Numerical Modeling of Seawater Intrusion in Coastal Aquifer Using Finite Volume Unstructured Mesh Method

Saltwater intrusion widely occurs in coastal areas. Therefore, dissolved salts are the most common contaminants in freshwater in coastal aquifers and this contamination arises from saltwater invasion, caused primarily by human activities due to heavy urbanization. For investigation of the methods of increasing storage of fresh ground water and prevention of seawater encroachment, predicting the location and movement of the saltwater interface is crucial. Saltwater intrusion problems are so complex and generally cannot be analytically solved. Hence, numerical methods are ideal tools for the simulation and prediction of results. In this paper, a two-dimensional finite volume unstructured mesh method (FVUM) based on a triangular mesh is developed for analyzing the evolution of the saltwater intrusion into coastal aquifer systems. The model formulation consists of a ground-water flow equation and a salt transport equation. Simulation results are compared with previously published solutions where good agreement is observed. Key-Words: Saltwater Intrusion, Coastal Aquifer, Dispersion, Unstructured Finite Volume, Vertex-Centered