An Ensemble Approach Modelling to Assess Water Resources in the Mékrou Basin, Benin

Abstract

The aim of the study was to test the possible adequacy of an ensemble model to reproduce the observed flows in the Mékrou basin and in what measure this ensemble simulation could be used instead of a unique model. Single model applications showed shortcomings in terms of simulating both high and low flows at the same time. Thereby, the models were calibrated according to two different modes (high and low flows) and they were tested further through the elaboration of three various ensembles. The observed hydrographs were separated in three parts each in order to evaluate with much precision which model or ensemble fits best the hydrographs. On the basis of the Root Mean Squared Error (RMSE), the models and derived ensembles were assessed using discharge data. In this paper, the comparison is made between models, mean and median ensembles. Good results were obtained for all models and ensembles but the best ones were achieved by the mean-based ensemble.