长江口深水航道治理一期工程前后泥沙运动特性初步分析

利用长江口徐六泾、横沙和佘山三站三年逐日表层含沙量、盐度和气象观测资料，以及北槽河段沿线含沙量洪、枯季准同步观测资料，对长江口深水航道治理一期工程实施前后北槽河段含沙量沿程分布规律和垂向变化特征，以及滩槽泥沙交换的机理进行了分析。结果表明：北槽河段高含沙区分布位置在一期工程后适量下移；风浪对浅滩泥沙的掀动作用和滩槽问泥沙交换是造成工程区河段含沙量增加的主要动力因素；滩槽泥沙交换及输移途径取决于滩槽间流场变化，南北导堤在二期工程继续下延后，将进一步削弱滩槽泥沙交换量，有利于对深水航道的维护。

Primary Analysis on Sediment Motion before & after 1st Phase Engineering of the Deep Waterways in Changjiang Estuary

In this paper, characteristic of vertical and stream-wise sediment distribution in the Changjiang Estuary have been analyzed on the basis of the 3-year observations of surface concentration, salinity, and weather at the stations of Xuliujing, Hengsha, and Sbeshan, and the quasi-synchronous observations of sediment concentration from Hengsha station to outside estuary along the North Passage in flood season and low water season. The principles of the sediment exchange between the flat and pool have been studied too. The result shows that: in the reach of the North Passage, the site of high sediment concentration correspondingly moves down along the river after the first phase engineering; sediment suspended by wind wave and sediment exchange are the dominant dynamic forces of sediment increasing in the engineering reach of Changjiang Estuary. Sediment exchange and the track of migrating in flat and pool are determined by the variation of current field. The amount of sediment exchange between flat and pool will decrease after the second phase engineering. It is a favourable to keep the deep water of the North Passage.