基于EFDC的九龙江口-厦门湾三维潮流及盐度数值模拟研究

环境流体动力学模型(EFDC)集水动力模块、泥沙输运模块、污染物运移模块和水质预测模块于一体,可以用于河流、湖泊、水库、湿地和近岸海域一维、二维和三维物理和化学过程的模拟。为了研究岛屿多、岸线地形及流态复杂的九龙江口-厦门湾水动力过程,该文将EFDC模型运用于该水域三维潮流及盐度场的数值模拟,对比实测资料校核了模型参数,利用实测潮位、流速和盐度数据对模拟结果进行了充分的验证,吻合度高。该水域属于规则半日潮类型,平均涨、落潮历时约6 h;潮流以往复流运动为主,表层流速最大可达2 m/s;低平潮前后出现面积合计约74 km2的多处露滩;发现河口区分层及不同类型的盐度锋现象均在低潮后1 h时最显著。结果表明,该模式成功复演了九龙江口-厦门湾潮汐潮流和盐度场的时空变化过程,适用于模拟和分析河口及近海海域的水动力场。

Numerical simulation study on 3D tidal flow and salinity in the Jiulong Estuary-Xiamen Bay based on the EFDC

Environmental Fluid Dynamics Code (EFDC) fully integrate hydrodynamic,sediment transport,toxic contaminant transport with water quality-eutrophication simulation capabilities.The model can be used for 1,2,or 3-Dimensional physical and chemical simulation of rivers,lakes,reservoirs,estuaries,wetlands,and coastal regions.To study the Jiulong Estuary andXiamen Bay with multi-islands,complex topography and flow patterns,the model was for the fnst time applied to the simulation on tidal and salinity field in this area.Some parameters were calibrated and verified using observational data.The model datacomparisons are water elevation,flow velocity,and salinity and the simulation results showed good agreement with measured data.Xiamen Bay has a regular semi-diurnal tide and the average rising and falling time is approximately 6 h.Currents almost flow rectilinearly along channels and the maximum surface current speed can reach 2 m/s.About 74 km2 tidal plats emerge at low tide in and around Xiamen Bay.Stratification and different kinds of salinity fronts in estuary are most strongly formed one hour after low water.The tidal current and salinity field were re-acted successfully in the study area and the model can be applied for estuary and coastal regions.