Study on hydrodynamic and sedimentation problems in development of harbors located at offshore area with many islands and tidal channels

The Yangshan sea area which locates in the Qiqu Archipelago is a typical offshore area with muti-island and muti-channel. In this paper, taking Yangshan sea-area of the Qiqu archipelago as an example, a 2D numerical model of tidal currents and sediments is established to study the change of the current and sediment field.The validity of the model is verified by the observation data obtained in April, 2007 including the tidal flow and suspended sediment concentration in the vicinity of the harbor. The verification of calculation shows the calculated values are in good agreement with the measured data. The field of tidal currents, suspended sediment concentration and the seabed deformation can be successfully simulated. Finally, two layouts are simulated to study the changes of the current and suspended sediment field. And the seabed evolution is predicted with the model. Computational results show that the Branch Channel Layout is advantageous to the present situation.