The Vertical Electrical Sounding (VES) technique was carried out in Alode Community of Eleme Local Government Area in Rivers State to determine the geo-electrical and hydrogeological characteristics of the aquifers present in the area, and to delineate the geo-electric stratigraphy of each VES station.
A total of three (3) VES were carried out with the ABEM Terrameter SAS 300C, using the Schlumberger Configuration. Maximum half-current electrode spread (AB/2) of 1m up to 150m was used, while the half potential electrode separation (MN/2) was maintained between 0.5m and 7.5m. The VES curves were quantitatively interpreted by partial curve matching and computer iteration techniques, using the IP1 WIN computer software.
The results of the interpreted VES data confirm the following stratigraphies: top soil (40.2-65.2Ωm), shale (32.2-86.3Ωm), fine-medium sand (172-204Ωm), medium-coarse sand (532Ωm), and medium sand (417Ωm). Geo-electric sections reveal that the aquiferous units are mostly confined, with depth to aquifer range of 47m for VES 1 and 2 and 21m for VES 3.
Table of Contents
CHAPTER ONE: INTRODUCTION
1.1 BACKGROUND
1.2 PROBLEM STATEMENT
1.3 AIM/OBJECTIVES OF THE STUDY
1.4 SCOPE OF STUDY
1.5 SIGNIFICANCE OF THE STUDY
1.6 RESEARCH METHODOLOGY
1.7 PROJECT LAYOUT
1.8 THE STUDY AREA
1.8.1 LOCATION AND ACCESSIBILITY
1.8.2 CLIMATE AND RAINFALL (HYDROGEOLOGY)
1.8.3 GEOLOGY OF THE AREA
CHAPTER TWO: LITERATURE RCUEW
2.1 GROUNDWATER
2.1.1 HOW ARE AQUIFERS RECHARGED AND DISCHARGED?
2.2 THE ELECTRICAL RESISTIVITY METHOD
2.2.1 THEORY OF THE ELECTRICAL RESISTIVITY METHOD
2.2.2 ELECTRODE CONFIGURATION
CHAPTER THREE: INSTRUMENTATION AND METHODOLOGY (FIELD PROCEDURES)
3.1 INTRODUCTION
3.1.1 PRINCIPLE OF OPERATION OF THE ABEMTERRAMETER SAS 300C
3.2 METHODOLOGY (FIELD PROCEDURE)
3.2.1 FIELD ACCESSORIES
3.3 FACTORS AFFECTING RESISTIVITY OF ROCKS
CHAPTER FIVE: CONCLUSION AND RECOMMENDATION
Research Objectives and Focus
This study aims to address the challenges of groundwater accessibility and quality in the Alode Community by utilizing the electrical resistivity method to conduct geophysical investigations. The primary research objective is to identify uncontaminated groundwater potential zones and characterize the subsurface hydrogeological properties to prevent the drilling of sub-optimal or contaminated boreholes.
- Mapping of subsurface geological layers and identification of aquifer thickness.
- Application of the Vertical Electrical Sounding (VES) technique using Schlumberger configuration.
- Determination of geo-electrical characteristics to distinguish between potentially contaminated and safe aquifers.
- Establishment of optimal drilling depths for future water exploration projects in the community.
Excerpt from the Book
2.1 GROUNDWATER
Groundwater is freshwater (majorly from precipitation, snow or ice) that has infiltrated through the soil and is stored in tiny open spaces (pores), fractures or fissures within rocks or soil particles. Groundwater exists in two zones, the unsaturated zone (also known as the vadose zone or the zone of aeration) and the saturated zone (phreatic zone). The unsaturated zone exists directly below the land surface and it contains air and water in its pores. Some of the water in these pores is held by molecular attraction forces which do not allow the water flow away. The saturated zone lies underneath the unsaturated zone. In this zone, all the pore spaces, fissures or rock fractures are always completely filled with water.
How well a rock body holds water (porosity) depends on the size and shape of the rock particles that it possesses; a rock with loosely arranged particles of uniform size (such as sand) will hold more water than a rock with particles of different sizes. This is because the rock with different particle sizes will contain smaller rock particles that can settle in the pore spaces between the larger particles, thereby decreasing the amount of pore spaces that can hold water. Also, rock particles with round shape will pack more tightly together than particles with angular shaped edges. In other words, rocks with angular shaped particles will retain more water because of its large pore spaces.
Summary of Chapters
CHAPTER ONE: INTRODUCTION: This chapter outlines the necessity of potable groundwater, defines the problem of contamination and borehole failure in Alode Community, and establishes the objectives of using geophysical methods for exploration.
CHAPTER TWO: LITERATURE RCUEW: This section reviews existing research on groundwater exploration, discusses the fundamentals of aquifers and their recharge processes, and provides an in-depth explanation of the electrical resistivity method.
CHAPTER THREE: INSTRUMENTATION AND METHODOLOGY (FIELD PROCEDURES): This chapter details the technical specifications of the ABEM Terrameter SAS 300C, the field procedures for data acquisition using the Schlumberger configuration, and the factors influencing rock resistivity.
CHAPTER FIVE: CONCLUSION AND RECOMMENDATION: The final chapter summarizes the findings regarding the unconfined aquifers in the Niger Delta region and recommends the involvement of professional hydro-geologists to oversee future drilling projects.
Keywords
Groundwater, Electrical Resistivity, Vertical Electrical Sounding, VES, Schlumberger Configuration, Aquifer, Subsurface, Hydrogeology, Alode Community, Niger Delta, Borehole, Geophysics, Resistivity Survey, Stratigraphy, Groundwater Exploration
Frequently Asked Questions
What is the core focus of this research project?
The project focuses on using the electrical resistivity method to locate uncontaminated groundwater potential zones in the Alode Community to solve issues related to low borehole yield and water contamination.
What are the primary themes discussed in the work?
Key themes include the principles of groundwater storage in sedimentary terrains, the practical application of the Vertical Electrical Sounding (VES) technique, and the interpretation of subsurface geological structures.
What is the main research objective of this study?
The objective is to identify safe and productive aquifer zones and determine their depth, thickness, and electrical characteristics to guide future drilling activities in the study area.
Which scientific method is utilized in this study?
The study employs the Electrical Resistivity Method, specifically the Vertical Electrical Sounding (VES) technique with a Schlumberger electrode configuration.
What topics are covered in the main body of the work?
The work covers literature reviews on groundwater, the theory behind electrical resistivity measurements, descriptions of the instrumentation used (ABEM Terrameter), field procedures, and the analysis of results derived from the study sites.
Which keywords best describe this research?
Key terms include Groundwater, Electrical Resistivity, Schlumberger Configuration, Aquifer, Subsurface, Hydrogeology, and Geophysical exploration.
How does the author define the difference between confined and unconfined aquifers?
Unconfined aquifers are open to the influence of surface conditions and extend from the water table, whereas confined aquifers are overlain by a low-permeability layer, such as clay, which restricts water movement.
What specific equipment was used for data collection in the field?
The researcher used the ABEM Terrameter SAS 300C, along with stainless steel electrodes, measuring tapes, cables, and a GPS for marking survey locations.
What do the results from the specific VES stations indicate about the study area?
The results show varying depths to aquifers across different locations, suggesting that careful geophysical site assessment is required before drilling to ensure the boreholes reach productive water-bearing layers rather than contaminated or shallow perched aquifers.
- Citation du texte
- Joseph Amadi (Auteur), 2016, Application of the Electrical Resistivity Method in Groundwater Exploration, Munich, GRIN Verlag, https://www.grin.com/document/501569
