An integrated geoinformatics and hydrogeological approach to delineating groundwater potential zones in the complex geological terrain of Abuja, Nigeria

Abuja is the federal capital territory of Nigeria, and it is characterized by complex geological configuration, high water scarcity, and dense human population. Given the complex geology and increasing population, the need for groundwater for human use and socioeconomic growth has increased. Previous studies in this region have mostly utilized conventional geological, electromagnetic, resistivity, and topographical methods in attempts to provide accurate quantitative evaluations of groundwater resources for effective and sustainable water development and management. Studies that have integrated innovative remote sensing (RS), geographic information system (GIS), and hydrogeological methods have not been obviously documented in the area. In this paper, RS, GIS, and hydrogeological techniques were combined to delineate the groundwater potential zones across Abuja. To achieve the objectives of this study, eight key factors (geology, lineament density, soil type, drainage density, slope, geomorphology, and land use/land cover) that influence the presence and movement of underground water were remotely extracted, rasterized, and used in producing their thematic maps using ArcGIS. The eight thematic maps were given weights according to their significance and based on expert opinion. The thematic factors were combined using weighted overlay approach to create a composite map of groundwater potential zones. Each of the map's four groundwater potential zones—very poor, poor, moderate, and good—represents 2%, 52%, 43%, and 3% of the entire study area, respectively. The performance of the map was evaluated using hydrogeological (borehole) data gathered from 185 wells across Abuja. The validation outcomes show strong agreement with the reality on site; and thus, suggests that the study’s outcomes could support the effective and sustainable development of groundwater resources.