Individuals’ perceptions of areas exposed to coastal flooding in four French coastal municipalities: the contribution of sketch mapping

Abstract

Background: This study analyzes individuals’ perceptions of areas exposed to coastal flooding at a local level using sketch mapping methodology. In this way, 318 individuals were surveyed in four coastal municipalities in France (Barneville-Carteret, Saintes-Maries-de-la-mer, Châtelaillon-Plage and Sainte-Anne). We assessed the disagreement between expert estimates and individuals’ perceptions of areas exposed to coastal flooding using sketch mapping indicators. We also determined the relationships between individuals’ living environments and the way they perceived the spatial extent of coastal flooding. Results: Respondents were likely to under-assess the exposure of areas that are actually exposed according to expert hazard maps. Perceived distance to coastal flooding areas appeared to be a predominant factor in assessing individuals’ perceptions. Conclusions: Local preventive actions could take into account the individuals’ tendency to under-estimate the areas exposed to coastal flooding. Individual perception of the spatial extent of coastal flooding appeared to be more influenced by the perceived distance of the home to exposed areas than the objective distance. It is a result that raises the question about the individuals’ understanding of hazard maps and regulatory maps. This may necessitate the improvement of the appropriation of these documents by the inhabitants by involving them more closely in the application and decision process that directly concerns.