2012年以来,金沙江下游向家坝水电站、溪洛渡水电站相继蓄水运用,拦截了金沙江下游泥沙。为了解梯级水库泥沙淤积情况及其拦沙作用对下游三峡水库的影响,基于大量水沙、固定断面观测资料,采用输沙法和地形法,计算分析了向家坝水电站、溪洛渡水电站2库自运用以来的库区泥沙淤积量及分布特征,研究了梯级水库拦沙作用对三峡水库的影响。结果表明:向家坝、溪洛渡库区泥沙淤积量较小,金沙江下游梯级拦沙使得三峡入库沙量及库尾重点河段淤积强度均减小。研究成果对梯级水库运行、三峡水库运行及调度方式优化具有十分重要的意义。

Xiangjiaba Reservoir and Xiluodu Reservoir have successively entered impoundment stage since 2012, and in the meantime intercepted sediment from the lower Jinsha River. According to field data of runoff, sediment and some cross-sections, the amount and distribution features of sediment deposition in the cascade reservoirs since their operation are calculated, and their influences on the Three Gorges Reservoir (TGR) are studied. Results indicate that sediment deposition in Xiluodu Reservoir and Xiangjiaba Reservoir are both less than the estimated amount. The cascade reservoirs reduced the incoming sediment of TGR, and correspondingly reduced the deposition in its tail reach. The research results are of great significance for the operation of cascade reservoirs and the regulation optimization of TGR.