PROJECTED HYDROLOGICAL CHANGE IN THE DANO CATCHMENT, BURKINA FASO: IMPLICATIONS OF CLIMATE AND LAND-USE SCENARIOS FOR WATER SCARCITY AND DROUGHT RISK

Water resource shortages are a growing concern in the semi-arid Dano catchment, Burkina Faso, where climate and land-use change jointly reshape the ecosystem services local communities depend on. This study uses the Soil and Water Assessment Tool (SWAT), integrating four bias-corrected CORDEX-Africa Regional Climate Models under RCPs 4.5 and 8.5 with two CA-Markov-projected 2050 land-use scenarios, Business-as-Usual (BAU) and Afforestation, to quantify impacts on surface runoff, groundwater/base flow, lateral flow, evapotranspiration (ET), and water yield. Projected land use shows continued forest degradation, agricultural expansion, and settlement growth, with savannah cover declining 8.18% under BAU but recovering 2.13% under Afforestation. Under LULC change alone, water balance components rise modestly: water yield by 0.18-0.28%, runoff by 0.02-3.30%, and ET by 0.21%, while lateral flow falls by up to 1.46% under Afforestation. Under climate change alone, precipitation is projected to fall 20-22% and temperature to rise 1.50-1.70°C (RCP4.5/8.5), driving sharp declines in runoff (up to 77%), groundwater flow (up to 90%), lateral flow (30%), and water yield (64%), alongside a 3.6-3.9% rise in potential evapotranspiration (PET). Combined signals indicate an overall decline in water balance components by 2050, with PET rising 3.2-3.7% even as urban and cropland expansion marginally elevate streamflow. These results reveal a significant association between climate, streamflow, and human land-use pressures, heightening drought and flood risk. Afforestation is identified as key to sustaining future flows, though its benefit is strongly moderated by climate severity. Findings support water managers in pursuing afforestation, erosion control, and water conservation to advance SDGs 6, 13, and 15.