消落期三峡水库库尾泥沙冲淤特性研究

Study on sediment erosion and deposition characteristics in fluctuating backwater area of Three Gorges Reservoir in the drawdown period

铜锣峡至涪陵河段位于三峡水库库尾,长约110km,以该河段为研究对象,在深入研究河段内泥沙冲淤规律的基础上,分析了其冲淤变化的主要影响因素,结果表明,消落期该河段的泥沙冲淤变化主要受消落前期泥沙冲淤量、入库水沙条件、三峡水库坝前水位及其消落速率等因素影响,其规律十分复杂;研究提出了三峡水库库尾河段复杂因素影响(包括床沙组成、水沙条件、三峡水库运行调度方式等)的走沙条件,为三峡水库的泥沙调度提供了必要的参考数据和技术支持。

The reach from Tongluoxia to Fuling in the Yangtze River, with a length about llOkm, is in the fluctuating backwater area of Three Gorges Reservoir （TGR）. This reach is selected as the research object. Based on analysis of the scouring and silting in the fluctuating backwater area of TGR, the mainly affecting factors to the scouring and silting change law is studied. Results show that in the falling period, the sediment scouring and silting amount is mainly affected by three factors： the early scouring and silting amount, incoming flow and sediment condition, the water level of Three Gorges Reservoir in front of the dam and its falling rate. The erosion and deposition conditions at the fluctuating backwater area are presented, including bed sediment composition, flow and sediment conditions, and the dispatching operation of the TGR. Those results provide the necessary reference data and technical support for the sediment scheduling of the TGR.