タンクモデルにより求まるタンクからの 流出量が流域からの表層崩壊・土石流に伴う土砂移動量に及ぼす影響

抄録

In the 2014 Hiroshima disaster, there were differences in the collapse density and sediment discharge volume between granite and mudstone areas. In this study, we clarify the cause of these differences from hydrological observations and calculations using the tank model.

First, we observed water discharge and made hydrological observations at slopes in the granite and mudstone areas. We examined the differences in the hydrological properties. Then, based on the observed results, we fitted the parameters to the tank model. Finally, we simulated the conditions of the 2014 Hiroshima disaster and examined the cause of the differences.

We found that water discharge along the slope in the mudstone area was greater than that in the granite area. This was thought to cause the increased sediment discharge volume in the mudstone area.