In this paper grid method of continues forward characteristics and rectangular grid broken backward characteristics is presented, for the solution of saint Venant equations for free surface flow. The method yield depth and velocity hydrographs at predetermined distances from which depths and velocity are obtained. The distance steps used in this method need not be equal, and may be chosen in such a manner as to deal with each channel geometry and spatial distribution of lateral inflows. Studies so far show that there are minimal differences in accuracy between the direct and iterative formulation of method.
Journal of the Nigerian Association of Mathematical Physics, Volume 19 (November, 2011), pp 291 – 300