Abstract
In order to deal with natural disaster risks, residents need to understand that serious situations exceeding our ordinary estimation can occur in the event of disasters. This study focuses on a cognitive bias in which risks of disaster events beyond the scope of our presumption are relatively underestimated. It developed a new type of flood hazard map providing reflective opportunities regarding assumptions of the map. It examined the effect of the hazard map for mitigating the cognitive bias about flood disaster through an experiment targeting 605 residents living near the Hijikawa river at Ozu-city in Ehime prefecture. The result showed that people tend more to recognize the possibility of occurrence of situations exceeding their own estimation in case of flood disaster in the Hijikawa river and reduce the tendency of the cognitive bias through reading the new type of flood hazard map than through an ordinary hazard map, indicating the importance of reflective opportunities.
