16. Geospatial-Based Groundwater Potential Zone Investigation and Mapping: A Case Study of the Upper Awash Basin, Ethiopia

Rapid population growth and diversified activities have increased the utilization of groundwater resources for domestic and industrial processes and irrigation in the Upper Awash Basin. The objective of this study was to identify prospective groundwater zones (GWPZs) in the Upper Awash Basin by utilizing remote sensing and auxiliary data. Thematic layers of the parameters that influence groundwater occurrence and movement in the study area were produced using satellite images and other auxiliary data. Accordingly, eight thematic maps, geomorphology, geology, slope, rainfall, lineament density, land use/land cover (LULC), drainage density, and soil, were prepared and transformed into raster datasets using ArcGIS 10.7. Weights were allocated to theme layers based on their significance in the generation of groundwater potential in the study area. The AHP pairwise comparison matrix was utilized to calculate the hierarchical rank of each parameter, and the final normalized weights of each layer were estimated. The layers were then integrated using a weighted overlay technique, and a GWPZ map was produced. The study area’s GWPZ map was classified into five categories: excellent (0.60%), very good (54.21%), good (32.21%), medium (12.73%), and poor (0.25%). Finally, to evaluate the validity of the results, the GWPZ map was verified using data from 201 boreholes distributed throughout the basin. The validation result confirmed that 82.3% of high-yield boreholes correspond to “very good” category of the GWPZ. Therefore, the applied method provides acceptable result that can help future planning and sustainable utilization of the groundwater resources in the Upper Awash Basin.