Investigating ways to better communicate flood risk: the tight coupling of perceived flood map usability and accuracy

Abstract

ABSTRACT Flooding is increasing worldwide, and many current maps and models available to help people understand their risk are not designed with risk communication best practices in mind. This study is one of the first to combine comparative U.S. flood modelling approaches with measures of perceived flood map usability and accuracy to begin to understand how maps may be used to communicate flood risk. Using a survey of residents in Texas, U.S. counties affected by a 2017 flood event (N = 404), this study captures their perceptions of two different types of flood maps and three different map legends. Findings suggest that even when including demographic, geographic, and prior experience factors – all shown to be important predictors for flood studies – the only significant relationships were between perceived map usability and perceived map accuracy. When comparing the three map legends, presenting flood hazard index areas using general risk language was rated as most useful, and there were minimal differences between people who had prior flood damage and those who lived in an identified flood hazard area. Discussions explain this tight linkage between perceived usability and perceived accuracy and offer suggestions for how to better communicate flood risk in the face of change.