Groundwater Potential Mapping of Oluku Community, Benin City Utilizing Analytical Hierarchy Process (AHP) and Geographic Information System (GIS)

Abstract

Lack of groundwater potential mapping makes issues worse in areas where water scarcity is already a problem. Groundwater potential mapping provides valuable insights into the availability and sustainability of groundwater resources. Without this information, it becomes challenging to plan and develop water supply systems effectively. This research aims at presenting a method of determining the groundwater potential zones within Oluku community in Benin city using the multi-criteria decision analysis approach, particularly the Analytical Hierarchy Process (AHP) method and GIS. Eight groundwater conditioning factors were employed to comprehensively analyze groundwater potential within the study area. These factors encompassed soil, geology, land use/ land cover, drainage density, slope, flow direction, elevation and lineament density. These factors were ranked based on their potential contribution to groundwater occurrence and given factor weights according to the AHP technique, the combination of these groundwater conditioning factors with their corresponding weights in the ArcGIS software resulted in the groundwater potential map. Findings revealed that 7.62% (0.62 km²), 70.59% (5.76 km²), 21.16% (1.73 km²) and 0.63% (0.05 km²) of the entire study area had low, moderate, high and very high groundwater potential respectively. The research concluded that very few locations within the study area have very high likelihood of groundwater occurrence. The resulting groundwater potential map is essential in pinpointing locations that are ideal for groundwater extraction, reducing water scarcity and supplying water to expanding populations within the study area. Thus, groundwater potential mapping is a crucial and valuable tool for sustainable development, water security, and environmental protection.