Intergrated Remote Sensing and GIS Based Approach for Aquifer zone Detection: A Case Study of Garaku, Nasarawa State

Abstract

Groundwater, a dynamic renewable natural resource is a vital source of freshwater. Compared to surface water, it accounts for about 30% of the Earth’s freshwater. The demand for water for various purposes have drastically increased. Surface water cannot meet this demand, and so, the dependency on groundwater has increased. An efficient and sustainable means of exploring for groundwater is necessary. This research methodology involves utilizing Remote sensing and Geographic Information Systems (GIS) for detecting aquifer zones in Garaku. Seven thematic maps (Geology, lineament density, drainage density, slope, LULC, rainfall, soil maps) were generated from remotely sensed data. Using Multi-criteria DecisionAnalysis-Analytical Hierarchy process, the thematic maps assigned weights. Rainfall ranking the highest was assigned 40.2%, Geology ranked 22.6%, lineament density ranked 14.6%, drainage density ranked 9.7%, soil ranked 6.1%, slope ranked 4%, and land use/cover ranked the lowest at 2.8%. The thematic maps were integrated to ascertain groundwater potential zones. The analysis revealed that 8% of the study area has very poor groundwater potential, 67% has poor groundwater potential, 24% shows good groundwater potential and 1% shows very good groundwater potential. A depth model was produced from the analysis of profiles taken along a few selected target zones. This revealed subsurface depressions within the groundwater potential zone. This study demonstrated the efficacy of remote sensing and GIS methodologies in mapping groundwater targets, and the produced maps can be used for groundwater production and management planning. Regular updates to the groundwater potential mapare essential to account for changes in land use, climate, and other factors influencing groundwater availability.