A preliminary assessment for groundwater in a part of North Central Nigeria using Landsat ETM

Ayb Anifowose,Oo Aladejana

doi:10.4314/gjgs.v14i1.1

Abstract

In a basement environment where groundwater is restricted to secondary permeability, structural analysis using remote sensing is a reliable and cheap method for the start-up process for groundwater exploration. In this study, remote sensing and GIS technology were employed as a major tool for groundwater prospecting in a part of North Central Nigeria; an area prone to water scarcity for more than half of every year. The geological map of the study area, Landsat7 ETM+, and Shuttle Radar Topographic Mission (SRTM) imageries covering the area were employed in this study. Edge enhancements and directional filtering were carried out to enhance the visibility of lineaments on the Landsat imagery. To eliminate bias and subjectivity, Normalized Difference Vegetation Index (NDVI) and Digital Elevation Model (DEM) of the study area were processed for further lineament detection. Results indicate that lineaments extracted from the Landsat imagery were in agreement with those obtained from the DEM. Those obtained from the NDVI analysis were also in agreement, except for a number of entirely new lineaments detected. This showed the importance of healthy vegetation aligned in a linear or curvilinear way as a major guide to detecting subsurface water-bearing zones that are not visible on the surface. Results also show that the dominant lineaments trend along the NE-SW direction. The northwest and central parts of the study area have relatively high lineament density, while the southern part has very low lineament density. These areas with high lineament density values are more feasible zones for groundwater prospecting. Keywords: Basement complex, Edge enhancement, Groundwater exploration, Landsat ETM+, NDVI

Highlights

The application of remote sensing technology in geology has greatly advanced through the years, with its usefulness spanning through mineral exploration, geological mapping, hydrogeological mapping, and structural geology, among others
Remote sensing products ranging from aerial photographs and different forms of satellite imageries have proved to be efficient in structural geology; the structures obtained from the field very much correlate with those obtained from satellite imagery, most of the time with perfect structural manifestations (Morelli and Piana 2006; Kaliraj et al 2014)
The result of the analysed lineaments shows that the lineaments/fractures within the study area are aligned mainly in the NNE-SSW directions, as obtained from the satellite imagery of the study area

Summary

Introduction

The application of remote sensing technology in geology has greatly advanced through the years, with its usefulness spanning through mineral exploration, geological mapping, hydrogeological mapping, and structural geology, among others. Joints, bedding planes and foliations are discontinuous structural trends that can be detected in various forms for several environmental applications which include landslide studies, hydrogeology and mineral exploration without being limited to using ground mapping techniques Such discontinuous structural trends can be detected by carrying out ground mapping and using remotely sensed data such as conventional aerial photographs and satellite imagery. The synoptic view provided by remotely sensed data is a convenient way of understanding the interrelationship between various meso-and megastructures on the earth surface. Such features and their trends consequent on the deformational episodes experienced by rocks in the study area are clearly represented on satellite imageries

Methods

Findings

Discussion

Conclusion