When the parameter optimization of hydrological models is done under the framework of multiobjective, how to select or construct proper combination of objective functions is one of the most important issues.To solve this problem, one simple and convenient method for the comparison of the influence of different objective function combinations on the optimization results, which were obtained by multi-objective evolutionary algorithms,was proposed.A hydrological model for daily streamflow forecasting was taken as an example.Three objective function combinations were constructed,and the multiobjective algorithm NSGA-II was employed to optimize the hydrological model.Based on the optimization results,the proposed method was applied to analyze the performance of model calibration with different combinations of objective functions.It was also expected to find a combination of objective functions which can well balance different objective functions.The results showed that the proposed method is effective to analyze the performance of different combinations of objective functions,can provide more comprehensive evidence for decision making in hydrological forecasting, and has good prospects in practical engineering.
