Social Vulnerability and Perceived Risk of Floods

In the wake of recent flood disasters, there is an increasing number of studies about the roles of either social vulnerability or human cognition in explaining risk perceptions of flood hazards. This study combined two theories – social vulnerability and protective motivation – to investigate the risk perception “paradox.” The paradox is revealed in some studies that find high risk perceptions may not always lead people to take protective actions that could reduce their potential flood risks. We conducted a social survey of 9,250 individuals in 1,752 Zip Codes in nine large US urban areas about flood risk perceptions. Survey responses were georeferenced to the National Flood Hazard Layer product and the National Land Cover Dataset at the Zip Code level to estimate potential exposure to flood hazards. Social vulnerability, potential flood hazard exposure, and past experience with floods each significantly increased flood risk perceptions, while self-appraisals of high coping capacity significantly lowered flood risk perception. Socially vulnerable groups had lower levels of confidence in their own ability and in government institutions to protect them from floods. We examined social vulnerability characteristics as potential effect modifiers of exposure, experience, and self-appraisal on flood risk perception. We argue that resource constraints for socially vulnerable groups may restrict their choices and prevent them from taking protective actions, thus producing a risk perception “paradox.” Individual hardship, social disruption, and property damage that follow major flood events call for flood risk managers to devise better institutional adaptation strategies combined with social and economic support for vulnerable populations.