Perceptions on Hurricane Information and Tracking Maps

Tropical storms and hurricanes have caused extensive casualties and damage in past decades. Recent data indicate that the annual losses from hurricanes are increasing, partly because the U.S. coastal population has increased significantly in the past 20 years. Moreover, the housing values in these areas have increased as well. Thus, population and economic growth in the vulnerable coastal areas have made hurricanes a serious problem and created the potential for a catastrophic loss of life. The existing research literature lacks a sufficient scientific understanding of hurricane information searching and dynamic protective action decision making during events in which additional information becomes available over time. The hurricane evacuation decision context is well understood; the National Hurricane Center (NHC) issues hurricane forecast advisories every 6 hours until a hurricane turns into a tropical depression. Emergency managers and residents in the risk area are most likely to make decisions on their protective actions based on these hurricane forecast advisories. Therefore, this study uses the DynaSearch program to conduct a computer-based experiment that examines hurricane information search pattern by students playing the roles of county emergency managers, their understanding of hurricane strike probabilities and their choices of protective action recommendations during four different hurricane scenarios. This study simulates the approach of a hurricane by providing experiment participants a sequence of hurricane forecast advisories and examining how they search for information, change their threat perceptions and implement protective actions over time. The results show that (1) People prefer graphic information (especially the forecast track and uncertainty cone) over numeric and text information about hurricanes; (2) hurricane intensity was the parameter that was most commonly viewed and hurricane wind radius was the parameter that was least commonly viewed; (3)forecast track had a large number of clicks and long click durations, whereas uncertainty cone had fewer clicks but longer click durations; (4) participants? judgments of the extent to which they used each of the parameters were not entirely consistent with their search patterns; (5) participants found a hurricane?s current location and day-5 forecast were the most informative time periods; (6) there was no evidence that participants? personal concern (whether a hurricane will head toward to their county or not) affected their information search pattern in this study; (7) participants failed to evacuate appropriate risk areas in timely manner; and (8) participants had difficulty interpreting strike probabilities. These results suggest the problem of misinterpretation of the uncertainty cone is less severe than some might have concluded from the evidence provided by Broad et al. (2007). Moreover, the results suggest that participants were able to utilize the available information in the tables and tracking maps to make reasonable judgments about each city?s relative strike probability. However, their failure to take appropriate actions suggests a need for more comprehensive training on what actions to take in response to the hurricane information displays.