Abstract

In this paper, the impact of the Three Georges Project on downstream flow and sediment discharge is estimated, and channel evolution characteristics of different reaches are predicted. After impoundment of the dam, downstream flow process and sediment discharge is altered by dam operation, and sediment discharge along the river changes with a dynamic process because of availability of sediment supply in river bed. For different distance from the dam, the change extents of flow and sediment regime are different. On the basis of characteristics of pre-dam channel evolution and prediction of sediment discharge, the possible channel adjustment is estimated considering the factors of geological environmental, hydrological and sediment regime change. The result shows that river patterns can’t change obviously but the change of sand bar size and thalweg position will be obvious in some reaches. These conclusions have significant implications for river training and protection of engineering structure along the reach.

Keywords: the Three Georges Project, Dam effect, Channel adjustment, Downstream