Résumé
<p>In hydrology, enhancing existing models are good ways to establishing efficient and accurate conceptual frameworks for hydrological simulation’s purposes. Methodologically, a framework that has two parameters and three input variables, called SimulHyd, is used in this study to modelling runoff data, on sixteen watersheds of the <em>Niger</em> River and its tributaries, from 1950 to 1999. Purposely, this paper focuses on a model’s inter-comparison method, which summarizes, in tables, then in graphics and in maps, the obtained results. We enhance modelling outputs both in modifying the former french’s GR2M model to obtain a model called SimulHyd model and in developing a semi-distributed modelling from a lumped modelling approach.  SimulHyd stands for Simulation of Hydrological systems.</p>