Geospatial technology-based identification of groundwater potential zone in the Upper Dawa River Basin, Southern Ethiopia

Abstract

Groundwater (GW) is a vital freshwater resource and essential for meeting domestic, irrigation, and industrial demands. As the demand for water rises, evaluating groundwater potential (GWP) and aquifer productivity becomes increasingly important. This research focuses on mapping groundwater potential zones (GWPZ) in the Upper Dawa River Basin (UDRB), Southern Ethiopia, utilizing a Geographic Information System (GIS)-based Analytical Hierarchy Process (AHP). Seven factors influencing GW availability, recharge, and distribution were considered: drainage density(DD), geology(GL), lineament density(LD), soil type, land use/land cover(LULC), rainfall, and slope. The WOA (weighted overlay analysis) tool in ArcGIS 10.8 generates the final GWPZ map. The results identified five categories of GWPZ: very low, low, moderate, high, and very high, covering 0.26 %, 45.9 %, 8.8 %, 16.34 %, and 28.08 % of the area under study, respectively. The volcanic terrain in the north and northwest, the limestone terrain in the southeast, and patchy or elongated small areas in the basement terrain in the center and south of the research area were mapped as high to very high GWPZs. Conversely, a significant portion of the basement terrain was classified as low-very low GWP. The GWPM (groundwater potential map) accuracy is assessed by utilizing the area under the curve (AUC) approach, resulting in an AUC value of 0.834, indicating a dependable outcome. The findings of this research contribute to ongoing efforts to ensure sustainable water sources for vulnerable communities in the area under investigation.