2020年洪水后长江下游东流河段河床演变新特征

东流河段为长江下游的典型分汊浅滩河段，河段治理难度大。基于历年实测资料，对东流河段滩群演变规律进行分析。结果表明，2020年洪水后东流河段局部河床变化较为剧烈，如左岸华阳闸以下岸坡大范围崩退，棉花洲头高程削低，与鱼骨坝工程趋向分离，洲滩演变趋向不利，建议对进口段左岸岸坡采取守护工程措施，并对棉花洲头守护工程进行延长，抑制滩面水流冲刷，以利于河段分汊分流格局的长远稳定。

New evolution characteristics of riverbed in Dongliu reach of lower Yangtze River after flood in 2020

Dongliu reach of lower Yangtze River is a typical multi-branched shoal reach and faces difficult regulation. Based on the measured data over the years, this paper analyzes the evolution law of beach groups in Dongliu reach. The results show that part of the riverbed in Dongliu reach has changed greatly after a flood in 2020. Specifically, lower bank slopes of Huayang Sluice on the left bank have collapsed in a wide range, and the elevation on the head of Mianhua shoal has cut down and tended to separate from the fish-bone dam project. In addition, the evolution of shoals and beaches is unfavorable. Therefore, the paper suggests that the bank slope on the left bank of the inlet reach should adopt measures to protect the project, and the project for protecting the head of Mianhua shoal should expand its application range, so as to restrain the flow scour on the beach surface and ensure the long-term stability of the multi-branched and water-diversion pattern of the reach.