LONG TERM PREDICTION OF EXPANSION AND DESTRUCTION OF RIPARIAN VEGETATION AND SEDIMENT DEPOSITION AT THE DOWNSTREAM REACH OF THE TENRYU RIVER

Abstract

A numerical simulation model was presented to predict the long term change of vegetated area and the resulting deposition of fine sediment at the down stream reach of the Tenryu river. In constructing the model, the river cross-section was divided into three areas, main flow area, bare bar area and vegetated area, in which the flow velocity at three areas and the deposition of fine sediment at vegetated area were calculated by using mass and momentum balances of each area and the cross-sectional transport of suspended sediment. It was found that the present simulation model can roughly estimated the transition of vegetated area and total amount of sediment deposition. The long-term change of vegetated area and sediment deposition was investigated by using the model.