大規模洪水時における河岸侵食危険箇所の検出法

抄録

Heavy rainfall that occurred in July 2018 caused severe damage along rivers in western Japan widely such as bank erosion, collapse of dikes, etc. Those also broke many the evacuation routes along rivers. In this paper, we aim to investigate a method of detecting the vulnerable points at the time of large flood occurrence to a wide area of rivers including the upper stream of a first class river and the second class river with a small amount of data. It is presented by the BVC method that the bank erosions are considered to be induced by the high turbulence energy produced by local three dimensional flow structure, such as the secondary flow in meandering rivers. Then simple evaluation method for vertical velocity distribution variating by two dimensional model and the strength of the secondary flow by a one-dimensional model are proposed.