Identification of Groundwater Potential Zones Using Remote Sensing and GIS Techniques: A Case Study in Jowhar, Somalia

Groundwater is the principal source of water supply in Jowhar District, Middle Shabelle Region, Hirshabelle State, Somalia, yet borehole siting has proceeded with limited systematic assessment of the conditions governing its occurrence. This study identified and mapped groundwater potential zones in the district by integrating remote sensing, geographic information systems and the Analytical Hierarchy Process. Nine thematic layers, namely geology, rainfall, soil, drainage density, land use and land cover, slope, lineament density, elevation and the normalized difference vegetation index, were derived from Landsat 8 OLI/TIRS imagery, SRTM digital elevation data, CRU TS rainfall records for 2015 to 2025 and ancillary geological and soil datasets. Each layer was reclassified onto a five-point suitability scale and weighted by pairwise comparison on Saaty's scale. Geology at 26.22 per cent and rainfall at 26.17 per cent emerged as the dominant controls, together accounting for 52.39 per cent of the total weight, with a consistency ratio of 0.038 confirming the acceptability of the judgements. Weighted overlay analysis in ArcGIS produced a groundwater potential index classified into four zones: Good, covering 3,023.99 km² or 67.54 per cent of the district; Moderate, 1,306.52 km² or 29.18 per cent; Poor, 135.22 km² or 3.02 per cent; and Excellent, 11.66 km² or 0.26 per cent. The map was validated against 48 boreholes obtained from the Ministry of Energy and Water Resources of Hirshabelle State and verified in part by field inspection, giving an overall concordance of 47.9 per cent and an area under the receiver operating characteristic curve of 0.486. Because no borehole lay within the Poor or Excellent zones, two classes remained untested, and the map is accordingly recommended for regional planning rather than for site-specific borehole siting.