Groundwater recharge assessment under climate change scenarios: a case study of Kiryandongo, Uganda

ABSTRACT Groundwater recharge is an important element in ensuring the sustainability of groundwater reservoirs. Unfortunately, its spatial distribution patterns and volume are influenced by climate and land use/land cover changes. This article uses the WetSpass-M model to assess the impacts of climate and land use/land cover changes on groundwater recharge in the Kiryandongo area. Long Ashton Research Station Weather Generator-8 (LARS-WG8) model was calibrated and used to downscale the future climatic variables from the Coupled Model Intercomparison Project Phase-6. The downscaled temperature shows an increase in the annual mean temperature of 1.05 and 1.23 °C under the shared socioeconomic pathways (SSPs), SSP126 and SSP245, respectively. However, annual precipitation is projected to increase by 6.7% under SSP126 and 9.3% under SSP245. The WetSpass-M model was calibrated, and coefficients of determination (R2) of 0.83 and Nash Sutcliffe efficiency of 0.82 were obtained. It was then used to simulate groundwater recharge. The simulated groundwater recharge, considering the combined effects of climate and land use/land cover changes, shows an increase of 14.79% under the SSP126 and 13.31% under the SSP245 scenarios. However, if land use/land cover changes are kept constant, recharge would increase by 21.9% under SSP126 and 19.8% under SSP245 compared to the baseline.