三峡工程蓄水后，水库调度以及库区淤积改变了长江中下游来水来沙特性，进入长江中下游泥沙大幅度减少，“清水”下泄、河床冲刷，使沿程沙量逐步恢复。在以往研究的基础上，增加新的水沙系列对三峡工程蓄水运用 20 年三峡水库淤积和坝下游长河段冲淤进行一维数学模型计算，研究分析长江中下游年来水量、年输沙量变化规律以及沿程变化趋势，并根据三峡工程蓄水后的实测资料进行对比验证。其成果可为其他行业研究提供基础。

The regulation of Three Gorges Reservoir(TGR) and reservoir deposition have changed the characteristics of coming water and coming sediment of middle-lower Yangtze River, the sediment-laden entrancing the downstream of the Three Gorges Dam(TGD) has been greatly decreased, so clear water discharged over the spillway of the dam is scouring the river-beds and river banks and then sediment-laden volumes along distance are being gradually recovered. On the basis of previous studies, a 1-D mathematics model simulating TGR sedimentation and scouring-silting of the dam downstream was established with the conditions of TGR early 20-year operation and adding a new water-sediment series-year. Annual coming water volume, annual sediment transport amount and their changing trends along distance at several hydrologic stations were analysed. The calculated results were compared with measured data, and corresponding values were basically close. So the results of this research are rational, believable.