Erosion and sedimentation of a bump in fluvial flow

The 2D laminar quasistationary interacting boundary layer flow with mass transport of a suspended sediment is solved over an erodable bump (or dune) in the case of a fluvial regime. It is assumed that if the skin friction goes over a threshold value, the bump is eroded, then, the concentration of sediment in suspension is convected but falls at a constant settling velocity. This changes the shape of the dune, examples of displacement toward final equilibrium states are presented. (C) 2000 Academie des sciences/Editions scientifiques et medicales Elsevier SAS.