斜面崩壊による古災害を記録したディザスターマップの作成 : 平成30年7月豪雨の広島県南部を対象に

A massive disaster, including a large number of slope movements and the flooding of large rivers, was triggered by record-breaking torrential rain in July 2018 over a broad area of western Japan. Severe damage in the southern part of Hiroshima prefecture was mainly caused by the debris flow, with a total of 108 people reported killed or missing. The geographer group for “the Hiroshima University Disaster Investigation Team for July Torrential Rain of 2018” recorded the distribution of slope movements as geographical data and prepared detailed maps on the geographic information system (GIS) since just after its initiation. The authors also created “disaster maps” with photographs of locations of slope movements, broken artificial features, and floods taken in the field were depicted in Higashihiroshima City, where the largest number of slope movements occurred in Hiroshima prefecture. In this paper, we described the process of making these maps and their contents, and the possibility of utilizing them for disaster prevention education. We also proposed referring to all past disasters as “paleo-disaster” to progress the research that reveals the distribution and history of past disasters.