鄱阳湖二维水动力和水质耦合数值模拟

针对大型通江湖泊水位变化剧烈,地形起伏多变,岸线复杂,湖泊内部窄小洪道与大面洲滩和洼地连接复杂,湖泊洲滩出露、淹没频繁交替等湖泊水情和地貌特征,基于二维浅水方程和对流扩散方程组构建了鄱阳湖二维水动力和水质耦合模拟模型.模型采用非结构网格有限体积法进行离散,以HLLC算法计算单元界面的水量、动量和物质输运通量.水陆边界通...

Two-dimensional numerical simulation of hydrodynamic and pollutant transport for Lake Poyang

The present study aims to develop a mathematical model for analyzing and predicting the hydrodynamic and water quality in one large lake (Lake Poyang) with great and rapid stage fluctuation, the complex topography and geometry, the complicated connectivity of narrow channels and depressions inside the lake, the frequently switch between exposed grass beach and water.Based on the two-dimensional shallow water equations and pollutant transport equations, the coupled two-dimensional hydrodynamic and pollutant transport model is developed.The unstructured finite volume method is applied to discretize the equations.The nor-mal water mass, momentum and pollutant fluxes are computed by the HLLC solver.The water front moving boundary is identified automatically by the judgment of the latest water stage.It makes the model be capable of simulating the complex flow regime and the dynamic of pollutant transport in the lake with drying and wetting processes.The hydrodynamic model is calibrated by the water regime of the year 1998.Based on the calibrated hydraulic parameters, the hydrodynamic and water quality (COD_Mn and ammo-nia) from January to October in 2008 are simulated by the proposed model.The time series data of measured water stage, COD_Mn and ammonia, and remotely water extent of CBERS data are both used to validate the results of computation in time and space.The results indicate that the model has the capability to model the flows dynamic and the pollutant transport in this kind of lake.