长江口南北港分流口河段近期河势变化及对区域重大整治工程的影响

南北港分流口河段近期河势发生新的变化,对区域重大涉水工程的安全稳定产生较大威胁,甚至可能给区域现状河势格局的稳定带来不利影响。通过多年实测水下地形资料对比分析,得知近期下扁担沙尾部南侧淤涨下延、新新桥通道逐步萎缩、新桥沙下移南压以及下扁担沙滩面串沟发育等,给维持南北港分流口现状河势格局的新浏河沙头部护滩工程、南沙头通道限流工程、中央沙头部圈围工程以及青草沙水源地工程等自身安全稳定带来较大压力,使南北港分流口现状河势格局的稳定存在隐患。

Evolution of ditributary reach of south and north channels in the Yangtze Estuary andinfluence on surrounding regulation projects

Some new changes occurred in the distributary reach of south and north channels recently,which threaten the stabilization of the important regulation projects nearby,and may influence the stabilization of the river regime.Based on the comparison of the riverbed data of several years,we analyze the new changes of the distributary of south and north channels recently.The results show that the sediment is silting at the Biandan shoal tail,the Xinxinqiao channel is withering away,the Xinqiao shoal is moving downstream and southwards,some new watercourses are developing on Biandan shoal,etc.The new changes mentioned above threaten the stabilization of the regulation project nearby,such as the Xinliuhe shoal protection project,the Nanshatou gully discharge control project,the reclamation project of Zhongyang shoal,the Qingcao shoal reservoir project,etc.These regulation projects maintain the stabilization of the distributary of south and north channels.