Integrating Climate Change, Hydrology, and Water Footprint to Measure Water Scarcity in Lesotho, Africa

This research integrated bias-corrected results from regional climate models, a watershed hydrology model, and water footprint analysis to measure the impact of climate change on future water scarcity in Lesotho, a water-rich yet data-poor country. Simulations from three climate models with two different Coupled Model Intercomparison Project Representative Concentration Pathways, 4.5 and 8.5, were bias corrected. Streamflows were simulated using the Soil Water Assessment Tool in the Senqu basin, which covers approximately two-thirds of Lesotho. This provided the future blue water availability of this river until 2100. Three scenarios were adopted to analyze the water scarcity of Lesotho. Scenario 1 used the national blue water footprint in the water scarcity calculation to investigate the worst-case scenario. Scenario 2 used the modified blue water footprint based on the population living within the Senqu River basin. Scenario 3 used a modified blue water footprint that accounted for the projected population growth of Lesotho. The results of Scenario 1 indicated 4 years of moderate water scarcity, and the results of Scenario 3 indicated 2 years of severe water scarcity. The modeling framework from this study can be applied to other remote places where limited data are available. (C) 2021 American Society of Civil Engineers.