Establishment And Application Of Coastal Surface Water And Groundwater Coupled Model

Coastal area is the transition zone between continents and oceans, groundwater involved in interactive movement such as Coastal erosion, saltwater intrusion and water pollution. In recent years, the study of surface water and groundwater interaction has attracted the attention of domestic and foreign scholars. Establish coupled model by numerical method is the main research measure. In current coupled models, surface water were regarded as one-dimensional river, or two-dimensional overland flow. Research in the coastal region is lacked, and the model was used mostly to experimental verification, rarely applied to calculate the actual situation.In this paper, the numerical simulation method is applied attempt to establish an integral model by coupling surface water and groundwater model, and then some research is taken on the seacoast groundwater under tidal condition. Further study of seawater intrusion coastal regions and contaminant transport can be done based on this model. The main contents are:(1) Three-dimensional finite-difference ocean model POM and three-dimensional finite element groundwater model SUTRA were selected to establish an coupled model in coastal areas using volume exchanging method to achieve interaction between surface and subsurface water.(2) Ebrahimi lagoon experiment is used to verify the coupled model, the simulate results of water level fluctuation and velocity agree well with the measured data. Solute transport base on the experiment is calculated to analyze the salinity intrusion in the sand bar.(3)The coupled model is attempted to applying to the actual terrain calculation, establishing the calculation model of Liugu River. Tide is considerd as the ocean dynamic conditions, to discusses and analysis the groundwater movement features based on different hydraulic conductivity or presence or absence rainfall condition respectively.