Climate change affects ecosystems, agriculture, human health, forestry, and water resource availability. This study is mainly aimed at assessing the climate change effect on the water resources of the Kessie Watershed in the Upper Blue Nile Basin, Ethiopia. The updated Coupled Model Intercomparison Project Phase 6 (CMIP-6) data outputs were used. The three climate model outputs: ACESS_ESM1-5, FGOALS_g3, and GFDL_ESM4 with two shared socioeconomic pathways (SSP2-4.5 and SSP5-8.5) scenarios, were used. The climate model output rainfall and temperature data were downscaled to the station level through bias correction. The catchment hydrology was represented by the SWAT—Soil and Water Assessment Tool—through calibration and validation. Future temperatures and rainfall change were evaluated by the Mann–Kendall trend test and Sen’s slope estimator. Future climate change trend analysis and streamflow simulation were done on two time horizons: the 2050s (2041–2070) and the 2080s (2071–2100). The baseline streamflow data (1985–2014) were used as a reference. The global climate model projection data indicated mean annual precipitation and temperatures show a slight increase for the future in both scenarios for all climate model outputs. According to the SSP2-4.5 and SSP5-8.5 scenarios, respectively, mean annual precipitation is expected to increase by 5% and 4.89% in the 2050s and 10.13% and 6.8% in the 2080s based on ACCESS_ESM1-5; 4.7% and 3.8% in the 2050s and 4.3% and 4.84% in the 2080s based on FGOALS_g3; and 4.67% and 3.81% in the 2050s and 4.67% and 3.81% based on GFDL_ESM4 models data. Yearly average maximum temperature may increase by 3.62 °C and 1.87 °C in the 2050s and 3.31 °C and 2.99 °C in the 2080s based on ACCESS ESM1-5, 1.76 °C and 1.25 °C in the 2050s and 3.44 °C and 2.61 °C in the 2080s based on FGOALS-g3, and 2.15 °C and 3.83 °C in the 2050s and 1.37 °C and 2.66 °C in the 2080s based on GFDL-ESM4 model data. Similarly, the mean annual minimum temperature is also expected to increase by 2.73 °C and 1.90 °C in the 2050s and 5.63 °C and 4.52 °C in the 2080s based on ACCESS ESM1-5, 3.04 °C and 2.43 °C in the 2050s and 3.55 °C and 4.36 °C in the 2080s based on FGOALS-g3, and 2.31 °C and 3.29 °C in the 2050s, and 3.16 °C and 3.87 °C in the 2080s based on GFDL-ESM4 model data. The streamflow is also expected to increase. In the 2050s, simulated annual streamflow is expected to increase from 12.1 to 21.8% and 9.8 to 15.4% in SSP2-4.5 and SSP5-8.5, respectively, whereas in the 2080s, the change is expected to increase from 15.14 to 24.08% and 13.08 to 41% in SSP2-4.5 and SSP5-8.5, respectively. Future water resource potential of the case study watershed seems able to support irrigation and other projects.

This study identifies groundwater potential zones (GWPZs) in the Borkena watershed, Ethiopia, using Geographic Information Systems (GIS), remote sensing, and the Analytical Hierarchy Process (AHP). Ten critical parameters elevation, slope, drainage density, land use/land cover (LULC), rainfall, soil type, aspect, curvature, lineament density, and geology were integrated to produce a GWPZ map. The results show that areas with slopes between 0° and 6.3°, elevations below 1500 m, and specific soil and lithological characteristics exhibit high groundwater potential, covering approximately 340 km². Additionally, 453 km² and 867 km² were identified as moderate and medium potential zones, respectively. Most existing studies focus on the technical and spatial aspects of delineating potential zones without explicitly addressing how these findings contribute to broader sustainability goals, particularly in the context of long-term water security, climate resilience, and socioeconomic development. This gap is significant given that effective groundwater management directly supports multiple Sustainable Development Goals (SDGs), especially SDG 6 (Clean Water and Sanitation), SDG 2 (Zero Hunger), and SDG 13 (Climate Action) But, This study underscores the effectiveness of multi-criteria decision-making (MCDM) and geospatial technologies in groundwater resource assessment and supports Sustainable Development Goals (SDGs), particularly SDG 6 (Clean Water and Sanitation), SDG 2 (Zero Hunger), and SDG 13 (Climate Action), by informing sustainable water resource planning and management.

As industrial and economic growth intensifies, greenhouse gases are released into the atmosphere, leading to a shift in global warming and climate change patterns. The Mille watershed faces significant challenges such as flooding, drought, irrigation, and water supply scarcity, as well as health issues stemming from climate change within the community. Thus, this study aims to assess the impact of climate change on hydrology in the Mille River, Awash River Basin, Ethiopia, utilizing multiple hydrological and climate models. The study examines three global circulation models (MIROC‐6, CMCC, and MRI) operating under two shared socioeconomic pathways emission scenarios (SSP2‐4.5 and SSP5‐8.5) for both mid‐term (near future) (2041–2070) and long‐term (far future) (2071–2100) periods. Precipitation and temperature scenarios data were obtained using the CMhyd Tool and then bias‐corrected using various methods based on the base time period (1985–2014). The projected annual rainfall is expected to increase by 8.91‐18.68% and 8.09‐18.65%, while the average temperature is projected to increase by 1.08–3.04°C and 1.59–4.05°C in the 2050s (2041–2070) and 2080s (2071–2100), respectively. The SWAT model shows daily responses with NSE (Nash–Sutcliffe efficiency) values of 0.77 for calibration and 0.79 for validation, R2 (coefficient of determination) values of 0.80 for calibration and 0.81 for validation, and PBIAS (percent bias) values of −10.6 for calibration and −8.6 for validation. Similarly, the HBV model shows NSE values of 0.683 for calibration and 0.706 for validation, R2 values of 0.705 for calibration and 0.71 for validation, and PBIAS values of −4.25 for calibration and −6.669 for validation. The results indicate a decrease in average annual streamflow ranging from −5.95% to −39.29% for SWAT and from −12.28% to −35.04% for HBV in the near future (2050s) and Far future (2080s) compared to the base period (1985–2014). The significance of this study lies in its contribution to understanding climate‐hydrology interactions in a vulnerable region, providing actionable insights for adaptation planning, policy formulation, and sustainable resource management in the face of climate change. Extreme high and low changes in flow were used to quantify this impact. Therefore, based on the observed trends of decreased streamflow volume, recommendations for the study area include the development of water sources such as microdams, ponds, and water wells, implementation of water harvesting techniques, improvement of land use and land cover practices, proper utilization and management of available discharge, drought assessment, and environmental impact assessment. These measures are crucial for mitigating the adverse effects of climate change and ensuring the resilience of the region’s water resources.