泥沙研究

龚嘴水库运行至今已有五十多年，库区淤积严重。随着瀑布沟水电站建设运行，龚嘴水库入库沙量大幅减少，为水库淤积控制提供了良好条件。基于龚嘴水库建库以来的水沙和断面资料，对入库水沙、库容变化和断面冲淤等进行分析，结果表明：龚嘴水库入库径流量没有明显变化趋势，输沙量受瀑布沟水库拦沙影响在2009年以后明显减少；龚嘴水库自建库以来淤积发展大致分为淤积期、冲淤平衡期和冲刷期三个阶段，在淤积期泥沙呈三角洲形态淤积到坝前，淤积量由入库输沙量决定，在冲淤平衡期库区冲淤变化不大，在冲刷期库区有较明显冲刷，且冲刷重点河段有向坝前推移趋势，冲刷主要出现在大洪水过程中。

Gongzui Reservoir has been in operation more than 50 years and the sedimentation in the reservoir is serious. With the operation of Pubugou Reservoir, the incoming sediment of Gongzui reservoir has been greatly reduced, which provides a favorable condition for the sedimentation control of Gongzui Reservoir. Based on the data of runoff and sediment at Shaping Hydrological Station and the cross sections in Gongzui reservoir since its operation, the variations of characteristics of incoming flow and sediment, as well as the reservoir erosion and deposition in Gongzui reservoir have been analyzed. The results indicate that the inter-annual variation of the inflow is not remarkable, however the sediment reduction trend is obvious since 2009 with the influence of upstream sediment retention in Pubugou Reservoir. The erosion and sedimentation processes in Gongzui Reservoir can be roughly divided into three stages: the early rapid sedimentation stage, the equilibrium stage of erosion and sedimentation, and the erosion stage. During the rapid sedimentation stage, the sediment is deposited in delta shape from the tail of the reservoir to the front of the dam, and the amount of sedimentation depends on the incoming sediment. The erosion and sedimentation in the reservoir is slight during the equilibrium stage. During the erosion stage, there is significant erosion which mainly occurs in the process of large floods, and the reservoir section with strong erosion continuously develops to the front of the dam over time.