Distributed hydrological model EasyDHM II. Application

The application of the distributed hydrological model EasyDHM to the upper Hanjiang River basin is presented. The runoff generation model of EasyDHM, the Muskingum method, the parameter sensitivity analysis method LH-OAT and the parameter optimization method SCE-UA are used. The results of parameter sensitivity analysis and parameter optimization show that the sensitivity of different parameters in runoff generation and confluence model varies with space, but changes not significanfly with the length of time series. It not only indicates the importance of parameter subregion partition, but also the parameter optimization should only be operated in a short correction period for hydrological simulation in a long period. The high precision result demonstrates the necessity of parameter optimization and the reasonable choice of optimization method in EasyDHM.