GIS-based multi-criteria evaluation of groundwater potential of the Beshilo River basin, Ethiopia

Application of modern techniques is a pre-requisite for sustainable groundwater development. In this study, Digital Elevation Model (DEM; resolution of 30 x 30 m) was used to obtain the elevation, slope, and drainage density themes that are necessary for targeting groundwater potential. The lineament and geology map (at a scale of 1:250,000) were collected from the Geological Survey of Ethiopia. The land use image (30 x 30 m resolution) was downloaded from the United States Geological Survey (USGS) website for the necessary analysis. The Analytical Hierarchal Process (AHP) was employed to assign weights to various thematic maps, and they were overlaid using the "Weighted sum" overlay analysis in the geographic information system (GIS) domain. The resulting output highlights the groundwater prospectus of the Beshilo River basin in the Upper Blue Nile, Ethiopia, which is characterized by an undulating terrain with the elevations varying from 1117 to 4235 m. The slope of the study area ranges from 0 to 77.05 degrees. The final result shows that 4551.93 km(2) (34.78%) of the study area falls in the "High" groundwater potential zone. The "Moderate," "Low," and "Very low" groundwater potential areas cover an areal extent of 4041.21 km(2) (30.88%), 3600.64 km(2) (27.51%), and 892.49 km(2) (6.82%) respectively. The effect of rainfall, elevation, and soil texture on the groundwater potential was also evaluated in this study. The main objective of this study is to decipher groundwater potential zones and to evaluate the influence of elevation and soil texture on groundwater potential zones.