Impacts of climate and land-use change on groundwater recharge in the semi-arid lower Ravi River basin, Pakistan

Abstract

Climate and land-use change significantly impact the hydrological cycle and water resources. Groundwater recharge of the Lower Ravi River Basin (LRRB), Pakistan, using the Soil and Water Assessment Tool (SWAT) hydrological model was studied. Three General Circulation Models (GCMs) under two Representative Concentration Pathways (RCP 4.5 and 8.5) were used to project future rainfall and temperature. Present climate and land-use were used to develop the SWAT model. Future land-use was generated by using land-use change predictor model, CA-Markov from present maps. Groundwater recharge fluctuated with changing climate and land-use with an increase of annual temperature by 2.1 °C and 3.7 °C for RCP 4.5 and 8.5 respectively, by 2050. The annual mean precipitation increased by 2.45% and 4.47% for both scenarios resulting in an 8% rise in recharge along with a seasonal shift. Future land-use change reduced recharge up to 38%. The combined impacts of climate and land-use change reduced groundwater recharge by 15%.