Deposition development in post-flood seasons between 1999-2015 at the entrance of typical tributaries of Xiaolangdi Reservoir, Yellow River*

支流作为水库综合效益发挥的重要组成部分，其河口泥沙大幅淤积会影响水库综合效益的发挥.选取多沙河流水库黄河小浪底库区畛水、石井两支流作为典型实例，在对1999-2015年汛后水库的来水来沙、水库调度、库区干支流淤积量与形态分析基础上，研究干支流淤积形态的变化，重点研究支流口门拦门沙坎抬升变化特征，结果表明：支流的分流及淤积与入库流量、含沙量及库区的淤积形态有关.入库流量越大，支流分流比小，支流淤积规模小；入库含沙量越大，支流分沙比越大，支流淤积规模越大.;Tributary, as an important part of the comprehensive benefit of the reservoir will affect the comprehensive benefit of the reservoir, with the large sediment deposition in its estuary. Based on the analysis of water and sediment input conditions, reservoir operation, sedimentation volume and morphology of main and branch streams in the reservoir area, this paper studies the change of sedimentation morphology of main and tributaries, and focuses on the uplift characteristics of sandbank at the entrance of tributaries. The results show that the diversion and deposition of tributaries are related to the discharge and the sediment content of inflow, and the form of sedimentation in the reservoir area. The larger the inflow of the reservoir, the smaller the flow ratio and the siltation scale of the tributary. The larger the sediment concentration in the reservoir, the larger the sediment ratio and the larger the siltation scale of a tributary.