Behavior of a finite disturbance in a mobile bed stream

摘要

The commonly adopted approach for modelling unsteady river morphological processes is to couple the Saint Venant equations, for unsteady flow routing, with the Exner equation, for sediment mass conservation. Despite this model is widely adopted, some of its properties do not match physical behavior. Recently, a new class of morphodynamical models has been proposed, in which the sediment dynamics is somewhat reproduced (four-equations models). The object of present note is to better exploit the response of a four-equations model to a small bed perturbation through a mixed analytical-numerical procedure in a quasi-linear approximation.