Groundwater potential mapping using GIS and remote sensing with multi-criteria decision-making in Shinile sub-basin, eastern Ethiopia

The main challenge for water resources development as well as food security in arid and semi-arid regions of Ethiopia is the hydroclimatic variability. Groundwater resources are largely the main sources of water supply in such regions, alleviating the pressure of hydroclimatic variability on water resources. The present study delineated the potential groundwater zones in the Shinile sub-basin by using geospatial techniques. The criteria used were: geology, geomorphology, slope, soil, lineament density, drainage density, land use land cover, topographic wetness index, topographic roughness index, and rainfall. The relative weights were given by the analytic hierarchy process. A validation was done using the area under the curve (AUC=0.941) of the receiver operating curve (ROC) from borehole data. The study region was partitioned to low, moderate, and high potential groundwater zones having respectively 1.5%, 43%, and 55% of the total area. The high potential areas are concentrated in the central part where alluvial and lacustrine sediment is the dominant geologic unit. The validation results suggest that the geospatial identification of groundwater potential zones effectively performed well in the study area. This study is very important for water management experts as well as for stakeholders and policymakers in the study region.