中文摘要：

长江上游溪洛渡、向家坝等水电工程的建设，改变了进入三峡水库变动回水区及库区的水沙环境。上游水库水沙调节后，变动回水区的泥沙淤积情况将会发生相应变化。在分析三峡工程变动回水区水沙特性的基础上，应用建立的适合多连通域的贴体正交曲线坐标系下的二维水沙数学模型，根据三峡工程初步设计阶段选定的1961—1970年（简称60系列）及上游水库水沙调节后的水文系列及相应进出口边界条件，预测了重庆主城区河段100年泥沙冲淤的时空变化规律。研究表明，60水沙系列条件下，该河段淤积比较严重，淤积主要位于岸线凹凸不平的弯沱、回流区及河道的宽浅河段；上游水沙调节后，仅局部岸线凹凸不平的弯沱有少量泥沙淤积，主城区川江段的淤积量仅为60系列的17．4％，嘉陵江段仅为印系列的10．3％，这对三峡水库有效库容的保持及主城区河段岸线利用有利。

英文摘要：

In the upstream of the Yangtze River, the construction of the hydroelectric power projects, such as Xiluedu reservoir and Xiangjiaba reservoir, changes the hydrodynamic and sediment environment of the backwater area of the Three Gorges Project（TGP）. After the adjusting of the runoff-sediment by the reservoirs in the upstream, the sediment deposition and ero- sion in the backwater area has the corresponding changes. In this paper, based on the water-sediment characteristics and fluvial process of the backwater area of the TGP, a 2D sediment mathematical model in the boundary fitting orthogonal curvilinear coordinate system is developed by the authors, then the rules of the space-time changes of the sediment deposition and erosion in the Chongqing reach is predicted in 100 years by using the model, and its effects on the harbors and navigation channels are detailedly analyzed. The Analysis of the results proves that, under the water-sediment conditions during 1960s, serious sedi- ment deposition occurred mainly in the river sinuses, the reeirculating zones and broad-shallow reach. After the construction of reservoirs, the sediment deposition volume decreases by 82.6% in the Yangtze River and 89.7% in the Jialingjiang River, compared with that of 1960s, which is advantageous for the maintenance of TGP and the development of Chongqing reach.