Michael K. Lindell

Immediate behavioural responses to earthquakes in Christchurch, New Zealand, and Hitachi, Japan.

This study examines peoples immediate responses to earthquakes in Christchurch, New Zealand, and Hitachi, Japan. Data collected from 257 respondents in Christchurch and 332 respondents in Hitachi revealed notable similarities between the two cities in peoples emotional reactions, risk perceptions, and immediate protective actions during the events. Respondents physical, household, and social contexts were quite similar, but Hitachi residents reported somewhat higher levels of emotional reaction and risk perception than did Christchurch residents. Contrary to the recommendations of emergency officials, the most frequent response of residents in both cities was to freeze. Christchurch residents were more likely than Hitachi residents to drop to the ground and take cover, whereas Hitachi residents were more likely than Christchurch residents to evacuate immediately the building in which they were situated. There were relatively small correlations between immediate behavioural responses and demographic characteristics, earthquake experience, and physical, social, or household context.

Effects of track and threat information on judgments of hurricane strike probability

Although evacuation is one of the best strategies for protecting citizens from hurricane threat, the ways that local elected officials use hurricane data in deciding whether to issue hurricane evacuation orders is not well understood. To begin to address this problem, we examined the effects of hurricane track and intensity information in a laboratory setting where participants judged the probability that hypothetical hurricanes with a constant bearing (i.e., straight line forecast track) would make landfall in each of eight 45 degree sectors around the Gulf of Mexico. The results from 162 participants in a student sample showed that the judged strike probability distributions over the eight sectors within each scenario were, unsurprisingly, unimodal and centered on the sector toward which the forecast track pointed. More significantly, although strike probability judgments for the sector in the direction of the forecast track were generally higher than the corresponding judgments for the other sectors, the latter were not zero. Most significantly, there were no appreciable differences in the patterns of strike probability judgments for hurricane tracks represented by a forecast track only, an uncertainty cone only, or forecast track with an uncertainty cone-a result consistent with a recent survey of coastal residents threatened by Hurricane Charley. The study results suggest that people are able to correctly process basic information about hurricane tracks but they do make some errors. More research is needed to understand the sources of these errors and to identify better methods of displaying uncertainty about hurricane parameters.

Perceptions and expected immediate reactions to tornado warning polygons

To provide people with more specific information about tornado threats, the National Weather Service has replaced its county-wide warnings with smaller warning polygons that more specifically indicate the risk area. However, tornado warning polygons do not have a standardized definition regarding tornado strike probabilities (ps) so it is unclear how warning recipients interpret them. To better understand this issue, 155 participants responded to 15 hypothetical warning polygons. After viewing each polygon, they rated the likelihood of a tornado striking their location and the likelihood that they would take nine different response actions ranging from continuing normal activities to getting in a car and driving somewhere safer. The results showed participants inferred that the ps was highest at the polygon’s centroid, lower just inside the edges of the polygon, still lower (but not zero) just outside the edges of the polygon, and lowest in locations beyond that. Moreover, higher ps values were associated with lower expectations of continuing normal activities and higher expectations of seeking information from social sources (but not environmental cues) and higher expectations of seeking shelter (but not evacuating in their cars). These results indicate that most people make some errors in their ps judgments but are likely to respond appropriately to the ps they infer from the warning polygons. Overall, the findings from this study and other research can help meteorologists to better understand how people interpret the uncertainty associated with warning polygons and, thus, improve tornado warning systems.

Strike probability judgments and protective action recommendations in a dynamic hurricane tracking task

This experiment assessed the strike probability (ps) judgments and protective action recommendations (PARs) of students playing the roles of county emergency managers during four different hurricane scenarios. The results show that participants’ ps judgments (1) increased for target cities (projected landfall locations) and generally decreased for adjacent cities and remote cities as hurricanes approached landfall, and (2) were significantly correlated with PARs, but (3) were not consistent with the requirement that Σpsxa0<xa01.0 for a set of non-exhaustive events. Participants also (4) chose more PARs as hurricanes approached landfall, especially for the counties to which they participants were assigned, but (5) failed to choose as many PARS as appropriate, especially evacuating areas at risk of hurricane impacts. Overall, the results suggest that participants were able to utilize the available hurricane information to make reasonable ps judgments, but failed to make the appropriate inferences about the significance of those ps judgments. This suggests a need for further research on people’s interpretation of threat information, development of better training manuals on hurricane evacuation decision making, and better hurricane information displays to guide people’s responses to hurricane threats.

Process Tracing Analysis of Hurricane Information Displays

To study peoples processing of hurricane forecast advisories, we conducted a computer-based experiment that examined 11 research questions about the information seeking patterns of students assuming the role of a county emergency manager in a sequence of six hurricane forecast advisories for each of four different hurricanes. The results show that participants considered a variety of different sources of information-textual, graphic, and numeric-when tracking hurricanes. Click counts and click durations generally gave the same results but there were some significant differences. Moreover, participants information search strategies became more efficient over forecast advisories and with increased experience tracking the four hurricanes. These changes in the search patterns from the first to the fourth hurricane suggest that the presentation of abstract principles in a training manual was not sufficient for them to learn how to track hurricanes efficiently but they were able to significantly improve their search efficiency with a modest amount (roughly an hour) of practice. Overall, these data indicate that information search patterns are complex and deserve greater attention in studies of dynamic decision tasks.

Warning triggers in environmental hazards: who should be warned to do what and when?

Determining the most effective public warnings to issue during a hazardous environmental event is a complex problem. Three primary questions need to be answered: Who should take protective action? What is the best action? and When should this action be initiated? Warning triggers provide a proactive means for emergency managers to simultaneously answer these questions by recommending that a target group take a specified protective action if a preset environmental trigger condition occurs (e.g., warn a community to evacuate if a wildfire crosses a proximal ridgeline). Triggers are used to warn the public across a wide variety of environmental hazards, and an improved understanding of their nature and role promises to: (1) advance protective action theory by unifying the natural, built, and social themes in hazards research into one framework, (2) reveal important information about emergency managers risk perception, situational awareness, and threat assessment regarding threat behavior and public response, and (3) advance spatiotemporal models for representing the geography and timing of disaster warning and response (i.e., a coupled natural-built-social system). We provide an overview and research agenda designed to advance our understanding and modeling of warning triggers.

Exposure Path Perceptions and Protective Actions in Biological Water Contamination Emergencies

This study extends the Protective Action Decision Model, developed to address disaster warning responses in the context of natural hazards, to “boil water” advisories. The study examined 110 Boston residents and 203 Texas students expectations of getting sick through different exposure paths for contact with contaminated water. In addition, the study assessed respondents actual implementation (for residents) or behavioral expectations (for students) of three different protective actions – bottled water, boiled water, and personally chlorinated water – as well as their demographic characteristics and previous experience with water contamination. The results indicate that people distinguish among the exposure paths, but the differences are small (one-third to one-half of the response scale). Nonetheless, the perceived risk from the exposure paths helps to explain why people are expected to consume (or actually consumed) bottled water rather than boiled or personally chlorinated water. Overall, these results indicate that local authorities should take care to communicate the relative risks of different exposure paths and should expect that people will respond to a boil water order primarily by consuming bottled water. Thus, they should make special efforts to increase supplies of bottled water in their communities during water contamination emergencies.

Human behaviour during and immediately following earthquake shaking: developing a methodological approach for analysing video footage

To reduce earthquake casualties, it is important to understand how human behaviour, during and immediately following earthquake shaking, exposes the individual to increased risk of injury. Research on human behaviour during earthquake shaking has identified three main influences: the environment the individual is located in immediately before and during the earthquake, in terms of where the individual is and who the individual is with at the time of the earthquake; individual characteristics, such as age, gender, previous earthquake experience and earthquake attributes, including intensity and duration of earthquake shaking. However, little research has systematically analysed the immediate human responses to earthquake shaking, mostly due to data constraints and/or ethical considerations. Research on human behaviour during earthquakes has relied on simulations or post-event, reflective interviews and questionnaire studies. Such studies are subject to potential limitations such as the quality of the participant’s memory, recall bias or (perceived) realism of a simulation. Thus, to better understand the relationship between human behaviour and injury, researchers need a robust and repeatable methodology. This paper discusses the development of a systematic process and coding scheme to analyse earthquake video footage of human behaviour during strong earthquake shaking. The coding scheme was developed in a two-part process, combining a deductive and inductive approach. Previous research studies of human behavioural response during earthquake shaking provided the basis for the coding scheme. This was then iteratively refined by applying the coding scheme to a broad range of video footage of people exposed to strong shaking during the Canterbury 2010–2011 earthquake sequence.

Perceptions of protective actions for a water contamination emergency

Local authorities who believe their water systems are contaminated need to warn those at risk to take protective actions. In the past, such efforts have often achieved only partial success in preventing people from deciding to continue consumption of contaminated drinking water. To examine the possible antecedents of decisions to comply with water consumption advisories, this study examined 110 Boston residents’ actual protective actions and 203 Texas students’ expected protective actions; their perceptions of three protective actions on seven attributes; and their risk perceptions, water contamination experience, facilitating conditions, and demographic characteristics. The profiles of the protective actions for the hazard-related and resource-related attributes suggest reasons why people preferred to use bottled water rather than boil or personally chlorinate water. In particular, perceived effectiveness in protecting health was the most important correlate of protective action, which means that a protective action can have a high level of implementation even though it has poor ratings on other attributes such as cost. In addition, this study indicates public health officials may also need to address people’s misconceptions about the hazard-related and resource-related attributes of any relevant protective actions. Finally, consistent with an extensive body of previous research, students were similar to residents in many important respects even though were some statistically significant differences.

Perceptions, behavioral expectations, and implementation timing for response actions in a hurricane emergency

This study examined the perceived attributes, behavioral expectations, and expected implementation timing of 11 organizational emergency response actions for hurricane emergencies. The perceived attributes of the hurricane response actions were characterized by two hazard-related attributes (effectiveness for person protection and property protection) and five resource-related attributes (financial costs, required knowledge/skill, required equipment, required time/effort, and required cooperation). A total of 155 introductory psychology students responded to a hypothetical scenario involving an approaching Category 4 hurricane. The data collected in this study explain previous findings of untimely protective action decision making. Specifically, these data reveal distinctly different patterns for the expected implementation of preparatory actions and evacuation recommendations. Participants used the hazard-related and resource-related attributes to differentiate among the response actions and the expected timing of implementation. Moreover, participants’ behavioral expectations and expected implementation timing for the response actions were most strongly correlated with those actions’ effectiveness for person protection. Finally, participants reported evacuation implementation times that were consistent with a phased evacuation strategy in which risk areas are evacuated in order of their proximity to the coast. However, the late initiation of evacuation in risk areas closest to the coast could lead to very late evacuation of risk areas farther inland.