A Method for Predicting and Taking Measures Against Soil Slips Generating Debris Flows in a Case Study of the 2014 Hiroshima Sediment Disasters

Yoshiharu ISHIKAWA, Hiroyuki UMEZAWA, Risa TANABE, Aya TAMEIKE and Quoc Dung DANG

The previous studies indicated that most of debris flows were generated by the soil slips in zero-order channels. If the places of soil slips were predicted accurately before occurrence of them, we could conduct more effective countermeasures against soil slips than usual countermeasures such as check dams for capture the large amount of debris for preventing disasters. The purpose of this study is to propose a method of predicting the places of soil slips and propose the way for preventing occurrence of soil slips or trapping the small amount of debris in the upper reaches of streams. The places of soil slips were examined in case study of the 2014 Hiroshima sediment disasters. The results indicated that about half of soil slips occurred in the zero-order channels and most of soil slips generated debris flows. We proposed that effective measures against the soil slips in zero-order channels to prevent debris flow disasters.

2018/1 139-144