GIS-Based Assessment of Groundwater Potential Zones in Lokoja Metropolis, Kogi State, Nigeria Using Remote Sensing and Analytical Hierarchy Process.

Abstract

Groundwater is essential for human survival but faces threats like contamination from agriculture, industry, domestic activities, over-extraction, and climate change impacts. These challenges cause health risks and water scarcity, affecting socio-economic stability. This study aimed to assess groundwater potential zones in Lokoja metropolis, Kogi State, Nigeria. With a view to provide relevant information for the sustainability and management of groundwater resources. Data used are Landsat 8 OLI satellite images, Digital Elevation Models, rainfall data, soil and geological map. The Analytical Hierarchy Process (AHP) evaluated factors influencing groundwater, including geology, rainfall, lineament and drainage density, slope, elevation, soil, and land use, with groundwater potential zones mapped via Weighted Index Overlay Analysis in ArcGIS. The zones were classified from very low to very high potential. The very low zone covers 14.01% of the area, mainly amphibole schist; low potential (24.02%) aligns with granite and charnockite; moderate (24.93%) with migmatite; high (23.75%) with sandstone and siltstone; and very high (13.24%) with undifferentiated alluvium, concentrated centrally. Geology was the most influential factor (37%), followed by lineament density (18%). The west showed very high potential due to dense lineaments and flat terrain, while the east had lower potential. The study recommends that government may provide alternative water sources in low potential areas to address water scarcity.

Keywords:  Groundwater, RS, GIS, AHP, GWPZ