FLOOD HAZARD MAP OF MEDIUM AND SMALL SIZE RIVERS ON REGIONAL TOWNS IN HOKKAIDO

Abstract

 A lot of regional towns are located in small size river basins in Hokkaido. Existing flood Hazard Map is not including the flood of these small size river. However, these regional towns have the risk of the flood from small size river occurred by a localized torrential downpour which occurs frequently in recent years. In these towns, depopulation and aging has been going on recently, so the rate of the person requiring support has been increasing. In this study, we performed a numerical flood simulation on a typical regional towns in Hokkaido, and a questionnaire survey in the flood area. The several problems were found in the existing flood Hazard Map from the results of the simulation and the quesrionnaire survey.