Evaluating the effect of climate change and fast population growth on water supply and demand in Jimma town, Ethiopia, using the WEAP modeling tool

ABSTRACT Water is vital for life and various biophysical processes, yet despite covering over 71% of Earth's surface, it remains a scarce resource due to uneven distribution and management challenges. Water scarcity is a growing global issue, and in Jimma town, Ethiopia, the mismatch between water supply and demand is especially severe. This is exacerbated by rapid population growth and urban expansion, which stress the town's already limited water resources. This study assesses the impacts of climate change and land use changes on Jimma's water supply and demand using the Water Evaluation and Planning (WEAP) model. The research employs a scenario-based approach, considering five scenarios: current conditions, climate change, land use changes, combined impacts, and population growth. Results show that Jimma faces significant water shortages in November, December, January, and February, with additional shortages in April and May. Supply coverage is especially low in February (92%) and fluctuates in August and September due to prioritization of demand. Projections suggest that water demand could rise to 4.5 gigaliters by 2030, with unmet demand reaching 1.6 GL. The combined effects of climate change and land use changes may worsen these shortages, underscoring the urgent need for effective water management to ensure long-term sustainability.