Application Of Geoelectrical Resistivity Imaging To Investigate Groundwater POTENTIAL

APPLICATION OF GEOELECTRICAL RESISTIVITY IMAGING TO INVESTIGATE GROUNDWATER POTENTIAL

Abstract

The PAS earth resistivity meter was used to conduct geoelectrical resistivity imaging at Atan, Ado/Odo Ota Local Government, Ogun State, Nigeria utilizing both the 2D and Vertical Electrical Sounding (1D) methods.Using both a Wenner and a Schlumberger array arrangement, three profiles were run. The data was decoded using the WinResist computer iteration method for VES and RES2DINV for 2D. The geological structure of the studied area is represented by five primary layers, according to the results. According to the structures, the resistivity values range from 1200 m to 4000 m, 500 m to 1000 m, 400 m to 800 m, 200 m to 400 m, and 60.7 m to around 100 m, respectively. The various layers and their matching thicknesses are shown on the apparent resistivity curves for VES1, VES 2, VES 3, and VES 4. The study region showed that the aquifer’s depth ranged from 130 to 140 meters.

Text Of The Chapter

Acknowledgements, Certification, II, and Dedication iv-v Table of Contents viii Figures List A viii–ix

x Abstracts

chapiter 1

First paragraph 1–3 1.2 Geological Description of Underground Water 3–4 1.2.1 Occurrence of Groundwater 5–6 1.2.3 Transmission of Groundwater 6–8 1.2.4 Recharge 8–9 1.2.6 Withdrawal 8–9 1.2.7 Aquifers 9–11

Location of the research area 12

1.4 Purpose and Goals 14

1.5 Study’s Purpose 14

1.6 Arguments in favor of the study 14 PART TWO

2.1 Review of the Literature and Geological Context 15–21

2.2 The research area’s geological setting. 21–22 PART THREE

3.1 Theory and Methodology of Electrical Resistivity 23

3.1.1 A Single Current Electrode at a 24 Degree Depth

3.1.2 A Surface 25 Single Current Electrode

3.1.3 Surface Electrode with Two Currents 25

26 “3.2 Apparent Resistivity and Electrode Configuration

27–28 of the 3.3 Resistivity Survey

28–30 in 3.4 Field Measurement Procedure

3.5 The Fieldwork Methodology 30-34 PART FOUR

4.1 Findings and Analysis 35-36

4.2 Information Gathered for Profile 1 37–40

4.3 Information Gathered for Profile 2 41–44

4.4 Information Gathered for Profile 3 44 CHAPTER 5

5.1 Findings, Interpretation, and Recommendation 45

5.1.1 Character 1 Conversation 45–47

5.1.2 Discussion in Profile 2: 48–50

5.1.3 Character 3 Dialogue 51–53

5.2 Verdict 54

53–55 Recommendations

5.4 Knowledge Contribution 55 References 56-61

Tables List In Appendix

Table 4.1 presents raw data for 2D in Profile 1 in the following tables: 37 Table 4.2 presents raw data for 2D in Profile 1 in the following tables: 38 Table 4.3 presents raw data for 2D in Profile 1 in the following tables: 39

Table 4.5 shows the raw data for the 2D profile in row 39. Table 4.6 shows the raw data for the 2D profile in row 40. Table 4.9 shows the raw data for the 2D profile in row 40. Table 4.10 shows the raw data for the 2D profile in row 40. Table 4.11 shows the raw data for the 2D profile in row 41. Table 4.12 shows the raw data for the 2D profile in row 42. Table 4.13 shows the raw data for the 2D profile in row 43. Table 44

Number Of Figures

Figure 1.1 shows an estimate of the infiltration rate as a function of time.

Sketch diagrams of homogeneous, inhomogeneous, and anisotropic aquifers are shown in Figure 1.2. 9

Figure 1.3 shows the hydrological cycle and type 11 aquifers.

Base map of the research region in Figure 1.4 12

Figure 1.5 shows the study region on a geological map of Ogun State. 13

Figure 3.1 shows a typical four-electrode array for subsurface measurement. Resistivity 27

Common resistivity survey arrays and their geometric factors are shown in Figure 3.2 (Loke, M.H. 1997; 1999). 28

Figure 3.3: Wenner arrangement configuration used for 2D measurement (Loke, 1999) 30

Schlumberger Array Configuration 32, Figure 3.4

Figure 4.1 displays the PAS Earth Resistivity Meter that was used to collect data for 40.

Figure 5.1 displays the measured data for profile 1 of the study region, whereas Figure 5.2 displays the profile 1’s measured apparent resistivity, calculated apparent resistivity, and inverse model resistivity section. 47

Figure 5.3 displays the current field work survey 48.

Figure 5.4 displays the measured data for profile 2 of the study region, whereas Figure 5.5 displays the profile 2’s measured apparent resistivity, calculated apparent resistivity, and inverse model resistivity section. 50

Figure 5.6 displays the standard VES 1 curve.

Figure 5.7 displays the normal VES 2 curve.

Figure 5.8 displays the usual VES 3 52 curve.

Figure 5.9 displays the typical VES 4 52 curve.