Application of remote sensing and electrical resistivity technique for delineating groundwater potential in North Western Nigeria.

ABSTRACT

Improving the living condition of residents of Palladan and Basawa community requires access to drinking water. The main objectives of this paper are to identify suitable groundwater zones for productive drilling and to assess groundwater mineralization in the coastal aquifers of the study area. Geographic Information Systems (GIS) and Analytical Hierarchy Process (AHP) were used in the methodology to generate the groundwater potential map. Slope, landcover/land use, lineament density, rainfall, soil cover and drainage density were taken into account to characterize the groundwater potential zones. Weights were assigned to the various parameters and their characteristics according to their impact on groundwater recharge. The groundwater potential map was classified into five zones namely poor, fair, moderate, good, excellent. Based on the lineament density map, the distribution of these lineaments reveals the degree of porosity or permeability in each area and, consequently, its groundwater potential. Aeromagnetic data filtering permits the construction of a structural map that illustrates various geophysical lineaments that are known to be fault systems in the research area. These faults are the main routes via which groundwater seeps into the subsurface and granitoid-type magnetic rocks intrude into the basement. The research region is badly fractured/failed and made up of four lithologic units, including the aquifer layer (clayey sands in the cracked basement) with thicknesses varying from 12-55 m, according to the vertical electrical sounding (VES) applications. According to geoelectric cross-sections, the subsurface structures are made of granitic rocks that are surrounded by normal faults that trend both NW and NE. It is believed that groundwater flows into the hard rock aquifers in the studied locations through these notable geological features, such as faults and fractures. Two phenomena are responsible for the mineralization of water a process of interaction between water and rock; and a process of salinization resulting from natural phenomena or anthropic activities. The present study could guide hydrogeological investigations and groundwater resource management planning in the study area.