Shallow water equations for large bathymetry variations

7 pages. Other author's papers can be downloaded at http://www.lama.univ-savoie.fr/~dutykh/International audienceIn this study, we propose an improved version of the nonlinear shallow water (or Saint-Venant) equations. This new model is designed to take into account the effects resulting from the large spacial and/or temporal variations of the seabed. The model is derived from a variational principle by choosing the appropriate shallow water ansatz and imposing suitable constraints. Thus, the derivation procedure does not explicitly involve any small parameter