Examining residents' dynamic flood-related risk perceptions during Hurricane Ian 2022

In order to better understand the dynamic elements of risk during Hurricane Ian, we developed and demonstrated a novel, rapidly deployable, longitudinal panel survey methodology for collecting data from at-risk members of the public in real-time as Ian threatened. Multiple surveys were conducted that asked the same questions repeatedly of the same individuals (i.e., a longitudinal panel survey) over just a few days as Hurricane Ian evolved and approached landfall in the mainland U.S. We fielded three survey waves during the predictive phase, when Ian was threatening and approaching landfall in Florida, and one post-storm wave. A total of n=945 people responded to all four survey waves.

According to a recent study conducted by the National Hurricane Center, approximately 57% of direct fatalities from landfalling tropical cyclones in the United States from 2013-2022 were caused by freshwater flooding (https://blog.ametsoc.org/2023/08/08/recent-trends-in-tropical-cyclone-fatalities-in-the-united-states/). Although Ian was predominantly known for the significant storm surge hazard and associated fatalities in southwest Florida, the hurricane also caused tremendous heavy rainfall which led to inland, freshwater flooding. Rainfall totals from 10-20” occurred in central and eastern Florida, north of Ian’s track, with the highest rainfall total at nearly 27”. Many other areas received 5” or more. Thus, Ian offered an interesting case to assess the dynamics of the inland rainfall flooding hazard and impacts.

The predictive survey waves included questions to measure respondents’ perceptions of flood hazards and related impacts. For instance, questions measured respondents’ perceived exposure to and severity of flooding due to heavy rain and perceived susceptibility of impacts such as road closures due to debris or flooding. Additionally, the survey measured multiple behavioral responses–such as evacuation, moving indoor furniture or other valuables to a safer location, and getting emergency supplies–all of which can be analyzed in conjunction with respondents’ flood-related risk perceptions. Moreover, we have already curated and integrated with our survey dataset some NWS flood forecast products that were in effect at the time we fielded the different survey waves, including WPC’s Excessive Rainfall Outlook and quantitative precipitation forecasts (QPFs) and WFO flood and flash flood watches, warnings, and advisories. In this talk, we will present preliminary findings about how survey respondents perceived risk of freshwater flooding and the behavioral responses they engaged in during Hurricane Ian, and how these responses evolved over time in the days leading up to landfall. We will also discuss our initial efforts to integrate our survey data with other datasets (e.g., forecast and warning products, power outage data) in order to enrich understanding of people’s dynamic, flood-related risk perceptions, responses, and other impacts.