Channel flow routing using the method characteristic and four-point implicit finite difference method

Principle equations governing the movement of a flood wave in open channels have been described in their simplified form, that are applicable to practical problems. A procedures for the numerical solution of the complete equations of unsteady flow, aimed at their application to flood routing, is described. A detailed treatment of explicit and implicit characteristic method as well as four-point implicit fixed mesh finite difference method have been given. The initial and boundary conditions appropriate for stream flow routing are prescribed. An implicit iterative method, which is the Newton-Raphson method has been applied to solve nonlinear equations. For practical application of the numerical methods, a Fortran programs has been developed and then tested on a test problem. In addition sensitivity of the models developed to channel characteristics have been analyzed. The practical application of these models to test data and their requirements for this application favour to choose method that can provide relatively fast and accurate solutions extending over a relatively long time scale.