STUDY ON SEDIMENT PROBLEMS AT THE FLUCTUATING BACKWATER AREA OF THREE GORGES RESERVOIR

摘要

Based on the analysis of the reservoir inflowing runoff and sediment feature and the silting and scouring law at the fluctuating backwater area during its pre & post operation period of Three Gorges project(TGP), it can be concluded that: Silting and scouring are basically equilibrated year-to-year before the building of the reservoir in the reach and inflowing sediment load decreased greatly within 8-year operation of TGP after the building of the reservoir; it is generally silted in the reach, primarily on the marginal bank, while it has little siltation even some scouring in the trough; River regime of Tunaozi reach has been changed; As a result of the silt trapping of up-stream reservoir, the speed of the sediment siltation will be little than prediction.