长江口南槽江亚南沙近期演变及碍航特性分析

利用实测水下地形资料,结合数学模型研究成果,分析南槽江亚南沙演变特征及原因。结果表明:江亚南沙沙头窜沟发育,江亚南沙下沙体整体向下游淤涨,5 m沙尾下延成为南槽5.5 m航道维护困难段,同时江亚北槽冲深发展,主要是由于长江口深水航道治理工程南导堤封堵原九段沙窜沟以及南槽主槽与江亚北槽之间存在的水位差,南槽河床持续发展的结果。随着江亚南沙头部窜沟、江亚北槽的发展、贯通,南槽河段将形成新的分流支汊,对南槽整体河势、航道治理不利。

Recent river regime evolution and navigation-obstructing characteristics of Jiangya south shoal in South Passage of the Yangtze estuary

Based on the measured underwater topographic data and the results of the mathematical model,we analyze the characteristics and causes of Jiangya south shoal regime evolution in South Passage of the Yangtze Estuary.The results show that the channel developed in the head of Jiangya south shoal,the lower segment of Jiangya south shoal silt towards downstream,and 5 m deep tail of the shoal extended downward and forms the maintenance difficult section of South Passage 5.5 m channel.Meanwhile,Jiangya north channel scours and develops mainly because of the water level difference between the main channel of South Passage and Jiangya north channel and continuous development of the South Passage riverbed.With the development and transfixing of the channel in the head of Jiangya south shoal and Jiangya north channel,new diffluent outlet will form in South Passage,which has an adverse effect on the regime evolution and channel regulation of South Passage.