长江下游澄通河段九龙港节点控制作用变化趋向研究

Evolution trend of Jiulong Port node control in Chengtong reach of Lower Yangtze River

长江下游澄通河段洲滩、汊道河势格局复杂,九龙港人工节点具有承上启下作用,对于稳定该河段河势起着重要作用。近期受上游水流条件及河势变化的影响,民主沙右侧滩岸冲刷后退,如皋中汊出流变化引起左侧边滩冲刷,九龙港节点段顶冲点下移,进而影响通州沙东水道进流条件。九龙港节点对下游河势的控制作用呈趋弱态势。基于此,提出了九龙港节点河势控制建议:尽快实施民主沙滩岸守护工程形成弯段控制顶冲点下移,重点是实施尾滩强化固滩;实施九龙港节点整治工程,从而恢复并加强九龙港节点的控制作用。

The node control plays an important role in stabilizing the complicated channel-shoal river regime of the Chengtong Reach of the Yangtze River,especially the artificial node of Jiulong Port which connects the upstream and downstream. Due to recent upstream hydrodynamic and morphological changes,the right bank of Minzhu Shoal eroded and retreated. The outflow change from the Rugao Middle Distributary induced scouring at the marginal shoal of left side and the head scouring and moving down of the Jiulong Port node reach,and further impacted the inflow condition of the east distributary of the Tongzhou Shoal. Therefore,the control role of the Jiulong Port to the lower river channel gradually reduces. In the light of this condition,the suggestions on the regime control of Liuhaisha reach are put forward,including:①carrying outbank protection project for the Minzhu Shoal as soon as possible to form a curved section for controlling the moving down of the head scouring point,in which,the key point is to stablize the shoal tail;②carrying out regulation project of the Jiulong Port node to recover and enhance the controlling effect of this node.