基于Delft3D-flow模型的长江口盐度扩散规律模拟

为了研究长江口环流动力过程下的河口盐度扩散和分层混合机制,采用河口三维模型(Delft3D-flow)模拟了长江口盐度分层扩散规律和扩散系数变化对河口分层的影响。通过模拟实际水文情况下的长江口水动力过程,反映了该区域受到较强的径潮流动力作用后,对盐度在涨落潮周期内的垂向混合分层产生了重要影响,进一步验证了分层河口紊动扩散系数对盐度的水平扩散输移、垂向非稳定层化和混合的影响均较大。模拟结果较好地反映了河口在复杂水动力过程下盐度扩散和分层规律。

Simulation of salinity diffusion of Yangtze River estuary based on Delft3 D-flow model

To study the salinity diffusion and stratification mechanism under the circulation dynamics of Yangtze River estuary, the Delft3D-flow model was used to simulate the influence of salinity stratification and diffusion laws and diffusion coefficient sensitivity on estuarine stratification. Through simulation of hydrodynamic of Yangtze River estuary under practical hydrological conditions, it shows that the strong river and tidal dynamics play an important role in the vertical salinity stratification during the flood to ebb tidal cycle, which confirms that the turbulent diffusion coefficient significantly affects the horizontal salinity transport, vertical salinity unstable stratification and mixing. The simulation result can well reflect the salinity diffusion and stratification laws under complex hydrodynamic conditions in estuarine region.