Abstract
Movement of sediment in rivers can be described in terms of three one- dimensional equations. Two are the well-known St.Venant flow continuity and dynamic equations, the third is a mass continuity equation for sediment. Although there are many different methods of solution of these equations, they can usually be generically classified as either coupled or uncoupled and linear or non-linear. The sediment continuity equation is only explicitly coupled to the two St.Venant equations by one term, representing the rate of deposition. If this is ignored, then the equations can be solved in an uncoupled manner. The finite-difference solution of the above equations, leads to a non-linear set of simultaneous equations. These may