Study on Processes of Changshou Waterway after 175m Experimental Impoundment of the Three Gorges Reservoir

Abstract

In 2008, the normal pool level in front of the Three Gorges Dam was set at 175m, and afterwards the spatial distribution of sedimentation in fluctuating backwater region changed significantly. Moreover, with the operation of Xiluodu and Xiangjiaba Reservoirs in the upstream of Yangtze River, sedimentation in fluctuating backwater area has also changed accordingly. In order to analyse the characteristics of erosion and deposition in the fluctuating backwater area under new water and sediment conditions, Changshou Waterway which located in the middle section of the fluctuating backwater region is chosen as one typical waterway, and the measured data of Changshou Waterway is then investigated. Results show that: the riverbed of the middle section in the fluctuating backwater area is changed from silting to slight scouring, there is no accumulated deposition after the experimental impoundment of the Three Gorges Reservoir, and the riverbed deformation in the Zhongshui Moraine of the Changshou Waterway is much more sensitive to water and sediment conditions while the downstream curved channel near Matou Moraine is relatively stable.