Page - 362 - in Book of Full Papers - Symposium Hydro Engineering

COMMISSION INTERNATIONALE DES GRANDS BARRAGES ------- VINGT-SIXIÈME CONGRÈS DES GRANDS BARRAGES Autriche, juillet 2018 ------- OBSERVATION AND ESTIMATION METHOD OF SEDIMENT PRODUCTION IN KAMANASHIGAWA BASIN, FUJIKAWA RIVER SYSTEM ―TOWARD AN ACCURATE ESTIMATION OF DAM SEDIMENT VOLUME― Kunihiro TOMITA, Zhengxing YE, Takashi HIKITA CIVIL ENGINEERING AND ECO-TECHNOLOGY CONSULTANTS CO., LTD. Tetsuya SUMI Professor, DISASTER PREVENTION RESEARCH INSTITUTE, KYOTO UNIVERSITY JAPAN 1. INTRODUCTION Conventionally, the sediment production and the flowing down situation from the upstream of the river are estimated by aerial photointerpretation or topographic survey etc. The design sediment volume in a dam is usually estimated according to sedimentation results of neighboring dams that have similar watershed condition. And the sediment transport in river channel is not properly measured during the flood event. In recent years, the observation technology of sediment discharge in the river has greatly improved, so that the bedload can be directly observed by a hydrophone, and the suspended load by a turbidimeter. Additionally, the sediment volume variations in a mountain stream can be estimated from temporal change of riverbed height by satellite SAR (Synthetic Aperture Radar) analysis. In this paper, using the model of Omukawa River, a branch of Kamanashigawa, Fujikawa River system, we combine the data of sediment discharge obtained by various observation techniques and try to improve the 362