Predicting Responses to Flash Flooding : A Case Study of Boulder, Colorado

Abstract

Flash floods are among the deadliest weather phenomena in the world. Unfortunately, people continue to move to risky areas, resulting in high losses due to flash floods. Because of the short lead times associated with these events, it is important that those in danger understand their risk in order to respond quickly and appropriately to watches and warnings. There are, however, many factors involved in one's likelihood to respond. To assess these factors, a mail survey was conducted for a random sample of the general public in flash flood-prone Boulder, Colorado. Indices, including antecedent knowledge about flash floods, risk perception, and warning receptiveness in addition to past flash flood experience, location, and socio-demographic indicators, were included in the analysis. These variables predict both the likelihood to take protective action in a flash flood warning (REACT) and whether or not the respondent had already taken measures to prepare for flash flooding (PREPARE). Older respondents, females, and respondents with more imminent risk perceptions and higher antecedent knowledge about flash floods are more likely to react in a flash flood warning. Many respondents cited that they would not respond to a flash flood warning because they feel safe from flash flooding. PREPARE is positively correlated with length of residence, real and perceived location in the floodplain, antecedent knowledge, and warning receptiveness. The most common form of preparation is planning an evacuation route. Results from this research can be used to target at-risk populations and provide information to help prepare them for flash flooding.