In a two-dimensional shallow water flow model advective-diffusion derivative equation is discretized with cell center finite volume method.Flux reconstruction and support operators method are used for advective and diffusive terms,respectively.The model is second order and can be used for arbitrarily unstructured grids.A pure advective problem and a pure diffusion problem verify the algorithm.The model is used to simulate salt transport in Oujiang estuary.Water level,velocity and salt calculated are in good agreement with measurement.