木曽川大規模深掘れにおける粘性土層の破壊・剥離現象と深掘れ拡大要因の推定

抄録

Riverbed degradation and subsequent exposure of the clay layer have occurred in the Kiso River, which has the local scouring with 20 m in maximum water depth. To identify the progression mechanism and the causes of local scouring expanding, we investigated the riverbed morphology and flow field in case of flood by using the narrow multi-beam sonar and ADCP.

Two kinds of acoustic survey of the riverbed clarifies that the scouring area has moved upstream and developed in the direction of the left bank from 2012 and 2016. As the result of survey and numerical simulation, it is estimated that the scouring area expands when the clay clod peels from the riverbed surface.