长江口南汇咀岸滩围垦工程潮流数值模拟研究

南汇咀岸滩地处长江河口最大浑浊带,是长江河口淤涨速度最快的岸滩,是上海市规划围垦的重点区域。目前上海在南汇咀岸滩上已实施了围垦工程,围垦工程改变了长江口南汇岸线,也改变了南汇咀的水动力条件。为了解围垦工程实施后的水动力条件的变化,本文利用Delft3D-flow建立了长江口-杭州湾垂向平均的二维水动力模型,在对现场实测资料验证良好的基础上,对南汇咀海域围垦工程前后的潮流场进行了数值模拟,就围垦工程对周边海域的影响进行了分析研究。同时,对比南汇咀围垦前后的海图,采用GIS方法分析地形变化,利用地形变化来进一步验证海域的水动力变化。结果表明:工程后,杭州湾北岸流速增强,地形冲刷加剧;南汇东滩流速减弱,地形淤涨。

STUDY OF TIDAL FLOW NUMERICAL SIMULATION ON THE RECLAMATION PROJECT OF NANHUIZUI BEACH

Nanhuizui Beach is located in the maximum turbidity zone of Changjiang estuarine.Due to the fast silting,it is a key area of reclamation plan in Shanghai nowadays.The reclamation project has been put in practice,which has changed the costal line and the hydrodynamic condition of Nanhuizui Beach.A 2-D tidal flow mathematics model was set up by Delft3D-flow to study these changes and the influence of the project on surrounded sea area.Supported on GIS,sea charts before and after projects were analyzed to study topography changes which further validate hydrodynamic changes.It is found that after the reclamation project the tidal velocity in the north of Hangzhou Bay strengthen and seabed is stronger scoured,while the tidal velocity in the east of nanhui shore weaken and seabed is silted.