Evaluating wetting and drying algorithms for finite element models of shallow water flow

Three methods for the treatment of partially wet elements in finite element (FE) models of shallow water flow are evaluated: two previously used techniques, the element masking (EM) method and the free surface correction method, and a technique using a continuity correction to the EM method. A simple 1D Runge-Kutta method is used to develop a uniform velocity solution to the problem of inundation of a planar beach, which is used to assess the success of the FE model and the three wetting and drying algorithms in reproducing the water free surface profile. The EM technique is found to be most successful at reproducing the profile, but at the expense of mass balance errors, which can be reduced by use of a finer mesh. This has implications for environmental models of moving boundary shallow water flows, where different wetting and drying algorithms may be required in different parts of the mesh. Copyright (C) 2002 John Wiley Sons, Ltd.