A Study on the Timing for Providing Information Affecting the Evacuation Decision-making at Flooding

AbstractAlong with global warming, extreme weather event has been pointed out. In Japan, flood that exceeds the plan scale is increasing. The flood control policy in Japan of the river basin, not only do they need a structural measure, but also non structural measure that lead to evacuation by conveying the proper information.Hazard map is one of the non-structural measures and it can prompt to evacuate. In September 2015 Kanto-Tohoku heavy rain, the Kinugawa river in Joso city is flooded. Even if the anticipated flooded areas of the hazard map are almost the same as the actual flooded areas, about 4300 residents in Joso could not evacuate and isolate their home [1]. The fact is that non-structural measures can be effective if only residents properly understand and use them [2]. To minimize human suffering in flood zone, we need to reveal the actual situation of the evacuation and to improve non-structural measures.In this research, we analyzed the actual situation of evacuation at the time of flood and the effects of past flood experience on evacuation decision-making at flooding by conducting a hearing survey at the inundation assumption area of Yuragawa river running through Kyoto Fukuchiyama (the flood occurred in 2013 and 2014). Furthermore, we conducted similar hearing survey in the inundation assumption area of Kinugawa river running through Ibaraki pref. Joso. And we compared disaster awareness in Fukuchiyama and that of Joso. And we analyzed the relationship between the awareness of hazard map and evacuation behavior.From here on, in order to examine the necessary information and the best timing for evacuation, we are planning to carry out the flood analysis that takes into account the tributaries in addition to the main river