Prediction of Riverbed Evolution under Different Operation Modes of Three Gorges Reservoir at A Reach with Beaches in Flood Seasons

Abstract

Different reservoir operation modes in flood seasons will have a profound impact on the evolution of the downstream reach of the dam. In this paper, a sandy reach with beaches in the downstream of the dam is selected. Based on the water and sediment conditions output from the Three Gorges Reservoir under different operation modes in flood seasons, the erosion and deposition trend in the reach is predicted and calculated. The results show that the total inflow of the reach is basically the same during the operation period, but with the decrease of the controlled discharge, the action time of the bank full discharge increases, and the total scouring amount of the reach slightly increases, which is conducive to the development of the channel.