Abdou Boko BOUBACAR
This study has assessed the integrated hydrological response to climate change impact on large scale, semi-arid watershed using the fully integrated HydroGeoSphere (HGS) model. The model was calibrated using a novel, straightforward 3-steps methodology : 1) steady state, 2) dynamic equilibrium and 3) daily transient. Simulations results show that exchange flux between groundwater and surface water are important processes in the basin. The durations and occurrences of the Minimum Environmental Flow (MEF) conditions of the Niger river at Niamey required to supply drinking and agricultural water of the Niamey city were found to be very sensitive to changes in runoff resulting from climate changes. The groundwater table response to climate change impacts is shown to be more perturbed in topographically high area, than in low altitude zones.