An assessment of conceptual hydrological models for simulating low-flow in the anthropized Kou catchment (Burkina Faso)

Abstract

Pressure on water resources is constantly increasing due to a growing demand and the impacts of climate variability and change. In such a context, marked by a limited knowledge of water resources, the analysis of low-flows is of growing interest. The current study aims to fill the gap related to the scarcity of information on low-flows in the Kou catchment. It applied a comparative approach based on the abilities (performance and robustness) of the GR4J, GR6J and HBV-light models to simulate low-flows over the 1981-2010 period. The methodology implied searching for the optimal parameters of the models using the Generalized Split-Sample Test method, and evaluating their performance during the validation on the basis of the robustness criteria. The results show that the GR4J model has the highest performance over the 2006-2008 period with an interquartile range for the logNSE criteria of 0.52 - 0.62, a mean of 0.58 and a calibration value of 0.8. The robustness of this model is 0.22 considering the mean of the criteria for the validation.