Chen, Chen; Koll, Charles; Wang, Haizhong; Lindell, Michael K . 2023. “An Interdisciplinary Agent-Based Evacuation Model: Integrating the Natural Environment, Built Environment, and Social System for Community Preparedness and Resilience.” Natural Hazards and Earth System Sciences 23 (2).
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Abstract
Previous tsunami evacuation simulations have mostly been based on arbitrary assumptions or inputs adapted from non-emergency situations, but a few studies have used empirical behavior data. This study bridges this gap by integrating empirical decision data from surveys on local evacuation expectations and evacuation drills into an agent-based model of evacuation behavior for two Cascadia subduction zone (CSZ) communities that would be inundated within 20–40 min after a CSZ earthquake. The model also considers the impacts of liquefaction and landslides from the earthquake on tsunami evacuation. Furthermore, we integrate the slope-speed component from least-cost distance to build the simulation model that better represents the complex nature of evacuations. The simulation results indicate that milling time and the evacuation participation rate have significant nonlinear impacts on tsunami mortality estimates. When people walk faster than 1 m s -1 , evacuation by foot is more effective because it avoids traffic congestion when driving. We also find that evacuation results are more sensitive to walking speed, milling time, evacuation participation, and choosing the closest safe location than to other behavioral variables. Minimum tsunami mortality results from maximizing the evacuation participation rate, minimizing milling time, and choosing the closest safe destination outside of the inundation zone. This study's comparison of the agent-based model and the beat-the-wave (BtW) model finds consistency between the two models' results. By integrating the natural system, built environment, and social system, this interdisciplinary model incorporates substantial aspects of the real world into the multi-hazard agent-based platform. This model provides a unique opportunity for local authorities to prioritize their resources for hazard education, community disaster preparedness, and resilience plans. [ABSTRACT FROM AUTHOR]
Lindell, Michael K., Meen Chel Jung, Carla S. Prater, and Donald H. House. 2023. “US Pacific Coast Communities’ Past Preparedness and Preparedness Intentions for Cascadia Subduction Zone Tsunamis.” International Journal of Disaster Risk Reduction 84.
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Abstract
This study examined tsunami awareness and preparedness by 225 respondents in three communities exposed to Cascadia Subduction Zone (CSZ) tsunamis. Some participants viewed a tsunami brochure, but all participants reported their degree of information sufficiency about tsunamis and protective actions to take when a tsunami threatens, expected warning sources for local and distant tsunamis, past preparedness actions and preparedness intentions, tsunami experience, past tsunami information, perceived tsunami zone, and demographic characteristics. In addition to the results showing that the brochure had a significant positive effect on tsunami information sufficiency and expected warning sources, the latter two variables affected intentions to engage in future preparedness actions. In addition, tsunami experience, past tsunami infor-mation, and past preparedness also affected these variables. Although psychological responses were significantly related to preparedness intentions, they were not related to hypothesized antecedent variables-tsunami experience, past preparedness, past information, and de-mographic characteristics. The data suggest that emergency managers can promote tsunami hazard education by distributing comprehensive tsunami brochures, but should also work with local news media to direct CSZ residents to agency web sites where they can access additional information about tsunami hazard, expected warning sources, appropriate preparedness, and response actions.
Keywords
Cascadia subduction zone tsunamis; Risk communication; Tsunami hazard awareness; Tsunami preparedness
Lindell, Michael K; Jung, Meen Chel; Prater, Carla S; House, Donald H (2023). Evaluation of Hazard Brochures Using Topic Viewing Durations: Application to Tsunami Evacuation Brochures. Risk Analysis.
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Abstract
This study describes a novel method of assessing risk communication effectiveness by reporting an evaluation of a tsunami information brochure by 90 residents of three Pacific coast communities that are vulnerable to a Cascadia Subduction Zone earthquake and tsunami—Commencement Bay, Washington; Lincoln City, Oregon; and Eureka, California. Study participants viewed information that was presented in DynaSearch, an internet‐based computer system that allowed them to view text boxes and tsunami inundation zone maps. DynaSearch recorded the number of times each text box or map was clicked and the length of time that it was viewed. This information viewing phase was followed by questionnaire pages assessing important aspects of tsunami hazard and sources of tsunami warnings. Participants gave the longest click durations to what to do in the emergency period during earthquake shaking and in its immediate aftermath before a tsunami arrives—topics that should be displayed prominently in tsunami brochures and emphasized in talks to community groups. The smallest adjusted click durations were associated with advance preparations for a tsunami—topics that can be posted on websites whose URLs are printed in the brochures.
Keywords
DynaSearch; hazard awareness brochure; Protective Action Decision Model
In the United States, flooding is a leading cause of natural disasters, with congressional budget office estimates of $54 billion in loss each year. Although both urban and rural areas are highly vulnerable to flood hazards, most natural disaster resilience studies have focused primarily on urban areas, overlooking rural communities. One such area that has been overlooked are the numerous rural communities bordering the Great Lakes. These communities face unprecedented challenges due to rising water levels, particularly since 2012, which have resulted in increased coastal flood hazard. Despite their flooding risk, they continue to lack flood hazard assessments and inundation maps, exacerbating their vulnerability. The Federal Emergency Management Agency (FEMA) commonly recommend counties to use a freely available tool—called HAZUS to develop hazard mitigation plans and enhance community resilience and adaptation. However, the usage of HAZUS for rural communities is challenging due to existing data gaps that limit the analytical potential of HAZUS in these communities. Continued use of standard datasets for HAZUS analysis by rural counties could likely leave the communities underprepared for future flood events. The proposed project’s vision is to develop methods that use remote sensing data resources and citizen engagement (crowdsourcing) to address current data gaps for improved flood hazard modeling and visualization that is scalable and transferable to rural communities.
The results of the project will expand the traditional frontiers of preparedness and resilience to natural disasters by drawing on the expertise and backgrounds of investigators working at the interface of geological engineering, civil engineering, computer science, marine engineering, urban planning, social science, and remote sensing. Specifically, the proposed research will promote intellectual discovery by i) improving our understanding of remote sensing data sources and open-source processing methods to assist rural communities in addressing the data gaps in flood hazard modeling, ii) developing sustainable geospatial visualization tools for communicating hazards to communities, iii) advancing our understanding of the utility of combining remote sensing and crowdsourcing to flood hazard delineation, iv) understanding ways to incentives the crowd for greater participation and accuracy in hazard in addressing natural disasters, and v) identifying critical community resilience indicators through crowdsourcing. These advancements will lead to prepared and resilient rural communities that can effectively mitigate hazards related to lake level rise and flooding.
While community lifeline service providers and local emergency managers must maintain coordinated response and recovery plans, their timelines may not match expectations of local consumers of lifeline services. Indeed, it is quite likely consumers have unrealistic expectations about lifeline restoration, which could explain current inadequate levels of disaster preparedness. This hypothesized expectation gap has received little attention because engineering research typically addresses providers’ capacities, whereas disaster research addresses household and business preparedness. Our project will address this neglected issue by assessing consumers’ (households, business owners/managers, nonprofit managers) expectations about lifeline system performance, and comparing them to lifeline provider capacity in a post-hazard event scenario (following a Cascadia subduction zone earthquake of 9.0 magnitude or greater) in two communities—Kirkland and Shoreline, WA (likely to experience most shaking in this scenario).
Our research will assess the role of the expectations gap in influencing consumers’ and providers’ preparedness as well as response. First, we estimate the gap between consumers and providers expectations using an earthquake scenario in two case study communities. We posit that low consumer preparedness for lifeline disruption is in part a function of low expectations that lengthy disruption will occur. Next, we test the effect of providing consumers and providers with information about this gap. Our proposed sharing estimates of lifeline restoration times should change these beliefs if our assumption about this specific basis for low preparedness is correct and if our audiences attend to, process, and act upon this information. In our longitudinal research, consumers (households, businesses, and nonprofits) and lifeline providers will complete two questionnaires each. Besides lifeline provider surveys, we will collect information about lifeline providers’ capabilities and work with them to estimate restoration times using an expert elicitation-based estimation framework. We will address the following research questions:
- What do consumers think is the likely level of critical lifeline disruption from an earthquake and the timeline for restoration?
- What are consumers’ current levels of preparedness for lifeline interruption?
- What do lifeline providers and an independent engineering expert think are providers’ capabilities to maintain and restore lifeline services?
- How do consumers’ expectations compare with providers’ capabilities (expectations gap)?
- How will this study’s feedback about the expectations gap affect consumers’ and providers’ lifeline resilience expectations, as well as their mitigation and preparedness intentions?
Lindell, Michael K.; Jung, Meen Chel; Prater, Carla S.; House, Donald H. (2022). Improving Cascadia Subduction Zone Residents’ Tsunami Preparedness: Quasi-experimental Evaluation of an Evacuation Brochure. Natural Hazards, 114(1), 849-881.
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Abstract
This study surveyed 227 residents in three US Pacific Coast communities that are vulnerable to a Cascadia subduction zone tsunami. In the Brochure condition, information was presented online, followed by questions about tsunamis. Respondents in the Comparison condition received the same questionnaire by mail but did not view the brochure. Respondents in the Brochure condition had higher levels of perceived information sufficiency than those in the Comparison condition about three of the five tsunami topics. Both conditions had generally realistic expectations about most tsunami warning sources. However, they had unrealistically high expectations of being warned of a local tsunami by social sources, such as route alerting, that could not be implemented before first wave arrival. They also had unrealistically high expectations being warned of a distant tsunami by ground shaking from the source earthquake, whose epicenter would be too far away for them to feel. Moreover, respondents in both conditions expected higher levels of personal property damage and family casualties than is the case for most hazards, but their levels of negative affective response were not especially high. Overall, only 10% of the sample accessed the tsunami brochure even when sent repeated contacts and the brochure demonstrated modest effects for those who did access it. These results suggest that state and local officials should engage in repeated personalized efforts to increase coastal communities' tsunami emergency preparedness because distribution of tsunami brochures has only a modest effect on preparedness.
Keywords
Subduction Zones; Tsunamis; Emergency Management; Tsunami Warning Systems; Brochures; Preparedness; Communities; Cascadia Subduction Zone Tsunami; Hazard Warnings; Quasi-experiment; Risk Communication; Risk Information-seeking; Natural Warning Signs; Earthquake; Awareness; Responses; Behavior; Model; Wellington; Hazard; Threat; Earthquakes; Casualties; Subduction; Vulnerability; Emergency Preparedness; Emergency Warning Programs; Levels; Seismic Activity; Property Damage; Shaking; Earthquake Damage; Subduction (geology); Disaster Management; Cascadia
Brody, Samuel D.; Highfield, Wesley E.; Wilson, Morgan; Lindell, Michael K.; Blessing, Russell. (2017). Understanding the Motivations of Coastal Residents to Voluntarily Purchase Federal Flood Insurance. Journal Of Risk Research, 20(6), 760 – 775.
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Abstract
Federally-backed flood insurance is the primary mechanism by which residents in the United States (US) prepare for and recover from floods. While there is a growing literature on the general uptake of flood insurance, little work has been done to address the factors motivating residents to voluntarily buy and maintain federally-based insurance policies. We address this issue by conducting a survey of coastal residents in four localities in Texas and Florida. Based on survey responses, we quantitatively examine the factors influencing whether residents located outside of the 100-year floodplain obtain insurance policies when it is not required. Using two-sample t-tests and binary logistic regression analysis to control for multiple contextual and psychological variables, we statistically isolate the factors contributing most to the decision to purchase insurance. Our findings indicate that a resident located outside the 100-year floodplain who has voluntarily purchased federal flood insurance can be characterized, on average, as more highly educated, living in relatively expensive homes, and a long-time resident who thinks about flood hazard relatively infrequently but who, nonetheless, thinks flood insurance is relatively affordable. Unexpectedly, the physical proximity of a respondent to flood hazard areas makes little or no discernible difference in the decision to obtain flood insurance.
Keywords
Action Decision-model; Hazard Adjustments; Risk; Perceptions; Adoption; Florida; Losses; Determinants; Preferences; Responses; Insurance; Floodplain; Purchase Decision; Texas
Chen, Chen; Wang, Haizhong; Lindell, Michael K.; Jung, Meen Chel; Siam, M. R. K. (2022). Tsunami Preparedness And Resilience: Evacuation Logistics And Time Estimations. Transportation Research Part D-transport And Environment, 109.
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Abstract
Extensive research has studied the near-field tsunami threat in the Cascadia Subduction Zone (CSZ), but little research has examined the ability to evacuate the inundation zone before the first tsunami wave arrives. To address this gap, this study provides empirical evidence about people's expectations about hazard onset and evacuation logistics when a tsunami threatens. We surveyed households in five CSZ communities to assess residents' expected first wave arrival time, as well as their expectations about evacuation destinations, route choices, preparation times, travel times, and clearance times. Heatmaps are used to summarize residents' evacuation destinations and route choices, and probabilistic functions are used to model evacuation distances and time estimates. The results suggest that respondents have similar patterns of time estimates, but a few plan to evacuate within the inundation zone, and some plan to evacuate on routes that were congested in a previous event and end their evacuations at destinations within the inundation zone.
Keywords
Disaster; Tsunami Evacuation; Time Estimate; Cascadia Subduction Zone; Behavior; Decision-making; American-samoa; Earthquake; Oregon; Washington; Wellington; Responses; Hazard; Model
Cova, Thomas J.; Dennison, Philip E.; Li, Dapeng; Drews, Frank A.; Siebeneck, Laura K.; Lindell, Michael K. (2017). Warning Triggers in Environmental Hazards: Who Should Be Warned to Do What and When? Risk Analysis, 37(4), 601 – 611.
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Abstract
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.
Keywords
Situation Awareness; Evacuation; Model; Management; Simulation; Decisions; Vehicles; Support; Systems; Hazards; Protective Actions; Warning Systems; Emergency Communications Systems; Disasters; Emergency Preparedness; Environmental Hazards; Environmental Conditions; Public Concern; Risk Perception; Emergency Management; Situational Awareness; Information Management; Geography; Emergency Warning Programs; Wildfires; Action; Risk Assessment; Timing; Warnings
Huang, Shih-kai; Wu, Hao-che; Lindell, Michael K.; Wei, Hung-lung; Samuelson, Charles D. (2017). Perceptions, Behavioral Expectations, and Implementation Timing for Response Actions in a Hurricane Emergency. Natural Hazards, 88(1), 533 – 558.
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Abstract
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.
Keywords
Action Decision-making; Interrater Agreement; Evacuation; Time; People; Preparatory Actions; Response Action Attributes; Trigger Timing; Hurricane; Psychology; Hurricanes; Costs; Emergency Response; Data; Proximity; Coastal Environments; Hazards; Decision Making; Emergencies; Emergency Preparedness; Risk; Equipment Costs; Cooperation; Protection; Equipment; Evacuations & Rescues; Behavioral Psychology; Time Measurement