Assessing the Effect of Land/Use Land Cover and Climate Change on Water Yield and Groundwater Recharge in East African Rift Valley using Integrated Model

• Main Authors: Bisrat Ayalew Yifru, Il-Moon Chung, Min-Gyu Kim, Sun Woo Chang
• Format: Article
• Language: English
• Published: Elsevier 2021-10-01
• Series: Journal of Hydrology: Regional Studies
• Subjects: Climate change; Land use/Land cover change; Rift Valley; SWAT-MODFLOW; Water yield; Groundwater recharge
• Online Access: http://www.sciencedirect.com/science/article/pii/S2214581821001555

Study region: East African Rift Valley basin. Study focus: Water availability in the rift valley relies heavily on the discharge from the highlands to rivers that run to the rift floor. This research explores the effect of Land use/Land cover (LULC) and climate change on water yield and groundwater recharge (WYGR) using coupled SWAT-MODFLOW, which integrates Soil and Water Assessment Tool (SWAT) and Newton Modular Finite Difference Groundwater Flow (MODFLOW-NWT). The LULC change was analyzed using artificial neural network-based cellular automata. New hydrological insights: The dominant LULC is cultivated land and expanded by 5% to the forest and grassland areas. The average temperature and precipitation are expected to rise by 8–11% and 3–6%, respectively. Climate change affects the spatiotemporal distribution of WYGR significantly, while LULC change has a trivial effect. Under the baseline scenario, the recharge was 10% of the average annual precipitation, but climate change is projected to reduce it by 47–53%. Water yield reduction up to 48% and change of perennial rivers to intermittent are expected in the coming decades. The region will experience water scarcity, emerging mainly from climate change.