急流河川における巨石を用いた新たな河岸侵食対策の立案と検証

抄録

The Joganji River in Toyama Prefecture is one of the steepest gravel river beds in Japan. Once flooding occurs, as the energy of river flow rises, river bank scouring and erosion are comparatively greater than normal. As a result, during floods the shape of the river bed is greatly affected and the river’s path may change. However, it is difficult to predict potential erosion damage points in advance. After flooding, some countenneasures such as splicing work of revetment are carried out on damaged banks. Nevertheless, as the river bank reinforcement work is being carried out, water flow concentrates on fixed points. Thus, scouring progresses and flow attack points may expand in size. Up to now, effective river bank erosion countermeasures have not been developed. In this paper we report the experimental work on bank erosion countermeasures which use boulders taken from the Joganji River bed, and show validity of the new countermeasure work