2020年三峡水库泥沙淤积特点及原因分析  

Study on characteristics and causes of sediment deposition in Three Gorges Reservoir in 2020

作　　者：许全喜 袁晶 XU Quanxi;YUAN Jing(Bureau of Hydrology,Changjiang Water Resources Commission,Wuhan 430010,China)

机构地区：[1]长江水利委员会水文局,湖北武汉430010

出　　处：《人民长江》2022年第5期7-13,共7页Yangtze River

基　　金：国家自然科学基金联合基金项目(U2040218);三峡后续工作项目“三峡水库区间支流水沙变化”(21303)。

摘　　要：2020年汛期,长江上游暴雨洪水频发,三峡水库入库沙量显著增大,年入库沙量达到了1.94亿t。在系统分析长江上游水沙变化特性的基础上,总结提炼了2020年三峡库区泥沙淤积出现的新特点,主要是库区泥沙淤积量较往年明显偏大,同时库尾河段和防洪库容内泥沙淤积明显。铜锣峡以上河段由以往的冲刷变为淤积353万m^(3),淤积量占三峡库区总淤积量的3%;防洪库容内淤积泥沙2440万m^(3),为三峡水库175 m试验性蓄水以来最大值,此外坝前河段淤积强度显著增大。分析原因后认为主要是8月上游嘉陵江、岷江等支流暴雨产沙导致入库沙量偏多与水库拦洪导致坝前水位偏高所致。相关结论可为三峡水库科学调度提供更有力的技术支撑。In the flood season of 2020,heavy rains and floods occurred frequently in the upper reaches of the Yangtze River,and the amount of sand entering the Three Gorges Reservoir had increased significantly with annual amount of 194 million tons.We first systematically analyze the features of water and sand variation in upper reaches of Changjiang River,and point out the new characteristics of sediment deposition of Three Gorges Reservoir in 2020:the amount of sediment deposition in the reservoir area was significantly larger than that in previous years.At the same time,the reservoir tail and flood control storage capacity had obvious deposition.Among them,the river section above Tongluoxia had changed from previous erosion to deposition with volume of 3.53 million m^(3),accounting for 3%of the total deposition volume in the Three Gorges Reservoir area;the Three Gorges Reservoir suffered the highest deposition of 24.4 million m^(3) in its flood control storage capacity since the 175m pilot impoundment;and the deposition intensity in front of the dam had increased significantly.Based on the systematic analysis on characteristics of water and sediment changes in the upper reaches of the Yangtze River,we summarize reasons of sedimentation in the Three Gorges Reservoir area in 2020,namely the heavy rain-induced sand yield in upper tributaries,such as Jialing River and Minjiang River,and the higher water level in front of dam site due to flood retention operation.The results provide more powerful technical support for the scientific operation of the Three Gorges Reservoir.

关 键 词：输沙量 泥沙淤积 库尾 防洪库容 淤积强度 三峡水库 

分 类 号：TV697[水利工程—水利水电工程]