TR-27 : Comparison of some variable parameter simplified hydraulic flood routing models

Abstract

The three point variable parameter Muskingum Cunge method envisaged by Ponce and Yevjevich is based on the concept of relating the physical diffusion with the numerical diffusion at every routing time level which is achieved by averaging the discharges and the wave celerities at both the inflow and outflow sections of the previous time level, and at the inflow section corresponding to present time level. It has been found that this method is able to reproduce the St.Venant's solution for a given inflow hydrograph and for a given channel reach closely than the constant parameter Muskingum-Cunge Method. Another variable parameter Muskingum flood routing method proposed by Perumal is based on the concept of linear variation of flow depth along the reach. Like variable parameter Muskingum-Cunge method, in this method also, both the-parameters can be varied at every routing time level , but still adopting the linear form of solution. In this report the solutions of both these methods have been compared with the St.Vanant's routing solution for a given inflow hydrograph and the given channel reach. The results show that the variable parameter Muskingum method developed by Perumal performs better than the variable parameter Muskingum-Cunge method developed by Ponce and Yevjevich.