A METHOD FOR PREDICTING SEDIMENT RUNOFF CAUSED BY EROSION OF STREAM CHANNEL BED

Abstract

The present study describes a method for predicting sediment runoff caused by erosion of sediment stored in river channels. The method is developed by combining a newly developed channel model, a rain-fall runoff model and a storage-type sediment runoff model. The channel model, which is based on a unit channel having two inflow points and one outflow point, can easily reproduce stream channels distributed in a drainage basin. A kinematic wave runoff method is employed in rainfall runoff prediction, and the sediment runoff model is developed by integrating partial differential equations for water and sediment with respect to the reach of unit channel. The present method can predict temporal and spatial change of water discharge, sediment discharge, sediment storage and sediment size when rainfall data are given as in-put. It is applied to the upper basin of Kumano river, and its applicability is verified by comparing the predicted results and reservoir sedimentation data.