GEOELECTRIC MAPPING OF GROUNDWATER POTENTIAL IN THE SPORTS COMPLEX

ABSTRACT

Geo-electrical survey using Vertical Electrical Sounding (VES) was carried out in the Sports Complex of Federal University of Petroleum Resources, Effurun Delta State (FUPRE) in order to determine the groundwater potential of the area and the aquifer distribution. The Schlumberger electrode configuration was used with a maximum current electrode separation of 120m. A total of three (3) VES points were used where at VES1we had 23 measurements, 14 at VES2 and 22 at VES3. The data were analysed by computer aided iteration techniques using the resistivity modelling software (IPI2Win+IP). The geo-electric model parameters and curves were obtained from the software. The result of the analysis shows six geo-electric layers. The result of the survey has allowed the delineation of ground water potential in the study area and it is recommended sinking of a reliable borehole for good portable water be sited at locations VES1 and VES3 at recommended drill depth of 40.8m respectively.

CHAPTER ONE

INTRODUCTION

1.1 BACKGROUND OF THE STUDY

Hidden beneath the varied landscapes of the Niger Delta is a treasured and important natural resource. It is neither petroleum nor natural gas, which are the natural resources that are certainly important and have brought wealth to many people. This hidden treasure is water, and to be more specific, groundwater. Groundwater occurs everywhere but sometimes its availability in economic quantity depends solely on the distribution of the subsurface geologic units that are referred to as the aquifers. This implies that where groundwater is not potentially endowed enough, there may be either complete lack or inadequacy due to increasing industrial and domestic needs (Akpan, 2006 and George, 2010). Although groundwater is a renewable resource, fear is being nursed about its imagined danger in case of inadequacy or lack. The universality of its utility heightens the degree of fear as no other fluid can replace the uncountable roles played by water in our communities. However, when many people think of a water source, they think of lakes, rivers and streams; in other words, surface water. Of all the usable freshwater in the world, approximately 97 percent of it is groundwater. According to the United Nations, 10 million cubic kilometres of water are stored underground. The United States Geological Survey states that there is about 4.2 million cubic kilometres of water within 0.8 kilometre of the earth’s surface.

Groundwater is the water that lies beneath the ground surface, filling the pore space between grains in bodies of sediment and elastic sedimentary rocks and filling cracks and cavity in all types of rocks (Plummer et al, 1999). Observations have shown that a good deal of surplus rainfall runs-off over the surface of the ground while the other part of it infiltrates underground and becomes the groundwater responsible for the springs, lakes and wells (Oseji et al., 2006). Groundwater is often withdrawn for agricultural, municipal and industrial use by constructing and operating extraction wells. Groundwater is also widely used as a source for drinking supply and irrigation (UNESCO, 2004). Although groundwater cannot be seen above the earth, a scope of techniques can be used in determining its availability in the subsurface. Surface investigation allows us in deciding the information about type, porosity, water content and density of subsurface condition. This is usually done with the help of electrical and seismic methods and without any drilling on the ground. The data supplied by these techniques are partly reliable and it is less expensive. It gives only indirect signs of groundwater so that the underground hydrologic record must be inferred from the subsurface investigations. Of all the surface geophysical methods, electrical resistivity has been employed most for groundwater exploration (Egbai, 2011). This is because the equipment is portable, simple, field logistics are easy and straightforward and the analysis of data is economical and less tedious than other methods (Zhody et al, 1993;Egbai, 2011).

As time goes on the demand for water for various purposes will be increasing day by day due to increasing population within Federal University of Petroleum Resources Effurun.

This work is aimed at delineating the depth to groundwater using Vertical Electrical Sounding (VES) with the Schlumberger electrode configuration in the Sports Complex of FUPRE to be able to infer suitable locations where prolific boreholes can be sited.

1.2        STATEMENT OF PROBLEM

Here this study focuses mainly on the delineating of good groundwater aquifer in the Sports Complex of FUPRE and how it can be evaluated using resistivity method. But first I will like to discuss briefly about the basic terms in groundwater study.