A METHOD TO EVALUATE SEDIMENT TRANSPORTATION AND BED DEFORMATION IN THE DAM DRAINAGE BASIN

Abstract

The present study proposes a method to predict sediment runoff and bed deformation in dam drainage basin. The channel model is based on a unit channel model which can easily reproduce stream channels distributed in a drainage basin. The sediment transport model includes bedload, suspended load and wash load transportation. In addition, the method involves a model to predict sediment entrainment from debris cones formed along the channel due to sediment supplies by landslides flows. Flow discharge at each unit channel is predicted by means of two methods; one is to employ observed dam discharge and the other is to employ analysis of rainfall-runoff analysis. Validity of proposed model is tested in the Hatanagi-daiichi dam basin. As a result of numerical simulation with the proposed model, sediment runoff and bed deformation are well simulated in both ways.