Abstract

In June 2003, the Three Gorges Project (TGP) reservoir commenced impounding for flood control, power generation, navigation improvement, and so on. Based on the observed data of hydrology and sediment since impoundment, systematic analysis on characteristics of input and output runoff and sediment and deposition in reservoir area have been carried out, and result shows that, during the period from June 2003 to December 2005, the total sediment deposited in the reservoir is 3.77×10⁸ t, and the sediment delivery ratio of the reservoir is 40%, and deposition occurs mostly in the strath reaches, which occupies 95% of the total deposited sediment amount in the TGP, by contrast, in the narrow and deep reaches, the amount of sediment deposited is rather small, and in some place slight scouring occurs, and the deposition in the reservoir area is focused on main bed, which accounts for 79% of the total deposited sediment amount.

Keywords: The Three Gorges Project reservoir, characteristics of input and output runoff and sediment, deposition in the reservoir area