长江口北支强潮河道悬沙运动及输移机制  

The suspended sediment transportation and its mechanism in strong tidal reaches of the North Branch of the Changjiang Estuary

作　　者：陈炜[1] 李九发[1] 李占海[1] 戴志军[1] 闫虹[2] 徐敏[1] 赵军凯[1] 

机构地区：[1]华东师范大学河口海岸学国家重点实验室,上海200062 [2]荷兰代尔夫特理工大学

出　　处：《海洋学报》2012年第2期84-91,共8页

基　　金：国家自然科学基金(50939003;51061130544(中荷合作);40976055)

摘　　要：随着崇明北侧岸滩的自然淤涨和人工圈围,北支河道显著束窄,"喇叭口"顶点位置下移。在新的地形及流域来水来沙变异背景下,作为长江河口的分支强潮汊道,其悬沙运动与输移特点值得探讨。根据2010年4月小潮至大潮连续8d的半个半月潮水沙观测,结合多年不同河段水沙观测数据得到的含沙量过程曲线显示:整个河道潮流强、含沙量高,含沙量过程曲线呈"单峰—双峰—单峰"的变化特点;河道悬沙的输移以平流输移和"潮泵输移"为主,以"喇叭口"顶点为界,上游段河道平流输移占主导地位,"潮泵输移"次之;下游段"潮泵输移"占主导,平流输移次之。净输沙总量呈:上段河道向海,下段河道向陆,在"喇叭口"顶点附近存在一个泥沙汇聚的最大浑浊带区域。As the effect of natural accreting processes and artificial reclamation,the river channel of the North Branch in the Changjiang Estuary has narrowed significantly,and the position of summit of the funnel-shape has moved down.As an important strong tidal bifurcation of the Changjiang Estuary,the transport characteristics of suspended sediment in the North Branch is deserving of further discussion and research by considering the changes in river morphology and sediment load from the Changjiang drainage area.According to the continuousl observation of flow and sediment during one spring-neap tide cycle in April 2010,together with historical data from different locations,the obtained results are as follows： the current is strong and suspended scdiment content（SSC） comparatively high in the North Branch,the process curve of the SSC shows a pattern of ＂unimodal-bimodal-unimodal＂in a half 14 d cycel.Lagrangian advection and tidal pumping effect are two main constituents of sediment transport in the North Branch,with spatial variations.Touxing Port can be considered as a transition,where Lagrangian sediment transport dominantes in the upper mouth and the tidal pumping in the lower section.As for the net sediment transport flux,it moved seaward in upper mouth and landward in the lower section.The result suggests a turbidity maximum due to sediment accumulation around the summit.

关 键 词：长江口北支河道 含沙量 悬沙输运 潮流 机制分析 

分 类 号：P333.4[天文地球—水文科学]