Groundwater potential zone assessment using integrated analytical hierarchy process-geospatial driven in a GIS environment in Gobele watershed, Wabe Shebele river basin, Ethiopia
Jerjera Ulu Guduru, Nura Boru Jilo
Abstract
Gobele watershed, Wabe Shebelle River Basin, Ethiopia. Recently, extremely increasing population numbers, and irrigation demand have imposed water problems in the study area. Hence, this study aimed to delineate groundwater potential zones through an integrated approach of remote sensing, geographical information system (GIS), and Analytical Hierarchy Process (AHP) in the Gobele watershed. Numerous factors like rainfall, geology, land use/land cover, slope, soil types, drainage density, lineament density, and topographic wetness index were considered to demarcate groundwater recharge. The relative weight of each factor was determined using AHP. Ultimately, all thematic layers were aggregated by a weighted sum overly analysis in a GIS environment to map groundwater potential zones using relative weights derived from the AHP. Finally, to verify the result, of the model was validated with 30 observed springs and well yield. The distribution of groundwater potential zones was spatially varied in that a high groundwater recharge zone covers 2.4 % of the watershed, a moderate (93.7 %) and a low (3.9 %). The validation analysis revealed a 90 % agreement between the groundwater inventory data and the developed groundwater potential zone. Hence, the results are reliable and enable water users and decision-makers to sustainably utilize the available groundwater in the study area. Furthermore, this study is one of the rare groundwater investigations in the hydrogeological setting of the study area.