Sediment transfer to overbank sections

This paper presents a numerical model for simulating the transfer of suspended sediment from a channel to an adjacent flood plain under conditions of steady, longitudinally uniform flow. The model accounts for transverse transfer of sediment by convection and turbulence. Turbulent transfer is modelled by the diffusion analogy and empirical relationships are used to evaluate the distributions of diffusivity and bed shear stress. The elliptic partial differential equation describing the distribution of suspended sediment concentration under the influence of these transfer mechanisms is solved numerically by the method of Successive Over-Relaxation. The model can be applied to sediments of different sizes and densities and can be used to predict the extent and relative distributions of deposits over the flood plain as well as the size and density characteristics of deposited material at any position on the flood plain. The model is verified by comparing predicted distributions of fine sand deposits with those measured in laboratory experiments for extreme plain surface conditions.