The Combination of Simulated Discharges of Hydrological Models: Application to the WMO Intercomparison of Conceptual Models of Snowmelt Runoff

Hydrological models are frequently used to simulate streamflow. A method for improving performance is to combine the simulated discharges of two or more models. Three different methods are given in detail for the calculation of the weights used in the combination. This paper applies the methods of Granger and Newbold (1977) to the combination of simulated discharges of conceptual deterministic models which participated in the recent WMO intercomparison of models of snowmelt runoff WMO (1985). The numerical criteria adopted in the above study were used to evaluate the performance of the combined simulated discharges. The results of this study show that the combination of discharges results in improved performance in 80 % of the cases and that in cases where there is no improvement, the losses in the values of the criteria are small.