洋山港海域余流分离和会聚现象研究

洋山港海域岛链峡道具有下层水体余流分离现象和会聚现象两个主要特征，它们对峡道内的悬沙浓度分布、底质沉积物分布和海床冲淤均产生显著影响。悬沙浓度在余流会聚区呈现高浓度特征，在余流分离水域具有低悬沙浓度趋势。余流分离和会聚现象使砂质沉积物在峡道西部集结并形成大型沙体，余流会聚现象导致了峡道西部粘土沉积区的形成。余流分离现象是峡道深槽形成的主要原因，余流会聚现象是峡道西部浅滩区形成的主要原因。洋山港北港区工程将会使峡道西部海床淤浅，东部深槽加深。

Separation and convergence of residual flows in Yangshan Harbor area

The authors analyzed the hydrological and sedimentation data in the Yangshan Harbor area The separation and convergence of residual flows of lower water in the channel of this area were of two important hydrodynamic features. They remarkably influenced the concentration of suspended sediment, the distribution of surface sediment and the sub-aqueous landform. The concentration of suspended sediment in the convergence area of residual flows was higher than that around, while it would be lower in the separation area. Large-scale sand dune existed in the west of the channel, which was mainly caused by hydrodynamic action of the convergence and separation of the residual flows. Deposition of fine sediment and the shoal bar in the west of the channel was induced by the convergence of residual flows. A deep trough of the channel was mainly caused by the separation of residual flows. The northern part of the Yangshan Harbor project would shoal the west and deepen the east of the channel.