Abstract

The optimization of the Muskingum method coefficients is important for increasing the accuracy of the method. One of the main problems in this method is the estimation of the outflow rate at the time of flood initiation, which usually is taken equal to the inflow rate at the same time. In this study, due to the uncertainty of this assumption, the Particle Swarm Optimization (PSO) algorithm was used and in addition to calculating the coefficients of the linear Muskingum method (X, K), the outflow value in the flood initiation time is optimized in proportion to the amount of inflow at the same time. The calculated coefficients and the optimized input outflow rate using a flow considered as observed flood can then be used to calculate the flood outflow for other related floods at the same hydrometric stations. The accuracy of the Muskingam method has been increased using the proposed approach in this research.