Abstract

Preliminary results of mathematical modelling of plane deformations of an open stream, the channel of which is combined from non-cohesive materials, are presented. This modelling is carried out at various regimes of unsteady water motion with different rates of sediment saturation. The equations of water motion (the St. Venant equations) and the equation of balance of a firm material are considered simultaneously. The mechanism of channel expansion and the factors influencing for the speed of bank erosion are discussed. The comparison of various techniques for calculation of coastal deformations is given. Examples of numerical results are presented.

Keywords: the mathematical modelling, unsteady flow, meandering, the channel band, the channel deformation, the bank erosion