CRPC-TR97689 February 1997 Title: Finite Element Approximation to the System of Shallow Water Equations, Part I: Continuous Time A Priori Error Estimates Authors: S. Chippada, C. Dawson, M. Martinez, M. Wheeler Abstract: Various sophisticated finite element models for surface water flow based on the shallow water equations exist in the literature. Gray, Kolar, Luettich, Lynch and Westerink have developed a hydrodynamic model based on the generalized wave continuity equation (GWCE) formulation, and have formulated a Galerkin finite element procedure based on combining the GWCE with the nonconservative momentum equations. Numerical experiments suggest that this method is robust, accurate and suppresses spurious oscillations which plague other models. We analyze a slightly modified Galerkin model which uses the conservative momentum equations (CME). For this GWCE-CME system of equations, we present a continuous-time a priori estimate based on an L^2 projection. Key Words: shallow water equations, surface water flow, mass conservation, momentum conservation, finite element method, a priori error estimate AMS Subject Classifications: 35Q35, 35L65, 65N30, 65N15