery activities constitute measures that are intended to remedy negative disaster impacts, restore social units as much as possible to their pre-disaster levels of functioning, enhance resilience, and ideally, realize other objectives such as the mitigation of future disaster losses and improvements in the built environment, quality of life, and long-term sustainability. 6 Recovery activities include the provision of temporary and replacement housing; the provision of resources (government aid, insurance payment, private donations) to assist households and businesses with replacement of lost goods and with reconstruction; the provision of various forms of aid and assistance to affected government units; the development and implementation of reconstruction and recovery plans in the aftermath of disasters; coping mechanisms developed by households, businesses, and other affected social units; the provision of mental health and other human services to victims; and other activities designed to overcome negative disaster impacts. In some circumstances, recovery activities can also include the adoption of new policies, legislation, and practices designed to reduce the impacts of future disasters.

Recovery processes are significantly influenced by differential societal and group vulnerability; by variations in the range of recovery aid and support that is available; and by the quality and effectiveness of the help that is provided. The available “mix” of recovery activities and post-disaster coping strategies varies across groups, societies, and different types of disasters. For example, insurance is an important component in the reconstruction and recovery process for some societies, some groups within society, and some types of disasters, but not for others.

Recovery outcomes —or the extent to which the recovery activities are judged, either objectively or subjectively, as “complete” or “successful”—also show wide variation across societies, communities, social units, and disaster events. Outcomes can be assessed in both the short and the longer terms, although, as noted earlier, the literature is weak with respect to empirical studies on the outcomes of longer-term disasters. Additionally,

The word “intended” is used here purposely, to highlight the point that the recovery process involves decisions made and actions carried out to remedy the problems that disasters create. Such decisions and actions can be made by governments, private sector entities, groups, households, and individuals.

outcomes consist not only of the intended effects of recovery programs and activities, but also of their unintended consequences. For example, the provision of government assistance or insurance payments to homeowners may make it possible for them to rebuild and continue to live in hazardous areas, even though such an outcome was never intended.

Keeping in mind the multidimensional nature of recovery, post-disaster outcomes can be judged as satisfactory along some dimensions, or at particular points in time, but unsatisfactory along others. Outcomes are perceived and experienced differently, when such factors as level of analysis and specific recovery activities of interest are taken into account. With respect to units of aggregation, for example, while a given disaster may have few discernible long-term effects when analyzed at the community level, the same disaster may well be economically, socially, and psychologically catastrophic for hard-hit households and businesses. A community may be considered “recovered” on the basis of objective social or economic indicators, while constituent social units may not be faring as well, in either objective or subjective terms. The degree to which recovery has taken place is thus very much a matter of perspective and social position.

In a related vein, research has also led to a reconsideration of linear conceptions of the recovery process. Past research tended to see disaster events as progressing from the pre-impact period through post-impact emergency response, and later recovery. In a classic work in this genre— Reconstruction Following Disaster (Haas et al., 1977:xxvi), for example—the authors argued that disaster recovery is “ordered, knowable, and predictable.” Recovery was characterized as consisting of four sequential stages that may overlap to some degree: the emergency period; the restoration period; the replacement reconstruction period; and the commemorative, betterment, and developmental reconstruction period. In this and other studies, the beginning of the recovery phase was generally demarcated by the cessation of immediate life saving and emergency care measures, the resumption of activities of daily life (e.g., opening of schools), and the initiation of rebuilding plans and activities. After a period of time, early recovery activities, such as the provision of temporary housing, would give way to longer-term measures that were meant to be permanent. Kates and Pijawka’s (1977) frequently cited four-phase model begins with the emergency period, lasting for a few days up to a few weeks, and encompassing the period when the emergency operations plan (EOP) is put into operation. Next comes the restoration period—when repairs to utilities are made; debris is removed; evacuees return; and commercial, industrial, and residential structures are repaired. The third phase, the reconstruction replacement period, involves rebuilding capital stocks and getting the economy back to pre-disaster levels. This period can take some years. Finally, there is the development phase, when commemorative structures are built, memo-

rial dates are institutionalized in social time, and attempts are made to improve the community.

In another stage-like model focusing on the community level, Alexander (1993) identified three stages in the process of disaster recovery. First, the rehabilitation stage involves the continuing care of victims and frequently is accompanied by the reemergence of preexisting problems at the household or community level. During the temporary reconstruction stage, prefabricated housing or other temporary structures go up, and temporary bracing may be installed for buildings and bridges. Finally, the permanent reconstruction stage was seen as requiring good administration and management to achieve full community recovery.

Later work sees delineations among disaster phases as much less clear, showing, for example, that decisions and actions that affect recovery may be undertaken as early as the first days or even hours after the disaster’s impact—and, importantly, even before a disaster occurs. The idea that recovery proceeds in an orderly, stage-like, and unitary manner has been replaced by a view that recognizes that the path to recovery is often quite uneven. While the concept of disaster phases may be a useful heuristic device for researchers and practitioners, the concept may also mask both how phases overlap and how recovery proceeds differently for different social groups (Neal, 1997). Recovery does not occur at the same pace for all who are affected by disasters or for all types of impacts. With respect to housing, for example, owing to differences in the availability of services and financing as well as other factors, some groups within a disaster-stricken population may remain in “temporary housing” for a very long time—so long, in fact, that those housing arrangements become permanent—while others may move rapidly into replacement housing (Bolin, 1993a). Put another way, as indicated in Chapters 1 and 3 , while stage-like approaches to disasters are framed in terms of chronological time, for those who experience them, disasters unfold in social time.

Researchers studying recovery continue to contend with a legacy of conceptual and measurement difficulties. One such difficulty centers on the question of how the dependent variable should be measured. This problem itself is multifaceted. Should recovery be defined as a return to pre-disaster levels of psychological, social, and economic well-being? As a return to where a community, business, or household would have been were it not for the occurrence of the disaster? The study of disaster recovery also tends to overlap with research on broader processes of social change. Thus, in addition to focusing on what was lost or affected as a consequence of disaster events and on outcomes relative to those impacts, recovery research also focuses on more general post-disaster issues, such as the extent to which disasters influence and interact with ongoing processes of social change, whether disaster impacts can be distinguished from those resulting

from broader social and economic trends, whether disasters simply magnify and accelerate those trends or exert an independent influence, and the extent to which the post-disaster recovery period represents continuity or discontinuity with the past. Seen in this light, the study of recovery can become indistinguishable from the study of longer-term social change affecting communities and societies. While these distinctions are often blurred, it is nevertheless important to differentiate conceptually and empirically between the recovery process, specific recovery outcomes of interest, and the wide range of other changes that might take place following (or as a consequence of) disasters.

Analyzing Impacts and Recovery Across Different Social Units. Following from the discussions above, it is useful to keep in mind several points about research on disaster recovery. First, studies differ in the extent to which they emphasize the objective, physical aspects of recovery—restoration and reconstruction of the built environment—or subjective, psychosocial, and experiential ones. Second, studies generally focus on particular units of analysis and outcomes, such as household, business, economic, or community recovery, rather than on how these different aspects of recovery are interrelated. This is due partly to the fact that researchers tend to specialize in particular types of disaster impacts and aspects of recovery, which has both advantages and disadvantages. While allowing for the development of in-depth research expertise, such specialization has also made it more difficult to formulate more general theories of recovery. Third, the literature is quite uneven. Some aspects of recovery are well understood, while there are others about which very little is known.

Even with these limitations, more general theoretical insights about recovery processes and outcomes have begun to emerge. Key among these is the idea that disaster impacts and recovery can be conceptualized in terms of vulnerability and resilience . As noted in Chapters 2 and 3 , vulnerability is a consequence not only of physical location and the “hazardousness of place,” but also of social location and of societal processes that advantage some groups and individuals while marginalizing others. The notion of vulnerability applies both to the likelihood of experiencing negative impacts from disasters, such as being killed or injured or losing one’s home or job, and to the likelihood of experiencing recovery-related difficulties, such as problems with access to services and other forms of support. Social vulnerability is linked to broader trends within society, such as demographic trends (migration to more hazardous areas, the aging of the U.S. population) and population diversity (race, class, income, and linguistic diversity). Similarly, resilience , or the ability to survive and cope with disaster impacts and rebound after those events, is also determined in large measure by social factors. According to Rose (2004), resilience can be conceptualized

as both inherent and adaptive, where the former term refers to resilience that is based on resources and options for action that are typically available during nondisaster times, and the latter refers to the ability to mobilize resources and create new options following disasters. 7 As discussed in Chapter 6 , resilience stems in part from factors commonly associated with the concept of social capital, such as the extensiveness of social networks, civic engagement, and interpersonal, interorganizational, and institutional trust. (For an influential formulation setting out the vulnerability perspective, see Blaikie et al., 1994). As subsequent discussions show, the concepts of vulnerability and resilience are applicable to individuals, households, groups, organizations, economies, and entire societies affected by disasters. The sections that follow, which are organized according to unit of analysis, discuss psychosocial impacts and recovery; impacts and recovery processes for housing and businesses; economic recovery; and community-level and societal recovery.

Psychological Impacts and Recovery. There is no disagreement among researchers that disasters cause genuine pain and suffering and that they can be deeply distressing for those who experience them. Apart from that consensus, however, there have been many debates and disputes regarding the psychological and psychosocial impacts of disasters. One such debate centers on the extent to which disasters produce clinically significant symptoms of psychological distress and, if so, how long such symptoms last. Researchers have also struggled with the questions of etiology, or the causes of disaster-related psychological reactions. Are such problems the direct result of trauma experienced during disaster, the result of disaster-induced stresses, a reflection of a lack of coping capacity or weak social support networks, a function of preexisting vulnerabilities, or a combination of all these factors? Related concerns center on what constitute appropriate forms of intervention and service delivery strategies for disaster-related psychological problems. Do people who experience problems generally recover on their own, without the need for formally provided assistance, or does such assistance facilitate more rapid and complete recovery? What types of assistance are likely to be most efficacious and for what types of problems?

Research has yielded a wide array of findings on questions involving disaster-related psychological and psychosocial impacts and recovery. Findings tend to differ depending upon disaster type and severity, how disaster victimization is defined and measured, how mental health outcomes are measured, the research methodologies and strategies used (e.g., sampling,

Rose was referring specifically to economic resilience, but the concepts of inherent and adaptive resilience can be (and indeed have been) applied much more broadly.

timing, variables of interest), and not inconsequentially, the discipline-based theoretical perspectives employed (Tierney, 2000). With respect to the controversial topic of post-traumatic stress disorder (PTSD), for example, well-designed epidemiological studies have estimated the lifetime prevalence of PTSD at around 5.4 percent in the U.S. population. An important epidemiologic study on the incidence of trauma and the subsequent risk of developing PTSD after various types of traumatic events estimates the risk at about 3.8 percent for natural disasters (Breslau et al., 1998; Kessler and Zhao, 1999). NEHRP-sponsored surveys following recent earthquakes in California found PTSD to be extremely rare among affected populations and not significantly associated with earthquake impacts (Seigel et al., 2000). Other studies show immense variation, with estimates of post-disaster PTSD ranging from very low to greater than 50 percent. Such variations could reflect real differences in the traumatic effects of different events, but it is equally likely that they are the result of methodological, measurement, and theoretical differences among investigators.

One key debate centers on the clinical significance of post-disaster emotional and mental health problems. Research is clear on the point that it is not unusual for disaster victims to experience a series of problems, such as headaches, problems with sleeping and eating, and heightened levels of concern and anxiety, that can vary in severity and duration (Rubonis and Bickman, 1991; Freedy et al., 1994). Perspectives begin to diverge, however, on the extent to which these and other disaster-induced symptoms constitute mental health problems in the clinical sense. In other words, would disaster victims, presenting their symptoms, be considered candidates for mental health counseling or medication if those symptoms were present in a nondisaster context? Do their symptoms correspond to survey based or clinically based measures of what constitutes a “case” for psychiatric diagnostic purposes? Again, as with PTSD, findings differ. While noting that many studies do document a rise in psychological distress following disasters, Shoaf et al. (2004:320) conclude that “those impacts are not of a nature that would significantly increase the rates of diagnosable mental illness.” With respect to severe psychological impacts, these researchers found that suicide rates declined in Los Angeles County following the Northridge earthquake—a continuation of a trend that had already begun before that event. They also note that these findings are consistent with research on suicide following the Kobe earthquake, which showed that the suicide rate in the year following that quake was less than the average rate for the previous 10 years (Shoaf et al., 2004). Yet many researchers and practitioners rightly contend that psychosocial interventions are necessary following disasters, both to address clinically significant symptoms and to prevent more serious psychological sequelae.

There is also the question of whether some types of disasters are more

likely than others to cause negative psychological impacts. Some researchers argue that certain types of technological hazards, such as nuclear threats and chronic exposures to toxic substances, are more pernicious in their effects than natural disasters because they persist longer and create more anxiety among potential victims, and especially because they tend to result in community conflict, causing “corrosive” rather than “therapeutic” communities to develop (Erikson, 1994). Events such as the Oklahoma City bombing, the Columbine school shootings, and the events of September 11, 2001 lead to questions about whether intentional attacks engender psychological reactions that are distinctive and different from those that follow other types of community crisis events. Some studies have suggested that the psychological impacts of terrorist attacks are profound, at least in the short term (North et al., 1999). Other research, focusing specifically on the short-term impacts of the September 11, 2001 terrorist attacks, indicates that the psychological impacts resulting from the events of 9/11 “are consistent with prior estimates of the impact of natural disasters and other terrorist events” (Miller and Heldring, 2004:21). Again, drawing conclusions about the relative influence of agent characteristics—as opposed to other factors—is difficult because studies vary so much in their timing, research designs, methodological approaches, and procedures for defining disaster victimization.

Another set of issues concerns factors associated with risk for poor psychological outcomes. Perilla et al. (2002) suggest that such outcomes can vary as a consequence of both differential exposure and differential vulnerability to extreme events. With respect to differential exposure, factors such as ethnicity and social class can be associated with living in substandard and vulnerable housing, subsequently exposing minorities and poor people to greater losses and disaster-related trauma. Regarding differential vulnerability, minorities and the poor, who are more vulnerable to psychosocial stress during nondisaster times, may also have fewer coping resources upon which to draw following disasters.

In a comprehensive and rigorous review of research on the psychological sequelae of disasters, Fran H. Norris and her colleagues (Norris et al., 2002a,b) carried out a meta-analysis of 20 years of research, based on 160 samples containing more than 60,000 individuals who had experienced 102 different disaster events. These data sets included a range of different types of surveys on both U.S. disaster victims and individuals in other countries, on various subpopulations, and on disasters that differed widely in type and severity. Impacts documented in these studies included symptoms of post-traumatic stress, depression, and anxiety; other forms of nonspecific distress not easily related to specific syndromes such as PTSD; health problems and somatic complaints; problems in living, including secondary stressors such as work-related and financial problems; and “psychosocial resource

loss,” a term that refers to negative effects on coping capacity, self-esteem, feelings of self-efficacy, and other attributes that buffer the effects of stress. According to their interpretation, which was based on accepted methods for rating indicators of psychological distress, the symptoms reported by as many as 39 percent of those studied reached clinically significant levels. However—and this is an important caveat—they found negative psychological effects to be much more prevalent in disasters occurring outside the United States. Generally, symptoms were most severe in the year following disaster events and declined over time.

Norris et al. (2002a, 2002b) classified U.S. disasters as low, moderate, and high in their psychosocial impacts, based on empirical data on post-disaster distress. The Loma Prieta and Northridge earthquakes were seen as having relatively few adverse impacts, and Hurricane Hugo and Three Mile Island were classified as moderate in their effects. Hurricane Andrew, the Exxon oil spill, and the Oklahoma City bombing were classified as severe with respect to their psychological impacts. As these examples suggest, the researchers found no evidence that natural, technological, and human-induced disasters necessarily differ in their effects.

This research review uncovered a number of vulnerability and protective factors that were associated with differential psychological outcomes following disasters. Broadly categorized, those risk factors most consistently shown to be negatively associated with post-disaster psychological well-being include severity of disaster exposure at both the individual and the community levels; being female; being a member of an ethnic minority; low socioeconomic status; experiencing other stressors or chronic stress; having had other mental health problems prior to the disaster; employing inappropriate coping strategies (e.g., withdrawal, avoidance); and reporting problems with both perceived and actual social support.

Overall, these findings are very consistent with perspectives in disaster research that emphasize the relationship between systemically induced vulnerability, negative disaster impacts, lower resilience, and poor recovery outcomes. Recent research situates disasters within the context of other types of stressful events (e.g., death of a loved one or other painful losses) that disproportionately affect those who are most vulnerable and least able to cope. At the same time, studies—many conducted under NEHRP auspices—show how social inequality and vulnerability both amplify the stress that results directly from disasters and complicate the recovery process over the longer term. For example, Fothergill (1996, 1998, 2004) and Enarson and Morrow (1998) have documented the ways in which gender is associated both with the likelihood of becoming a disaster victim and with a variety of subsequent post-disaster stressors. Peacock et al. (1997) and Bolin and Stanford (1998) have shown how pre-disaster conditions such as income disparities and racial and ethnic discrimination contribute both to

disaster losses and to subsequent psychosocial stress and make recovery more difficult for vulnerable groups. Perilla et al. (2002), who studied ethnic differences in post-traumatic stress following Hurricane Andrew, also note that ethnicity can be associated with variations in personality characteristics such as fatalism, which tends to be associated with poor psychosocial outcomes resulting from stressful events, as well as with additional stresses associated with acculturation. 8

Hurricane Katrina represents a critical test case for theories and research on psychosocial vulnerability and resilience. If, as Norris and her collaborators indicate, Hurricane Andrew resulted in relatively high levels of psychosocial distress, what will researchers find with respect to Katrina? For many victims, Katrina appears to contain all of the ingredients necessary to produce negative mental health outcomes: massive, catastrophic impacts; high property losses resulting in financial distress; exposure to traumas such as prolonged physical stress and contact with dead and dying victims; disruption of social networks; massive failures in service delivery systems; continual uncertainty about the future; and residential dislocation on a scale never seen in a U.S. disaster. Over time, research will result in important insights regarding the psychosocial dimensions of truly catastrophic disaster events.

Household Impacts and Recovery. Within the disaster recovery area, households and household recovery have been studied most often, with a significant proportion of that work focusing on post-earthquake recovery issues. Although this line of research predates NEHRP, many later studies have been undertaken with NEHRP support. Studies conducted prior to NEHRP include Bolin’s research on household recovery processes following the Managua earthquake and the Rapid City flood, both of which occurred in 1972 (Bolin, 1976). Drabek and Key and their collaborators had also examined disaster impacts on families and the household recover process (Drabek et al., 1975; Drabek and Key, 1976, 1984). With NEHRP support, Bolin and Bolton studied household recovery following tornadoes in Wichita Falls, Vernon, and Paris, Texas; a hurricane in Hawaii; flooding in Salt Lake City; and the Coalinga earthquake (Bolin, 1982; Bolin and Bolton, 1986). Bolin’s monograph Household and Community Recovery after

This study found significant differences in post-disaster psychological well being among Caucasians, Latinos, and African Americans, with minority group members experiencing poorer outcomes. Interestingly, differences were seen between Latinos whose preferred language was English and those who preferred to speak Spanish. The latter experienced more overall psychological distress, while the reactions of the former more closely resembled those of their Caucasian counterparts.

Earthquakes was based on research on the 1987 Whittier Narrows and 1989 Loma Prieta events (Bolin, 1993b). Households have also been the focus of more recent studies on the impacts of Hurricane Andrew (Peacock et al., 1997) and the 1994 Northridge earthquake (Bolin and Stanford, 1998). Other NEHRP-sponsored work has focused more specifically on issues that are important for household recovery, such as post-disaster sheltering processes (Phillips, 1993, 1998) and housing impacts and recovery (Comerio, 1997, 1998). As Bolin (1993a:13) observes

[d]isasters can have a multiplicity of effects on a household, including physical losses to property, injury and/or death, loss of job or livelihood, disruption of social and personal relations, relocation of some or all members of a family, physical disruption or transformation of community and neighborhood, and increased household indebtedness.

Accordingly, the literature has explored various dimensions of household impacts and recovery, including direct impacts such as those highlighted by Bolin; changes in the quality and cohesiveness of relationships among household members; post-disaster problems such as conflict and domestic violence; stressors that affect households during the recovery process; and coping strategies employed by households, including the use of both formal and informal sources of post-disaster support and recovery aid.

The literature also points to a number of factors that are associated with differences in short- and longer-term household recovery outcomes. Housing supply is one such factor—as indicated, for example, by housing costs, other real estate market characteristics, and rental vacancy rates Temporary housing options are affected by such factors as the proximity of friends and relatives with whom to stay, although use of this housing option is generally only a short-term strategy. Extended family members may not be able to help if they also are victims (Morrow, 1997). Such problems may be more prevalent in lower-income groups that have few alternative resources and when most members of an extended family live in the same affected community.

Availability of temporary and permanent housing generally is limited by their pre-impact supply in and near the impact area. In the U.S., in situations in which there is an insufficient supply of housing for displaced disaster victims, FEMA provides mobile homes, but even this expedient method of expanding the housing stock takes time. Even when houses are only moderately damaged, loss of housing functionality may be a problem if there is massive disruption of infrastructure. In such cases, tent cities may be necessary if undamaged housing is beyond commuting range (e.g., Homestead, Florida after Hurricane Andrew, as discussed in Peacock et al., 1997).

In the longer term, household recovery is influenced by such factors as household financial resources, the ability to obtain assistance from friends and relatives, insurance coverage, and the mix of housing assistance pro-

grams available to households. Typically, access to and adequacy of recovery resources are inversely related to socioeconomic status. Those with higher incomes are more likely to own their own homes, to be adequately insured, and to have savings and other financial resources on which to draw in order to recover—although disasters can also cause even better-off households to take on additional debt. With respect to formal sources of aid, the assistance process generally favors those who are adept at responding to bureaucratic requirements and who are able to invest time and effort to seek out sources of aid. The aid process also favors those living in more conventional, nuclear family living arrangements, as opposed to extended families or multiple households occupying the same dwelling unit (Morrow, 1997). Recovery may be particularly difficult for single-parent households, especially those headed by women (Enarson and Morrow, 1998; Fothergill, 2004).

The picture that emerges from research on household recovery is not that of a predictable and stage-like process that is common to all households, but rather of a multiplicity of recovery trajectories that are shaped not only by the physical impacts of disaster but also by axes of stratification that include income, race, and ethnicity, as well as such factors as the availability of and access to different forms of monetary aid, other types of assistance, and informal social support—which are themselves associated with stratification and diversity. Disaster severity matters, both because disasters that produce major and widespread impacts can limit recovery options for households and because they tend to be more damaging to the social fabric of the community. As Comerio’s extensive research on housing impacts and issues following earthquakes and other disasters in different societal contexts illustrates, household recovery processes are also shaped by societal-level policy and institutional factors—which themselves have differential impacts (Comerio, 1998). 9

Large-Scale Comparative Research on Household Recovery. Although there is clearly a need for such research, few studies exist that compare household recovery processes and outcomes across communities and disaster events. With NEHRP funding, Frederick Bates and his colleagues carried out what may well be the largest research efforts of this kind: a multicommunity

Importantly, Comerio’s work also highlights how policies themselves change and evolve in response to disasters and how these changes affect recovery options and outcomes in subsequent events. She shows, for example, that experience with deficiencies in housing programs after the Loma Prieta earthquake influenced the way in which programs were financed and managed in other major disasters, notably Hurricane Andrew.

longitudinal study on household and community impacts and recovery after the 1976 Guatemala earthquake and a cross-national comparative study on household recovery following six different disaster events. The Guatemala study, designed as a quasi-experiment, included households in 26 communities that were carefully selected to reflect differences in the severity of earthquake impacts, size, population composition, and region of the country. That study focused on a broad spectrum of topics, including changes over time in household composition and characteristics; household economic activity; housing characteristics and standards of living; household experiences with relief and reconstruction assistance; and fertility, health, and nutrition. Never replicated for any other type of disaster, the study provided detailed information on these topics, focusing in particular on how different forms of aid provision either facilitated or hampered household recovery (for detailed discussions, see Bates, 1982; Hoover and Bates, 1985; Bates et al., 1979).

The second study carried out by Bates and his colleagues extended methods developed to assess household recovery following the Guatemala earthquake to measure household recovery in disaster-stricken communities in six different countries. The tool used to measure disaster impacts and household recovery across different events and societies, the Domestic Assets Scale, made possible systematic comparisons with respect to one dimension of household recovery—the restoration of household possessions, tools, and technologies (Bates and Peacock, 1992, 1993).

Vulnerability, Resilience, and Household Recovery. Like the other aspects of recovery discussed here, what happens to households during and after disasters can be conceptualized in terms of vulnerability and resilience. With respect to vulnerability, social location is associated with the severity of disaster impacts for households. Poverty often forces people to live in substandard or highly vulnerable housing—manufactured housing is one example—leaving them more vulnerable to death, injury, and homelessness. As discussed in Chapter 3 with respect to disaster preparedness, factors such as income, education, and homeownership influence the ability of households to mitigate and prepare for disasters. Social-structural factors also affect the extent to which families can accumulate assets in order to achieve higher levels of safety, as well as their recovery options and access to resources after disasters strike—for example the forms of recovery assistance for which they are eligible. Households are thus differentially exposed to disasters, differentially vulnerable during the recovery period, and diverse in terms of both inherent and adaptive resilience.


As discussed in Chapter 3 , assessing how much disasters cost the nation and its communities has proven to be a major challenge. A National Research Council (NRC, 1999c) study concluded that such calculations are difficult in part because different agencies and entities calculate costs and losses differently. Moreover, no universally accepted standards exist for calculating economic impacts resulting from disasters, and there is no single agency responsible for keeping track of disaster losses. For any given disaster event, assessments of economic impacts may vary widely depending on which statistics are used—for example, direct or insured losses versus total losses.

NEHRP-sponsored research has addressed these problems to some degree. For example, as part of the NEHRP-sponsored “Second Assessment of Research on Natural Hazards,” researchers attempted to estimates losses, costs, and other impacts from a wide array of natural and technological hazards. 10 For the 20 year period 1975–1994, they estimated that dollar losses from disasters amounted to $.5 billion per week, with climatological hazards accounting for about 80 percent of those losses; since 1989, losses have totaled $1 billion per week (Mileti, 1999a). Through work undertaken as part of the Second Assessment, data on losses from natural hazard events from the mid-1970s to 2000 are now available at the county level in geocoded form for the entire United States through the Spatial Hazard Events and Losses Database for the United States (SHELDUS). This data collection and database development effort has made it possible to analyze different types of losses, at different scales, using different metrics, and to assess locations in terms of their hazard proneness and loss histories. (For discussions of the data used in the SHELDUS database and associated challenges see Cutter, 2001.) What is still lacking is a national program to continue systematically collecting and analyzing impact and loss data.

Studies on economic impacts and recovery from earthquakes and other disasters can be classified according to the units of analysis on which they focus. Most research concerns economic losses and recovery at the community or, more frequently, the regional level. A smaller set of studies has analyzed economic impacts and recovery at the firm or facility level. There is even less research documenting national-level and macroeconomic impacts.

However, it should be noted that, once again, those estimates were based on statistics from widely varied sources.

Community-Level and Regional Studies

Studies on the economics of natural disasters at the community and regional levels of analysis differ significantly in methods, topics of interest, and conclusions. Some researchers, such as Rossi et al. (1978) and Friesema et al. (1979) have argued that at least in the United States, natural disasters have no discernible social or economic effects at the community level and that nondisaster-related trends have a far more significant influence on long-term outcomes than disasters themselves. This position has also been argued at the macroeconomic level, with respect to other developed and developing countries (Albala-Bertrand, 1993). 11 Dacy and Kunreuther (1969:168) even argued (although more than 30 years ago) that “a disaster may actually turn out to be a blessing in disguise” because disasters create reconstruction booms and allow community improvements to be made rapidly, rather than gradually. However, most research contradicts the idea that disasters constitute economic windfalls, emphasizing instead that economic gains that may be realized at one level (e.g., the community, particular economic sectors) typically constitute losses at another (e.g., the national tax base). One analyst has called the idea that disasters are beneficial economically “one of the most widely held misbeliefs in economics” (DeVoe, 1997:188).

Other researchers take the position that post-disaster economic and social conditions are generally consistent with pre-disaster trends, although disasters may amplify those changes (Bates and Peacock, 1993). Disasters may further marginalize firms and sectors of the economy that were already in decline, or they may speed up processes that were already under way prior to their occurrence. For example, Homestead Air Force Base was already slated for closure before Hurricane Andrew despite ongoing efforts to keep the base opened. When Andrew occurred, the base sustained damage and was closed for good. The closure affected businesses that had depended on the base and helped lead to the exodus of many middle-class families from the area, which in turn affected tax revenues in the impact region. These changes would have taken place eventually, but they were accelerated by Hurricane Andrew.

Related research has analyzed the distributive effects of earthquakes and other disasters. In an early formulation, Cochrane (1975) observed that lower-income groups consistently bear a disproportionate share of disaster losses, relative to higher-income groups. This theme continues to be promi-

These findings refer to the impacts of disasters on societal-level economic indicators. Albala-Bertrand did document many instances in which disasters had both short- and longer-term political and economic impacts.

nent in the disaster literature; the notion that disasters create economic “winners and losers” has been borne out for both households and businesses (Peacock et al., 1997:Chapter 11; Tierney and Webb, forthcoming).

Another prominent research emphasis at the community and regional levels of analysis has grown out of the need to characterize and quantify the economic impacts of disasters (as well as other impacts) in order to be better able to plan for and mitigate those impacts. A considerable amount of NEHRP research on economic impacts and recovery has been driven by concern about the potentially severe economic consequences of major earthquakes, particularly those that could occur in highly populated urban areas. That concern is reflected in a number of NRC reports (1989, 1992, 1999c) on projected losses and potential economic impacts. Within the private sector, the insurance industry has also committed significant resources in an effort to better anticipate the magnitude of insured losses in future disaster events. (For new developments in research on the management of catastrophic insurance risk, see Grossi et al., 2004.)

Stimulated in large measure by NEHRP funding, new tools have been developed for both pre-disaster estimation of potential losses and post-disaster impact assessments, particularly for earthquakes. HAZUS, the national loss estimation methodology, which was originally developed for earthquakes and which has now been extended to flood and wind hazards, was formulated under FEMA’s supervision with NEHRP funding. NEHRP funds have also supported the development of newer and more sophisticated modeling approaches through research undertaken at earthquake centers sponsored by the National Science Foundation (NSF).

The framework for estimating losses from natural hazards was initially laid out more than 20 years ago in publications such as Petak and Atkisson’s Natural Hazard Risk Assessment and Public Policy (1982) and in applied studies such as the PEPPER (Pre-Earthquake Planning for Post-Earthquake Rebuilding) project (Spangle, 1987), which analyzed potential earthquake impacts and post-disaster recovery strategies for Los Angeles. According to the logic developed in these and other early studies (see, for example, NRC, 1989) and later through extensive NEHRP research, loss estimation consists of the analysis of scenario or probabilistic models that include data on hazards; exposures , or characteristics of the built environment at risk, including buildings and infrastructural systems; fragilities , or estimates of damage likelihood as a function of one or more parameters, such as earthquake shaking intensity; direct losses , such as deaths, injuries, and costs associated with damage; and indirect losses and ripple effects that result from disasters. Within this framework, recent research has focused on further refining loss models and reducing uncertainties associated with both the components of loss estimation models and their interrelationships (for

representative work, see theme issue in Earthquake Spectra, 1997; Tierney et al., 1999; Okuyama and Chang, 2004).

This line of research has led both to advances in basic science knowledge and to a wide range of research applications. At the basic science level, loss modeling research—particularly studies supported through NEHRP—has helped distinguish and clarify relationships among such factors as physical damage, direct economic loss, business interruption effects, and indirect losses and ripple effects. For example, it is now more possible than ever before to disaggregate and analyze separately different types of economic effects and to understand how particular types of damage (e.g., damage to electrical power or transportation systems) contribute to overall economic losses. This research has shed light on factors that contribute to the resilience of regional economies, both during normal times and in response to sudden shocks. It has also shown how the application of newer economic modeling techniques, such as computable general equilibrium modeling and agent-based modeling, constitute improvements over more traditional input-output modeling, particularly for the study of extreme events (for discussions, see Rose et al., 2004; Chang, 2005; Rose and Liao, 2005). Econometric modeling provides another promising approach at both the micro and the regional levels (see West and Lenze, 1994), but this potential remains largely untapped.

At the applications level, loss estimation tools and products have proven useful for raising public awareness of the likely impacts of disaster events and for enhancing community preparedness efforts and mitigation programs. They have also made it possible to assess mitigation alternatives, not only in light of the extent to which those measures reduce damage, but also in terms of their economic costs and benefits. When applied in the disaster context, rapid economic loss estimates have also formed the basis for requests for federal disaster assistance. For the insurance industry, loss models provide important tools to improve risk management decision making, particularly with regard to catastrophic risks.

As noted earlier, loss modeling originally was driven by the need to better understand the economic impacts of earthquakes. In addition to economic losses, earthquake loss models are increasingly taking into account other societal impacts such as deaths, injuries, and residential displacement, as well as secondary effects such as earthquake-induced fires. The methodological approach developed to study earthquakes was first extended to other natural hazards and is now being used increasingly to assess potential impacts from terrorism. The nation is now better able to address the issue of terrorism-related losses because of the investments that had been made earlier for earthquakes and other natural hazards. Significantly, when the Department of Homeland Security decided in 2003 to begin funding

university-based “centers of excellence” for terrorism research, the first topic that was selected for funding was risk and economic modeling for terrorist attacks in the United States. 12 Many of the investigators associated with that center had previously worked on loss modeling for earthquakes.

Business and Facility-Level Impacts and Recovery. Most research on recovery processes and outcomes has focused on households and communities. Prior to the 1990s, most research on the economic aspects of disasters focused not on individual businesses but rather on community-wide and regional impacts. Almost nothing was known about how private sector organizations are affected by and recover from disasters. Since then, a small number of studies have focused on business firms or, in some cases, commercial facilities, as units of analysis. Much of this work, including studies on large, representative samples of businesses, has been carried out with NEHRP support. Business impacts and recovery have been assessed following the Whittier Narrows, Loma Prieta, Northridge, and Kobe earthquakes; the 1993 Midwest floods; Hurricane Andrew; and other flood and hurricane events (for representative studies and findings, see Dahlhamer, 1998; Chang, 2000; Webb et al., 2000; Alesch et al., 2001). Long-term business recovery has been studied in the context of only two disaster events—the Loma Prieta earthquake and Hurricane Andrew (Webb et al., 2003).

These studies have shown that disasters disrupt business operations through a variety of mechanisms. Direct physical damage to buildings, equipment, vehicles, and inventories has obvious effects on business operation. It might be less obvious that disruption of infrastructure such as water/sewer, electric power, fuel (i.e., natural gas), transportation, and telecommunications frequently forces businesses to shut down in the aftermath of a disaster (Alesch et al., 1993; Tierney and Nigg, 1995; Tierney, 1997a, b; Webb et al., 2000). For example, Tierney (1997b) reported that extensive electrical power service interruption after the 1993 Midwest floods caused a large number of business closures in Des Moines, Iowa, even though the physical damage was confined to a relatively small area.

Other negative disaster effects include population dislocation, losses in discretionary income among those victims who remain in the impact area—which can weaken market demand for many products and services—and competitive pressure from large outside businesses. These kinds of impacts can cause small local businesses to experience major difficulties recovering from the aftermath of a disaster (Alesch et al., 2001). Indeed, such factors

This research is being carried out by a consortium of universities, led by the University of Southern California. That consortium is called the Center for Risk and Economic Analysis of Terrorist Events (CREATE).

can produce business failures long after the precipitating event, especially if the community was already in economic decline before the disaster occurred (Bates and Peacock, 1993; Webb et al., 2003).

It is difficult to generalize on the basis of so few studies, particularly when the issues involved and the methodological challenges are so complex. However, studies to date have uncovered a few consistent patterns with respect to business impacts and recovery. First, studies show that most businesses do recover, and do so relatively quickly. In other words, typical businesses affected by disasters show a good deal of resilience in the face of major disruption.

Second, some businesses do tend to fare worse than others in the aftermath of disasters; clearly, not all businesses are equally vulnerable or equally resilient. Although findings from individual studies differ, the factors that seem to contribute most to vulnerability include small size; poor pre-disaster financial condition; business type, with wholesale and retail trade appearing to be especially vulnerable, while manufacturing and construction businesses stand to benefit most from disasters; and severity of disaster impacts. With regard to this last-mentioned factor, studies show that negative impacts on businesses include not only direct physical damage, lifeline-related problems, and business interruption, but also more long-lasting operational problems that businesses may experience following disasters, such as employee absenteeism and loss of productivity, earthquake-induced declines in demands for goods and services, and difficulties with shipping or receiving products and supplies.

Third, business recovery is affected by many factors that are outside the control of the individual business owner. For example, businesses located in highly damaged areas may experience recovery difficulties independent of whether or not they experience losses. In this case, recovery is complicated by the fact that disasters disrupt local ecologies on which individual businesses depend. Business recovery processes and outcomes are also linked to community-level decision making. After the Loma Prieta earthquake, for example, the City of Santa Cruz offered extensive support to businesses and used the earthquake as an opportunity to reinvent itself and to revitalize a business district that had fallen short of realizing its potential prior to the disaster (Arnold, 1998). Actions that communities take with respect to land-use, structural mitigation, infrastructure protection, community education, and emergency response planning also affect how businesses and business districts fare during and after disasters.

Fourth, recovery outcomes following disasters are linked to pre-disaster trends and broader market forces. For example, focusing on an important transport facility, the Port of Kobe, Chang (2000) showed that the port’s inability to recover fully after the 1995 earthquake was due in part to losses in one part of the port’s business—trans-shipment cargo—that had already

been declining before the earthquake owing to severe competition from other ports in the region. Similarly, Dahlhamer (1998) found that businesses in the wholesale and retail trade sectors were more vulnerable to experiencing negative economic outcomes following the Northridge earthquake, perhaps because they constitute crowded and highly competitive economic niches and because turnover is high in those sectors during normal times. He also found that firms in industries that had been experiencing growth in the two-year period just before the earthquake were less likely than firms in declining industries to report being worse off following the Northridge event. Such findings are consistent with a more general theme in recovery research discussed earlier—that disasters do not generate change in and of themselves, but rather intensify or accelerate preexisting patterns.

Community Recovery. Although the topic of community recovery is still not well studied, significant progress has been made in understanding both recovery processes and factors that are associated with recovery outcomes for communities. Earlier research indicated that communities rebound well from disasters and that, at the aggregate level and net of other factors, the impacts of disasters are negligible (Friesema et al., 1979; Wright et al., 1979). However, other more recent research suggests that such findings paint an overly simplified and perhaps overly optimistic picture of post-disaster recovery. This may have been due to methodological shortcomings—for example, the tendency to aggregate data and to group together both more damaging disasters and those that did comparatively little damage—or because such studies were based on “typical” disasters in the United States, rather than catastrophic or near-catastrophic ones. 13 In contrast, in a methodologically sophisticated study focusing on a much more severe disaster, the 1995 Kobe event, Chang (2001) analyzed a number of recovery indicators, including measures of economic activity, employment in manufacturing, changes in the spatial distribution of work activities, and differences in recovery indicators among different districts within the city. She found that the earthquake did have lasting and significant negative effects on the City of Kobe. Equally important, poor recovery outcomes were more pronounced in some parts of the city than in others—specifically those areas that had already been experiencing declines. This study provides yet another illustration of how disasters exploit existing vulnerabilities. It also cautions against making blanket statements about disaster impacts and recovery.

Additionally, recall that U.S. disasters began becoming more “disastrous” in the late 1980s. Both recent events (e.g., the 2004 hurricanes in Florida and Hurricanes Katrina and Rita) and scientific projections suggest that this trend will continue. It would thus be imprudent to overgeneralize from earlier work.

Another limitation of earlier work on community recovery was that it provided too little information on what actually happens in communities during the recovery process or what communities can do to ensure more rapid and satisfactory recovery outcomes. Later research, much of which has been undertaken with NEHRP support, has addressed these issues. For example, in Community Recovery from a Major Natural Disaster , Rubin et al. (1985) developed a set of propositions regarding factors that affect community recovery outcomes. That monograph, which was based on case study analyses of recovery following 14 disasters that occurred in the early 1980s, emphasized the importance of three general constructs—personal leadership, knowledge of appropriate recovery actions, and ability to act—as well as the influence of intergovernmental (state and federal) policies and programs. This work highlighted the effects of both government decision making and broader societal policies on community recovery.

Some more recent research has more explicitly incorporated community and population vulnerability as factors affecting community-level recovery. Bolin and Stanford (1998) traced how the post-Northridge recovery experiences of Los Angeles and smaller outlying towns differed as a function of such factors as political expertise and influence, preexisting plans, institutional capacity, involvement of community organizations, and interest group competition. In these diverse communities, the needs of more vulnerable and marginalized groups were sometimes addressed during the recovery process. However, recovery programs ultimately did little to improve the safety of those groups, because they failed to address the root causes of vulnerability (Bolin and Stanford, 1998:216):

[s]ince vulnerability derives from political, economic, and social processes that deny certain people and groups access or entitlements to incomes, housing, health care, political rights, and, in some cases, even food, then post-disaster rebuilding by itself will have little effect on vulnerability.

Societal-Level and Comparative Research on Disaster Recovery. International research on disasters is discussed in greater detail in Chapter 6 . This chapter focuses in a more limited way on what little research exists on disaster impacts and post-disaster change at the societal level. Regarding long-term societal impacts, researchers have generally found that disasters, even very large ones, typically do not in and of themselves result in significant change in the societies they affect. Instead, the broad consensus has been that to the extent disasters do have lasting effects, it is because they interact with other factors to accelerate changes that were already under way. Albala-Bertrand, for example has argued that while disasters can highlight preexisting political conflicts, whether such effects are sustained over time “has little to do with the disaster itself, but with preexisting economic and sociopolitical

conditions” (1993:197). This research found that the potential for such changes was generally greater in developing countries than developed ones, although not great in any case.

With respect to the political impacts of disasters at the societal level, comparing very large disasters that occurred between 1966 and 1980, political scientist Richard Olson found that that major disasters can result in higher levels of political unrest, particularly in developing countries that are already politically unstable (Olson and Drury, 1997). In other research, Olson argues that under certain (and rare) circumstances, disasters can constitute “critical junctures,” or crises that leave distinctive legacies within those societies. The 1972 earthquake in Managua, Nicaragua, was one such case. Following that devastating event, the corrupt and dictatorial Somoza regime took a large share of post-disaster aid for itself and mismanaged the recovery, in the process alienating Nicaraguan elites, the business establishment, and finally the middle class, and paving the way for the Sandanistas to assume power in 1979. The 1985 Mexico City earthquake also affected the political system of that nation by, among other things, helping to weaken the hegemony of the Institutional Revolutionary Party. However, rather than having a direct and independent influence on subsequent political changes, that earthquake interacted with factors and trends that were already beginning to affect Mexican society before it occurred. That disaster, which was not well managed by the ruling government, provided the Mexican people with a sharp contrast between the vibrancy and the capability of civil society and the government’s lack of preparedness. Grass-roots response and recovery efforts also facilitated broader mobilization by groups that had been pressing for change. Although not a “critical juncture” in its own right, the earthquake did play a role in moving the political system in the direction of greater pluralism and strengthened the power of civil society institutions vis-à-vis the state (Olson and Gawronski, 2003).

Such findings assume particular significance in the aftermath of the December 2004 Indian Ocean earthquake and tsunami. The impacts of that catastrophe span at least 12 different nations and a number of semi-autonomous subnational units, each with its own distinctive history, mode of political organization, internal cleavages, and preexisting problems. Research is needed to better understand both recovery processes and outcomes and the longer-term societal effects of this devastating event.


Disaster experience and the mitigation of future hazards.

Social science research has also focused in various ways on the question of whether the positive informational effects of disasters constitute learning

experiences for affected social units by encouraging the adoption of mitigation measures and stimulating preparedness activity. While this idea seems intuitively appealing, the literature is in fact quite equivocal with regard to the extent to which disasters actually promote higher levels of safety. On the one hand, at the community and societal levels, there is considerable evidence to suggest that disasters constitute “windows of opportunity” for those seeking to enact loss reduction programs, making it possible to achieve policy victories that would not have been possible prior to those events (Alesch and Petak, 1986). Disasters have the potential to become “focusing events” (Birkland, 1997) that can alter policy agendas through highlighting areas in which current policy has failed, energizing advocates, and raising public awareness. On the other hand, many disasters fail to become focusing events and have no discernible impacts on the adoption and implementation of loss-reduction measures. For example, Burby et al., (1997), who studied communities in five different states, found no relationship between disaster experience and adoption of mitigation measures. Birkland (1997) suggests that these differences are related in part to the extent to which advocacy coalitions exist, are able to turn disaster events to their advantage, and are able to formulate appropriate policy responses.

Further complicating matters, policies adopted in the aftermath of disasters, like other policies, may meet with resistance and be only partially implemented—or implemented in ways that were never intended. While it is possible to point to examples of successful policy adoption and implementation in the aftermath of disasters, such outcomes are by no means inevitable, and when they do occur, they are typically traceable to other factors, not just to disaster events themselves.

Research does suggest that households, businesses, and other entities affected by disasters learn from their experiences and take action to protect themselves from future events. Those who have experienced disasters may, for example, step up their preparedness for future events or be more likely to heed subsequent disaster warnings. At the same time, it is also clear that there is considerable variability in the relationship between experience and behavioral change. While some studies document the positive informational effects of experience, others show no significant impact, and some research even indicates that repeated experiences engender complacency and lack of action (for a review of the literature, see Tierney et al., 2001).

Role of Prices and Markets

Mainstream economic theory, models, and analytical tools (e.g., benefit-cost analysis) assume that markets generally function efficiently and equilibrate. Barring various situations of market failure, prices serve a key role as signals of resource scarcity. In this context, two broad areas of research

needs can be identified. One is the role of prices and markets in pre-disaster mitigation (see also Chapter 3 ). Market-based approaches to reducing disaster risk involve such questions as how prices can serve as better signals of risk taking and risk protection, and the potential for new approaches to risk sharing (e.g., catastrophe bonds). At the same time, better understanding is also needed of market failures in mitigation (e.g., externalities in risk taking and risk protection). The second broad research need concerns markets in post-disaster loss and recovery. Little empirical research has been conducted on the degree to which assumptions of efficient markets actually hold in disasters, especially those having catastrophic impacts, and the degree to which markets are resilient in the face of disasters. Research is also needed on how economic models can capture the adjustment processes and disequilibria that are important as economies recover from disasters, and how economic recovery policies can influence recovery trajectories.

Disaster Recovery and Sustainability

As discussed in more detail in Chapter 6 , which focuses on international research, disaster theory and research have increasingly emphasized the extent to which vulnerability to disasters can be linked to unsustainable development practices. Indeed, the connection between disaster loss reduction and sustainability was a key organizing principle of the NEHRP-sponsored Second Assessment of Research on Natural Hazards. The title of the summary volume for the Second Assessment, Disasters by Design (Mileti, 1999b), was chosen to emphasize the idea that the impacts produced by disasters are the consequence of prior decisions that put people and property at risk. A key organizing assumption for the Second Assessment was the notion that societies and communities “design” the disasters of the future by failing to take hazards into account in development decisions; pursuing other values, such as rapid economic growth, at the expense of safety; failing to take decisive action to mitigate risks to the built environment; and ignoring opportunities to enhance social and economic resilience in the face of disasters. Conversely, communities and societies also have the ability to design safer futures by better integrating hazard reduction into their ongoing policies and practices in areas such as land-use and development planning, building codes and code enforcement, and quality-of-life initiatives.

Just as disasters dramatically highlight failures to address sources of vulnerability, the post-disaster recovery period gives affected communities and societies an opportunity to reassess pre-disaster plans, policies, and programs, remedy their shortcomings, and design a safer future (Berke et al., 1993). The federal government seeks to promote post-disaster mitigation through FEMA’s Hazard Mitigation Grant Program, as well as programs

that seek to reduce repetitive flood losses through relocating flood-prone properties. The need to weave a concern with disaster loss reduction into the fabric of ongoing community life has also guided federal initiatives such as Project Impact, FEMA’s Disaster Resistant Communities program.

Yet the research record suggests that those opportunities are often missed. While it is clear that some disaster-stricken communities do act decisively to reduce future losses, for others the recovery period brings about a return to the status quo ante, marked at most by gains in safety afforded by reconstruction to more stringent building codes. The section above noted that disasters create “windows of opportunity” for loss reduction advocates, in part by highlighting policy failures and temporarily silencing opponents. At the same time, however, research evidence suggests that even under those circumstances, it is extremely difficult to advance sustainability goals in the aftermath of disasters. Changes in land use are particularly difficult to enact, both during nondisaster times and after disasters, despite the fact that such changes can significantly reduce vulnerability. Land use decision making generally occurs at the local level, but local jurisdictions have great difficulty enacting controls on development in the absence of enabling legislation from higher levels of government. Even when land-use and zoning changes and other mitigation measures are seen as desirable following disasters, community leaders may lack the political will to promote such efforts over the long term, allowing opponents to regroup and old patterns to reassert themselves (see, for example, Reddy, 2000; for more detailed discussions on land-use and hazards, see Burby, 1998). Assessing reconstruction following recent U.S. disasters, Platt (1998:51) observed that “[d]espite all the emphasis on mitigation of multiple hazards in recent years, political, social and economic forces conspire to promote rebuilding patterns that set the stage for future catastrophe.” Overall, the research record suggests that while the recovery period should ideally be a time when communities take stock of their loss reduction policies and enact new ones, post-disaster change tends to be incremental at best and post-disaster efforts to promote sustainability are rare.


This chapter closes by making recommendations for future research on disaster response and recovery. As the foregoing discussions have indicated, existing research has raised numerous questions that need to be addressed through future research. This concluding section highlights general areas in which new research is clearly needed, both to test the limits of current social science knowledge and to take into account broad societal changes and issues of disaster severity and scale.

Recommendation 4.1: Future research should focus on further empirical explorations of societal vulnerability and resilience to natural, technological, and willfully caused hazards and disasters.

Discussions of factors associated with differential vulnerability and resilience in the face of disasters appear in many places in this report. What these discussions reveal is that researchers have only begun to explore these two concepts and much work remains to be done. It is clear that vulnerability is produced by a constellation of psychological, attitudinal, physical, social, and economic factors. However, the manner in which these factors operate and interact in the context of disasters is only partially understood. For example, while sufficient evidence exists to indicate that race, gender, and ethnicity are important predictors of hazard vulnerability and disaster-related behavior, research has yet to fully explore such factors, their correlates, and their interactions across different hazard and disaster contexts. In many cases age is associated with vulnerability to disasters (see Ngo, 2001; Anderson, 2005), but other factors such as ethnicity and socioeconomic status have differential effects within particular age groups (Bolin and Klenow, 1988), and the vulnerability of elderly persons may be related not only to age but also to other factors that are correlated with age, such as social isolation, which can cut off older adults from sources of lifesaving aid under disaster conditions (Klinenberg, 2002).

Even less is known about how to conceptualize, measure, and enhance resilience in the face of disasters—whether that concept is applied to the psychological resilience of individuals or to the resilience of households, communities, local and regional economies, or other units of analysis. Resilience can be conceptualized as the ability to survive disasters without significant loss, disruption, and stress, combined with the ability to cope with the consequences of disasters, replace and restore what has been lost, and resume social and economic activity in a timely manner (Bruneau et al., 2003). Other dimensions of resilience include the ability to learn from disaster experience and change accordingly.

The large volume of literature on psychological resilience and coping offers insights into factors that facilitate resilient responses by individual disaster victims. Other work, such as research on “high-reliability organizations,” organizational adaptation and learning under crisis conditions, and organizational effectiveness (Roberts, 1989; La Porte and Consolini, 1998; Comfort, 1999; Drabek, 2003) also offers insights into correlates of resilience at the organizational and interorganizational levels. As suggested in Chapter 6 , the social capital construct and related concepts such as civic engagement and effective collective action are also related to resilience. The challenge is to continue research on the resilience concept while synthesizing theoretical insights from these disparate literatures, with the ultimate objective of developing an empirically grounded

theory of resilience that is generalizable both across different social units and across different types of extreme events.

Recommendation 4.2: Future research should focus on the special requirements associated with responding to and recovering from willful attacks and disease outbreaks.

A better understanding is needed of likely individual, group, and public responses to intentional acts of terrorism, as well as disease outbreaks and epidemics. As indicated in this chapter, there appears to be no strong a priori reason for assuming that responses to natural, technological, or intentionally caused disasters and willful or naturally occurring disease outbreaks will differ. However, research on hazards and disasters also calls attention to factors that could well prove to be important predictors of responses to such occurrences, particularly those involving unique hazards such as chemical, biological, nuclear, and radiological agents. Research on individual and group responses to different types of disasters has highlighted the importance of such factors as familiarity, experience, and perceptual cues; perceptions about the characteristics of hazards (e.g., their dread nature, lethality and other harms); the content, clarity, and consistency of crisis communications; knowledge of appropriate self-protective actions; and feelings of efficacy with respect to carrying out those measures (see, for example, classic work on risk perception, discussed in Slovic, 2000, as well as Lindell and Perry, 2004).

Recent research has also highlighted the importance of emotions in shaping perceptions of risk. Hazards that trigger vivid images of danger and strong emotions may be seen as more likely to occur, and more likely to produce harm, even if their probability is low (Slovic et al., 2004). If willful acts engender powerful emotions, they could potentially also engender unusual responses among threatened populations.

The potential for ambiguity and confusion with respect to public communications may also be greater for homeland security threats and public health hazards such as avian flu than for other hazards. For example, warning systems and protocols are more institutionalized and more widely understood for natural hazards than for homeland security and public health threats. While it is generally recognized that organizations such as the National Hurricane Center and the U.S. Geological Survey constitute reliable sources of information on hurricanes and earthquakes, respectively, members of the public may be less clear regarding responsibilities and authorities with respect to other risks, particularly since such threats and the expertise needed to assess them are so diverse.

These kinds of differences could translate into differences in public perceptions and subsequent responses. Research is needed on the manner in which the distinctive features of particular homeland security and public

health threats, such as those highlighted here, as well as official plans and management strategies, could affect responses during homeland security emergencies.

Recommendation 4.3: Future research should focus on the societal consequences of changes in government organization and in emer gency management legislation, authorities, policies, and plans that have occurred as a result of the terrorist attacks of September 11, 2001, as well as on changes that will almost certainly occur as a result of Hurricane Katrina.

The period since the 2001 terrorist attacks has been marked by major changes in the nation’s emergency management system and its plans and programs. Those changes include the massive government reorganization that accompanied the creation of the Department of Homeland Security (DHS); the transfer of FEMA, formerly an independent agency, into DHS; the shifting of many duties and responsibilities formerly undertaken by FEMA to DHS’s Office of Domestic Preparedness, which was formerly a part of the Justice Department; the development of the National Response Plan, which supercedes the Federal Response Plan; Presidential Homeland Security Directives 5 and 8, which make the use of the National Incident Management System (NIMS) mandatory for all agencies and organizations involved in responding to disasters and also mandate the establishment of new national preparedness goals; and increases in funding for special homeland security-related initiatives, particularly those involving “first responders.” Other changes include a greater emphasis on regionalized approaches to preparedness and response and the growth at the federal, state, and local levels of offices and departments focusing specifically on homeland security issues—entities that in many cases exist alongside “traditional” emergency management agencies. While officially stressing the need for an “all-hazards” approach, government initiatives are concentrating increasingly on preparedness, response, and recovery in the context of willful attacks. These changes, all of which have taken place within a relatively short period of time, represent the largest realignment of emergency management policies and programs in U.S. history.

What is not known at this time—and what warrants significant research—is how these changes will affect the manner in which organizations and government jurisdictions respond during future extreme events. Is the system that is evolving more centralized and more command-and-control oriented than before September 11? If so, what consequences will that have for the way organizations and governmental entities respond? What role will the general public and emergent groups play in such a system? How will NIMS be implemented in future disasters, and to what effect? What new forms will emergent multiorganizational networks assume in future

disasters? Which agencies and levels of government will be most central, and how will shifts in authority and responsibility affect response and recovery efforts? Will the investment in homeland security preparedness translate into more rapid, appropriate, and effective responses to natural and technological disasters, or will the new focus on homeland security lead to an erosion in the competencies required to manage other types of emergencies? A major research initiative is needed to analyze the intended and unintended consequences in social time and space of the massive changes that have taken place in the nation’s emergency management system since September 11, 2001.

These concerns loom even larger in the aftermath of Hurricane Katrina. That disaster revealed significant problems in virtually every aspect of intergovernmental preparedness and response. The inept management of the Katrina disaster was at least in part a consequence of the myopic institutional focus on terrorism that developed in the wake of the September 11, 2001 attacks—a focus that included marginalizing and underfunding FEMA and downplaying the challenges associated with responding to large-scale natural disasters (Tierney, 2006, forthcoming). Katrina is certain to bring about further efforts at reorganizing the nation’s response system, particularly at the federal level. These reorganizations and their consequences merit special attention.

Recommendation 4.4: Research is needed to update current theories and findings on disaster response and recovery in light of chang ing demographic, economic, technological, and social trends such as those highlighted in Chapter 2 and elsewhere in this report.

It is essential to keep knowledge about disaster response and recovery current. The paragraphs above highlight the need for new research on homeland security threats and institutional responses to those threats. Research is also needed to update what is known about disaster response and recovery in light of other forms of social change and to reassess existing theories. Technological change is a case in point. Focusing on only one issue—disaster warnings—the bulk of the research that has been conducted on warning systems and warning responses was carried out prior to the information technology and communications revolutions. With the rise of the Internet and interactive Web-based communication, the proliferation of cellular and other wireless media, and the growing potential for ubiquitous communications, questions arise regarding the applicability of earlier research findings on how members of the public receive, interpret, and act on warnings. Changes in the mass media, including the rise of the 24-hour news cycle and the trend toward “narrowcasting” and now “podcasting” for increasingly specialized audiences, also have implications for the ways in which the public learns about hazards and receives warning-related

information. In many respects, warning systems reflect a preference for “push-oriented” information dissemination approaches. However, current information collection practices are strongly “pull oriented.” These and other trends in communications technology introduce additional complexity into already complex processes associated with issuing and receiving warnings, decision making under uncertainty, and crisis-related collective behavior. New research is needed both to improve theories and models and to serve as the basis for practical guidance.

Much the same can be said with respect to organizations charged with responding during disaster events. Along with being affected by policy and programmatic changes such as those discussed above, crisis-relevant agencies are also being influenced by the digital and communications revolution and by the diffusion of technology in areas such as remote sensing, geographic information science, data fusion, decision support systems, and visualization. In the more than 15 years since Drabek (1991b) wrote Microcomputers and Emergency Management , which focused on the ways in which computers were affecting the work of local emergency management agencies, technological change has been rapid and massive. How such changes are affecting organizational performance and effectiveness in disasters is not well understood and warrants extensive systematic study.

Recommendation 4.5: More research is needed on response and recovery for near-catastrophic and catastrophic disaster events.

Chapter 1 discusses issues of determining thresholds of disastrous conditions. NEHRP-sponsored social science research indicates that, in the main, U.S. communities have shown considerable resilience even in the face of major disasters. Similarly, at the individual level, U.S. disasters have produced a range of negative psychosocial impacts, but such impacts appear to have been neither severe nor long-lasting. While recognizing that disasters disproportionately affect the most vulnerable in U.S. society and acknowledging that recovery is extremely difficult for many, disasters have been less devastating in the United States and other developed societies than in the developing world. Disaster-related death tolls have also been lower by orders of magnitude, and economic losses, although often large in absolute terms, have also been lower relative to the size of the U.S. economy. At least that was the case until Hurricane Katrina, a catastrophic event that has more in common with disasters in the developing world than with the typical U.S. disaster.

The vast majority of empirical studies on which such generalizations are based have not focused on truly catastrophic disasters, and therefore research results may not be “scalable” to such events. Katrina clearly demonstrates that the nation is at risk for events that are so large that they overwhelm response systems and produce almost insurmountable post-

disaster recovery challenges. What kinds of social and economic impacts and outcomes would result from a large earthquake under downtown Los Angeles, a 7.0 earthquake event on the Hayward Fault in the San Francisco Bay area, a repeat of Hurricane Andrew directly striking Miami, or another hurricane landfall in the already devastated Gulf Coast region? What about situations involving multiple disaster impacts, such as the 2004 hurricane season in Florida and multiple disaster events that produce protracted impacts over time, such as the large aftershocks that are now occurring after the Indian Ocean earthquake and tsunami? To move into the realm of worst cases, what about an attack involving weapons of mass destruction, or simultaneous terrorist attacks in different cities around the United States? Such events are not outside the realm of possibility. There is a need to envision the potential social and economic effects of very large disasters, to learn from catastrophic events such as Hurricane Katrina, and to analyze historical and comparative cases for the insights they can provide.

Recommendation 4.6: More cross-societal research is needed on natural, technological, and willfully caused hazards and disasters.

Most of the research discussed in this chapter has focused on studies conducted within the United States, but it is important to recognize that findings from U.S. research cannot be overgeneralized to other societies. Disaster response and recovery challenges are greater by many orders of magnitude in smaller and less developed societies than in larger and more developed ones.

Disaster impacts, disaster responses, and recovery processes and outcomes clearly vary across societies. Although the earthquakes that struck Los Angeles in 1994, Kobe in 1995, and Bam, Iran, in 2003 were roughly equivalent in size, they differed in almost every other way: lives lost, injuries, extent of physical damage, economic impacts, and subsequent response and recovery activities. Research suggests that such cross-societal differences are attributable to many factors, including differences in physical and social vulnerability; governmental and institutional capacity; government priorities with respect to loss reduction; and response and recovery policies and programs (see, for example, Davis and Seitz, 1982; Blaikie et al., 1994; Berke and Beatley, 1997; Olson and Gawronski, 2003). NEHRP has made significant contributions to cross-societal research through initiatives such as the U.S.-Japan research program on urban earthquake hazards, which was launched following the Northridge and Kobe earthquakes, as well as a similar initiative that was developed after the 1999 Turkey and Taiwan earthquakes. In some cases, these initiatives have led to longer-term research partnerships; Chapter 6 contains information on one such collaboration, involving the Texas A&M University Hazard Reduction and Recovery Center and the National Center for Hazards Mitigation at the National

Taiwan University. Significantly more cross-national and comparative research is needed to further document and explain cross-societal variations in response and recovery processes and outcomes across different scales and different disaster events. Disasters such as the Indian Ocean earthquake and tsunami merit intensive study because they allow for rich comparisons at various scales (individuals, households, communities, and institutional and societal levels), providing an opportunity to greatly expand existing social science knowledge.

Recommendation 4.7: Taking into account both existing research and future research needs, sustained efforts should be made with respect to data archiving, sharing, and dissemination.

As noted in detail in Chapter 7 , attention must be paid to issues related to data standardization, data archiving, and data sharing in hazards and disaster research. NEHRP has been a major driving force in the development of databases on response and recovery issues. However, vast proportions of these data have yet to be fully analyzed. For social scientists to be able to fully exploit the data that currently exist, let alone the volume of data that will be collected in the future, specific steps have to be taken to make available and systematically collect, preserve, and disseminate such data appropriately within the research community. As recommended in Chapter 7 , information management strategies must be well coordinated, formally planned, and consistent with federal guidelines governing the protection of information on human subjects. Assuming that these foundations are established, the committee supports the creation of a Disaster Data Archive organized in ways that would encourage broader use of social science data on disaster response and recovery. Contents of this archive would include (but not be limited to) survey instruments; cleaned databases in common formats; code books, coding instructions and other forms of documentation; descriptions of samples and sampling methods; collections of papers containing analyses using those databases; photographs and Internet links (where applicable); and related research materials. Procedures for data archiving and sharing would build on existing protocols set out by organizations such as the Inter-University Consortium for Political and Social Research (e.g., ICPSR, 2005).

The distributed Disaster Data Archive would perform a number of important functions for social science hazards and disaster research and for the nation. The existence of the archive would make it much more likely that existing data sets will be used to their full potential by greatly improving accessibility. The archive would serve as an important tool for undergraduate and graduate education by making data more easily available for course projects, theses, and dissertations. By enabling researchers to access instruments used in previous research and incorporate past survey and

interview items into their own research, the archive should help make social science research on disasters more cumulative and replicable. An archive would also make it easier for newcomers to the field of disaster research to become familiar with existing research and enable researchers to identify gaps in past research and avoid unnecessary duplication. The archive would also serve an important function in preserving data that might otherwise be lost. Finally, such an archive would enable social science disaster research to better respond to agency directives regarding the desirability of data sharing.

For an effort of this kind to succeed, a number of conditions must be met. Funds will be needed to support the development and maintenance of the archive, and researchers must be willing to make their data sets and all relevant documentation available. This second condition is crucial, because the committee is aware of a number of important data sets that are not currently being shared, and the archive cannot succeed without broad researcher support. Challenges related to human subjects review requirements, confidentiality protections, and disclosure risks must be fully explored and addressed. Other issues include challenges associated with the development and enforcement of quality control standards, rules and standards for data sharing, procedures to ensure that proper acknowledgment is given to project sponsors and principal investigators, and questions about long-term management of the archive.

Related to the need for better data archiving, sharing, and dissemination strategies, social scientists must be poised to take advantage of new capabilities for data integration and fusion. Strategies are needed to integrate social science data with other types of data collected by both pervasive in situ and mobile ad hoc sensor networks (Estrin et al., 2003), such as networks that collect data on environmental and ecological changes and disaster impacts. In light of the availability of such a wide array of data, the hazards and disasters research community must recognize that hazards and disaster informatics—the application of information science and technology to disaster research, education, and practice—is an emerging field.

To realize this potential, and with the foundation established through implementing recommendations in Chapter 7 , the committee further supports the creation of a Data Center for Social Science Research on Hazards and Disasters. In addition to maintaining the Disaster Data Archive, this center would conduct research on automated information extraction from data, including the development of efficient and effective methods for storing, querying, and maintaining both qualitative and quantitative data from disparate and heterogeneous sources.

Social science research conducted since the late 1970's has contributed greatly to society's ability to mitigate and adapt to natural, technological, and willful disasters. However, as evidenced by Hurricane Katrina, the Indian Ocean tsunami, the September 11, 2001 terrorist attacks on the United States, and other recent events, hazards and disaster research and its application could be improved greatly. In particular, more studies should be pursued that compare how the characteristics of different types of events—including predictability, forewarning, magnitude, and duration of impact—affect societal vulnerability and response. This book includes more than thirty recommendations for the hazards and disaster community.


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Executive Summary

Compared to the average over the last 30 years (1991-2020), the total frequency of global natural disasters in 2021 was 13% higher, with 81% lower in deaths, 48% less in the affected population, and 82% more in direct economic losses. Global flood disasters in 2021 were the most frequent, 48% more than the historic levels, causing 4,393 deaths, which was more than the death toll from other natural disasters but 35% less than the historical average of flood-related deaths; the direct economic losses caused by storm disasters were the largest, reaching USD 137.7 billion, 133% more than the historical average; there were fewer strong earthquakes and their disaster losses were relatively small; the number of deaths from wildfires decreased, but the population affected rose by 219% and the direct economic losses were 109% higher than the historic levels. Regionally, Asia has seen the highest frequency of natural disasters in 2021, followed by North America; among all continents, Asia had the largest number of deaths due to disasters, followed by North America; North America has seen the highest economic losses due to disasters, followed by Europe; compared with developed countries, developing countries were more severely affected by natural disasters, mostly floods, storms, and extreme temperatures.

In 2021, deaths from natural disasters in China were at an above-average level in the world, basically consistent with the level of its economic development; the proportion of direct economic losses in GDP was at a lower-middle level, which was largely consistent with the level of its economic development. The flood losses in China were higher than those from other disasters and accounted for a large proportion of the global flood losses.

In 2021, China faced a complicated natural disaster situation , with extreme weather and climate events occurring frequently. The natural disasters mainly included flood, strong wind and hail, drought, typhoon, earthquake, geological disasters and cold wave, while sand and dust storm, forest and grassland fires and marine disasters also hit to varying degrees. On the whole, however, natural disaster situation in China was relatively moderate.

The report analyzes the characteristics of global extreme weather disasters from 2000 to 2021. During this period, annual direct economic losses from extreme disasters in Asia, America, Europe and Africa showed an increasing trend. The frequency of such disasters was far higher in Asia than on other continents, and the total losses in Asia from 2011 to 2021 were twice those of Asia from 2000 to 2010. The report also summarizes the characteristics of global climate, and the major weather and climate events in 2021, coupled with an analysis of the causes of typical major weather and climate events, including rainstorm-in- duced flood, drought, tropical cyclone, heat wave and wildfire, cold wave and severe convection. The report calls for greater world attention to tackling increasingly frequent extreme weather and climate events, and boosting collaborative research toward that end.

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A review of risk analysis methods for natural disasters

  • Original Paper
  • Published: 21 December 2019
  • Volume 100 , pages 571–593, ( 2020 )

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  • Ruiling Sun 1 , 2 ,
  • Zaiwu Gong   ORCID: 4 &

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Between 1998 and 2017, 1.3 million people were killed and another 4.4 billion were left injured, homeless, displaced, or in need of emergency assistance due to climate-related and geophysical disasters. A risk analysis of natural disasters is helpful not only for disaster prevention and reduction, but also in reducing economic and social losses. Currently, there are many methods for natural disaster risk analysis. Based on the uncertainty, unfavorable and future characteristics of natural disaster risk, this paper summarizes the methods for disaster risk analysis based on the scope of application, research results, and focus; it also clarifies the advantages and disadvantages of various methods, as well as the scope of application, to provide a reference for selecting and optimizing methods for future disaster risk analysis.

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This research is partially supported by the National Natural Science Foundation of China (71971121, 71571104), NUIST-UoR International Research Institute, the Major Project Plan of Philosophy and Social Sciences Research in Jiangsu Universities (2018SJZDA038), the 2019 Jiangsu Province Policy Guidance Program (Soft Science Research) (BR2019064), and the Spanish Ministry of Economy and Competitiveness with FEDER funds (Grant number TIN2016-75850-R).

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School of Applied Meteorology, Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, Nanjing, 210044, Jiangsu, China

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National Climate Center, Beijing, 100081, China

School of Management Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, 210044, Jiangsu, China

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Sun, R., Gao, G., Gong, Z. et al. A review of risk analysis methods for natural disasters. Nat Hazards 100 , 571–593 (2020).

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Received : 10 July 2019

Accepted : 17 December 2019

Published : 21 December 2019

Issue Date : January 2020


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Natural disaster preparedness in a multi-hazard environment: Characterizing the sociodemographic profile of those better (worse) prepared

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Affiliations Engineering Sciences Department, Universidad Andres Bello, Santiago, Chile, National Research Center for Integrated Natural Disaster Management CONICYT/FONDAP/15110017, Santiago, Chile

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Roles Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Software, Supervision, Validation, Visualization, Writing – original draft, Writing – review & editing

Affiliations National Research Center for Integrated Natural Disaster Management CONICYT/FONDAP/15110017, Santiago, Chile, Industrial and Systems Engineering Department, Pontificia Universidad Catolica de Chile, Santiago, Chile

Roles Conceptualization, Formal analysis, Investigation, Methodology, Supervision, Validation, Writing – original draft, Writing – review & editing

Affiliations National Research Center for Integrated Natural Disaster Management CONICYT/FONDAP/15110017, Santiago, Chile, Department of Psychology, Pontificia Universidad Catolica de Chile, Santiago, Chile

Roles Writing – original draft, Writing – review & editing

Affiliation Department of Psychology, Pontificia Universidad Catolica de Chile, Santiago, Chile

  • Nicolás C. Bronfman, 
  • Pamela C. Cisternas, 
  • Paula B. Repetto, 
  • Javiera V. Castañeda


  • Published: April 24, 2019
  • Reader Comments

Fig 1

The growing multi-hazard environment to which millions of people in the world are exposed highlights the importance of making sure that populations are increasingly better prepared. The objective of this study was to report the levels of preparedness of a community exposed to two natural hazards and identify the primary sociodemographic characteristics of groups with different preparedness levels. A survey was conducted on 476 participants from two localities of the Atacama Region in the north of Chile during the spring of 2015. Their level of preparedness at home and work was assessed to face two types of natural hazards: earthquakes and floods.The findings show that participants are significantly better prepared to face earthquakes than floods, which sends a serious warning to local authorities, given that floods have caused the greatest human and material losses in the region’s recent history of natural disasters. Men claimed to be more prepared than women to face floods, something that the authors attribute to the particular characteristics of the main employment sectors for men and women in the region. The potential contribution of large companies on preparedness levels of communities in the areas in which they operate is discussed. The sociodemographic profile of individuals with the highest levels of preparedness in an environment with multiple natural hazards are people between 30 and 59 years of age, living with their partner and school-age children. The implications of the results pertaining to institutions responsible for developing disaster risk reduction plans, policies and programs in a multi-hazard environment are discussed.

Citation: Bronfman NC, Cisternas PC, Repetto PB, Castañeda JV (2019) Natural disaster preparedness in a multi-hazard environment: Characterizing the sociodemographic profile of those better (worse) prepared. PLoS ONE 14(4): e0214249.

Editor: Florian Fischer, Bielefeld University, GERMANY

Received: November 15, 2018; Accepted: March 8, 2019; Published: April 24, 2019

Copyright: © 2019 Bronfman et al. This is an open access article distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Data Availability: All relevant data are within the manuscript and its Supporting Information files.

Funding: This research was partially funded by Chile’s National Science and Technology Commission (Conicyt) through the National Fund for Scientific and Technological Research (Fondecyt, Grant 1130864; NCB - Grant 1180996; NCB) and by the National Research Center for Integrated Natural Disaster Management CONICYT/ FONDAP/15110017; NCB, PBR, PCC. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.


A World Bank report that assessed the main natural disaster hotspots in the world [ 1 ] found that approximately 3.8 million km 2 and 790 million individuals are exposed to at least two natural hazards, while 0.5 million km 2 and 105 million individuals are exposed to three or more natural hazards. An increase in the magnitude, frequency and geographic distribution of natural disasters has been recently demonstrated, particularly for those related to climate change [ 2 ]. Records show that between 1994 and 2013, floods were the most frequent event (43% of all events registered), affecting approximately 2.5 billion people [ 3 ] and caused the greatest material costs and losses. In the same period, earthquakes and tsunamis caused the highest number of fatalities, estimated at around 750,000, with tsunamis being twenty times more lethal than earthquakes [ 3 ]. These statistics demonstrate the critical multi-hazard environment to which the global population is exposed.

The combination of human and economic losses, together with reconstruction costs, makes natural disasters both a humanitarian and an economic problem [ 1 ]. Between 1994 and 2013, natural disasters produced economic losses of more than USD 2.6 trillion [ 3 ]. More recently, in 2017, USD 314 billion were spent globally on damage related to natural disasters [ 4 ]. There is currently an unresolved debate regarding whether natural disasters hinder a country’s economic growth, given that the empirical evidence is somewhat heterogeneous [ 5 ]. However, high expenditure associated with natural disasters may reduce investment in other priority areas for a country, such as education, health, transport and security [ 5 ].

There are no countries or communities that are currently immune to the impact of natural disasters. It is, however, possible to reduce the effects of these events through management strategies focused on risk reduction [ 6 ]. Citizen preparedness strategies play a key role in reducing the effects of hazards that cannot be mitigated [ 6 – 8 ], as such strategies seek to improve the ability of individuals and communities to respond in the event of a natural disaster [ 7 ].

Chile, located in the Pacific Ring of Fire, is one of the countries that is most exposed to earthquakes/tsunamis and volcanic eruptions on the planet. Among the OECD member countries, Chile is the most exposed to natural hazards, where 54% of its population and 12.9% of its total surface area are exposed to three or more hazards [ 1 ]. Between 2008 and 2018, Chile was affected by ten natural disasters (earthquakes, tsunamis, wildfires, floods and volcanic eruptions), which translated into more than four million affected individuals and close to 800 fatalities [ 9 ]. The 2010 earthquake and tsunami alone caused the death of 562 people, and gave rise to more than USD 30 billion in material losses [ 10 ]. As such, the multi-hazard environment to which the population is exposed, and the high expenditure associated with natural disasters in Chile, emphasize the importance of adopting a multi-hazard approach to progress in the design of preparedness strategies. In order to move forward in this direction, the main objective of this study is to understand the current levels of preparedness of a community exposed to multiple natural hazards and identify the primary sociodemographic characteristics of groups that show different levels of preparedness. The results of this study are expected to contribute to the development of disaster risk reduction strategies and programs in multi-hazard environments.

Preparedness in a multi-hazard environment

The complexity of territories and social structures expose communities to various hazards, both natural and man-made. Against this backdrop, the leading institutions responsible for disaster risk reduction worldwide indicate the importance of nations being able to assess, recognize and integrate the various hazards in their territories in their planning, in order to prepare the population to effectively mitigate the damages associated with these multiple hazards [ 11 ].

Although addressing a multi-hazard environment requires significant economic and political efforts, several studies have indicated that the multi-hazard approach has major benefits for the design of effective disaster risk reduction policies [ 12 , 13 ]. A multi-hazard assessment permits not only more reliable territorial planning for a country’s inhabitants but also lets stakeholders show that focusing mitigation measures on a single hazard may increase vulnerability to others [ 12 ].

The main recommendations for multi-hazard environments include strengthening risk assessment within territories, informing the population of these risks to raise awareness, and establishing multi-disciplinary and multi-sectoral efforts to develop integrated public policies [ 14 ].

Natural hazard preparedness

In recent decades, numerous studies have been focused on assessing individuals’ levels of preparedness for natural hazards, and the factors that promote the adoption of preparedness measures [ 15 – 17 ]. In the literature, there are different theoretical frameworks to conceptualize the adoption of preparedness measures to face natural hazards, where the Protective Action Decision Model [ 16 , 18 ] and the Social-Cognitive Model [ 19 , 20 ] are the most cited models. The first model recognizes that preparation is a behavior dependent on risk perception, previous experience and some demographic characteristics, among other variables. The social cognitive model focuses on the role of motivational factors on the decision to adopt preparedness actions, including awareness of the threat, anxiety, self-efficacy, and sense of community among others. Both models can help describe and understand the preparedness, however, for the purposes of the present study we incorporate elements of the Protective Action Decision Model, mainly in aspects related to the relation between sociodemographic factors and preparedness levels. This model also recognizes the role of experience that is relevant for this particular study considering that the communities that were studied had experienced both events.

One of the most common ways to study natural disaster preparedness levels is by characterizing these measures within the places where individuals spend most of their time, such as their homes (with their families) and their workplaces [ 21 – 23 ]. These areas are representative not only of the types of preparedness measures adopted by the population [ 22 ], but also the areas that people recognize as sources of common and relevant information for taking preparedness measures [ 24 ]. Preparedness actions involve developing plans, stockpiling of supplies and performing exercises and drills, all aimed to reduce the impact of the disaster [ 25 ]. These actions have been translated into recommendations, checklists and actions that organizations provide to households, communities and workplace in order to be prepared in case of a disaster. Response organizations recommend to frequently assess and evaluate whether these actions have been implemented.

Researchers have proposed several models to explain the decision to take action and implement preparedness actions, with a particular emphasis on the role that social cognitive processes [ 26 ]. Traditionally these models have emphasized the role of risk perception and have also shown that previous experience may be relevant, but with mixed results in relation with preparedness [ 18 ]. For the purposes of this study we focused on a community that had experienced different hazards in the past years, so we could examine also whether they appeared to be prepared to respond to different hazards.

Household preparedness.

Researchers have mostly focused on understanding family preparedness when characterizing the preparedness levels of the population [ 23 , 27 ]. Family preparedness has been researched and measured through different types of activities, such as survival measures, mitigation measures and planning measures [ 21 , 23 , 28 – 30 ]. Family planning measures in the face of natural hazards are those which are adopted least frequently, but whose importance is highly recognized among individuals [ 23 , 30 ]. Family preparedness is recognized as the base from which other preparation actions take place [ 27 ].

Workplace preparedness.

Despite the fact that research on natural disaster preparedness has primarily focused on family preparedness, the study of workplace preparedness is emerging as a relevant focus for research, given the role that organizations play in local economies, the lives of the people they employ and even recovery following natural disasters [ 31 , 32 ].

As in the case of family preparedness, workplace preparedness involves planning activities, such as speaking with employees about the impact and importance of preparing the company for natural hazards, having an emergency plan in place, alternative energy supplies for the company’s operation following a natural disaster, insurance for this type of events, and the presence of an emergency kit in the company, among many others [ 21 , 23 , 27 , 31 , 33 ].

One factor that is most closely related to workplace preparedness is company size [ 27 , 31 , 33 ]. This is because companies with a larger number of employees have formalized risk reduction processes, and greater resources to implement them [ 31 ].

Sociodemographic variables and preparedness level

Several of the studies that link gender to the adoption of preparedness measures conclude that women prepare more than men [ 29 , 34 ], especially when it comes to measures related to creating a family emergency plan, the safety of household members, and the use of preparedness messages [ 35 ]. Similarly, it has been reported that married people or those who live with their partner show higher levels of preparedness than those who do not [ 23 , 36 , 37 ].

The age of subjects is also a predictor for the adoption of preparedness measures. While some studies conclude that older people adopt more preparedness measures, with one of the main reasons being previous exposure to and/or experience with natural disasters [ 29 , 38 ]. In other studies researchers suggest that age is not significantly related to the adoption of preparedness measures [ 36 , 39 ].

The presence of children under 18 years of age in the household is associated to higher levels of preparedness [ 37 , 40 , 41 ]. In a study conducted on a random sample of 1,158 households in Memphis, Tennessee, Edwards [ 39 ] suggests that parents feel responsible for the safety of children, and also because children receive more information (from their school environment) about how to prepare for natural hazards, motivating parents to implement these types of measures. Similarly, Pfefferbaum & North [ 42 ] indicate that parents are more concerned about what their children will experience during a natural disaster, which may prompt a desire to anticipate its consequences and to prepare in advance to mitigate any possible negative effects.


The research focused on the inhabitants of Copiapó and Tierra Amarilla municipalities (see Fig 1 ) in the Atacama Region in the north of Chile, since they are at risk of multiple natural hazards, particularly earthquakes and floods.


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The maps in the top left show the earthquakes that affected the Atacama Region. The map on the right shows the Copiapó and Tierra Amarilla municipalities, the flooded area of the 2015 event and the location of the households surveyed.

Geographic characteristics.

The Atacama Region, Chile, has a surface area of 75,176 km 2 , equivalent to 9.94% of the country’s total (see Fig 1 ). Copiapó and Tierra Amarilla municipalities account for the 37% of the Region’s surface area. The climate of Copiapó and Tierra Amarilla is semi-arid, with scarce and light rainfall during the winter months. A phenomenon known as the “Altiplanic winter” takes place here, which triggers rainfall between the summer months of December and March [ 43 ]. The “Altiplanic winter” is the name given to the phenomenon of rainfall between December and March in the north of the country, as a result of moisture originating from the Atlantic Ocean [ 43 ]. However, rainfall has occurred during winter produced by the “Altiplanic winter” phenomenon that may intensify and produce extreme hydrometeorological events, due to the presence of weather patterns known as El Niño and La Niña [ 44 ].


Copiapó and Tierra Amarilla municipalities (see Fig 1 ) are home to more than 60% of the Atacama Region’s population. The proportion of women in these municipalities is 48.6% and 42.4%, respectively [ 45 ]. Regarding age, the region’s population can be classified as follows: 19.3% are between 18 and 29 years of age, 21.0% are between 30 and 44 years of age, 19.3% are between 45 and 59 years of age, and 13.2% are above 60 years of age. A similar trend occurs for the populations of the Copiapó and Tierra Amarilla municipalities.

On December 2017, the unemployment rate in these localities reached 6.7%, slightly above the national average, which was 6.4% [ 46 ]. Mining is the sector which has the greatest influence on the country’s economic development, accounting for 10% of national GDP, generating 8.4% of national income, and representing at least half of total exports (55%) as of 2017 [ 47 ]. Currently, Chile is the largest copper producer in the world. As with other regions in the north of Chile, the main economic activity of Copiapó and Tierra Amarilla is mining (copper and other minerals), which accounts for 28% of the region’s GDP and is one of the main factors affecting employment rates. As of 2017, 15% of all workers in the region were employed in the mining sector, of which 92% were men [ 45 ].

Natural disasters in the study area.

The localities of the Atacama Region have an extensive history of natural disasters, particularly extreme hydrometeorological events causing significant floods, with the events that took place in 1997 and 2015 considered the most catastrophic. In April 1997, intense rainfall caused rivers in the Atacama Region to overflow, producing floods that affected mostly to Copiapó (see Fig 1 ). A total of 22 people died, and material losses were estimated at USD 180 million [ 9 ]. Almost two decades later, in March 2015, there was a hydrometeorological event considered the largest in its history. More than 45mm of rain fell in approximately 48 hours [ 48 ]. The effects were devastating, mainly for the towns of Copiapó, Paipote, and Tierra Amarilla. A total of 31 people died, 16 were declared missing, 30,000 were displaced, and more than 164,000 people were affected by the event [ 49 ]. The material damages were estimated at more than USD 1.5 billion.

The Atacama Region’s localities are not only vulnerable to the occurrence of major floods but also, like the rest of the country, to severe geophysical events. Chile’s location in the Pacific Ring of Fire makes it one of the countries with the highest levels of seismic and volcanic activity on the planet. The largest earthquake recorded in the study area occurred in 1877, with a magnitude of 8.8 Mw on the Richter scale [ 50 ]. The second largest earthquake in the area occurred in 1922, with a magnitude of 8.5 Mw on the Richter scale [ 51 ]. The consequences of this event were devastating: 40% of houses were reduced to ruins, a further 45% requiring demolition, and the rest in dire need of repair [ 52 ]. The most recent earthquake in the area occurred in 2014 and is considered the third most destructive to hit the region. It had a magnitude of 8.2 Mw on the Richter scale, affected 13,000 homes, and caused the death of six people. Economic losses were estimated at more than USD 100 million. Despite these events, the scientific community has demonstrated that there are still subduction zones that have not been activated for more than 150 years, and as such the probability of another event with similar characteristics occurring in the near future is very high [ 53 ].

The survey was separated into three sections, in which two types of natural hazard that affect the region were studied: earthquakes and floods. The first section contained questions about the level of preparedness for these two hazards. The second section assessed the participants’ prior experience of floods, and their evacuation experience in the latest event of 2015. Finally, the third section included questions about the participants’ sociodemographic characteristics. As this survey forms part of a larger study, only the measures that were used in this study are described below.

Preparedness . The earthquake and flood preparation scale was structured into two sub-scales; one to measure household preparedness (2 items) and another to measure workplace preparedness (3 items). The items on both sub-scales were adapted from previous studies [ 21 , 23 , 28 , 29 ]. The participants were required to answer the questions associated with each sub-scale on each hazard (earthquake and flood) using a dichotomous scale (1) Yes, (0) No, as shown in Table 1 . The set of preparedness actions of the questionnaire considered the main actions suggested by International Agencies as minimum elements of preparation of individuals. The yes/no answers to these questions would be indicative of participants' perception of preparedness rather than an objective measure of the actions they actually perform.


Sociodemographic characteristics . The participants were asked about various sociodemographic characteristics, including their age, gender, marital status, work activity, and whether children under 18 years of age live in their household.

Procedure and participants

The understanding of the questionnaire was assessed and validated through a focus group directed by the research team. The sample was designed through simple random sampling, based on population forecasts for the Atacama Region developed by the National Statistics Institute of Chile in 2015. The first stage considered the random selection of geographic clusters (housing blocks) by block code. Then, households were selected using the Kish table and systematic sampling. Finally, people were selected on the basis of a quota system (to allow variability of gender and age). The survey took place between November and December 2015 with a statistically representative sample in the Copiapó and Tierra Amarilla municipalities. A group of interviewers contacted voluntary participants, who had to complete a paper questionnaire face to face at their homes (receiving no compensation of any form). Finally, a total of 476 people successfully completed the survey. The average age of the sample was 49 years (SD = 17.6 years, with a range of 18–94 years of age), and 66.9% of the participants were women. All procedures were approved by the Ethics Committee of the University Andres Bello.

Regarding participants’ work activity, 37.2% declared that they were employed, 35.5% were homemakers, 4.6% were studying, and 11.8% were retired. Of the total number of participants who declared that they were employed (179 participants), 45% were women. While the main employment sectors for women were services (social, personal and community) and commerce, for men, the main sectors were large and medium-scale mining, transport (mainly related to mining) and construction.

Data analysis

First, a descriptive analysis of the data was carried out to assess the existence of coding errors and lost data. Then, an internal consistency analysis was performed on the full sample ( n = 476 ). The internal consistency of each sub-scale was assessed through two measures: Cronbach's alpha and corrected item-total correlation. For the first measure, values above 0.7 suggest highly consistent scales [ 54 ]. For the second measure, values above 0.3 are suggested [ 55 ]. Item-total correlation values lower than the cutoff level imply that the item is not correlated with the sub-scale, and as such it should be omitted.

To characterize the profile of participants with higher (or lower) levels of preparedness, difference in means analyses (using post-hoc Tukey tests) and a Factorial ANOVA were carried out.

Internal consistency

The internal consistency of the preparedness sub-scales was analyzed through alpha-Cronbach and corrected item-total correlation. For each participant, the preparedness sub-scales were calculated as the sum of the items that compose each one (see Table 1 ). For both hazards considered, the values of household preparedness range from 0 to 2, and for workplace preparedness range from 0 to 3. The sub-scales complied with all of the predefined requirements, and as such no items were eliminated. The α -Cronbach values for the household and workplace preparedness sub-scales for earthquakes and floods were above 0.8, and can be considered to be highly consistent (see Table 1 ).

Earthquake vs. flood preparedness

Table 1 shows the descriptive analysis of the participants’ responses to earthquake and flood preparedness questions. Significant differences are observed when comparing the participants’ degree of household preparedness and workplace preparedness to face both hazards. While the majority of participants said that they were prepared for an earthquake both at work and at home (see Table 1A ), a significantly lower proportion claimed to be prepared at work and at home for a flood (see Table 1B ).

Household preparedness

Table 2 shows the average values associated with household preparedness for earthquakes and floods, broken down by the sociodemographic characteristics of the sample. It can be observed that the participants stated that they were significantly more prepared at home for an earthquake than a flood ( p < 0.001), regardless of their age, gender, marital status, and work activity. This result is an important warning sign for local and regulatory authorities, given that the recent history of natural disasters in the region reveals that floods have caused the greatest human and material losses.


Similarly, for both earthquakes and floods, it can be observed that the level of household preparedness by marital status and age group showed statistically significant differences ( p < 0.1). In the former case, participants who were married or living with their partner declared higher levels of household preparedness than single, separated or widowed participants. In the latter case, subjects 60 years of age and above declared the lowest levels of household preparedness among the different age groups. In general, subjects between 30 and 59 years of age declared the highest levels of household preparedness to face both earthquakes and floods.

In the case of household preparedness for floods , women declared a lower level of preparedness compared to men.

To characterize the sociodemographic profile of subjects with higher (or lower) levels of declared household preparedness , a factorial ANOVA was carried out using sociodemographic characteristics as independent variables, and household preparedness as the dependent variable. The first columns in Table 3 show the results of the model for household preparedness for earthquakes ( F = 204.292, p = 0.000), which explained 23.2% of the variance. The results suggest that the groups defined for the Work Activity variable have significantly different levels of household preparedness ( p < 0.10). Similarly, the effects of two-way interactions (AgeGroup x MaritalStatus) and (WorkActivity x MaritalStatus) also showed significantly different levels of household preparedness for earthquakes . Three-way interactions (AgeGroup x MaritalStatus x Gender) and (WorkActivity x MaritalStatus x ChildrenAge) were statistically significant for household preparedness for earthquakes .


Fig 2A . shows the groups associated with the two-way interaction between (AgeGroup x MaritalStatus) and (WorkActivity x MaritalStatus). Based on Table 2 and Fig 2A ., it can be concluded that the profile of subjects with the highest level of household preparedness for earthquakes are between 30 and 59 years of age, married or living with their partner, and working or studying. On the other hand, the subjects with the lowest levels of household preparedness for earthquakes are those below 30 years old or above 60 years old, retired and single, separated or widowed. With regard to the three-way interactions, no clear trends were observed that enable to infer an evident profile.


The columns on the right-hand side of Table 3 show the results of the model for household preparedness for floods ( F = 39.125, p = 0.000), which explained 19.6% of the variance. The only groups which show significantly different levels of household preparedness for floods were those defined by the Gender variable. Meanwhile, the three-way interactions (ChildrenAge x MaritalStatus x WorkActivity) and (ChildrenAge x AgeGroup x WorkActivity) were statistically significant for household preparedness for floods .

Based on the results shown in Table 2 and Table 3 , we can conclude that men aged between 45 and 59 years of age who live with their partner declared the highest level of household preparedness for floods . On the other hand, the subjects who declared the lowest level of preparedness are women above 60 years of age who are single, separated, divorced or widowed. About the three-way interactions, no clear trends that suggest an evident profile may be inferred.

Workplace preparedness

Table 4 shows the average values associated with workplace preparedness for earthquakes and floods, according to the sociodemographic characteristics of the sample ( n = 179 participants who declared that they were employed). The results indicate that participants are significantly better prepared at work to face an earthquake than a flood ( p < 0.001), regardless of their age, gender, and marital status.


Both for earthquakes and floods, the MaritalStatus variable showed statistically significant differences ( p < 0.10); that is, participants who are married or living with their partner declared higher levels of workplace preparedness .

In the case of workplace preparedness for earthquakes , participants who declared that they live with children under 18 years of age in their household showed higher levels of preparedness. Similar to the situation that occurred for household preparedness , women declared a lower level of workplace preparedness for floods compared to men.

The first columns of Table 5 show the results of the factorial ANOVA model using sociodemographic characteristics as independent variables and workplace preparedness for earthquakes as the dependent variable. The model explained 23.9% of the variance ( F = 171.612, p = 0.000). The results indicate that the effects of the two-way interactions between the AgeGroup and Children variables show significantly different levels of workplace preparedness for earthquakes .


Fig 2B . shows the two-way interaction between the AgeGroup and Children variables. Based on the results shown in Table 5 and Fig 2B ., it can be concluded that the profile of subjects who have the highest level of workplace preparedness for earthquakes are married or living with their partners, between 45 and 59 years of age, and have school-age children in their household. On the other hand, the participants with the lowest levels of workplace preparedness for earthquakes are those who are single (separated, divorced or widowed), above 60 years of age, and do not have school-age children living in the household.

The columns on the right-hand side of Table 5 show the results of the model using workplace preparedness for floods as the dependent variable. This model explained 17.7% of the variance ( F = 32.020, p = 0.000). The results show that the groups defined by the Gender and MaritalStatus variables have significantly different levels of workplace preparedness ( p < 0.10). Likewise, the two-way interaction effects of the Gender and MaritalStatus variables show significantly different levels of workplace preparedness for floods . Fig 2C . shows the two-way interaction between the Gender and MaritalStatus variables. Based on the results shown in Table 4 and Fig 2C ., it may be concluded that while the profile of subjects with the highest declared level of workplace preparedness for floods is men who are married or living with their partner, the profile of those with the lowest level is women who are single, separated, divorced or widowed.

The objective of this study was to assess the level of household and workplace preparedness of people living in an area exposed to multiple natural hazards and identify those groups of people with different preparedness levels.

Household and workplace preparedness

We conclude that significant differences exist in the preparedness levels declared by participants depending on the type of hazard analyzed. In fact, participants declared that they were significantly more prepared (both at home and at work) to face an earthquake than a flood, regardless of their age, gender, marital status and work activity. These results are an important warning sign for regulators and authorities, given that the recent history of natural disasters in the study area reveals that floods have caused the greatest human and material losses. Additionally, the influence of climate change is expected to produce an increase in weather phenomena, which would increase the frequency of extreme hydrometeorological events in the northern of Chile.

Among the reasons that may explain the above results is the fact that, historically, the country and the study area have placed greater emphasis on preparedness measures for earthquakes than for floods. In recent years, Chile has been affected by major earthquakes, with one of the most destructive one taking place on February 27, 2010 in the south of the country. This event caused great alarm and concern among citizens and government authorities, not only due to the destructive effects of the event, but also the shortcomings uncovered regarding the level of preparedness and coordination of government institutions responsible for disaster risk reduction. This situation received widespread media coverage, and was the subject of intense political debate which lasted for several years [ 56 , 57 ].

In addition to the above, the scientific community has indicated that the recent earthquakes that have occurred in the north of the country provide evidence that there are still subduction zones which have not been activated in almost 150 years [ 53 ]. As such, the scientific community and authorities still expect a mega-earthquake to affect the study area. This situation has led to the implementation of many communication and community preparedness plans and programs to face a potential mega-earthquake in the region in recent decades. Awareness from communities about the likelihood of an earthquake is high and motivate them to be prepared for a future event.

Our results also show high levels of declared workplace preparedness for earthquakes , which could have its roots in the presence of large mining companies in the region. In fact, the mining industry has for decades constituted the main source of development in the region, in which large mining companies have played an important role in local economies. The presence of large mining companies represents one of the greatest opportunities for the development and implementation of preparedness programs in the face of hazards, given that, as they have large numbers of employees, their emergency risk reduction and response processes are more formalized.

Although the history of earthquakes in Chile have led both public and private-sector organizations to develop increasingly effective citizen and institutional preparedness strategies, the floods that occurred in 2015 demonstrated that the Atacama Region also reveal the need to improve preparedness strategies, programs and plans to face extreme hydrometeorological events. It is therefore recommended that institutions responsible for disaster risk reduction in the region design preparedness plans and programs that recognize and integrate the different hazards present in the region, given that the prioritization of preparedness strategies for one hazard may increase vulnerability to others.

A sociodemographic profile of preparedness

Regarding the sociodemographic variables which are related to the family and workplace preparedness and in line with previous studies [ 29 , 38 ], it is concluded that the subject’s age is significantly related to their declared levels of preparedness: in general, subjects of 30 to 59 years of age declared the highest levels of preparedness. Some authors posit that this could be explained because adults in this stage of life acquire greater care responsibilities (either for others or their own assets), which may give rise to increased interest in involving themselves in preparedness measures [ 41 ]. On the other hand, the low levels of preparedness declared by young people may be explained by the fact that, in general, they have a lower perception of natural disaster risk, which translates into lower willingness to adopt preparedness measures [ 58 ].

Being married or living with a partner was significantly related to higher levels of preparedness within the household. Previous studies have concluded that the presence of a significant other generates greater concern among subjects, and therefore greater willingness to prepare for potential natural disasters [ 39 ]. Regarding these arguments, the presence of school-age children in the household also produces higher levels of preparedness for natural hazards. Previous studies have argued that the presence of children in the household increases participation in preparedness measures due to the fact that children motivate the actions of adults, bring information regarding safety home from school, and because adults aim to protect children through this type of measures [ 39 ].

Finally, our results suggest that the level of preparedness for floods significantly differs depending on the subject’s gender: in general, men declare that they are more prepared for floods than women, contrary to what was expected. The authors attribute this result to the fact that the majority of men in the sample who are employed work in the large and medium-scale mining sector, while almost all women work in the services and commerce sectors. As mentioned throughout this study, the mining sector is the main source of employment and development in the region, characterized by the presence of large mining companies who provide direct employment to more than 15% of workers in the region, 92% of which are men [ 46 ]. Due to regulatory requirements, these companies have advanced security, hygiene and prevention standards which are frequently monitored. In line with previous studies [ 27 , 31 , 33 ], the employees of these large companies have greater learning and training opportunities with regard to emergency risk reduction and response processes, so it is reasonable to believe that those who work in such companies (mainly men) would have higher levels of preparedness for earthquakes and floods.

The above highlights the potential importance of large companies in the areas where they operate, not only because of their impact on local economies, but also due to their potential influence on communities’ degree of preparedness for natural disasters. Therefore, the presence of large companies in the region is a relevant and important factor to be considered by government authorities when designing disaster risk reduction programs. Families with some members working in large mining companies may improve their levels of family preparedness for natural disasters to the extent in which these members bring information and experience from work regarding emergency risk reduction and response processes home with them.

Based on the results obtained, we conclude that sociodemographic variables such as age, marital status, gender and the presence of school-age children in the household characterize the profile of subjects with greater (or lower) levels of family and workplace preparedness to face potential natural disasters in multi-hazard environments. One of the greatest influencers on the motivation to prepare for natural disasters is the presence of significant others in the household. In general, adults between 30 to 59 years of age who live with their partners and have school-age children in the household constitute the sociodemographic profile of subjects with the highest declared levels of preparedness to face potential natural disasters. On the other hand, adults below 30 years of age or above 60 years old who are single, separated or widowed, and do not have school-age children living in the household represent the profile of subjects with the lowest declared levels of preparedness to face a potential natural disaster. Groups that are less prepared should be target of interventions in order to raise awareness and motivate them to adopt preparedness actions.

Also, our findings reveal the need to continue investigating how people perceive/adopt the recommendations provided by local authorities (i.e., if they understand them and if they are capable of carrying them out), so to be able to evaluate which factors facilitate (or discourage) the adoption of preparedness actions. As some studies indicate, the preparedness actions are not always carried out by the individuals in the same way that authorities recommended it [ 59 ]. Therefore, it is necessary to keep a continuous dialogue between authorities and the civil population to effectively communicate preparedness strategies. This is a crucial element to go forward in the design of public policies that take into account the social, cultural and political context in which people live.

Finally, the institutions responsible for developing local disaster risk reduction plans and programs must appropriately characterize their target audiences if they expect to obtain more effective and efficient results. We hope that the results and conclusions reported in this study become a useful input to achieve this.


There are certain limitations to this study. The number of participants in the study was small, as it was made up of a representative sample of solely the Copiapó and Tierra Amarilla municipalities in the Atacama Region. Therefore, studies must be carried out in other cities in the country in order to capture the different events that they experience, as well as geographic and cultural differences.

The level of preparedness was assessed for participants solely through a single measure and using the self-reporting method. Even though dichotomous questions assess the perceived level of preparedness and do not allow to evaluate their objective level (or if they comprehend the emergency plan of their workplace or city), these questions provide an estimate of the basic actions of preparedness recommended by leading International Agencies, which should be done by individuals to face natural hazards. Although this method is extensively used in the literature, it does limit greater understanding of preparedness behavior.

Supporting information

S1 dataset. data set used in the research..

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Valuing Human Impact of Natural Disasters: A Review of Methods

Aditi kharb.

1 Institute of Health and Society (IRSS), Universite Catholique de Louvain, 1200 Brussels, Belgium

Sandesh Bhandari

2 Department of Medicine, University of Oviedo, 3204 Oviedo, Spain

Maria Moitinho de Almeida

Rafael castro delgado, pedro arcos gonzález, sandy tubeuf.

3 Institute of Economic and Social Research (IRES/LIDAM), Universite Catholique de Louvain, 1200 Brussels, Belgium

Associated Data

Not applicable.

This paper provides a comprehensive set of methodologies that have been used in the literature to give a monetary value to the human impact in a natural disaster setting. Four databases were searched for relevant published and gray literature documents with a set of inclusion and exclusion criteria. Twenty-seven studies that quantified the value of a statistical life in a disaster setting or discussed methodologies of estimating value of life were included. Analysis highlighted the complexity and variability of methods and estimations of values of statistical life. No single method to estimate the value of a statistical life is universally agreed upon, although stated preference methods seem to be the preferred approach. The value of one life varies significantly ranging from USD 143,000 to 15 million. While an overwhelming majority of studies concern high-income countries, most disaster casualties are observed in low- and middle-income countries. Data on the human impact of disasters are usually available in disasters databases. However, lost lives are not traditionally translated into monetary terms. Therefore, the full financial cost of disasters has rarely been evaluated. More research is needed to utilize the value of life estimates in order to guide policymakers in preparedness and mitigation policies.

1. Introduction

Since 1960, more than 11,000 disasters triggered by natural hazards have been recorded. The number has steadily increased from an annual total of 33 disasters in 1960 to a peak of 441 disasters in 2000 [ 1 ]. Hazards such as storms, floods, heatwaves, droughts and wildfires have increased in number, intensity and variability in recent years [ 2 ]. Between 2000 and 2019, there were 510,837 deaths and 3.9 billion people affected by 6681 natural disasters [ 3 ]. This rising death rate highlights the continued vulnerability of communities to natural hazards, especially in low- and middle-income countries. The Analysis of Emergency Events Database(EM-DAT) shows that, on average, more than three times as many people died per disaster in low-income countries than in high-income nations [ 1 ]. A similar pattern was evident when low- and lower-middle-income countries were grouped together and compared to high- and upper-middle-income countries. Taken together, higher-income countries experienced 56% of disasters but lost 32% of lives, while lower-income countries experienced 44% of disasters but suffered 68% of deaths [ 1 ].

Disasters datasets usually report the human impact of disasters fairly precisely, and also include the economic impact mainly related to damages to insured goods; for example, EM-DAT, NatCatservice, MunichRe [ 1 , 4 ]. While economic damages of disasters are available in monetary terms, the human impact is measured in different natural units (lost lives, lost life years, disability-adjusted life years (DALY), etc.). Transforming those human impacts into monetary terms is not straightforward. However, it is of great importance in disaster contexts, as it could serve as a vital tool for a multitude of purposes, not limited to informing policy decision making.

Reinsurance companies could utilize this value to generate risk assessments, calibrate loss-estimation models and validate compensation claims; investors and international organizations could make use of it to advise strategic risk mitigation plans; and academic institutions could use it to measure inequalities and identify research gaps. Additionally, for individuals, the perceived disaster severity and knowledge of disaster-related risks might be limited and can be supplemented by providing monetary value to the physical and psychological health risks they might face [ 5 ]. Similarly, as the principal focus of health, safety and environmental regulations and many public health-related policies is to enhance individual health, where the most consequential impacts often pertain to reductions in mortality risks, policymakers seeking to assess society’s willingness to pay for expected health improvements need some measures of the associated benefit values to monetize the risk reductions and to facilitate comparison of benefits and costs. In this context, evaluating the global impact of a disaster would rely on using a unique metric to translate both the human and the economic costs of disasters.

Providing a monetary value to lost lives or health losses relies on the value of statistical life literature. The economics and disaster literature today has shown that although it is difficult to ‘put a price on life’, observation of individual and group behaviors seem to indicate otherwise. People regularly weigh risks and make decisions through a cost–benefit analysis framework, where they weigh the willingness to pay for risk reduction and the marginal cost of enhancing safety [ 6 , 7 ]. According to Kniesner and Viscusi (2019) [ 8 ], the value of statistical life can be defined as the local trade-off rate between fatality risk and money. The utility associated with reducing a risk must compensate for the disutility associated with the cost of reducing that risk. This argument is further strengthened by the cost assessment of intangible effects of natural disasters in the literature in welfare economics [ 9 , 10 ]. Individuals derive welfare from non-market goods such as environmental and health assets in more ways than only direct consumption [ 11 ]. For example, does the cost of reinforcing and strengthening buildings in a seismically active zone and ensure earthquake resistance save enough lives and prevent enough injuries that, in the long run, individual productivity for the state overshoot the costs exhausted by the state [ 12 ]?

This review aims to provide an overview of the methodologies used to evaluate the value of life in a natural disaster context and to present the differences in values of statistical life calculated using these alternative methodologies. The review also highlights the areas in the literature where more research is needed. To this end, the first section of this review reports the methodology for the selection and analysis of the literature. The second section explains the results of the analysis. Finally, we discuss the results and shortcomings of the current literature and draw conclusions from the study.

2. Methodology

We conducted a review of the literature reporting on the value of life in disasters adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines [ 13 ]. The research question was formulated with the collaboration of the co-authors and the search strategy was then developed following extensive discussion.

2.1. Search Strategy

Several databases were used to search for literature, including PubMed MeSH, EMBASE and ECONLIT. In addition to this, the search was also performed in SCOPUS and Google Scholar so as not to miss any relevant papers, but only the first 200 results sorted by relevance were picked up from the two latter databases. We then screened the references of included full texts to identify any potential misses from our initial search strategy.

Various keywords synonymous to the two concepts “Value of Life” and “Disasters” were identified to undertake the search for literature. For “Value of life”, words and phrases such as cost of life, value of statistical life, VSL, willingness to pay, value of life lost and economic value of life were identified as relevant. Similarly, for “Disasters”, two additional terms, i.e., natural disasters and hazards, were used. The two concepts were searched separately as one and two, and then the combination of one and two was searched to obtain the results. More details about the search strategy are available in Appendix A .

2.2. Eligibility Criteria

The primary inclusion criteria for the search were peer-reviewed articles or gray literature such as conference papers, dissertation and discussion papers on disasters and value of life written in English from 2000 to 2020. We included studies that primarily quantified the value of life in a disaster setting and studies discussing methodology of estimating the value of life without providing a value by itself. No geographical limitations were set.

2.3. Data Collection and Analysis

The hits from different databases were exported onto Mendeley citation manager (Mendeley version 1.19.8) for subsequent screenings. Duplicates were excluded first. Titles and abstracts were then screened, and finally, full texts were screened for the papers included after abstract screening, excluding papers clearly outside the scope of this study. All uncertainties about eligibility were discussed between three co-authors (SB, MMA, ST) in all steps of the selection process.

Several papers were excluded in subsequent screening steps. Papers only talking about environmental pollution and climate change without a reference to natural disasters were excluded, as these topics are quite broad and, if not a cause for natural disasters, fall outside the scope of this study. Additionally, articles mainly concerned with terrorism, conflicts and landmines were not included in the final selection. Other categories of papers that were excluded were coal mine accidents, traffic accidents and forest fires. Papers solely talking about housing insurance and policy recommendations were also excluded. A total of five papers were requested directly from the authors as they could not be accessed online.

A data extraction form was developed for this review after consultation with the authors. The data extraction form recorded the descriptive aspect of all the studies included in the review, including methodology used to calculate the value of statistical life (VSL), results, strengths and limitations. This form was then pilot tested to ensure all the information was covered. The excluded studies were also tested against the form to check why they did not fit the form and revised as needed in subsequent steps. More details about the form are available in the Appendix A .

We first provided a descriptive overview of the included studies in terms of disaster types, the year in which studies were published, distribution of studies among countries according to the level of income as classified by the World Bank, simple geographical distribution and methodologies mentioned in the studies which were used to calculate the VSL. We then synthesized the information provided according to major predefined themes, such as methods of estimation of VSL, calculated VSL, and variations in VSL by geographical regions. These were identified before the analysis following discussions within the research team. Additionally, the possibility of emerging themes was considered and actively looked for during identification and processing of predefined themes.

3.1. Descriptive Overview of Included Studies

The initial search yielded a total of n = 2121 articles, coming down to n = 2084 after duplicates were removed. After screening titles and abstracts, n = 115 papers were considered for full text screening. Subsequently, a further n = 87 articles were excluded and two additional papers were excluded during the data extraction process. In addition to the remaining n = 26 papers for the review, one article was included from the reference screening, making the final count of papers for the review n = 27. The detailed process of article selection is presented in a PRISMA flow diagram ( Figure 1 ) [ 13 ].

An external file that holds a picture, illustration, etc.
Object name is ijerph-19-11486-g001.jpg

PRISMA flow chart of search, inclusion and exclusion screening and accepted studies of the review. Source: Authors.

The biggest proportion of the included papers (n = 8, 29.6%) focused on value of life lost due to floods. This was closely followed by papers discussing unspecified disasters or disasters in general (n = 5, 18.5%). Five articles (18.5%) focused on earthquakes specifically, followed by three papers (11.1%) examining the value of life in the context of avalanches and rockfalls. Two articles (7.4%) discussed tornadoes and three papers (11.1%) dealt with a group of disasters consisting of four types of disasters, namely flood, drought, alpine and coastal hazards. One article (3.7%) was about heatwaves ( Figure 2 ).

An external file that holds a picture, illustration, etc.
Object name is ijerph-19-11486-g002.jpg

Numbers of included studies by type of disaster. Source: Author.

Most studies (n = 16, 59%) concerned countries classified as high-income countries by the World Bank, including four papers (15%) from the United States of America (USA), three (11%) from the Netherlands and two each (7%) from Switzerland and Australia. Germany, Austria, Russia, Italy, New Zealand and Japan also had one article each in the final pool. Four studies (15%) were from upper-middle-income countries, including two studies from China and one each from Russia and Iran. Only one paper considered a lower-middle-income country, namely Vietnam. Four papers (15%) were not specific to any country and discussed the value of statistical life in general, without geographical consideration. Finally, one paper (3.7%) talked about developing countries in general while talking about value of life and reconstruction costs resulting from earthquakes.

Regarding where the articles were published, all but 4 out of 27 articles (85%) were published in peer-reviewed journals. As we included gray literature, two out of the four were discussion papers, one was a conference proceedings and the remaining one was a doctoral dissertation. The included studies were published in a variety of disaster-related, economics, policy and environmental journals.

3.2. Methods Used to Estimate Value of Life

A number of methods used to estimate the value of life were highlighted after reviewing the literature. Table 1 summarizes the different methods used in the included literature.

Value of statistical life estimation methods.

Stated Preference:
- Choice Modeling (CM)
- Contingent Valuation
Method (CVM)
VSL is based on the willingness to pay for a reduction in the risk
of dying. CM differ from CVM in that respondents make repeated choices
between different risk attributes.
 [ ];
 [ ];
 [ ];
 [ ];
 [ ];
 [ ]
Adaptation MethodVSL is based on the marginal rate of substitution of disaster loss
decrease to disaster prevention investment, which is measured as
the ratio of total benefits to total cost.
 [ ];
 [ ];
 [ ]
VSL is based on available VSLs in other countries. It is converted
using the income elasticity of VSL and the Gross Domestic Product
per capita. A greater income elasticity of VSL when transferring
from a higher- to lower-income country results in lower estimates
of the VSL.
 [ ];
 [ ];
 [ ]
Human Capital
VSL is based on individual’s future contributions to social
production measured by either the gross human capital (foregone
earnings) or the net human capital (forgone earnings minus future
 [ ];
 [ ]
Quality of life
index method
VSL is measured as an acceptable level of public expenditure to
reduce the risk of death that results in improved quality of life.
 [ ]
of welfare
VSL is based on lost wellbeing using welfare theory, which considers
the value of one’s life at the aggregate economy-wide level, including
expected incomes, failed inputs and benefits.
 [ ]
  • (a) Revealed preference methods.

The revealed preference method utilizes observed behavior among the individuals that has already occurred and makes use of this to approximate suggested willingness to pay for a change in mortality risk. This method has an advantage over the stated preference approach in that if a person pays a certain amount for a commodity, it is known with conviction that the same person’s WTP for that commodity is at least the amount he/she is willing to pay. The four methods used to reveal preferences include: (a) the hedonic pricing method; (b) the travel cost method; (c) the cost of illness approach; (d) the replacement cost method [ 14 , 15 , 16 ].

  • (b) Stated preference methods.

In contrast with revealed preference methods, the stated preferences method creates a hypothetical market in a survey. It parallels a market survey and estimates a willingness to pay for hypothetical reduction in mortality risks, since it resembles market behavior. In addition, stated preference methods incorporate both active and passive use of a commodity by the consumer. Direct or active values arise when an individual physically experiences the commodity, while passive or indirect values entail that an individual does not directly experience the commodity. The three methods used for stated preferences include: (a) the contingent valuation method; (b) the choice modeling method; (c) life satisfaction analysis [ 17 , 18 , 19 ].

  • (c) Non-behavioral methods

Non-behavioral methods are not necessarily based on human choices and cognitive biases which affect the choices subconsciously. They include the human capital method (HCM) [ 20 ] and life quality index method (LQI) [ 21 ] to estimate the valuation of statistical life, and they are used to elicit the value of an individual in a society in the absence of a possibility to conduct a survey pre- or post- disaster.

In the selected literature, 7 papers out of 16 used stated preference methods. Within stated preference methods, two papers used choice modeling, while the other five used a contingent valuation method.

Papers using choice modeling method included Bockarjova et al. (2012) [ 22 ] and Rheinberger (2011) [ 23 ]. While Bockarjova et al. (2012) [ 22 ] carried out a choice modeling experiment via an internet-based questionnaire and elicited responses from people living in flood prone areas in the Netherlands in two separate studies, Rheinberger (2011) [ 23 ] undertook a choice experiment by recruiting respondents via a phone call prior to a mail survey.

For contingent valuation method, Leiter et al. (2010) [ 24 ] used face-to-face interviews and elicited people’s willingness to pay to prevent an increase in the risk of dying in a snow avalanche. Similarly, Hoffmann et al. (2017) [ 26 ] used a computerized payment card method to estimate the willingness to pay to reduce mortality risk in Chinese population living in four different cities in China. In contrast, Ozdemir (2011) [ 25 ] used a contingent valuation method as well, but used a mail survey to elicit willingness to pay to reduce the risks from tornadoes in the USA.

For non-behavioral methods, Dassanayake et al. (2012) [ 35 ] used a quality of life index method to evaluate intangible flood losses and integrate them into a flood risk analysis.

Other papers used one or a combination of methods. For example, Porfiriev (2014) [ 31 ] approached the economic valuation of human losses resulting from natural and technological disasters in Russia using the theory of welfare and an international comparative approach. Cropper and Sahin (2009) [ 12 ] used the comparative approach, along with transferring the VSL from USA to a whole list of countries classified by income groups by the OECD to estimate VSL.

3.3. Values Provided in the Literature

There was a wide range of VSL values in the literature, ranging from ISD 143,000 to 15 million for one life [ 12 , 25 ]. Table 2 summarizes the estimated value of statistical lives in the articles included in the review. Disaster types range from natural disasters to technological disasters with some disaster types appearing more often than others in the literature, with earthquakes and floods being the most common. The VSLs appeared to increase over the years: while it was estimated to be USD 0.81 million in 2005 in Switzerland in the context of avalanches [ 34 ], it was evaluated between USD 6.8 and 7.5 million in 2011 [ 23 ].

Estimated values of statistical life in included articles.

ReferenceVSL (in Millions USD *)CountriesDisaster Types
Cropper and Sahin (2009) [ ]0.143 (Low-Income-Country)
4.27 (High-Income-Country)
Not SpecifiedNot Specified
Porfiriev (2014) [ ]0.19 (International comparison)
0.33 (Welfare method)
RussiaNatural and technological
Hoffmann et al. (2017) [ ]0.61ChinaNot Specified
Sadeghi et al. (2015) [ ]0.73–1.4IranEarthquakes
Fuchs and Mcalpin (2005) [ ]0.81SwitzerlandAvalanches
Daniell et al. (2015) [ ]2.2Australia,
calculations applied to case studies in Turkey and Croatia
Cheng (2018) [ ]2.34AustraliaHeatwave
Leiter et al. (2010) [ ]2.3–4AustriaAvalanches
Dassanayake et al. (2012) [ ]2.5–9.2GermanyFloods
Zhai et al. (2003) [ ]3.3–9.2JapanFloods
Johansson and Kristrom (2015) [ ]5.2–12.8USAFloods and storms
Rheinberger (2011) [ ]6.8–7.5SwitzerlandSnow avalanche and rockfalls
Barbier (2022) [ ]1.25–7.7ItalyEarthquake
Bockarjova et al. (2012) [ ]9.6The NetherlandsFloods
Hammitt et al. (2019) [ ]10ChinaNot specified
Ozdemir (2011) [ ]15USATornado

* Values were converted into United States Dollars (USD) in respective years. Source: Authors [ 37 ].

4. Discussion

Disasters are complex events, and the assessment of losses they have caused is a compounded task. This review’s exploration of literature estimating the value of statistical life with regard to disasters highlighted the complexity and variability of the estimation of values of statistical life and the methods involved.

The geographical locations of studies included in the review showed the parts of the world where most of the studies were focused. An overwhelming majority of studies estimated the value of statistical life in high-income countries. The main reasons for this are related to the data availability and the investment made by developed countries in research and development for the advancement of science in general [ 38 ]. Low- and middle-income countries often experience several disasters occurring year round, and become trapped in a loop of disaster recovery and management annually. Amid ever-present financial constraints, disaster risk reduction and management planning to deal with disasters and their impact in the country therefore becomes much more demanding [ 39 ].

The estimation of economic damages due to disaster in a low-resource setting can also be challenging. Not all the houses, agricultural land, crops and other assets are insured in low- and middle-income countries. The insurance coverage is relatively small if not non-existent in these countries [ 40 ] and the data to quantify the impacts of disasters, such as the number of deaths, missing, affected population as well as reconstruction costs, are often incomplete and not well recorded. So, the unavailability of appropriate information becomes a big challenge in the first step of conducting research. This might be the reason why low- and middle-income countries are not well represented in studies estimating the value of life in disasters. As a result, the lack of studies in low- and middle-income countries can lead to a certain degree of extrapolation of results found in VSL calculation in high-income-country-based studies.

Furthermore, we note that the majority of articles measuring the value of life were about floods. Floods are indeed the most common type of disasters. In an analysis of disasters recorded in the EM-DAT database from 2000 to 2019, nearly half (n = 3254) of all recorded events (n = 7348) were floods [ 41 ]. However, there are many other types of disasters, and it is important to rely on such studies where those disasters were considered when measuring the value of a statistical life.

Methods used for VSL estimations showed significant diversity among the articles included in this review. Although the stated preferences method is the most frequent, it is closely followed by the adaptation method. There could be various reasons for this difference in methodologies across the literature. For instance, non-marketed good with no complementary or substitute market good may not have readily available individual data, and hence may lead the researchers to undertake stated preference methods with which to elicit people’s willingness to pay to reduce a hypothetical disaster risk through surveys [ 19 ]. The scope of the study and the budgetary constraints may also explain why a researcher chooses one method over the other. Additionally, the characteristics of the survey participants are another important factor, as they influence the type of survey that can be conducted and the methodology adopted. For example, if the target population is old and poor, face-to-face interviews in respondents’ private homes might be more suitable than internet-based questionnaires [ 42 , 43 ].

There was a wide range of monetary values of the VSL in the literature. These differences could be due to the level of income of the country where the disaster occurred [ 40 ]. The method of calculation could be another reason for such differences, for example, as consumers optimize their lifetime utility, thus neglecting intergenerational (long-term) utility, using willingness to pay (WTP) methods for a reduction of risk can often lead to overestimated values [ 44 , 45 ]. It could also simply be due to the differences in cultural norms between countries [ 40 ]. Furthermore, the context and the aim of the research and its evolution over the years might also explain variations across the studies. Further studies are required to establish a concrete cause for this observation. It should also be highlighted that low VSL estimates in low-income countries do not inherently mean that a human life is worth less. It could simply reflect individual income, the cost of commodities and the value of currency [ 8 , 46 ].

This study presents a number of limitations. First, the review only included articles published in English, and some studies may exist in other languages. Second, papers that did estimate a VSL considered a range of different methods, and therefore direct comparison of estimated values was not straightforward. Papers referring to economic impact in terms of natural environment or animals were also excluded, as they do not refer to value of statistical life; however, they can be important for calculating overall economic cost of disasters [ 47 , 48 ].

5. Conclusions

This study aims to explore literature estimating the value of statistical life with regard to disasters through a systematic review. After applying the inclusion criteria on the 2121 articles found in the initial keywords search, only 27 articles were included for final review. In the included literature, several attempts at estimating the value of statistical lives in disasters were identified; however, there was no consensus on the method used, and few investigations were carried out in a low- and middle-income country context. This review therefore provides a limited view of the value of statistical life calculations in disaster settings, which may become useful when implementing disaster risk reduction policies and calculating global losses incurred due to disasters. It reveals that an agreed, robust and multi-sectoral approach for the disaster and economics community remains to be defined.

Appendix A. Search Strategy Description

For PubMed MeSH, terms such as sanctity of life, life sanctity, life sanctities, respect for life, economic life valuation, life valuation/s, economic valuation/s and economic life were used. In addition to this, the search was performed in SCOPUS and GOOGLE SCHOLAR.

The data extraction form recorded the descriptive aspect of all the studies included in the review, the including methodology used to calculate VSL, results, strengths and limitations. A total of 16 categories of information were extracted:

(1) Author, (2) Title, (3) Year published, (4) Journal, (5) Study location, (6) Aim of the study, (7) Disaster type, (8) Type of study (Theoretical/Empirical), (9) Study data source, (10) Study participants, (11) Method of VSL estimation, (12) VSL if given, (13) Strengths, (14) Limitations, (15) Relevant references and (16) Study design.

Funding Statement

We are grateful to the European Commission for providing the Erasmus Mundus Grant for completing the Erasmus Mundus Master Course in Public Health in Disasters (EMPHID). We also thank USAID/DCHA/OFDA [ref no. 72OFDA20CA00072] for funding the research at Centre for Research on the Epidemiology of Disasters at the Universite catholique de Louvain.

Author Contributions

A.K.: Formal analysis, investigation, writing—review & editing; S.B.: Formal analysis, investigation, writing—original draft; M.M.d.A.: Conceptualization, methodology, project administration, supervision, writing—original draft, writing—review & editing; R.C.D.: Funding acquisition, supervision, review & editing; P.A.G.: Funding acquisition, supervision, review & editing; S.T.: Conceptualization, funding acquisition, methodology, project administration, supervision, validation, writing—original draft, writing—review & editing. All authors have read and agreed to the published version of the manuscript.

Institutional Review Board Statement

Informed consent statement, data availability statement, conflicts of interest.

The authors declare no conflict of interest.

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

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Created: April 14, 2020.

Last Updated:  June 29, 2023.

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Hurricanes. Tornadoes. Earthquakes. Floods. Avalanches. Wild fires. These events have been happening for millennia and have affected humans throughout every part of the globe. According to the International Journal of Disaster Risk and Reduction External , natural disasters are defined as "...catastrophic events with atmospheric, geological, and hydrological origins (e.g., droughts, earthquakes, floods, hurricanes, landslides) that can cause fatalities, property damage and social environmental disruption."

Arguably the most famous earthquake in U.S. history is that of San Francisco in 1906. It occurred on April 18 and had an estimated magnitude of 7.9 (estimated because the Richter Scale, which is used to measure the magnitude of earthquakes, was not invented until 1935 by Charles F. Richter). Though it lasted less than a minute, the damage was extensive and the death toll, though uncertain, was up to 3,000. The earthquake and subsequent fires caused by ruptured gas mains, which lasted for four days, destroyed about 80% of city. The earthquake, one of many for this region, occurred due to the tectonic activity along the San Andreas Fault, which forms the boundary between the Pacific and North American plates.

In 1900, a hurricane made landfall near Galveston, Texas. Not only was it the deadliest hurricane in U.S. history, but it was the deadliest natural disaster in U.S. history! This hurricane made landfall on the night of September 8 and was estimated as a category 4 with a storm surge of over 15 feet that devastated the city. There has been speculation on the total number of fatalities, but the most cited number is 8,000, which is a significant portion of the nearly 38,000 in total population at the time.

The 2019-2020 bushfire season in Australia was the worst on record; 46 million acres were burned by hundreds of fires which caused dozens of fatalities. The fires' effect on air quality was demonstrated by the Air Quality Index putting several parts of the country into the hazardous zone, including areas around Sydney. The toll of the fires could also be seen in the wildlife populations. It is estimated that over 1 billion animals died during the course of the fires, including many endangered species.

The resources in this guide provide information on how and why these events occur and what people can do to better prepare for the next occurrence.

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Article contents

Disaster and emergency planning for preparedness, response, and recovery.

  • David Alexander David Alexander University College London
  • Published online: 03 September 2015

Emergency and disaster planning involves a coordinated, co-operative process of preparing to match urgent needs with available resources. The phases are research, writing, dissemination, testing, and updating. Hence, an emergency plan needs to be a living document that is periodically adapted to changing circumstances and that provides a guide to the protocols, procedures, and division of responsibilities in emergency response. Emergency planning is an exploratory process that provides generic procedures for managing unforeseen impacts and should use carefully constructed scenarios to anticipate the needs that will be generated by foreseeable hazards when they strike. Plans need to be developed for specific sectors, such as education, health, industry, and commerce. They also need to exist in a nested hierarchy that extends from the local emergency response (the most fundamental level), through the regional tiers of government, to the national and international levels. Failure to plan can be construed as negligence because it would involve failing to anticipate needs that cannot be responded to adequately by improvisation during an emergency.

Plans are needed, not only for responding to the impacts of disaster, but also to maintain business continuity while managing the crisis, and to guide recovery and reconstruction effectively. Dealing with disaster is a social process that requires public support for planning initiatives and participation by a wide variety of responders, technical experts and citizens. It needs to be sustainable in the light of challenges posed by non-renewable resource utilization, climate change, population growth, and imbalances of wealth. Although, at its most basic level, emergency planning is little more than codified common sense, the increasing complexity of modern disasters has required substantial professionalization of the field. This is especially true in light of the increasing role in emergency response of information and communications technology. Disaster planners and coordinators are resource managers, and in the future, they will need to cope with complex and sophisticated transfers of human and material resources. In a globalizing world that is subject to accelerating physical, social, and economic change, the challenge of managing emergencies well depends on effective planning and foresight, and the ability to connect disparate elements of the emergency response into coherent strategies.

  • emergency planning
  • disaster management
  • recovery planning
  • reconstruction planning
  • crisis management
  • scenario methodology
  • disaster response

What Is Emergency Planning?

Emergency planning can be defined as the process of preparing systematically for future contingencies, including major incidents and disasters. The plan is usually a document shared between participants and stakeholders that specifies tasks and responsibilities adopted in the multi-agency response to the emergency. It is a blueprint for managing events and, as such, should be responsive to management needs. It should specify the lineaments of action, collaboration, command, and communication during a civil contingency, such as a disaster or major event; in other words, it is the framework for emergency response. The maintenance of public safety, limitation of damage, protection of the vulnerable, and efficient use of life-saving resources are some of the goals of the plan. Although the end product is a document, emergency planning is more a process than an outcome, especially as the plan itself will need to be updated over time as circumstances change.

The Evolution of Emergency and Disaster Planning

As we know it today, emergency planning for disasters derives from civil defense, a form of social organization designed to protect civilians against armed aggression. The latter is a relatively new concept that in its modern form antedates the Second World War by only a very brief period. Although there had been rudimentary forms of organization for the protection of non-combatants in previous conflicts—for example, the American Civil War of the 1860s—the attack on Guernica, in the Basque country of Spain, on April 26, 1937 , by German aircraft was the first concerted aerial bombardment (it killed 1,654 civilians) and the first occasion that an attack had to be countered by properly organized measures of protection. It was a curtain raiser to the bombardments of the early 1940s, in which civil defense grew enormously, although largely without the benefits of fully codified plans. During this period, civil defense operatives were responsible for search and rescue, safeguarding and accommodating the survivors of bombing raids, ensuring public safety and interdicting areas that had become unsafe.

The temporary apogee reached by civil defense during the Second World War was subsequently followed by reorganization in order to face the demands of the Cold War, in which civilian life was overshadowed by the threat of a thermonuclear exchange between the great powers. During this period, plans were usually kept secret and were predicated on the assumption—highly debatable—that citizens could be protected and given shelter against nuclear blasts and radioactive fallout.

Détente and the dissolution of the Eastern Bloc led to the gradual end of the era of civil defense , and the slow rise of civil protection , which is designed to protect people against the effects of natural, technological, and societal hazards. In its purest form, civil defense is a service provided by the central state and directed at the national level (i.e., it is fundamentally “top-down”). Civil protection is a decentralized service (i.e., “bottom-up”), in which the basis of organization is local, which usually means that it is centered on the municipal level.

Emergency planning is a relatively young field that began to develop systematically in the 1970s, coincidentally with the rise of civil protection. Initially, it did so largely in response to technological hazards, such as toxic spills and industrial explosions. Later, there was an increasing emphasis on natural disasters, such as floods, storms and earthquakes.

Academic studies of disaster have a somewhat longer history than does civil defense. They began in earnest in the 1920s with the founding of a sociological approach and, in parallel, a human ecological school of thought, which was mainly based in the discipline of geography. Development was slow until the 1950s, when fear of the consequences of nuclear war gave impetus to the study of how human populations behave in crisis situations, using natural disasters as—rather inadequate—analogues for a thermonuclear exchange. Earlier, geographers had started to study the human dimensions of the flood problem, notably Gilbert Fowler White, whose thesis on adaptation to floods was published in 1945 . Starting in the 1970s, there was a sustained increase in studies of extreme natural phenomena, which gradually came to grips with the role of such hazards to human life and activities. In the late 1970s, a school of thought developed that suggested that vulnerability, not hazards, is the real key to understanding disaster. Despite countless demonstrations of this axiom, studies of vulnerability have lagged behind those of hazard, the other principal ingredient in the making of disaster. In terms of how academic work supports emergency planning, this means that there has been a plethora of studies of the inputs to plans (see, for example, the hazard scenarios in the section “The Use of Scenarios”), but a paucity of studies of how to construct and use emergency plans. On this basis, emergency planning has developed in a somewhat faltering mode, in which only some of the activities associated with it are well served with academic inputs.

From Incident to Catastrophe: The Range of Impacts

Most civil contingencies are small enough to be resolved adequately without qualitative changes in daily management procedures or quantitative changes in the availability of resources. Hence, this article concentrates on the small minority of emergencies, usually fewer than one in ten, that are large enough to substantially disrupt daily life and normal working procedures. There is no consistently reliable way of distinguishing among major incidents, disasters, and catastrophes (but see Table 1 for an attempt at this). Nevertheless, all of these events have in common the fact that they must be resolved by the suspension of normal procedures and substitution of emergency ones. In the latter, the imperatives, tasks, and relationships among participants are sufficiently exceptional to require substantial reorganization and working methods that differ from those employed in workaday routines.

Emergency response involves a mixture of plans, procedures, and improvisation. To some extent, the last of these is inevitable, but it needs to be limited by preparedness. It is axiomatic that planning and procedures should not be improvised during an emergency when they should have been thought through and created beforehand. The consequence of unwonted improvisation is inefficiency in emergency response, which may have serious or tragic consequences. A degree of uniqueness present in each new disaster means that improvisation cannot be avoided, but foresight and preparedness can constrain it to a necessary minimum. Moreover, emergencies are always occasions for learning, and a significant part of the body of experience on which plans are based comes from the mistakes, inefficiencies, and improvisations of the past. Although many publications have the phrase “lessons learned” in their titles, there is no guarantee that a lesson will indeed be learned. If that does indeed happen, measurable positive change will result directly from the lesson. For example, lack of search-and-rescue equipment may be keenly felt in structural collapses that trap people. Hence, probes, props, and personal protection equipment may be acquired and personnel trained in how to use them.

Table 1. Functional Differences Among Different Sizes of Event


Major incidents



Very localized

Fully or partially localized

Widespread and severe

Extremely large in the physical and social sphere

Local resources used

Mainly local resources used, with some mutual assistance from nearby areas

Intergovernmental, multi-agency, multi-jurisdictional response needed

Major national and international resources and coordination are required

Standard operating procedures used

Standard operating procedures used; emergency plans may be activated

Disaster or emergency plans activated

Disaster or emergency plans activated, but huge challenges may overwhelm them

Local resources will probably be sufficient

Local resources and some outside resources needed

Extensive damage to resources in disaster area; major inter-regional transfers of resources

Local and regional emergency response systems paralyzed and in need of much outside help

Public generally not involved in response

Public largely not involved in response

Public extensively involved in response

Public overwhelmingly involved in response

No significant challenges to recovery

Few challenges to recovery processes

Major challenges to recovery from disaster

Massive challenges and significant long-term effects

Note . Adapted from Tierney, K. (2008) Hurricane Katrina: Catastrophic impacts and alarming lessons. In Quigley, J. M., & Rosenthal, L. M., (Eds.). Risking House and Home: Disasters, Cities, Public Policy . Berkeley, CA: Institute of Governmental Studies, Berkeley Public Policy Press, 119–136.

There is a fundamental distinction between plans and procedures. An emergency plan should not have to teach a fireman how to put out a fire, or the police how to direct traffic. Instead, it should articulate and integrate the procedures to be used in a major emergency by assigning responsibilities and ensuring that all personnel involved in complex field operations understand both their own roles and those of other participants. Thus, one can make an analogy between the emergency response and a symphony. Individual instrumentalists have their own music (i.e., the procedures), while the conductor has the score (i.e., the plan). The common objective is to work in harmony.

Emergency and Disaster Planning as a Process

Above all, emergency planning should be a process , rather than a product or outcome. At its most essential, it must match urgent needs to available resources, and do so in a timely way that avoids procrastination and delay. Good emergency plans are realistic as well as pragmatic. For instance, there is no point in making arrangements to use resources that are not available and are not likely to be supplied within a useful time frame. Hence, plans should take account of both the limitations and the capabilities of response. At this point, it is useful to introduce the concept of thresholds (Table 2 ). The “bedrock” level of emergency planning is the municipal level or local area. This is because, however extensive a disaster may be, the theater of operations for managing and responding to it is always local. However, if local resources are overwhelmed, it becomes necessary to move up the scale of response to intermunicipal, regional, national, or even international responses. Each of these is associated with a threshold of capability, which is determined by the availability of trained personnel, expertise, equipment, supplies, communications, vehicles, and buildings. If the magnitude of the emergency exceeds or overwhelms local capabilities, then it is necessary to invoke higher levels of response. However, these should always aim to reinforce, not supplant, the local ability to respond to the emergency. Once the outside forces have departed, inhabitants of the local area will be left on their own to manage the aftermath, and hence they need to be in good shape to do so. Supplanting local resources, decision-making capabilities, and responses will only leave the local area weaker and less able to manage the longer-term aftermath and any emergencies that may occur in the future.

Table 2. Thresholds of Capacity in Emergency Response

Local incident

Local response


Small regional incident

Coordinated local response


Major regional incident

Intermunicipal and regional response


National disaster

Intermunicipal, regional, and national response


International catastrophe

Intermunicipal, regional, and national response, with international assistance


Note . Simplified version: A = local response, B = regional response, C = national response.

Emergency planning is an approximate process that, in many instances, is little more than codified common sense. It also involves a collective effort and is thus a participatory process. In order to avoid sins of omission or commission, it requires experience and training. Regarding the former, the lack of a plan could be construed as negligence in the face of a demonstrable need to protect the public. Despite this assertion, some emergency managers have argued that plans tend to be unnecessarily restrictive and an improvised response is somehow stronger and more vital than one conditioned by a plan. Military strategists from Napoleon Bonaparte to Dwight D. Eisenhower have noted that, when preparing for war, plans have little value, but planning is essential. This underlines the importance of planning as a process, and above all a process of discovery. In this sense, whether or not the plan works during an emergency is of secondary importance: more vital is what the plan tells us about the needs of preparedness and organization. Moreover, emergency plans generally need to be adapted to particular emergency situations, which further underlines the view that planning is a process, and an ongoing one.

At this point, it is opportune to consider what sorts of events and situations should be the object of emergency plans.

For What Should One Plan?

Much has been made of the need for “all-hazards” emergency plans. No place on Earth is entirely free from hazard and risk. Hence, all places need emergency preparedness, but few of them are likely to be subject to only one kind of hazard. An emergency plan must, therefore, be adaptable to both anticipated and unexpected hazards. For many years, the city of Florence, in Italy, had a municipal emergency plan that only addressed the contingency of flooding. In the postwar period, the largest disaster that the city had to manage was the major flood of 1966 . However, during the lifetime of the plan (about 20 years), only limited flooding occurred, and the biggest emergencies were an air crash and a terrorist bomb. Likewise, on September 11, 2001 , emergency coordinators in Washington, DC, had to manage the response to the aircraft that crashed into the Pentagon (and the ensuing citywide chaos) by adapting and using a plan made specifically to deal with the so-called “millennium bug,” or in other words anticipated widespread computer failure. A good emergency plan makes provision for managing all the known and anticipated hazards (the seasonal and recurrent events), while at the same time offering generic protocols to manage the unanticipated ones.

One issue that has long perturbed emergency planners is the size of event for which plans should be configured. If one assumes that recurrent hazards are in a steady state, then somewhere there should be a “happy medium,” in which an extreme event is neither too large and infrequent to be expected to occur during the life of the plan, nor too small and frequent to need significant emergency provisions. The first problem with this arrangement is that, especially regarding natural hazards, there are few cases in which an adequate magnitude—frequency relationship has been established. Hence, the likelihood of an extreme event of a given size may be conjectural, rather than scientifically determined. The second problem is that the time series of events may be nonstationary. For example, there is overwhelming scientific consensus on the occurrence of climate change, and few scientists now doubt the speed at which it is occurring. Damage tends to be a nonlinear function of extreme meteorological events, in the sense that small increases in, for example, wind speed lead to disproportionately large increases in wind damage to structures. The same may be true of casualties, although here the relationship is complicated by factors of perception and behavior in people’s reaction to immediate risk.

It is often said that “we plan for the last event, not the next one.” There is indeed a tendency to base assumptions about the size and characteristics of each event that will be faced in the future on the historical record of such events in the past, particularly the recent past. What if the next event is entirely out of character? The magnitude 9 earthquake that occurred off the east coast of Japan in March 2011 caused a tsunami that was considerably higher than those that most parts of the coast had prepared for (Figure 1 ). People were washed off refuge mounds, and the Fukushima Daiichi nuclear plant was overrun with water, leading to meltdown. The plant was protected against a tsunami that would have resulted from an offshore earthquake up to magnitude 7.5. Much emergency preparedness against riverine flooding is based on the notion of the 100-year flood, and the depths and geographical areas that such an event would inundate. Leaving aside the question of whether estimates of the magnitude of a flood with an approximate recurrence interval of once in a century are accurate, there is no hard-and-fast operational reason why the 100-year flood should be more significant or damaging than any other. However, it is legitimate to discuss the size of flood with a 1%, or once in a century, probability of occurring in any given year, whether or not that should be the flood for which protection measures are designed. In the final analysis, emergency planning has to be realistic. This means that it can only be applied to resources that actually exist or can be obtained within an appropriately brief time frame. On that basis, the question of what size of event to prepare for is more a policy issue than a planning one. In synthesis, the problem of how to prepare for exceptionally large events remains unresolved, both in terms of what is necessary and what is feasible.

write the complete components of a research report about natural disaster

Figure 1. The remains of the emergency management center at Shizugawa, on the northeast coast of Japan. Here, the tsunami of March 11, 2011, was higher than the building. Personnel were drowned while they struggled to broadcast warnings, although a few of them survived by climbing up the radio mast on top of the building. The size of the tsunami underlines the difficulty of estimating the magnitude of events when planning for them.

Anatomy of an Emergency Plan

Emergency and disaster planning is a relatively new field, and one that is evolving rapidly, driven by intensifying hazards, burgeoning vulnerabilities, and emerging risks. Hence, there is no established formula according to which a plan should be prepared. Nevertheless, there are canons and practices that must be respected. As noted above, a plan should focus on ensuring that a good response to threats, emergencies, and recovery processes occurs at the local level.

Emergency Planning and Emergency Management

The primary resource is information, and hence everything possible should be done to ensure that flows of vital data and communications are unrestricted and properly focused on essential needs. Emergency management, as supported by prior and ongoing planning, should ensure that organizations can work together effectively under unfamiliar circumstances, possibly including organizations that have no formal relations under normal, non-emergency circumstances. The plan should ensure that every participant in the response to an emergency has a role, and that all anticipated tasks are covered such that the risk of hiatuses or disputes about responsibilities is minimized.

One way to demonstrate the connection between emergency planning and emergency management is through the provisions to manage information. Emergency communication needs to be sustained, flexible, and clear. Decisions and communications need to be recorded. The emergency planner can help this process by ensuring that the technological means of communication are present and are robust in the face of potential failure, the protocols for sending messages are established, and the priorities for communication are known to participants.

Emergency Planning and Urban and Regional Planning

The process of formulating an emergency plan is similar, and parallel, to urban and regional planning. Sadly, the two disciplines rarely enjoy sufficient connection and interchange. This is unfortunate, because they have much in common. In emergency planning, as in urban and regional planning, perhaps 70% of the problem to be solved is spatial (i.e., geographical) in nature. The answer to the question “What is where?” is at the root of many provisions designed to manage emergency situations. Like urban and regional planners, emergency planners need to study the geography, demography, economics, social relations, and culture of the area that forms the jurisdiction of the plan. This is essential if the plan is to respond well to local hazards and vulnerabilities and be compatible with local perceptions, traditions, activities, and expectations. Other than that, the five stages of emergency planning are research, writing, publicity, operations, and revision. Research will ensure an adequate basis of knowledge of hazards, vulnerabilities, local characteristics, and capacities. Writing will create the plan, and its appendices and abbreviated aides memoires. Publicity and training will make it known to the users and the organizations they represent, and operations will test elements of the plan in terms of feasibility, appropriateness, and efficiency. Finally, the plan should be a living document; hence, it will need to be updated frequently and consistently to take account of changes and new knowledge.

The essence of emergency and disaster management is its capacity to tackle pressing needs with maximum efficiency and celerity but with scarce resources and in the absence of much necessary information. Before the event, the plan must make assumptions about what is needed during the event. Those assumptions need to be considered within the compass of what is feasible with the available human and technical resources. One reason why the plan must constantly be updated is that one assumes there will be a program of continuous improvement in the resources, and one trusts that it will take place in the light of the evolving body of knowledge of hazards and the needs that they provoke.

Plans and Relevant Legislation

Emergency plans need to be written in the light of the prevailing legislation, as well as the provisions it makes for tackling major incidents and disasters. In many countries, legislation exists at both the national level and the level of regions, states, provinces, departments, counties, or prefectures—what is known as the intermediate tier of government. In the United States, the main federal law is the Robert T. Stafford Disaster Relief and Emergency Assistance Act (the Stafford Act), which has evolved since 1974 . In India, another federal republic, the national law was formulated in 2005 . In the United Kingdom, the Civil Contingencies Act dates from 2004 , and in Italy, a law passed in 1992 establishes the national civil protection system. In most cases, the basic law assigns responsibilities for the principal tasks to be accomplished in national emergency situations. There may be a legal obligation to draw up emergency plans, but it seldom, if ever, extends to the quality and compatibility of such plans.

Usually, compliance with legislation is simply a matter of comparative reading, or in other words ensuring that there are no glaring incompatibilities. The compliance may also have to extend to other kinds of legislation, such as that pertaining to health and safety at work, environmental protection, industrial safety, national security, and the division of responsibilities between different tiers of government. Once again, compliance can usually be ensured by comparative reading, although there may be cases in which legal requirements conflict with one another, for example between environmental legislation and laws about resource utilization.

Multi-Agency Planning

One source of complexity in emergency planning is the need to integrate several dimensions into the programmed emergency response. Hierarchical divisions refer to the tiers of government—from national, through regional, to local. Geographical divisions indicate the spatial jurisdictions to which plans refer, and possibly also to questions of mutual assistance. Organizational divisions refer to the different agencies that participate in emergency responses, such as the “blue light” services (police, fire, and ambulance), technical groups, and volunteer organizations. Lastly, functional divisions indicate the different fields involved, such as government, health-care, public order, public works, economy and employment, finance, and the private sector (Figure 2 ). The emergency plan is one contribution to the process of articulating a system of response to civil contingencies, in which an optimum balance is sought between integrating these forces and allowing them a degree of autonomy and freedom of action.

write the complete components of a research report about natural disaster

Figure 2. The different dimensions of division and integration in emergency planning and management.

The Plan and Warning Processes

Whether natural or anthropogenic, hazards vary considerably in their predictability and the amount of lead time, if any, for preparations to take place. Nevertheless, warning and associated responses are two vital elements of most emergency plans. Short-term warning must be distinguished from the longer-term predictability of hazards. Earthquakes, for instance, are mostly predictable in terms of the basic tenets of magnitude, frequency, and location, but not with regard to impending shocks in a short time window, such as 48 hours. In contrast, with adequate monitoring using Doppler radar, warnings can be issued for tornadoes with lead times of 20 to 120 minutes, and remote sensing together with digital modeling can give a reliable picture of a hurricane track many hours before the storm makes landfall.

Warnings have three essential components: scientific and technical, administrative, and social (Figure 3 ). The absence or ineffectiveness of any of them renders the warning system inoperable. Scientific information on an impending hazard must be transformed into a message to be acted upon, and a decision must be taken to warn affected people, who must then hear and react appropriately to the warning. The emergency plan should determine how to transform information on hazards to advice or orders on how to react. It should prescribe the means of disseminating the message and monitoring the social reaction to it. In practical terms, evacuation or sheltering is usually the most appropriate reaction to warning and the best way of moving people out of harm’s way. However, the means and the routes to evacuate people must be available (or there must be appropriate, safe locations for in situ or vertical evacuation). Horizontal evacuation may require reception centers with staff, bedding, methods of procuring, preparing, and distributing food, and so on.

write the complete components of a research report about natural disaster

Figure 3. The components of the warning process.

The Role of Information and Communications Technology

Modern emergency responses are heavily reliant on information and communications technology (ICT). Many algorithms have been written to assist emergency operations, for example, by providing an “expert system” that aids decision making, or by helping record decisions as they are made. For example, terrestrial trunked radio (TETRA) systems can be used to provide flexible communications between different services and groups of responders. Emergency plans should reflect these innovations and the opportunities they bring for sharing information and developing a synoptic picture of a rapidly evolving situation on the ground. Plans can include or refer to protocols for messaging and communications, and thus help clarify and standardize them.

The emergency plan should either prescribe or describe the structure of command and management to be utilized in the case of a disaster or major incident. Modern information technology has tended to flatten the chain of command and has given rise to a more collaborative form of management, which lessens the reliance on militaristic principles of “command and control.” Nevertheless, there will need to be a web of formal relationships between different organizations and units that participate in the response to disaster. The focal point of many of these is the emergency operations center (EOC), which is usually also the “natural home” for an emergency plan, or, in other words, the place where it is most appropriate to draw up and maintain such an instrument. The EOC needs to be a center of communications and management, one that has functional autonomy (e.g., its own electrical generator and fuel stocks).

In a fully functional civil protection system, emergency resource hubs such as EOCs usually operate as a nested hierarchy. They will function within the compass of plans made at different levels of government and by different jurisdictions. It follows that the emergency plans themselves will need to ensure interoperability and a rational division of responsibilities, so that all tasks can be covered in emergencies of different sizes. Once again, this involves comparative reading of plans and, preferably, some national guidelines for ensuring compatibility.

Specialized Emergency Planning

A further issue is the need for emergency planning in different sectors. The United Kingdom’s Civil Contingencies Act of 2004 obliges the providers of fundamental services in the private sector to draw up emergency plans. This is necessary, as much of the nation’s critical infrastructure is run by private-sector operators. Industrial firms also need plans, so that they can cope with technological failures and their consequences, and commercial companies need to ensure business continuity. Emergency plans are needed in both hospitals and the health systems of which they form a part. Hospital plans should state the preparations needed for internal and external emergencies. The former refers to contingencies such as fire, structural collapse, or contamination, and the latter mainly deals with the need to cope with mass casualty influxes. In addition, public transport services need emergency plans to guarantee the movement of people and goods during a crisis and its aftermath. For example, the plans for an airport should be integrated with those of the city and region in which it is situated. Finally, there is an increasing realization that emergency plans are needed to protect cultural heritage, which includes a huge variety of sites and artefacts, many of which have highly specialized conservation requirements. Loss of cultural heritage in disasters such as floods and earthquakes can deal a catastrophic blow to the intellectual and artistic life of a country by obliterating or damaging an irreplaceable legacy.

Among specialized emergency plans, it is worth singling out those required for educational institutions. The collapse of thousands of schools in earthquakes in Pakistan ( 2005 ) and China ( 2008 ), and the consequential loss of thousands of young lives, underlines the importance of providing a safe education to pupils and students. This is a moral requirement, as well as one that all parents would support. Despite this, emergency planning for schools tends to be neglected and underrated. It is not merely a question of evacuation. Plans need to assess hazards and design strategies to manage situations safely. As in other forms of emergency planning, scenarios are needed. In one exemplary case, a school has developed different strategies to manage the response to floods and earthquakes, both of which threaten it. As teachers are in loco parentis for their young charges, there is a requirement to ensure that school students are looked after in safety throughout an emergency. Schools and other educational institutions have been the target of natural hazards,h such as earthquakes, tornadoes, landslides, floods, and snowstorms; terrorism, such as marauding gunmen; and structural collapse and fire. When many young lives are lost, the sense of moral inadequacy can be universal, but not enough has been done to ensure that emergency planning for schools is transformed into universal practical measures to protect children and young adults.

The art of emergency planning involves “anticipating the unexpected.” For example, one important aspect that is often overlooked is veterinary planning. This has three main categories: domestic, farm, and wild animals. Many people will not evacuate in the face of a major threat unless they can take their pets with them, and hence, provision needs to be made to accommodate domestic animals. In pastoral areas, farm economies are dependent on the care and welfare of animals, which can be trapped and drowned by floods, frozen by blizzards, affected by epizootic diseases, or deprived of feedstock. Planning to manage wild animals mainly refers to threats to the human population posed by ecological disruption in disasters due, for example, to the migration of dangerous reptiles or the possible spread of rabies. Another form of planning that is roundly neglected is that associated with prison populations. In floods, storms, and earthquakes, these individuals have been either confined to dangerous localities or released indiscriminately into the community. Prisoners have human rights, including the right to custodial safety, but to release hardened criminals into society may pose risks to the general population. Finally, during the difficult circumstances engendered by disaster, pharmaceutical emergency planning is needed in order to ensure continuity of medication for patients who depend on medical drugs.

Using the Plan in an Emergency

One ingredient of most emergency plans is a stipulation of the alert and call-up procedures for personnel. These need to be integrated with the potential phases of warning, which at their simplest are hazard watch (impact is possible or likely) and hazard warning (impact is highly likely or certain). A part of the plan may be dedicated to the preparations to be made before impact, if time is likely to be available to carry them out. Examples include putting up mobile flood defenses, marshalling and readying vehicles and equipment, and testing and readying the means of field communication. The impact phase of a disaster is usually a period, more or less brief, characterized by dynamic evolution and acute shortage of information. One of the first needs is for an assessment that determines whether to move into emergency mode. The declaration of a state of emergency allows the formal abandonment of normal working procedures and the immediate adoption of those that pertain strictly to the disaster. Hospital beds will be cleared, leave will be cancelled, personnel will move to predetermined locations, lines of communication will be opened, and so on. The emergency phase may continue for hours or days, and in exceptional cases for weeks. However, it should end with a formal declaration of “stand-down,” as prescribed in the plan, which releases personnel for leave and ordinary duties.

Testing and Revising the Plan

In most parts of the world, major incidents and disasters are, thankfully, rare, although they may be an ever-present threat. The emergency plan therefore needs to be tested under hypothetical conditions. Exercises and drills can be divided into table-top, command post, and field-based simulations. The last category is clearly the most onerous, and it may require up to six months of meticulous planning. Generally, none of these methods is capable of testing the whole plan, and so elements of it must be selected for verification by simulation. One common element is the ability of different organizations to work together under specific, unfamiliar circumstances; for example, the ability of different medical response organizations to set up and run a field hospital together. Exercises need to be designed with clear, well-formulated objectives, and the progress of the simulation needs to be carefully monitored so that any need for improvements can be detected and communicated to participants in post-exercise debriefings and reports. All of this needs to be done in an atmosphere of constructive support, and certainly not recrimination, as the aim is not to examine but to help participants improve their performance during future emergencies. Simulations need to be treated as learning processes, from which it may be possible to derive improvements to the plan. One hopes that in real emergencies it will also be possible to learn lessons and improve the emergency plan on the basis of real experience. One such lesson is that personal familiarity with other participants in emergency operations greatly improves the ability to work together. This underlines the value of emergency simulations and drills.

The emergency plan should be a living document. In fact, there is nothing worse than the “paper plan syndrome”—or its modern digital equivalent—in which the plan is formulated and relegated to a desk drawer (or a hard drive) without being used or updated. Such plans can do more harm than good when they are eventually put to the test by a crisis. As time wears on, both small and large changes will occur. Hence the plan should include provisions not only for disseminating it and training its users, but also for a process of constant updating, with checks at regular intervals, perhaps every six months.

The next section discusses the contents of emergency plans in more detail.

The Use of Scenarios

So far in this article, emergency plans have been viewed as if they consist of nothing but collections of generic provisions for managing a notional crisis. These are necessary, in that the plan may need to be adaptable to unexpected crises. However, many—perhaps most—emergencies are predictable events, at least in terms of what is likely to happen. Not all disasters are cyclical events (those of seasonal meteorological origin are the closest to this), but many are recurrent according to established magnitude—frequency relationships, although, as noted, these may be imperfectly known. Over the last 30 years or so, knowledge of natural hazards has increased spectacularly. The threats, probabilities, time sequences, and effects of floods, landslides, storms, earthquakes, volcanic eruptions, and so on, are now much better understood than was the case half a century ago. Unfortunately, despite calls in the early 1980s to make it a central issue, understanding of vulnerability to natural hazards has not evolved at the same pace. In most places, vulnerability, not hazard, is the key to disaster potential; this is unfortunate and needs immediate improvements in research. Nevertheless, in places where hazards are recurrent, emergency planning against them should be based on scenarios. These will enable urgent needs to be foreseen and situations to be anticipated by providing the right resources in the right place and at the right time. Hence, scenarios should be a vital ingredient of emergency plans.

A scenario is a postulated sequence or development of events. Scenarios can be used to reconstruct past disasters where the evolution of the events is incompletely known. However, the main use in emergency planning is to explore possible future events and outcomes. A scenario should not be a rigid prediction of future developments. It is instead an exploratory tool. In most scenarios, there is not one outcome of developments, there is instead a range of outcomes. To establish this is to think creatively about the future.

Typically, an emergency planning scenario will be based on a “reference event,” or possibly more than one event. This will be a disaster that in the past affected the area covered by the plan and that it is deemed may be repeated in the future. Efforts must be made to assemble a plausible set of hazard data that represent the range of possibilities for the physical impact: for example, the wind speed, precipitation, and track of a storm, or the magnitude and epicentral location of an earthquake. The nature of the built environment, the economy, demography, and social characteristics of the area, and the assets at risk will all have changed since the reference event. Modern conditions must be added to the scenario. This then needs to be developed as a temporal sequence of evolution in terms of hazard occurrence, the impact on vulnerable people and assets, and the response of emergency services (Figure 4 ). Because aggregate patterns of human behavior change during the day, the week, and possibly also the year, several runs of the scenario may be needed. For example, an earthquake scenario may use the last seismic disaster as its reference event, but the future projection may need to be made for an earthquake that occurs during the night, on a working day, and on a holiday, as there will be different effects on people and the buildings and structures that they use.

write the complete components of a research report about natural disaster

Figure 4. Scenario methodology in emergency planning.

It is opportune to use a simple systems theory methodology to construct the scenario. The inputs are the reference event and accompanying conditions (social, environmental, economic, etc.). The output is the outcome of the disaster and its management. The throughputs and transformations are the evolution of the scenario over time. One can, if necessary, construct subsystems that embrace, for example, the health system response to the disaster, or the impact on local civil aviation. The point of using scenarios in emergency planning is to be able to explore and anticipate needs generated by predictable future disasters. Hence, the scenario should produce a range of possible outcomes and should be used as an exploratory tool. It should be used in conjunction with an audit of emergency resources designed to answer the question of whether they are sufficient and appropriate to match the anticipated needs.

Emergency planners need not be frightened of the unknown. There has been much debate on the existence of so-called “black swans,” or unanticipated events. These may be all very well in economics, but in disaster management the black swan has become extinct, and its ecological niche has been occupied by the red herring—or thus is the present author’s opinion. This means that there is very little in future events that will not have occurred in some form in the past. The scale and configuration may be different, but the components are present in the historical record. However, this should not be interpreted as a call to look resolutely backwards. Scenario builders will require considerable skill if they are to make a reliable assessment of the magnitude and consequences of future events. This underlines the value of scenario methodology as an exploratory tool, in which known regularities and established evidence are projected into a hypothetical future space and are allowed to develop in an “envelope” of possible developments.

The Uses and Abuses of Emergency Plans

One way of extending the emergency plan into the crisis phase and adapting it to rapidly changing needs is to continue the planning process during the emergency (Figure 5 ). Strategic planning is essentially about finding resources and ensuring that the assemblage of response units, plans, and initiatives is generally going in the right direction, so that it will meet the needs of the population affected by disaster. Tactical planning is largely about apportioning resources so that they can be used on the ground by operational units. Operational planning is about assigning tasks, constituting task forces, and monitoring the evolution of the situation so that tasks are set and accomplished. At all three levels, the permanent emergency plan is a backdrop to activities. It should be neither slavishly and rigidly followed nor ignored. One hopes that it will ensure that fundamental tasks are apportioned, responsibilities are clear, and appropriate action is stimulated.

write the complete components of a research report about natural disaster

Figure 5. The dynamic hierarchy of emergency plans.

Emergency planning should be a co-operative effort in which the users and beneficiaries of the plan are stakeholders who have an interest in ensuring that the plan works well. It is also important to create and maintain interoperability, so that emergencies that require large-scale responses do not lead to chaos and to groups of people working at cross purposes.

A Variety of Administrative and Political Contexts

One example of success in ensuring cooperation is the introduction and diffusion of the incident command system (ICS) in the United States since 1970 , when it was first devised as a measure to combat wildfire in California. ICS is a modular system that is usually implemented at the site of an incident and can be aggregated to higher levels. It has been codified by the US Federal Emergency Management Agency and is available online at National Incident Management System , which ensures a degree of interoperability among many different forces. This is highly necessary, as in a major incident or disaster, scores of agencies and organizations may work together—not at cross purposes, one hopes!

In Europe, interoperability is gaining ground, but the diversity of legal and administrative systems among the states of Europe, and the different histories of civil protection that they enjoy, means that the process is slow and complex. During the response to the earthquake in Haiti on January 2010 , field hospitals sent from European countries lacked interoperability of equipment and procedures, because they were functioning according to different, not entirely compatible, standards. Thus, they experienced difficulty in supporting each other’s work.

One absorbing question about disaster response is the relationship between emergency planners and emergency or disaster managers. In some countries (for example, Italy), they are one and the same, which makes sense, in that the plan needs to be prepared by people who understand the dynamics of managing an emergency. In other countries, such as the United Kingdom, the planners and the managers tend to be separate figures. In traditional systems, the emergency manager is a commander, much as military officers command their battalions. In more modern, evolved systems, the manager is much more of a coordinator, a person who manages resources and ensures that autonomous work by experts and task forces is able to go ahead in a co-operative mode. Over the years, as emergency response has become more professional, the need for command has diminished. This does not reduce the need to apportion and assume responsibility, but it does make a subtle and profound shift in the way that that occurs. Modern emergency planning is less about specifying chains of command and more about ensuring a “joined up,” coordinated, approach that covers all essential tasks and uses resources in the most efficient, effective way possible.

The statement that “the need for command is diminishing” needs to be qualified by the cultural requisites of different countries. This observation is broadly true, thanks in part to the effect of information technology, but the degree to which it applies varies considerably from one country to another. In the United States, the management of large emergencies (such as Hurricane Katrina in 2005 ) still relies on considerable input from military and paramilitary forces (i.e., the National Guard). It should be noted that the response to Katrina revealed a terrible lack of preparedness at the key levels: state and local authority. Here, planning was extemporary, but compensatory response of the federal level of government was slow and initially rather disorganized. Militarized responses are very important in China, were the national government has been suspicious of the rise of volunteer groups. In many other countries, military forces are used in disasters to compensate for deficiencies in civilian response, which may be poorly organized and underfunded. However, in almost all cases, the civilian organization of response to disaster is improving, including in the field of planning, which lessens the need for help from military forces.

Emergency Planning and Ordinary Citizens

A significant portion of a good emergency plan will provide instructions on how to relay information to the general public. The role of, and tasks allotted to, a spokesperson may need to be defined. In democratic countries, the mass media are expected to have a role that is independent of government, but also to bear a sense of responsibility that induces them to provide public service information in times of crisis. Generally, emergency plans can specify the arrangements for working with the media, but they cannot fully coopt the media as if they were public servants. In news services, a degree of editorial independence is necessary, in order to draw attention to any abuses of office committed by members of a government, or, for that matter, emergency responders.

Increasingly, response to the threat and impact of disaster is a matter of human rights. There are many ways in which this is true. For example, the safety and well being of girls and women need to be ensured in disaster, as well, of course, as at all other times. Disaster should not be an opportunity for abuses to be committed, or for discrimination against women. Emergency planning can also contribute to human rights, for example, by embodying the principle of “design for all” that seeks to ensure that people with disabilities are not forgotten, discriminated against, or abused in disaster situations, and indeed, that they are given the assistance they need to give them as much parity as possible with people who do not have disabilities.

In the modern world, disasters have been occasion for forced migration, the imposition of restrictive ideologies, the persecution of minorities, and discrimination against marginalized groups. These are human rights abuses that need to be counteracted.

Forced migration has occurred in the wake of disasters in countries as diverse as Myanmar (formerly Burma), Indonesia, and the United States. In this, the upheaval caused by disaster, and in particular the destruction of housing and livelihoods, has been used as an opportunity to achieve a form of social engineering, by moving people to settle areas deemed less hazardous. A darker form of this is the persecution of minorities, possibly by propelling them into “ghettos” and enclaves. Concurrently, recovery from disaster has occasionally become the opportunity to impose ideologies, as was the case with the introduction of Islamic Sharia law after both the 2004 tsunami in Banda Aceh and the 2009 Padang earthquake in Indonesia. There is little doubt, moreover, that Cyclone Nargis, in 2008 in Myanmar, did nothing to alleviate the persecution of the Muslim Rohingya people by the Burmese junta. Generally, disasters have been associated with the occurrence, and possibly intensification, of marginalization right across the board, from the homeless in Tokyo to rural communities in Zimbabwe, minorities in the United States, and the poor of Latin American cities like Managua and Lima.

At the very least, emergency planners need to ensure that there is nothing in the plans that could be construed as a means of facilitating such abuses. It is as well to remember that the legacy of two world wars was political hostility to emergency planning, which was seen by some politicians as a handmaiden to totalitarianism. This was because the invocation of special powers to deal with emergency situations was viewed as a dangerous development that could easily be subverted toward forms of dictatorship. Fortunately, these fears have diminished over time. They have largely been supplanted by an understanding of the imperatives of natural and technological hazards, with their capacity to retard human and economic development, or even to throw such processes into reverse.

Planning the Recovery from Disaster

The so-called “disaster cycle” refers to the phases of resilience building, preparation, emergency response, recovery, and reconstruction. A cycle is used because many disasters are recurrent, although not all are truly cyclical. Clearly, emergency and disaster planning refer primarily to the response phase. However, they have some relevance to all the other phases as well. Emergency planning is largely practiced during the risk mitigation, or resilience-building, phase—the calm periods between major adverse events. It must address the preparation phase as well as the response phase, as there is a need to make preparations systematic, especially where there is enough prior warning of impact for this to be accomplished successfully. While recovery planning may be regarded as a separate process from emergency planning, the two go together in that the phases of recovery offer an opportunity to improve general emergency planning and readiness for the next impact.

In most sudden-impact disasters, there is no reason why recovery planning should not begin the day after the event. Having made that point, however, it is important to note that time is socially necessary in recovery. Consultation must take place, and alternative strategies must be investigated. The aim should not be to “bounce back,” but to “bounce forward” to a more resilient society that is able to face up to future disasters by a better combination of resistance and adaptation than existed before the current impact. Recovery from a major disaster can take decades, and during that time socio-economic conditions will change, and so probably will environmental and hazard conditions. A disaster characterized by death, injury, psychological impairment, destruction, damage, and loss of economic activities, assets, and employment will engender a complex aftermath. In this there is much potential for wrong decisions, unless objectives are carefully set, procedures are clearly identified, and there is a consensus about how the process should take place.

Major disasters such as large floods, cyclonic storms, and earthquakes may not only take a large toll of casualties but may also destroy a great deal of housing stock and business premises. This will stimulate a process of providing shelter, which may involve temporary and transitional solutions to the housing problem before permanent reconstruction of building stock can be achieved. In this process, there is, or rather there should be, a social contract that indicates that survivors will endure the privation of temporary or transitional housing, provided it is for a finite and not excessive period of time. In the aftermath of the March 2011 earthquake and tsunami in northeastern Japan, for example, 88,870 houses were damaged, most of them being completely demolished by the waves. Reconstruction will take about seven years, which is a remarkable achievement that has required very intensive planning at the local, regional, and national levels. Moreover, the planned reconstruction has to be secure against future tsunamis; land must be elevated, sea walls must be constructed, and residential areas need to be relocated to higher ground, all on an unprecedented scale.

The example of Japan’s response to the most expensive natural disaster in human history can be contrasted with that of other, less wealthy nations. The impact of disaster must be seen in relation to national wealth and the effect of a catastrophe on a nation’s commerce, trade, and livelihoods. In this sense, when Cyclone Haiyan (known locally as Yolanda) made landfall in the Philippine province of Eastern Visayas in November 2013 , the storm surge, which reached 5 meters in height, was very much like a tsunami and every bit as devastating. Evacuation saved many lives, but 7,300 people nevertheless died and almost 29,000 were injured. In this economic backwater of Philippine life, recovery was slow and patchy. Many survivors received very little assistance, which helped to perpetuate vulnerability. Although evacuation was more successful when the next major cyclone (named Hagupit) struck in December 2014 , many of the reconstructed shelters of poor people living in coastal communities were once again washed away.

Planning for Critical Infrastructure and Supply Chains

One of the most complex and challenging aspects for recovery planners is the rebuilding of critical infrastructure. In the case of the Japanese Sanriku coast, where the 2011 tsunami came on land, much of the infrastructure was completely devastated: roads, railways, and utility distribution networks had to be rebuilt after sustaining a very high level of damage. Critical infrastructure (which also includes sectors like food distribution and banking) can be divided broadly into that of national importance and that of purely local significance. In many cases, resilience in networks is a function of being able to find different routes through the network. However, blockages can be critical, and infrastructure may be peculiarly susceptible to cascading disasters. In these, the consequences of one failure are the cause of others, in a sort of “domino effect.” Thus, the Japanese Tōhoku earthquake and tsunami caused the Fukushima Daiiichi nuclear reactor meltdown and radiation release. The tsunami also caused failures in manufacturing supply chains around the world, as a result of shutting down vehicle production in Japan.

Supply chains are essential to humanitarian operations and emergency responses. Emergency planning for them has two aspects. The first is an element of business continuity. It seeks alternative ways to ensure supplies of goods or services, in order to keep productivity from falling as a result of interruption of normal business. It thus depends on redundancy, which is potentially an expensive quality, as it may require the duplication of assets. This requires planners to determine which assets are critical, and where the destruction or failure of assets may have a critical effect on the whole production cycle. The second aspect of supply-chain planning involves ensuring efficiency in humanitarian supply, such that the forces on the ground are not left bereft of the equipment, goods, and manpower that are needed to tackle the emergency effectively.

Reconstruction Planning

Planning to manage the reconstruction of housing involves some difficult choices about who should build what and where. It is important to avoid excessive price rises in the market for building materials. It is also essential to involve local people, the beneficiaries, in the process of designing, constructing, and adapting permanent housing. In some situations, the best housing is built by its users, while in others it is not possible to learn the necessary skills and so contractors must be used, but the designs should respond directly to the users’ needs.

An important matter in reconstruction planning is the extent to which transitional shelter should be provided. If the terrain studies, site urbanization, preparation, and building processes are likely to take years, and if funding for them is short, then it may be necessary to put people in temporary accommodation, usually consisting of prefabs or so-called “barrack houses.” The space allotted per family varies from 10 to 40 square meters. The upper limit is a tacit international standard that comes from the provision of transitional shelter in countries like Italy and Turkey, while the lower limit refers to very basic “bunkhouse” provision for families in rural locations in countries like Indonesia and the Philippines. In Japan, transitional shelters erected after the 2011 tsunami had floor areas of 27–33 square meters, while those in Sichuan, China, constructed after the 2008 Wenchuan earthquake were slightly smaller than 20 square meters in floor area. Hence, the figure tends to be lower in Asian countries, where urban space is limited and populations are large. One risk of transitional housing is that it may reduce the impetus for permanent reconstruction, and thus leave the survivors in limbo for years or decades. The solution lies in both a constant provision of resources for recovery and a transparent, democratic process of achieving it, with ample public participation.

Recovery and reconstruction planning should aim to revive the local area while at the same time making it safer against future disasters. Revival means rebuilding basic facilities, such as housing, infrastructure, and amenities, but it also means ensuring that livelihoods and the local economy are rebuilt. Experience suggests that this is easiest for settlements that are well connected politically and geographically, and hardest for those that are politically, spatially, and economically marginalized. There is a welfare function in recovery from disaster, and this begs the question of what welfare should involve. At its worst, copious but ill-thought-out assistance to a disaster area can bring the population into a state of aid dependency that is bound to end in negative consequences, as the assistance is unlikely to be perpetual. Reviving the local economy can instead create self-sufficiency and tax revenues that help the area revive itself.

Other Aspects of Recovery and Reconstruction Planning

The fundamental purpose of welfare is to support people who lack the ability and resources to provide themselves with a minimum acceptable standard of living. Disaster throws this issue into high relief by differentially affecting the poor and needy more than the wealthy. Welfare should not mean largesse, however attractive this may seem to politicians when they remember that disaster victims are also voters. Instead, scarce resources should be utilized to provide a safety net for the most vulnerable people in society, and thus to mitigate the differential effect of disaster.

From these reflections, it should be apparent that there will be parallel processes of planning that have different weights and salience at different points in the cycle of recurrent disasters (Figure 6 ). To ensure a holistic response to the threat of disaster, recovery, and reconstruction, planning should be linked to ongoing emergency planning initiatives and to business continuity planning. Urban and regional planning should have links to all of these processes, because they are all about reducing the risk to development and all about the “hazardousness of place.”

write the complete components of a research report about natural disaster

Figure 6. Parallel forms of planning in the sequence of response to, and recovery from, disasters.

Conclusion: The Future of Disaster and Emergency Planning

In recent decades, there has been a consistent upward trend in the impact of disasters. Rising populations in the areas of greatest hazard, increasing investment in fixed capital in such places, the complexity of global interconnections, and the impact of climate change in producing more extreme meteorological events all conspire to drive this trend. It has propelled disaster management from a recherché concept to a vital discipline, in which there is an increasing process of professionalization. Standards and guidelines for disaster planning do exist, although none has been universally accepted as the basic model. Nevertheless, there is a gathering consensus on what emergency plans should seek to achieve and how they should be structured.

Dealing with disaster is a social process that has environmental and economic ramifications and implications in terms of governance. Emergency planning needs to fit into a comprehensive program of risk reduction, in which structural defenses are built—for example, river levees and sea walls—and non-structural measures are used in a diversified strategy to bring risk under control and reduce the impact of disasters. The non-structural approach includes not only emergency planning and management but also land-use control, public education, and possibly, relocation of the premises that are most at risk.

Emergency planning now has to face up to the challenges of the information age, in which there is much more immediacy to the means of communication. Social media can be used to warn people, collect information from the field, manage public response, answer the public’s questions, and devise new ways of managing the emergency. For example, social media have begun to have an important role in accounting for missing people in disaster. Crowd sourcing and cooperative efforts can be powerful tools in the response to crises and emergency situations. Hence, social media and Internet communications need to be taken into account in emergency planning.

Over the period 2004–2013 , almost two billion people were directly affected by disaster. In 1995 , the Kobe earthquake in Japan was the world’s most costly disaster ever to have occurred, with total losses and costs of US$132.5 billion. The 2011 Tōhoku earthquake and tsunami will easily surpass this. Moreover, enormous potential for casualties and losses exists in the world’s megacities, such as Tokyo, Tehran, and Istanbul. Emergency planning is thus facing a challenge that is very much greater and more complex than it appeared to be in the 1960s, when the first attempts were made to devise a systematic approach to it. Emergency planners will need to be more professional and to benefit from more, and more sophisticated, training. Information technology will play an increasing role in planning. It is already prominent, for instance, in the use of geographic information systems (GISs) to depict hazards, vulnerabilities, and patterns of emergency response. GIS is already an integral part of many emergency plans.

Another challenge of contemporary emergency planning is internationalization. Cross-border disasters are common, and any increase in the size and strength of meteorological disasters will increase their importance. Most emergency planning is designed to cope with local, regional, or at least domestic inputs, but less so international ones, as these tend to be much less predictable. However, it will become increasingly necessary to guarantee international interoperability, common supply chains, reciprocal aid arrangements, and procedures for working together across borders.

Finally, more informed decisions will have to be made about the magnitude of events for which a response needs to be planned. The apparent tendency for climate to drive increases in extreme meteorological events is only one element of a complex picture in which the distributions of magnitudes and frequencies are not accurately known. Resources are too scarce to permit lavish preparations for notional high-impact events that may occur only once in a millennium. However, preparedness does need to raise its sights and tackle larger events than those that can confidently be expected to occur in a decade. Given restrictions on public spending, this will mean achieving efficiencies and reducing waste in emergency response, as well as developing a robust moral philosophy and ethical position on who deserves what in the postdisaster period.

Future emergency plans will be digital creations that are networked, interactive, and dynamically supported by different kinds of media, including real-time filming and photography and networked teleconferencing. One challenge here is to ensure that the increasing dependency on sophisticated electronic algorithms and communications does not create vulnerability in its own right. Discharged batteries and failed networks of electricity supplies can be enough to make information and communications technologies useless at the height of a crisis.

As noted, emergency planning needs to be a cooperative endeavor and, as such, it is bound up with questions of rights, responsibilities, and democratic participation. The plans that work the best have the broadest support. They are also well known to participants and are frequently referred to. Like all of the principal aspects of modern life, emergency planning and management need to be sustainable endeavors. There are two sides to this. One is to ensure that the planning process is continuous, and support for the civil protection system in which it takes place does not wane during the intervals between disasters. Budget cuts can throw valid programs of safety and security into reverse, but disasters are, unfortunately, inevitable events. The other side is the need to integrate emergency planning into the general process of planning to make human life more sustainable. It will therefore require interfaces with climate change adaptation plans and programs of sustainable resource usage. These are significant challenges, and they add up to a process of “mainstreaming” emergency and disaster planning. The alternatives, inefficient and ineffective responses to the threat and impact of disasters, delayed recovery, and vulnerable reconstruction, should not be allowed in any society, rich or poor.

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EL Education Curriculum

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  • ELA G5:M4:U1:L2

Launching Research of Natural Disasters

In this lesson, daily learning targets, ongoing assessment.

  • Technology and Multimedia

Supporting English Language Learners

Universal design for learning, closing & assessments, you are here:.

  • ELA Grade 5
  • ELA G5:M4:U1

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These are the CCS Standards addressed in this lesson:

  • W.5.7: Conduct short research projects that use several sources to build knowledge through investigation of different aspects of a topic.
  • W.5.8: Recall relevant information from experiences or gather relevant information from print and digital sources; summarize or paraphrase information in notes and finished work, and provide a list of sources.
  • I can cite evidence from a source to support answers to my research questions. ( W.5.7, W.5.8 )
  • Natural Disasters Research Note-catcher ( W.5.7, W.5.8 )
AgendaTeaching Notes

A. Reflecting on Module Guiding Questions (5 minutes)

B. Reviewing Learning Target (5 minutes)

A. Developing Research Questions (10 minutes)

B. Choosing Expert Groups (10 minutes)

C. Expert Group Work: Videos of Natural Disasters (15 minutes)

A. Launching Independent Reading (15 minutes)

A. Accountable Research Reading. Select a prompt and respond in the front of your Independent Reading journal.


). requires students to gather information from print and digital sources. As such, this lesson is designed for students to use internet sources to watch a video. Ensure the technology necessary for students to complete the research is available. ). Consider using the Independent Reading: Sample Plans if you do not have your own independent reading review routines (see the ).

). ).

  • Expert Group Natural Disaster signs by writing the name of each expert group natural disaster on a piece of paper: earthquakes, hurricanes, tornadoes, volcanoes, and tsunamis. Post in separate areas of the room.
  • Group the Infer the Topic Resources as follows and post by the Expert Group Natural Disaster signs:
  • Earthquakes: Resources 4, 5, 6, 17,
  • Hurricanes: Resources 1, 2, 3, 18
  • Tornadoes: Resources 7, 8, 15, 19
  • Volcanoes: Resources 9, 10, 14, 21
  • Tsunamis: Resources 11, 12, 13, 20
  • Technology necessary for students to access the links provided on the Natural Disaster Video Links sheet (see Materials).
  • Review the Independent Reading: Sample Plans in preparation for launching independent reading in the Closing (see the Tools page ).
  • Post: Learning targets and applicable anchor charts (see Materials).

Tech and Multimedia

  • Continue to use the technology tools recommended throughout Modules 1-3 to create anchor charts to share with families, to record students as they participate in discussions and protocols to review with students later and to share with families, and for students to listen to and annotate text, record ideas on note-catchers, and word-process writing.
  • Work Time C: Students use web research to answer research questions. There is a page of links (Natural Disaster Video Links) provided for them to quickly locate the videos.
  • Consider that YouTube, social media video sites, and other website links may incorporate inappropriate content via comment banks and ads. Although some lessons include these links as the most efficient means to view content in preparation for the lesson, preview links and/or use a filter service, such as , for viewing these links in the classroom.
  • Supports guided in part by CA ELD Standards 5.I.C.10 Important points in the lesson itself
  • The basic design of this lesson supports ELLs by allowing them to choose which natural disaster they will research, develop their own research questions, and work closely with an expert group to conduct their research. The offering of choice and supportive group work will increase students' motivation and level of engagement as they research their natural disaster during this unit and across the module.
  • ELLs may find it challenging to generate research questions before they have chosen a natural disaster to research. Remind them of the research they conducted in Module 2, and guide the process for developing questions for this module as much as possible. Additionally, ELLs may find it challenging to identify relevant information in their expert group video to answer the research questions (see Levels of Support and the Meeting Students' Needs column)

Levels of support

For lighter support:

  • After adding unfamiliar vocabulary words to the Academic Word Wall during Work Time A, invite students to use each word in a sentence with context. This will support their understanding of each word, as well as provide additional context for each word for students who need heavier support.

For heavier support:

  • Consider introducing students to the natural disasters and allowing them to decide which one to research prior to the lesson. Allow students to view the videos and review their notes before deciding. Invite them to prioritize two natural disasters to allow for flexibility when strategically grouping students during Work Time B.
  • Multiple Means of Representation (MMR): In order to facilitate effective learning during this lesson, ensure that all students have access to the directions in each activity, and feel comfortable with the expectations. Vary the ways in which you convey expectations for each activity or task. Consider engaging in a clarifying discussion about the directions, or creating an outline of the steps for each activity.
  • Multiple Means of Action & Expression (MMAE): Continue to support a range of fine motor abilities and writing need by offering students options for writing utensils. Alternatively, consider supporting students' expressive skills by offering partial dictation of student responses. Recall that varying tools for construction and composition supports students' ability to express information gathered from the text.
  • Multiple Means of Engagement (MME): Throughout this lesson, students have opportunities to share ideas and thinking with classmates. Some students may need support for engagement during these activities, so encourage self-regulatory skills by helping them anticipate and manage frustration by modeling what to do if they need help from their partners. Consider offering sentence frames to strategically selected peer models. Recall that offering these supports for engagement promotes a safe learning space for all students

Key: Lesson-Specific Vocabulary (L); Text-Specific Vocabulary (T); Vocabulary Used in Writing (W)

credible, affect, experience, relevant (L)

  • Module Guiding Questions anchor chart (begun in Lesson 1)
  • Working to Become Ethical People anchor chart (begin Module 1)
  • Performance Task anchor chart (begun in Lesson 1)
  • Natural Disasters Research note-catcher (one per student and one to display)
  • Natural Disasters Research note-catcher (example, for teacher reference)
  • Academic Word Wall (begun in Module 1)
  • Domain-Specific Word Wall (begun in Lesson 1)
  • Vocabulary log (from Module 1; one per student)
  • Expert Group Natural Disaster signs (to display; see Teaching Notes)
  • Infer the Topic resources (from Lesson 1; to display)
  • Natural Disaster video links (one per student and one to display)
  • Independent Reading: Sample Plans (for teacher reference; see the Tools page )

Materials from Previous Lessons

New materials.

Each unit in the 3-5 Language Arts Curriculum has two standards-based assessments built in, one mid-unit assessment and one end of unit assessment. The module concludes with a performance task at the end of Unit 3 to synthesize their understanding of what they accomplished through supported, standards-based writing.

OpeningMeeting Students' Needs

and remind students that in the previous lesson they were introduced to the guiding questions for the module. Review the anchor chart. and briefly review the characteristic of respect.



Work TimeMeeting Students' Needs

and focus students on the question at the top, telling them that it will be the focus of their research in this unit: and invite students to add them to their (to cause a change in or have an impact on) (to live through)

as necessary.

and the grouped around the room. Read each sign aloud.

1.Move to the part of the room labeled for the natural disaster you would like to study.

2.Once there, share with the group why you chose that natural disaster.


ClosingMeeting Students' Needs

to launch independent reading.
HomeworkMeeting Students' Needs

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  • Open access
  • Published: 25 June 2024

Evolution of natural disaster terminologies, with a case study of the covid-19 pandemic

  • H. Jithamala Caldera   ORCID: 1 &
  • S. C. Wirasinghe   ORCID: 1  

Scientific Reports volume  14 , Article number:  14616 ( 2024 ) Cite this article

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  • Climate change
  • Climate-change impacts
  • Environmental impact
  • Natural hazards

Disaster, catastrophe, and cataclysm are some English terminologies that describe the severity of adverse events. Civilians, reporters, and professionals often use these terminologies to communicate and report any event’s severity. This linguistic method is the most practical way to rapidly reach all levels of local/regional/national, and international stakeholders during disasters. Therefore, disaster terminologies play a significant role in disaster management. However, attaining the actual magnitude of a disaster’s severity cannot be comprehended simply by using these terminologies because they are used interchangeably. Unfortunately, there is no consistent method to differentiate disaster terminologies from one another. Additionally, no globally accepted standard technique exists to communicate the severity level when disasters strike; one observer’s ‘disaster’ can be another’s ‘catastrophe’. Hence, a nation’s ability to manage extreme events is difficult when there are no agreed terminologies among emergency management systems. A standard severity classification system is required to understand, communicate, report, and educate stakeholders. This paper presents perceptions of people about disaster terminologies in different geographical regions, rankings and differences in disaster lexical and lexicon. It explores how people perceive major events (e.g., the Covid-19 pandemic), and proposes a ranking of disaster terminologies to create a severity classification system suitable for global use.

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The linguistic method, which involves using generic terminology such as ‘emergency,’ ‘disaster,’ and ‘catastrophe’, plays a vital role in communicating the severity of natural disasters—events triggered by nature, such as biological, climatological, extraterrestrial, geophysical, hydrological, and meteorological disasters. Within a language community, terminologies serve to convey information and inter-subjective messages. Like all forms of written or oral communication, the meaning of a term (or sentence) carries a message and information from one person to another. The linguistic method represents the oldest and most practical method of communication and reporting during disasters of varying severity levels. It rapidly disseminates information to all levels of stakeholder groups (local, provincial, regional, national, continental, or international). Additionally, it is commonly employed for educational purposes due to its wide-reaching effectiveness.

The need for a common understanding of terminologies to communicate about the severity of an event is essential in disaster situations 1 , as they often require many stakeholders to work together toward a common goal. This need is compounded by the fact that many stakeholders involved in disaster relief may speak different languages and might not fully understand English words such as ‘disaster,’ ‘catastrophe,’ and ‘cataclysm.’ As a result, confusion and breakdowns in communication may occur because some stakeholders might not comprehend the exact meaning of the terminologies being used 2 . Yet, establishing a common understanding of these terminologies is vital to reduce confusion among stakeholders and create a well-understood framework for providing disaster relief. However, for this to happen, policymakers, academics, and practitioners must initiate the process of redefining terminology while simultaneously developing appropriate measures and scales that distinguish each term and its representation of disaster severity.

Similarly, although disasters are not universally understood in the same way 3 , reaching a common understanding—such as a universally agreed-upon approach about what category a disaster falls under–to classify disaster severity is essential 4 in disaster management and disaster risk management. This common understanding is crucial in situations where many stakeholders worldwide come together for a common cause. To initiate this process, English is the most suitable language for classifying natural disasters globally, given its predominance as the most widely spoken and used official language (see Supplementary A online). The disaster terminologies in English are even adapted with modifications when creating severity scales (for both individual and common classification systems, as shown in Supplementary B online) to emphasize the degree of impact an event has 5 . When an acceptable point of reference exists within a globalized language (i.e., a guideline or standard criterion) to classify disasters, it can be adapted to any particular language through translation and standard colour and number coding, as described in Section “ Limitations and future extensions ”.

Due to inconsistency in how stakeholders perceive various terminologies, the lack of agreed terminology poses a global challenge in formulating legislation and policies regarding disaster response 6 . Failing to identify a potential hazard during disaster communication can lead to devastating consequences 7 . For example, Hurricane Katrina’s devastating impacts were exacerbated by an ineffective government response and a failure to recognize the severity of the situation 8 . Another example is the series of decision-making errors that compounded disaster relief efforts during the 2004 Indian Ocean tsunami. These errors contributed to the Indian Ocean Tsunami becoming one of the world’s deadliest natural disasters, resulting in approximately 230,000 deaths and leaving over a million homeless in 14 countries. For instance, in India, word of the disaster went to the wrong official 9 . With no warning, coastal populations were caught off guard by the immense waves from the tsunami. The lack of communication was made worse because officials did not recognize or adequately classify the severity of the event. Consequently, coastal residents, tourists, and governments did not know the tsunami’s severity, so they did not effectively respond to the disaster 10 . In addition, inconsistent identification of disaster impacts results in overcompensation or under-compensation in assigning resources for mitigation 11 . Overcompensation may waste resources, while under-compensation could increase the impact severity. Properly and promptly identifying the disaster impact is crucial because lives depend on these decisions 12 .

These examples make it imperative that a standard severity classification system is required to understand, communicate, report, and educate stakeholders during a disaster, including in both the pre- and post-disaster period. Moreover, these natural phenomena have no national boundaries when they strike. The impacts of a disaster in a region, if not managed properly, can produce political and social instability, and affect international security and relations 13 . The recent Covid-19 pandemic is a good example of these consequences. A common communication platform for disaster severity is therefore needed to convey vital information in a standard format that a global audience understands.

Selecting specific terminologies, even within the English language, to represent varying levels of severity for a global audience is a challenging task that demands careful consideration. This challenge arises because the terminology we employ is not universally understood. The lexicon (dictionary) meaning and the lexical (verbal) meaning of these terminologies can vary based on factors such as time/era, location, individual experience, and situation (see Supplementary C online). Although the severity scales mentioned in Supplementary B online are developed using the linguistic method to categorize the different levels of severity, in all but the two common scales, the proposed labeling appears to be arbitrary, particularly in all individual and common scales. The two scales, Fatality-Based Disaster Scale 14 and Universal Disaster Severity Classification 15 , paid some attention when selecting the terminologies to label the levels of severity; however, they did not consider the current views of the people who are going to use these scales. Proposing a clear definition and criteria for disaster terminologies is important, but people often do not refer to the definition, especially in disaster situations, and they assume the lexical (verbal) meaning of the word. Therefore, it is important to consider the users’ perspectives when selecting labels/terminologies for unification to categorize disaster severity levels.

This research aims to propose a universal classification framework for defining disaster severity regardless of the geographical location of the disaster and the linguistic, lexical, and semantic nuances that can affect the interpretation of terminology. Moreover, the focus of this universal disaster framework will be measured specifically in terms of the adverse effects the event has on a community or an environment and not the degree of severity it has on an individual.


The terminologies that describe the magnitude of a natural phenomenon, including calamity, cataclysm, catastrophe, disaster, and emergency, were selected for investigation. The aim was to determine whether significant differences exist in the seriousness levels among these terms or if people perceive them as synonyms and use them randomly. The term ‘Armageddon,’ which describes “a usually vast decisive conflict or confrontation” or “a terrible war that could destroy the world” 16 , was excluded from consideration due to its relevance to human-caused catastrophes rather than natural events. Similarly, the term ‘apocalypse’ was excluded from the analysis due to its religious connotations, as some religious beliefs associate it with the destruction or end of the world.

Surveys have been conducted to investigate people’s perceptions of natural disaster terminologies and how they utilize these terms to indicate the severity levels of an event using a case study. The primary objective of these surveys was to determine whether differences exist in ranking disaster terminologies among individuals. The research question addressed was: Are there any differences in the ranking of disaster terminologies among people? The hypothesis posited is that there are no differences in the ranking of disaster terminologies among people. Therefore, the independent variables in this study were the disaster terminologies, and the dependent variable was the respondents’ rankings of the disaster terminologies. These surveys were approved by the University of Calgary Conjoint Faculties Research Ethics Board.

To examine the previous research question, two web-based surveys were conducted. All five terminologies (calamity, cataclysm, catastrophe, disaster, and emergency) were presented in alphabetical order to each respondent. Subsequently, the respondents were asked to rank the five terminologies based on their understanding of the term’s severity level, ranging from the lowest (Level 1) to the highest (Level 5). Respondents were not allowed to assign the same rank to two different terminologies within these surveys. The first survey, conducted from August 2015 to December 2020, involved presenting the terminologies without providing their definitions, resulting in rankings based on lexical (verbal) meaning. In the second survey (conducted from September 2020 to June 2021), respondents were given the definitions from the Oxford dictionary, resulting in rankings based on lexicon (dictionary) meaning. The study seeks to rank the severity of disaster terminologies for global audiences who typically rely on dictionary definitions rather than disaster literature when referencing meanings. It is noteworthy that none of the disaster literature, except for the literature related to the continuation of this research, provides definitions for all five terms considered in this study. Consequently, the current definitions from the Oxford English Dictionary for the aforementioned five terms are presented to the respondents to ensure consistency in the analysis. During the second survey, respondents were also queried about the single terminology they would use to describe the ongoing Covid-19 pandemic. Additionally, real-time Covid-19 statistics, including global confirmed cases, global deaths, and global recovered cases, were presented to the respondents while answering this question.

Web-based international surveys were conducted to provide access to large and geographically dispersed populations cost-effectively and efficiently. These web surveys were launched on the Alchemer platform (formerly known as SurveyGizmo) to reach participants globally. As this study was conducted in English, the target population comprised English-speaking adults aged 18 years or older who were internet users, amounting to fewer than 1 billion people. Approximately 1.4 billion out of 7.8 billion people spoke English, with around 26% of the global population being under 15 years of age 17 . Additionally, there were 4.914 billion active internet users worldwide, constituting 63% of the global population in 2021 18 . The survey was designed as an international web-based survey due to its focus on the adult English-speaking population (aged 18 and above). While no subgroups were identified within the global population analysis, subgroups were considered for geographical areas, such as the six populated continents. A general statistical guideline suggests that approximately 30 participants are needed in each group 19 . However, the sample size requirement for non-parametric tests was 1.15% of the parametric test’s sample size 20 . Consequently, a sample size of about 242 was necessary to represent all continents in non-parametric tests.

In this study, non-probabilistic sampling techniques are employed because the research focuses on the entire population of English-speaking adult internet users, a group too vast to be comprehensively examined. The study aims to establish a ranking suitable for a global audience, rendering it impractical to utilize random probability sampling, which would grant each population member a known (or equal) chance of participation. Consequently, a combination of convenience sampling (recruiting readily available and willing participants) 19 and snowball sampling (recruiting participants through existing participants) 19 was employed to gather respondents. Potential survey participants were invited through both professional and personal networks, including contacts gathered from the 3rd United Nations World Conference on Disaster Risk Reduction. Survey links were disseminated through various means, including emails, short message services, social media platforms (such as Facebook and LinkedIn), newsletters (e.g., the e-PEG newsletter of the Association of Professional Engineers and Geoscientists of Alberta, and the electronic newsletter of the World Federation of Engineering Organizations—Committee on Disaster Risk Management), websites, online discussion platforms (such as Catastrophe Indices and Quantification Inc. (CatIQ), and the Canadian Risk and Hazards Network (CRHNet)), and by distributing handouts at conferences (including the 12th and 13th Annual CRHNet Symposiums, the 5th International Natural Disaster Mitigation Specialty Conference of the Canadian Society for Civil Engineering, the 12th International Conference of the International Institute for Infrastructure Resilience and Reconstruction, and the Canadian Catastrophe Conference of the CatIQ).

Since the study was based on ordinal data (ranking/ordering values) 20 , it was better suited for representation by the median rather than the mean. Consequently, non-parametric tests were employed. The preference for the median over the mean stemmed from the skewed distribution nature of the study. The median better captures the center of the distribution, signifying that 50% of the values lie above it while 50% lie below. For instance, consider a scenario where most individuals assign higher rankings to a particular term, and very few assigns lower rankings (resulting in a few outliers) to that same term. In such cases, the mathematical mean may decrease even though the median remains stable. In situations where the distribution is significantly skewed, extreme values in the distribution’s tail can substantially affect the mean. Conversely, the median remains a more robust indicator of the distribution’s center.

In these surveys, the five samples of each terminology are interconnected, as respondents were unable to assign the same rank to two different terminologies. As a result, the ranks received for the five terminologies were interdependent. The non-parametric tests below 21 were conducted to address the following hypotheses:

The Friedman test was employed to determine whether people utilize these five terminologies randomly or if there exists a significant difference in the ranking of each terminology.

There is no significant difference between the mean ranks of the disaster terminologies.

If the ranks were not randomly distributed, Kendall’s W Test was performed to ascertain the agreement between respondents’ rankings.

There was no agreement among the respondents in ranking different terminologies (W = 0).

In cases where agreement among respondents’ ranking was observed, the Wilcoxon signed-rank test was conducted for each pair of terminologies. This aimed to identify terminologies with differing rankings and terminologies showing similar rankings, shedding light on peoples’ ranking of these natural disaster terminologies. Further details about the Wilcoxon signed-rank test are available in Supplementary D online.

The median difference (M A  - M B ) was equal to zero. For instance: H 0 : M Cataclysm  − M Calamity = 0.

Analysis of perception about natural disaster terminologies

To gauge public perceptions of commonly used severity terminologies, an initial survey collected 1170 responses. However, only 624 respondents (approximately 54%) completed rankings for all five terminologies based on their lexical (verbal) meanings. Notably, many respondents omitted rankings for ‘cataclysm’ or ‘calamity’ compared to the other three terminologies. ‘Emergency,’ ‘disaster,’ and ‘catastrophe’ were more widely recognized, likely due to their prevalence in governmental and insurance-related contexts, while ‘calamity’ and ‘cataclysm’ were viewed as more colloquial 15 . Some respondents may have refrained from ranking these terminologies due to their perceived subjectivity, favouring a more objective approach to assessing disaster severity. The initial assumption that ‘emergency,’ ‘disaster,’ ‘calamity,’ ‘catastrophe,’ and ‘cataclysm’ represent a perceived hierarchy of seriousness among disaster terminologies was derived from the frequency of completed survey rankings (see Fig.  1 ).

figure 1

Frequency distribution of respondents’ rankings (from 1 to 5) for natural disaster terminologies.

Based on the two-survey analysis (see Supplementary E online), Table 1 compares respondents’ rankings of disaster terminologies with and without the respective terminology’s definitions. In the global sample, the absence of the terminology’s definitions (i.e., lexical (verbal) meaning) resulted in four distinct levels of ranking for ‘emergency,’ ‘calamity,’ ‘disaster,’ and ‘catastrophe/cataclysm.’ However, when the definitions of the terminologies were provided (i.e., lexicon (dictionary) meaning), respondents did not differentiate between terminologies with more than two levels, specifically ‘emergency/calamity’ and ‘disaster/catastrophe/cataclysm.’ Similarly, for North Americans and Asians, the absence of terminology definitions led to clear differentiation among ranks, creating three distinct levels: ‘emergency,’ ‘calamity/disaster,’ and ‘catastrophe/cataclysm.’ However, with the presence of definitions, they did not differentiate terminologies with more than two levels. Additionally, Oceania respondents, who exhibited two distinct levels without the presence of disaster terminology definitions, showed only one level when definitions were provided (i.e., they randomly ranked the five terminologies). Europeans maintained the same rankings with or without definitions. However, it is important to note that the European and Oceania continents might not have yielded accurate results due to insufficient data (n < 60) for the Wilcoxon signed-rank test. Nevertheless, a clear differentiation between respondent rankings for lexicon (dictionary) meaning and lexical (verbal) meaning was evident among the global, North American, and Asian respondents.

The summary of the results in Supplementary E online and “ Analysis of perception about natural disaster terminologies ” section can be outlined as follows: Firstly, there is a consensus among global respondents regarding the representation of severity order for disaster terminologies in both their lexical (verbal) and lexicon (dictionary) meanings. Similarly, North Americans, Asians, and Europeans share a common perspective on the severity order representation of disaster terminologies for their lexical (verbal) and lexicon (dictionary) meanings. However, for Oceania respondents, agreement is observed only in the lexical (verbal) meaning, not in the lexicon (dictionary) meaning. In essence, an agreed-upon order of seriousness exists rather than random usage of these terms. Secondly, a slight variation exists in the understanding of these terminologies based on the geographical locations of English speakers, particularly in their lexical (verbal) meaning. Nonetheless, such differences are not significant when it comes to the lexicon (dictionary) meaning. In other words, the inclusion of definitions can lead to a general agreement among people, reducing the variance in the severity order representation based on geographical regions. Thirdly, a distinction is evident in perceptions about the order of severity for disaster terminologies between their lexical (verbal) meaning and their lexicon (dictionary) meaning. While a clear differentiation across four severity levels existed for lexical (verbal) meaning, the differentiation was limited to two levels for lexicon (dictionary) meaning. The provided disaster definitions (Oxford Dictionary definitions) did not facilitate differentiation among the disaster terminologies 22 , 23 . The analysis underscores that these provided definitions did not enhance understanding; rather, they introduced further confusion. Consequently, if these terminologies are to be employed for distinguishing severity levels within a standard classification system, precise definitions for each disaster terminology are imperative.

Dynamic nature of severity classification

Understanding the usage of disaster terminologies and how global respondents employ them in disaster situations is crucial, particularly when integrating them into a global severity classification system encompassing all types of disasters. In general, it is anticipated that global respondents comprehend and utilize the terminology accurately, and their classifications shift as the severity of an event changes. Within this context, a widespread understanding of disaster terminologies can be inferred. Consequently, these terminologies can be leveraged to delineate severity levels within a global severity classification system, provided that precise definitions are established to enhance people’s comprehension. To examine the hypothesis about how global respondents employ disaster terminologies to convey the severity of an event, a significant event characterized by its diffusion across space and time becomes a more suitable subject for analysis.

The Covid-19 pandemic, which originated in Wuhan, China, in December 2019, swiftly evolved from an endemic to an epidemic, eventually reaching global pandemic status within months. As of March 10, 2023, the pandemic has resulted in over 676.6 million confirmed cases and 6.8 million reported fatalities globally 24 , with new cases reported daily. Covid-19’s far-reaching impact, profoundly affecting various aspects of life worldwide from fatalities to financial crises, makes it a compelling example for this study. To understand public perceptions of major events, an investigation into individuals’ perceptions of the Covid-19 pandemic was conducted.

During the pandemic, a second survey was conducted to assess respondents’ choice of terminology to describe Covid-19’s severity. Respondents selected a single terminology from five options, with real-time Covid-19 statistics provided alongside. Out of 848 respondents, 674 (79.5%) chose one of the five terminologies to describe Covid-19’s severity. The majority described it as a disaster, followed by catastrophe, and emergency (see Fig.  2 ).

figure 2

Frequency distribution of people’s perceptions regarding the ongoing Covid-19 pandemic.

Respondents’ perceptions of Covid-19 may have shifted due to its increasing impact. The analysis of respondents’ choices over time revealed that each terminology displayed initial randomness in 2020, followed by a stable pattern emerging in the first half of 2021, and subsequently showed an upward trend for disaster and catastrophe and a downward trend for calamity, cataclysm, and emergency (see Fig.  3 ).

figure 3

Change in perception about the ongoing Covid-19 pandemic.

This shift coincided with the designation of variants of concerns (VOCs) (see Fig.  3 and Table 2 ). With the designation of Alpha and Beta variants, there was a gradual increase in describing Covid-19 as an emergency, calamity, disaster, and cataclysm, while labeling it as a catastrophe decreased. By January 2021, with the designation of the Gamma variant and total confirmed cases surpassing 100 million, with over two million fatalities, respondents consistently applied a variety of labels to the pandemic. Post-April 2021, as the Delta variant emerged and total confirmed cases surpassed 150 million, with over three million fatalities, the trend shifted towards identifying Covid-19 as a disaster or catastrophe, with a decrease in labeling it as an emergency, calamity, or cataclysm. By the survey’s end in June 2021, 50% of respondents characterized Covid-19 as a disaster, 33.3% as a catastrophe, and the remainder as an emergency; none used calamity or cataclysm. Throughout the survey period, the usage of calamity or cataclysm remained low compared to disaster, catastrophe, and emergency.

This case study provides valuable insights into how individuals reference major events and how their perceptions evolve with changing circumstances. As the severity of Covid-19 rapidly increased during the first four months of 2021, reaching over 0.1 to 0.2 billion global confirmed cases and over 2 to 3 million fatalities, people’s choice of terminology became more stable. Their preferences shifted towards terms indicating a higher order of seriousness rather than those with lower levels. As the severity of the pandemic continued to escalate, surpassing 0.2 billion global confirmed cases and 3 million fatalities, people’s usage of terms decreased for those with lower levels of seriousness, while there was an increase in the usage of terms indicating higher levels of severity. This suggests that individuals globally possess a general understanding of disaster terms, and their utilization of these terminologies is guided by their comprehension of the hierarchy of seriousness and events’ severity levels. Therefore, these terminologies can effectively define severity levels within a global classification system, contingent upon establishing precise definitions that enhance people’s comprehension.

Proposed qualitative universal disaster severity classification

Integrating descriptive terminologies within an emergency management system enhances mutual understanding and simplifies management, minimizing confusion. For instance, using terminologies with escalating severity levels such as ‘emergency,’ ‘disaster,’ and ‘catastrophe’ as descriptive headings aligns with increasing severity, rather than only employing headings like ‘Type 1,’ ‘Type 2,’ or ‘Type 3.’ This approach helps to avoid ambiguity regarding whether Type 1 or Type 5 holds greater significance, as it does for Incident Management Teams Typing (IMTs), a classification used by disaster managers and emergency responders 25 , 26 . Consequently, a universal linguistic approach that integrates existing severity classification systems becomes imperative. However, the selection of appropriate terminologies for distinct severity levels should be undertaken with meticulous evaluation 15 .

Proposed sequence of natural disaster terminologies for a global audience

Based on “ Analysis of perception about natural disaster terminologies ” section and Supplementary C and E online, the order of seriousness for the current dictionary definitions, etymological definitions, and people’s perceptions of natural disaster terminologies is presented in Table 3 . This order is being proposed to establish a hierarchy of seriousness for the considered terminologies, tailored specifically for a global audience. As previously mentioned, ‘apocalypse’ is unsuitable for representing severity levels for global audiences due to its religious bias. When determining this order, greater importance was given to the sequence of lexical (verbal) meanings (Column 4 in Table 3 ) compared to the lexicon (dictionary) meanings (Column 5 in Table 3 ), as perceived by individuals. This differentiation stems from the fact that the intended order of seriousness is meant for a worldwide audience, where people generally understand a term’s lexical (verbal) meaning without necessarily referring to the provided lexicon (dictionary) meaning. Consequently, the suggested sequence is as follows: emergency, calamity, and disaster for Levels 1, 2, and 3, respectively. However, both catastrophe and cataclysm are placed at the same level based on the convergence of people’s perceptions regarding the lexical (verbal) and lexicon (dictionary) meanings. Nonetheless, when considering the overall mean rank order obtained from respondents’ rankings (as depicted in Fig.  1 and Supplementary Table S6 online), catastrophe and cataclysm are recommended for Levels 4 and 5, respectively. Therefore, based on the analysis of both lexical (verbal) and lexicon (dictionary) meanings, the proposed sequence of the five terminologies from lowest to highest seriousness is as follows: emergency, calamity, disaster, catastrophe, and cataclysm. This arrangement is not arbitrary; it is substantiated by the data and reflects the contemporary viewpoints of individuals on a global scale. Consequently, this sequence is well-suited for a global audience, and these designations effectively function as categories within a comprehensive global severity classification system.

Proposed qualitative global severity classification system

To establish a universally accepted method of communicating disaster severity levels using a linguistic approach, we have applied the aforementioned proposed order of disaster terminologies to the Qualitative Universal Disaster Severity Classification (QUDSC) developed by Caldera and Wirasinghe 27 , incorporating certain modifications. The selection of QUDSC for this application is primarily attributed to five key factors as described in Supplementary F online.

Table 4 presents Advanced Qualitative Universal Disaster Severity Classification (AQUDSC), a comprehensive system for categorizing all types of natural disasters across stakeholder groups. Five modifications have been introduced to the existing QUDSC. Firstly, the order of seriousness for terminologies has been adjusted, incorporating ‘emergency,’ ‘calamity,’ ‘disaster,’ ‘catastrophe,’ ‘cataclysm,’ and ‘partial or full extinction’ aligning with the general understanding of the global audience as analysed above. Secondly, each level is now assigned a name and definition to create a complete 0–10 level system, including the addition of ‘Emergency Level 1’ to maintain consistency with sub-levels. Thirdly, ‘Type 1’ and ‘Type 2’ terms have been replaced by ‘Level 1’ and ‘Level 2’ to enhance clarity with hierarchical connotation. Fourthly, the definition of ‘emergency’ has been revised to accommodate disasters without human fatalities but substantial damage. Lastly, colour-coding has been adjusted to maintain consistency and aid memorization, with each term assigned a unique color: blue for ‘Emergency,’ green for ‘Calamity,’ yellow for ‘Disaster,’ red for ‘Catastrophe,’ gray for ‘Cataclysm,’ and black for ‘Partial or Full Extinction.’ Lower levels represent light colours, while upper levels represent dark colours. These modifications aim to enhance clarity and facilitate disaster management across all levels (see Supplementary G online for more details).

The QUDSC was used to create the Initial Universal Disaster Severity Classification (IUDSC) 27 . Subsequently, adjustments were made to the IUDSC to align with the AQUDSC. The resulting Modified Universal Disaster Severity Classification (MUDSC) is presented in Table 5 . These modifications have led to improvements to the QUDSC/IUDSC:

The ranking of disaster terminologies in AQUDSC/MUDSC is suitable for a global audience, as it considers the general understanding and lexical (verbal) meaning of users.

AQUDSC/MUDSC comprehensively represents the complete range of severity including disasters that lack direct fatalities but cause significant damage to communities, such as the 2016 Fort McMurray fire.

The system provides a clear labeling strategy to distinguish each level without causing confusion about their respective criticality. Additionally, a consistent colour-coded system facilitates broader communication between the public, emergency services, and media organizations, enabling easy adaptation for any language, country, or culture.

Therefore, AQUDSC/MUDSC enhances the differentiation of disaster severity levels for the global audience, offering a clear understanding of severity along the disaster continuum.

AQUDSC/MUDSC provides standardized terminologies and clear definitions for a global audience to describe the impact of natural disasters. Standardized definitions have significant implications, as outlined in the Technical Report on Hazard Definition and Classification Review 2020 28 . Clear definitions facilitate effective measurement and reporting of risks, thereby contributing to the development of appropriate disaster risk management measures and long-term planning. Standardization supports all aspects of risk management, including multi-hazard risk assessments, warnings and alerts, disaster response and recovery, long-term planning, and public awareness efforts. Furthermore, standardized definitions form the foundation for a uniform database of loss data and information, which makes a valuable contribution to forecasting future events. With consistent, standardized definitions and global-scale risk information, communities at local and national levels can determine the most effective strategies for mitigating the impacts of future events.

MUDSC serves as a global severity classification system for post-event assessment, accommodating various natural events irrespective of the disaster type, location, or occurrence time. It allows for the evolution of severity classifications over time as reports on impacts are updated, aiding responders, and informing public planning and relief efforts. Additionally, it is a comprehensive tool to describe, measure, categorize, compare, assess, rate, and rank the impact of various natural events, ranging from a lightning strike to a super volcanic eruption. Thus, MUDSC simplifies impact assessments, enhances disaster preparedness, and facilitates multi-hazard management by offering a unified classification for regions prone to multiple disasters.

MUDSC enhances warning communications by employing plain language to categorize disasters, ensuring the public comprehends the severity and urgency of evacuation. Plain language communication of warning indications ensures mutual understanding between emergency management systems and the general public. Populations are most sensitive to disasters with high human impacts 7 , and MUDSC explicitly establishes a direct relationship between a disaster and its human impacts. Employing MUDSC for preparedness and mitigation methods, including public awareness campaigns, disaster education, and disaster drills, helps reshape public opinion, capturing the public’s attention and fostering trust and response rates to warnings, minimizing fatalities and injuries during disasters. Its integration into multi-hazard early warning systems contributes to achieving Sendai Framework targets, specifically Target G 29 .

MUDSC enhances disaster preparedness and management globally by providing standardized severity levels. Its implementation is expected to eliminate inconsistencies, facilitate mutual communication among stakeholders, and assess the need for regional, national, and international assistance in managing global disasters. Additional detailed descriptions regarding the significance of the proposed AQUDSC/MUDSC are available in Supplementary H online.

AQUDSC and its application version, MUDSC, were developed to provide a common language for communicating the severity of natural disasters globally. This system aims to facilitate easier communication and management at all levels by selecting appropriate terminologies and using plain language to describe the magnitude of a disaster’s impact, considering the general public’s perception of disaster terminology.

The main advantage of the MUDSC is its ability to provide a standardized method for comparing natural disasters. It allows for the quantitative and qualitative description, measurement, categorization, comparison, assessment, rating, and ranking of a wide range of natural disasters occurring anywhere in the world. The system covers disasters resulting from various types of events, including those that are diffuse in space and time as well as events with less clear start and endpoints, such as droughts, pollution, and epidemics. It also encompasses conditions that could lead to extinction events or massive phenomena, such as super volcanoes or meteoroid impacts. Furthermore, by facilitating multi-hazards management, disaster risk reduction, and preparedness at all levels and within/across all sectors, MUDSC aligns with the goals of the Sendai Framework.

Importantly, the AQUDSC/MUDSC serves as a common categorization system for all stakeholder groups involved in disaster management and response, including civilians, emergency responders, disaster managers, relief agencies, international/regional/national/local government entities, non-governmental organizations, media, insurance managers/estimators, academics, researchers, and policymakers. By offering a comprehensive view of disaster severity, the system aids in public education, assessment purposes, and decision-making for resource allocation, mitigation, and recovery efforts.

Overall, the AQUDSC/MUDSC is expected to establish a universal standard severity classification system that promotes mutual understanding among different countries’ emergency management systems, eliminates inconsistencies, and provides a common language for describing the impact of disasters worldwide.

Ethical approval and informed Consents

Informed consent was obtained from all participants before data collection. Consents were granted only for the inclusion of group information in any presentation or publication of results. Please note that the dataset was collected following the Tri-Council Policy Statement: Ethical Conduct for Research Involving Humans 2010 (TCPS 2) and the University of Calgary Guidelines. Ethics approval was granted under certificate ID REB15-0031 and modification ID REB15-0031_MODI for additional questions added to the questionnaire using Covid-19 as a case study.

Limitations and future extensions

This ongoing research project aims to develop an advanced multidimensional Universal Disaster Severity Classification System (UDSCS) to comprehensively assess the disaster continuum both qualitatively and quantitatively 61 . The paper introduces an AQUDSC/MUDSC for global comparison of various natural disasters’ impacts. Initially focusing on fatalities alone, MUDSC’s limitation prompted the need for a multidimensional quantitative scale incorporating influential factors like fatalities and damage costs using a disutility function 30 .

The analysis explores the disparity between perceived severity and actual impact, demonstrating the dynamics of community communication. However, the non-random and restricted sample, especially in linguistically diverse regions, may result in deviations in severity perception. Covid-19 serves as an illustrative case study due to its global impact and evolving severity, although perceptions of epidemics and pandemics differ from other disasters. Consequently, there might be disparities in the perception of event severity.

The provided definitions and criteria in AQUDSC offer guidance for adapting the classification to different languages, aiming for equivalence in meaning rather than exact word translations. Future language adaptations may involve proposing suitable terminologies by bilingual experts, followed by surveys to select the most appropriate terms. However, this adaptation process falls beyond the current research scope and remains a potential avenue for future studies.

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The authors would like to thank Professor Emeritus R. B. Bond for his guidance, input, and comments on the disaster terminology section of this paper. The authors also thank all the respondents of the survey and those who assisted in distributing it worldwide. This research was funded in part by the Natural Sciences and Engineering Research Council of Canada, Alberta Innovates—Technology Futures, Alberta Motor Association, the University of Calgary, the Catastrophe Indices and Quantification Incorporated, the Canadian Risk Hazard Network, and the Ministry of Culture and Status of Women, Government of Alberta.

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HJC designed, developed, and conducted the survey, processed and analysed the data, interpreted the results, and wrote the manuscript. SCW supervised the project, reviewed the results and the manuscript, and granted approval for publication. Both authors collaborated in distributing the survey, discussing the results, and enhancing the manuscript.

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