In this paper the evolution of a schematic tidal basin, with non-uniform sediments and subject to geological and anthropogenic processes, is reproduced by means of a two dimensional morphodynamic model and qualitatively compared to the events which historically took place in the Venice Lagoon during the last four centuries; the trend for the next 200 years is also investigated. In particular, the effect on both morphology and bottom composition of river diversion, jetty construction, human-induced subsidence and channel dredging are presented and discussed.