Jon, Ihnji; Huang, Shih-kai; Lindell, Michael K. (2018). Perceptions and Reactions to Tornado Warning Polygons: Would a Gradient Polygon Be Useful? International Journal Of Disaster Risk Reduction, 30, 132 – 144.
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Abstract
To better understand people's interpretations of National Weather Service's tornado warning polygons, 145 participants were shown 22 hypothetical scenarios in one of four displays-deterministic polygon, deterministic polygon + radar image, gradient polygon, and gradient polygon + radar image. Participants judged each polygon's numerical strike probability (p(s)) and reported the likelihood of taking seven different response actions. The deterministic polygon display produced p(s) that were highest at the polygon's centroid and declined in all directions from there. The deterministic polygon + radar display, the gradient polygon display, and the gradient polygon + radar display produced p(s) that were high at the polygon's centroid and also at its edge nearest the tornadic storm cell. Overall, p(s) values were negatively related to resuming normal activities, but positively correlated with expectations of resuming normal activities, seeking information from social sources, seeking shelter, and evacuating by car. These results replicate the finding that participants make more appropriate p(s) judgments when polygons are presented in their natural context of radar images than when the polygons are presented in isolation and that gradient displays appear to provide no appreciable benefit. The fact that p(s) judgments had moderately positive correlations with both sheltering (a generally appropriate response) and evacuation (a generally inappropriate response) provides experimental confirmation that people threatened by actual tornadoes are conflicted about which protective action to take.
Keywords
Protective Action; Uncertainty; Risk; Psychology; Casualties; Tornado Warning Polygons; Risk Perceptions; Protective Actions
Jon, Ihnji; Huang, Shih-Kai; Lindell, Michael K. (2019). Perceptions and Expected Immediate Reactions to Severe Storm Displays. Risk Analysis, 39(1), 274 – 290.
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Abstract
The National Weather Service has adopted warning polygons that more specifically indicate the risk area than its previous county-wide warnings. However, these polygons are not defined in terms of numerical strike probabilities (p(s)). To better understand people's interpretations of warning polygons, 167 participants were shown 23 hypothetical scenarios in one of three information conditions-polygon-only (Condition A), polygon + tornadic storm cell (Condition B), and polygon + tornadic storm cell + flanking nontornadic storm cells (Condition C). Participants judged each polygon's p(s) and reported the likelihood of taking nine different response actions. The polygon-only condition replicated the results of previous studies; p(s) was highest at the polygon's centroid and declined in all directions from there. The two conditions displaying storm cells differed from the polygon-only condition only in having p(s) just as high at the polygon's edge nearest the storm cell as at its centroid. Overall, p(s) values were positively correlated with expectations of continuing normal activities, seeking information from social sources, seeking shelter, and evacuating by car. These results indicate that participants make more appropriate p(s) judgments when polygons are presented in their natural context of radar displays than when they are presented in isolation. However, the fact that p(s) judgments had moderately positive correlations with both sheltering (a generally appropriate response) and evacuation (a generally inappropriate response) suggests that experiment participants experience the same ambivalence about these two protective actions as people threatened by actual tornadoes.
Keywords
Decision-making; Tornado; Risk; Communication; Numeracy; Residents; Shelter; Events; Protective Actions; Risk Perceptions; Tornado Warning Polygons; Judgments; Tornadoes; Meteorological Services; Storms; Lymphocytes B; Polygons; Emergency Warning Programs; Evacuation; Displays; Inappropriateness; Weather; Warnings; Conditions; Ambivalence
Lindell, Michael K.; Arlikatti, Sudha; Huang, Shih-kai. (2019). Immediate Behavioral Response to the June 17, 2013 Flash Floods in Uttarakhand, North India. International Journal Of Disaster Risk Reduction, 34, 129 – 146.
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Abstract
The 2013 Uttarakhand flash flood was such a surprise for those at risk that the predominant source of information for their risk was environmental cues and, secondarily, peer warnings rather than official warnings. Of those who received warnings, few received information other than the identity of the flood threat. A survey of 316 survivors found that most people's first response was to immediately evacuate but some stayed to receive additional information, confirm their warnings, or engage in evacuation preparations. Unfortunately, engaging in these milling behaviors necessarily delayed their final evacuations. Mediation analysis revealed that psychological reactions mediated the relationship between information sources and behavioral responses. Further analyses revealed that immediate evacuation and evacuation delay were both predicted best by information search and positive affect, but correlation analyses indicated that a number of other models were also plausible. Final evacuation was best predicted by immediate evacuation and, to a significantly lesser extent, household together. Overall, results suggest that the Protective Action Decision Model (PADM) should be considered a useful framework for examining household responses to flash floods in developing countries like India. It supports the conclusion that a household's first warning source is a function of two distinct detection and dissemination systems within a community-an official system and an informal system. However, it fails to capture what pre-impact emergency preparedness entails for rapid onset events in a developing country context. Further research is needed to determine the relative importance of situational and cultural characteristics in producing these observed differences.
Keywords
Risk Perception; Mental Models; Warnings; Evacuation; Disaster; Tsunami; Communication; Earthquake; Beliefs; Hazard; Flash Flood; Warning; Psychological Reactions; India
Lindell, Michael K.; House, Donald H.; Gestring, Jordan; Wu, Hao-Che. (2019). A Tutorial on Dynasearch: A Web-Based System for Collecting Process-Tracing Data in Dynamic Decision Tasks. Behavior Research Methods, 51(6), 2646 – 2660.
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Abstract
This tutorial describes DynaSearch, a Web-based system that supports process-tracing experiments on coupled-system dynamic decision-making tasks. A major need in these tasks is to examine the process by which decision makers search over a succession of situation reports for the information they need in order to make response decisions. DynaSearch provides researchers with the ability to construct and administer Web-based experiments containing both between- and within-subjects factors. Information search pages record participants' acquisition of verbal, numeric, and graphic information. Questionnaire pages query participants' recall of information, inferences from that information, and decisions about appropriate response actions. Experimenters can access this information in an online viewer to verify satisfactory task completion and can download the data in comma-separated text files that can be imported into statistical analysis packages.
Keywords
Downloading; Text Files; Tasks; Access To Information; Statistics; Dynamic Decision Making; Process Tracing; Web-based Experiments; Information Search; Human-behavior; Eye-tracking; Choice; Expectations; Strategies; Mousetrap; Software; Time
Doyle, Emma E. H.; McClure, John; Potter, Sally H.; Lindell, Michael K.; Becker, Julia S.; Fraser, Stuart A.; Johnston, David M. (2020). Interpretations of Aftershock Advice and Probabilities After the 2013 Cook Strait Earthquakes, Aotearoa New Zealand. International Journal Of Disaster Risk Reduction, 49.
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Abstract
Probabilistic statements can be a valuable tool for natural hazard risk communication, including forecasts. However, individuals often have a poor understanding of such probabilistic forecasts caused by them distorting their interpretations of event likelihoods towards the end of the time window and discounting the risk today. We investigated the use of an 'anchoring' time statement to mitigate this bias via an opportunistic survey run after the 2013 Cook Strait earthquakes, near Wellington, New Zealand. Participants rated their interpretations of likelihoods for an immediate aftershock forecast, and for an earthquake in the future. We explored the influence of aftershock and information concern, emotions and felt shaking, gender and education, as well as preparedness actions. The anchoring time window statement mitigated the skew in interpretations for the short (24 h to within 1 week) aftershock forecast statement. However, the skew still existed for the longer future earthquake forecast (7 days to within 1 year). We also found that heightened sensory experience (felt shaking) or emotional reactions (nervousness, fear, alertness) during the earthquakes was associated with an increase in the perceived likelihoods of future events. Gender was found to significantly influence results, with females rating higher levels of information concern and anxiety, and recording higher perceived likelihoods for the immediate aftershock forecast. Findings, including the importance of 'anchoring' time windows within a forecast to encourage immediate preparedness actions, support recommendations for effective crafting of these forecasts and warnings.
Keywords
False Discovery Rate; Risk Perceptions; Natural Hazards; Communication; Uncertainty; Model; Preparedness; Information; Experiences; Intentions; Likelihood; Probabilities; Forecasts; Earthquakes; Emotions; Concern; Gender; Actions
Lindell, Michael K.; Mumpower, Jeryl L.; Huang, Shih-kai; Wu, Hao-che; Samuelson, Charles D. (2015). Exposure Path Perceptions and Protective Actions in Biological Water Contamination Emergencies. Environmental Health Insights, 9, 13 – 21.
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Abstract
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.
Keywords
Water Contamination; Exposure Paths; Risk Perception; Protective Action
Hua, Chunlin; Huang, Shih-Kai; Lindell, Michael K.; Yu, Chin-Hsien. (2020). Rural Households’ Perceptions and Behavior Expectations in Response to Seismic Hazard in Sichuan, China. Safety Science, 125.
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Abstract
This study analyzed data from 663 rural households in the city of Jiangyou, Sichuan, China to examine the correlations of expectations of taking nine indoor seismic hazard response actions to a hypothetical earthquake with preparedness efforts, risk perceptions, and information reliance. The results indicate that respondents expect to rely on TV and local authorities as their principal sources of earthquake information. Respondents have greater expectations of infrastructure disruptions than property damage and casualties. In addition, they have greater expectations of taking some alternative actions, such as running outside of the building and helping others, than recommended in-place protective actions such as drop, cover, and hold. However, some erroneous actions, such as protecting property and ignoring the threat, are the least likely. Furthermore, regression analyses indicated that risk perceptions, together with some demographic characteristics and earthquake experience, are significant predictors of recommended in-place protective actions and helping others, whereas evacuation is related to higher risk perceptions. Unsurprisingly, respondents having previous seismic damage experience tend to be concerned about property protection and, similarly, those having fewer years of education are more likely to ignore the threat. This study also found that residents expect to rely on different channels to receive information before and after an earthquake. Nonetheless, respondents expect to engage in similar patterns of behavior during and after an earthquake. The results of this study indicate a need for greater dissemination of earthquake information in such rural areas to increase residents' risk perceptions and, in turn, understanding of appropriate emergency responses.
Keywords
Seismic Response; Risk Perception; Households; Sensory Perception; Property Damage; Sichuan Sheng (china); Information Reliance; Protective Actions; Risk Perceptions; Seismic Hazard; Climate-change; Hurricane Evacuation; Earthquake; Preparedness; Adjustment; Education; Injuries; Communication; Intentions
Ge, Yue ‘gurt’; Lindell, Michael K. (2016). County Planners’ Perceptions of Land-Use Planning Tools for Environmental Hazard Mitigation: A Survey in the US Pacific States. Environment And Planning B-planning & Design, 43(4), 716 – 736.
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Abstract
Land-use planning tools have been extensively applied in the U.S. to achieve environmental sustainability and disaster resiliency for local communities. An important issue related to land-use planning tools is planners' beliefs about the ways in which these tools differ from each other and, thus, how planners choose among these tools for environmental hazard mitigation. A web-based survey collected data from planners in counties (or boroughs) in the five U.S. Pacific states (where county land-use planning is limited to unincorporated areas). The results indicate that planners substantially, but not completely, agreed in their perceptions of planning tools, that planners' perceptions of planning tools are minimally related to their personal characteristics and those of their jurisdictions, and that planners' perceptions of planning tools are significantly correlated with the capacity of their planning agencies. Planners viewed effectiveness (a desirable attribute) as positively correlated with economic costs and other impediments (which are undesirable attributes) so they must make trade-offs among these attributes and choose the most appropriate tool when formulating a growth management strategy.
Keywords
Interrater Reliability; Local Commitment; Management; Agreement; Index; Planners' Perceptions; Plan-making Processes; Land-use Planning Tools; Environmental Hazard Mitigation; Us Pacific States
Lindell, Michael K.; Sorensen, John H.; Baker, Earl J.; Lehman, William P. (2020). Community Response to Hurricane Threat: Estimates of Household Evacuation Preparation Time Distributions. Transportation Research Part D-transport And Environment, 85.
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Abstract
Household evacuation preparation time distributions are essential when computing evacuation time estimates (ETEs) for hurricanes with late intensification or late changing tracks. Although evacuation preparation times have been assessed by expected task completion times, actual task completion times, and departure delays, it is unknown if these methods produce similar results. Consequently, this study compares data from one survey assessing expected task completion times, three surveys assessing actual task completion times, and three surveys assessing departure delays after receiving a warning. In addition, this study seeks to identify variables that predict household evacuation preparation times. These analyses show that the three methods of assessing evacuation preparation times produce results that are somewhat different, but the differences have plausible explanations. Household evacuation preparation times are poorly predicted by demographic variables, but are better predicted by variables that predict evacuation decisions-perceived storm characteristics, expected personal impacts, and evacuation facilitators.
Keywords
Travel Demand Model; Decision-making; Communication; Prediction; Simulation; Hurricane Evacuation Models; Preparation Time Distributions; Mobilization Time Distributions; Departure Delay Time Distributions; Social Milling
Michael K. Lindell has conducted research on emergency preparedness and response for a wide range of natural and technological hazards over the past 40 years. He has conducted research or provided technical services to 40 different organizations in the public and private sectors. He has provided technical assistance on radiological emergency preparedness for the International Atomic Energy Agency, the US Nuclear Regulatory Commission, the Department of Energy, and nuclear utilities and also worked on hazardous materials emergency preparedness with State Emergency Response Commissions, Local Emergency Planning Committees, and chemical companies. He has served eight times as a consultant to National Research Council committees examining environmental hazards, and has been a member of three National Research Council committees—Disasters Research in Social Sciences, Assessing Vulnerabilities Related to the Nation’s Chemical Infrastructure, and Inherently Safer Chemical Processes: The Use of Methyl Isocyanate (MIC) at Bayer CropScience. In addition, he has reviewed research proposals for 20 different foreign, federal, and state agencies as well as performed manuscript reviews for over 75 different journals in the social and environmental sciences and engineering. He has written extensively on emergency management and is the author of 80 technical reports, 125 journal articles and book chapters, and nine books.