整治工程后长江口南北槽的分流分沙季节特征

Seasonal characteristics of flow and suspended sediment diversion in South and North channels of Yangtze Estuary after implementation of regulation project

利用2009年2,4,8和11月共4次长江口南北槽的全潮水文泥沙测验数据,分析全年4个季节期间长江口南北槽的分流、分沙特征.结果表明:南槽的分流比、分沙比均大于北槽的分流比、分沙比,进入南港河道的水流、泥沙通过南槽的通量大于其通过北槽的通量.在春夏秋3个季节,南北槽均处于由陆向海输运格局;在冬季,南槽处于由海向陆输移状态,泥沙更易于南槽落淤,而北槽处于由陆向海净输移状态.与2006年,2007年冬季相比较,长江口三期整治工程实施后,北槽的水动力作用进一步加强.

Based on measured data of water and sediment discharge in the South and North channels of the Yangtze Estuary in February, April, August, and November of 2009, the characteristics of the flow and suspended sediment diversion in four seasons of the year were analyzed. The results show that the diversion ratios of flow and suspended sediment in the South Channel were higher than those in the North Channel; the fluxes of water and sediment entering the Nangang Channel were larger when they flowed through the South Channel than through the North Channel; in spring, summer, and autumn, a large amount of suspended sediment was transferred from the land to the sea both in the South Channel and in the North Channel; in the winter, the suspended sediment was transferred from the sea to the land in the South Channel and from the land to the sea in the North Channel, and it was more easily deposited in the South Channel; and the hydrodynamic effect in the North Channel was more significant after implementation of the third-stage regulation project in the Yangtze Estuary, compared with that in the winter of 2006 and 2007.