Sensitivity of the HMS model to various modelling characteristics: case study of Bin El Ouidane basin (High Atlas of Morocco)

Due to their importance in water resource management, the hydrological models have been widely applied in different contexts and various circumstances. Common sensitivity analysis studies aim to determine the most influencing parameters, in order to focus on them during calibration. The main objective of this research is to investigate the sensitivity of the Hydrologic Modelling System (HMS) model to four others modelling characteristics: modelling formalisms, percent of impervious, parameters initial values and periods of simulation. The model is applied to the basin of Bin El Ouidane (Morocco), and the results show a substantial variation of calibration and validation efficiency depending on the four characteristics mentioned. In addition, we confirmed the applicability of the African soil grids map on estimating hydrological parameters of the loss methods, and we proposed an approach to determine the optimal percent of impervious for a basin required by the five HMS loss methods. This paper’s results represent guidelines for any further HMS hydrological modelling, in contexts where data availability issues persist and prevent the development of water resources field.