2018年7月豪雨災害における広島県での土石流による被害地域と土砂災害警戒区域の空間分析

抄録

This study analyzed spatial data of the affected areas by the debris flows in the heavy rain disaster of July 2018 and sediment disaster warning zones in Hiroshima prefecture. We revealed that almost 50% of the buildings in the affected areas are located still outside of the latest sediment disaster warning zones. Overflow and wide spreading of the debris from rivers were observed in the areas underestimated by the warning zones. Debris flow propagation analysis is performed to simulate the debris flow inundation areas based on the Flow-R and digital elevation model. We found that the analysis based smaller travel angle are required in order to reproduce the wide spreading of the debris in the downstream of rivers.