基于FVCOM的杭州湾三维泥沙数值模拟

3D numerical simulation of sediment in the Hangzhou Bay based on FVCOM

应用FVCOM建立了三维潮流泥沙数学模型,根据实测水文资料,对杭州湾开展了三维潮流泥沙验证,结果基本满意.应用模型计算了杭州湾大潮期间涨落潮泥沙输运过程,通过平面、立面的泥沙分布特征,成功再现了杭州湾潮流泥沙的运动过程.尽管模拟精度达不到平面二维模型的水平,但为三维潮流泥沙模型在强潮河口湾的应用作了重要的探索,通过进一步完善模型参数及分析,模型可以应用于涉水建筑物对附近三维水沙影响的分析评估,可为强潮河口湾开发、水环境保护及生态建设等提供更加丰富的研究成果,具有广阔的应用前景.

The region across the Hangzhou Bay is one of the most economically developed areas in China. There are lots of projects constructed in the Hangzhou Bay, which change the transport of current and sediment in the water area. The sediment transport in the Hangzhou Bay, a huge tidal estuary, is very complicated due to the effects of river runoff, wave and tide. The cohesive sediment is reciprocating its motion under the force of tide flow which comes dominantly from the Yangze River. Although 2D model has succeeded in simulating tide and sediment transport in huge tidal estuaries, it can only provide the depth-averaged data in plane. With the hydraulic and coastal engineering construction, more precise research products are needed. In this paper, a 3D current and sediment model is established through FVCOM. The measured data of the current and sediment in the Hangzhou Bay are collected to test the model, and the simulating process is generally consistent with real data. The sediment transport with tide current during spring tide period is simulated, then planar and vertical sediment distribution are obtained in the study. Although the precision is not as good as the planar 2D model, it is an important attempt to model 3 D sediment transport in a huge tidal estuary. The model can be applied to analyze the engineering 3 D effect on the territorial waters through ongoing improvement. There are broad application prospects in exploitation and protection of water ecology.