Investigation of debris flow and damaged areas of 2014 Hiroshima landslide disaster

Abstract

On 20th August, 2014, a series of slope failures and debris flows were occurred around city of Hiroshima , Japan due to the torrential rainfall. Debris flows took place at 107 valleys and slope failures occurred at almost 59 locations between 3 am to 4 am. This calamitous event costs 74 lives and left 44 injured. This report consists of the investigation results and considerations of the debris flows and slopes failures in the affected areas. The investigated damages were compared with the damages predicted in the field survey which was carried out to designate the restricted area and the special restricted area due sediment-related disaster. It was found that the volumes of debris flows and the damages were much larger than those predicted in the survey, and the problems of the field survey and the designation system were discussed.