An integrated method for mapping groundwater potential in part of Abuja, Central Nigeria

Abstract

This study used integrated remote sensing, geophysical and borehole data to evaluate and delineate promising sites for groundwater development. Groundwater conditioning parameters including geology, lineament density, elevation, slope, drainage density, NDVI, land use/land cover, static water level, aquifer resistivity, aquifer thickness, and overburden thickness were analyzed and rated based on their influence on groundwater recharge. To minimize bias in the rating techniques, 23 literature sources were consulted to evaluate each parameter. Thereafter, a series of pairwise comparisons was performed, and parameters were given weights using the Analytical Hierarchy Process (AHP) model. The final groundwater potential zones (GWPZs) map was created using the weighted linear overlay computation tool, which combines various factors influencing groundwater availability. Lineament and geology showed high percentage of influence. The GWPZs were classified into low (24.59%), moderate (64.36%), high (10.98%) and very high (0.07%) respectively. Given that low and moderate GWPZs cover a large proportion of the area, the GWPZs in the study area can be classified as low to moderate, which aligns with the findings of other researchers within Nigeria's basement complex. Model validation analysis revealed a 77.1% accuracy using existing borehole yield data. This suggests that the GWPZs results can act as a guide for the management and development of groundwater resources in the study area. It is recommended that comprehensive groundwater investigations, utilizing multiple approaches, be conducted to prevent the drilling of low-yield or unsuccessful boreholes in the study area