EXPERIMENTAL FLOW RELEASE BY A DAM FOR REPRODUCING GRAVEL BED IN SATSUNAI RIVER

Abstract

In the Satsunai River, increasing of vegetation and decreasing of gravel bed causes serious problems such as increases in flood risk or changes in wild life species. Therefore, Hokkaido Development Bureau, the management authority, is performing field experiments to sweep away vegetation and reproduce gravel bed by artificial flash flood with the use of snow melting water released from Satsunaigawa Dam. During this performance, variety of measurements such as discharge, elevation changes, and vegetation changes are carried out. Authors studied the accuracy of discharge measurements by floats and a microwave meter. Also, the authors performed one dimensional and two dimensional flow calculations, compared the results to observed data, and showed good applicability as well as some lessons to learn.