三峡工程动工三年来两坝间河道演变分析

Fluvial evolution between Yichang and Sandouping over 3 years since construction start of Three Gorges Project

根据葛洲坝运行以来的实测资料，首先分析了两坝之间达到冲淤平衡后河道的基本状况，然后重点分析了三峡工程动工以后两坝间河道的演变情况。认为三峡工程动工后，对两坝间河道的影响主要在：（１）施工中的填方和弃渣增大了河道的淤积量，增大了葛洲坝的库容损失；（２）弃渣使泥沙组成粗化，这有可能增大葛洲坝水轮机的磨损；（３）对航道的影响在三峡坝区主要是航道变窄。

In the light of measured data since the operating of Gezhouba Project, analysis was carried out firstly on the general river bed form in the river stretch between the Three Gorges dam and Gezhouba dam after equilibrium of scour and sedimentation, then emphatically on the river bed dvrelopment in this stretch since the construction of Three Gorges Project. It is considered that since the beginning of the TGP construction the influences on the river bed between the two dams are mainly in the following: (1) since the river sediment increases due to embankment filling and abandoned dumps during construction, the reservoir capacity of Gezhouba decreases accordingly; (2) the abandoned dumps coarsen the sediment gradation composition, it may increase the abrasion of the Gezhouba hydroturbines; (3) the navigation channel in this stretch becomes narrower, but the navigation channel depth keeps the same as that before the TGP construction.