Numerical Solution of Kinematic Wave Equations and Runoff Computation in Kardeh Catchment

摘要

There are several methods for the solution of Kinematic Wave (KW) approximation of the St. Venant equations. These methods comprise the analytical and the numerical solutions. The numerical methods for the solution of KW equations include implicit and explicit schemes, some are advantageous over the other in terms of stability and convergence and generally the implicit methods are preferred for these reasons. In this study, the four point implicit scheme is adopted for the solution of the St. Venant equations to overcome the problems related to stability and convergence in explicit schemes. Thus, the kinematic wave equations are converted into finite difference algebraic equations and the computer program is developed. The developed model is able to compute the spatial and temporal distribution of runoff over the catchment. The developed model is tested on several catchments. In this study, the model application on an Iranian catchment (Kardeh River) is presented. The model inputs are rainfall intensities and physiographic parameters of the catchment. The comparison of computed and observed hydrographs show that the model is able to computed catchment response satisfactorily.