scholarly journals Assessment of Hydrogeological Potential and Aquifer Protective Capacity of Odeda, Southwestern Nigeria

2020 ◽  
Vol 66 (3) ◽  
pp. 199-209
Author(s):  
J.O. Aina ◽  
O.O. Adeleke ◽  
V. Makinde ◽  
H.A. Egunjobi ◽  
P.E. Biere
Keyword(s):  
Groundwater Resources ◽  
Electrode Array ◽  
Electrode Spacing ◽  
Protective Capacity ◽  
Clayey Sand ◽  
Southwestern Nigeria ◽  
Current Electrode ◽  
Ogun State ◽  
Weathered Layer ◽  
Longitudinal Unit Conductance

AbstractHydrogeological assessment of groundwater resources was carried out with a view to evaluate the potential of the aquifers to provide portable water supply and access the distribution of electrical parameters of hydrogeologic units in some areas in Odeda, Ogun State, Nigeria. A geophysical survey using vertical electrical sounding (VES) with the Schlumberger electrode array, with half-current electrode spacing (AB/2) varying from 1 to 132 m was carried out at 30 different stations in the study area. The VES data were interpreted qualitatively and quantitatively. Three-to-five sub-surface layers consisting of topsoil, weathered layer consisting of clay, sandy clay, clayey sand and sand layers, and fractured/fresh basement were delineated. Layer resistivities and thicknesses obtained on the curves within the study area showed one main aquifer type, which is the fractured basement. The longitudinal unit conductance (ranging from 0.049720 to 1.4520000 mhos) of the study area aided the protective capacity to be rated into good, moderate and weak. About 33% of the study area falls within the weak protective capacity, 57% falls within the moderate protective capacity and 10% falls within the good protective capacity.

scholarly journals Geoelectrical Investigation of Subsurface Structures for Mapping Groundwater Potential of Joseph Ayo Babalola University Campus Environment, Ikeji Arakeji, Osun State, Southwestern Nigeria

2019 ◽  
pp. 1-12
Author(s):  
O. E. Odeyemi ◽  
O. M. Odeyemi ◽  
S. A. Owolabi ◽  
E. A. Mamukuyomi ◽  
R. A. Salako
Keyword(s):  
Electrode Array ◽  
Groundwater Potential ◽  
Vertical Electrical Sounding ◽  
Electrode Spacing ◽  
Clayey Sand ◽  
Southwestern Nigeria ◽  
Current Electrode ◽  
Campus Environment ◽  
Lateritic Clay ◽  
Electrical Sounding

Owing to fast increase in number of staff and students of Joseph Ayo Babalola University, Ikeji Arakeji, Southwestern Nigeria, it is therefore very important to carry out this research in order to recommend the actual locations where boreholes can be sunk for good potential yields of groundwater when the time comes. The aim of this research is to carry out vertical electrical sounding geophysical survey at study area with a view to determining good aquifers that are good for the accumulation of groundwater. The study area is located between latitude 0820225 m to 0820345 m (UTM) Northings and longitude 717320 m to 717450 m (UTM) Eastings. Schlumberger electrode array was employed for the study using Ohmega Resistivity meter for the data acquisition. The geoelectric survey of the study area comprised of twelve vertical electrical soundings, with maximum current electrode spacing (AB) of 100 m. The modeled curves are mainly KH-type. The geoelectric sections generated from the sounding curves revealed 4 major layers earth models. The topsoil is made up of clay, clayey sand/lateritic sand with resistivity and thicknesses varying from 54.7 – 210.1ohm-m and 0.2 –0.8m respectively. The second layer is the lateritic clay with resistivities and thicknesses varying from 334 – 963ohm-m and 1.5 – 10.8m respectively. The third layer constitutes the clay / sandy fractured quartzite and it serves as the aquifer unit. The resistivity values lie between 71.7 and 498 ohm-m while the thicknesses vary from 2.1 – 76.3 m. The fourth layer is the fractured/presumably fresh basement bedrock with the resistivity varying from 1879 – 13991.8 ohm-m. Areas characterized with fractured basement of low resistivity with appreciable thickness are therefore recommended for the siting of boreholes. It is concluded that the vertical electrical sounding points of the study area are good aquifers for groundwater accumulation.

Exploration for Marble Deposit in Parts of Okpella, South-Southern Nigeria

2019 ◽  
pp. 1-7
Author(s):  
K. O. Ozegin
Keyword(s):  
Electrical Resistivity ◽  
Electrode Spacing ◽  
Clayey Sand ◽  
Current Electrode ◽  
Electrical Resistivity Survey ◽  
Resistivity Method ◽  
Resistivity Survey ◽  
Surface Measurements ◽  
Electrical Sounding ◽  
Electrical Resistivity Method

The ultimate aim of the electrical resistivity survey is to determine the resistivity distribution with depth on the basis of surface measurements of the apparent resistivity and to interpret it in terms of geology. Marble deposit was investigated with the application of electrical resistivity method using Vertical Electrical Sounding (VES) technique with the aim of characterising this deposit in parts of Okpella. Six (6) VES were acquired using the Schlumberger array for data acquisition with current electrode spacing varying from 1.0 to 150.0 m. The VES data obtained were interpreted using ipi2win Software. The results showed three layers indicating subsurface geologic sequence probed 26.4 m and beyond with clay/clayey sand (23.3 – 219.1 Ωm), sand (423 - 2040 Ωm) and marble (12661 - 404498 Ωm). The occurrence of marble deposit was revealed at VES points at 1, 2 and 5 in the studied area.  This study concluded that the study area had occurrence of the marble deposits, which would be of economic importance, if exploited.

scholarly journals Evaluation of Aquifer Protective Capacity and Groundwater Potential in Part of Iju, Akure-North, Ondo State, Nigeria

2020 ◽  
pp. 197-204
Author(s):  
A. Olajide ◽  
S. Bayode ◽  
T. Fagbemigun ◽  
A. Oyebamiji ◽  
J. Amosun ◽  
...  
Keyword(s):  
Geophysical Methods ◽  
Low Frequency ◽  
Groundwater Potential ◽  
Electrode Spacing ◽  
Protective Capacity ◽  
Value Range ◽  
Weathered Layer ◽  
Ondo State ◽  
Geological Units ◽  
Matching Techniques

Groundwater potential and aquifer protective capacity of the overburden unit was evaluated in part of Iju, Akure North, Ondo State using integrated geophysical methods involving Very Low Frequency Electromagnetic (VLF-EM) profiling and Vertical Electrical Sounding (VES). Four major traverses were established of varying length extents. The VLF-EM measurements were taken along the four major profiles of 10 m station interval.Forty two (42) Vertical Electrical Soundings were also conducted with half electrode spacing varying between 1 and 100 m and interpretation was done using the partial curve matching techniques and computer aided iteration. Five subsurface geological units were identified from geoelectric sections, consisting of the top soil, lateritic, weathered, partly weathered and fresh basement layers consecutively. For the first layer, resistivityranges between 23 and 323 Ωm with values of thickness ranging between 0.5 and 2.2 m. The resistivity and thickness of the second (lateritic) layer range from 132 to 430 Ωm and 1.6 to 4 m respectively. The resistivity of the weathered layer ranges from 4 to 94 Ωm and variable thickness between 10 and 24.4 m. The fourth layer has a resistivity value range of 65 to 120 Ωm and thicknesses between 20 and 30 m. The basement bedrock (fifth layer) has resistivity values between 770 and 820 Ωm. The depth to bedrock ranges from 1.8 to 31 m. The geophysical data and the basement aquifer delineated were then used to evaluate the hydrogeological setting and aquifer protective capacity of the study area. The observation from the results shows that close to 70 % of the study area falls within the zones of low groundwater potential, 25 % falls within medium potential zones while only 5 % make up the high potential zones. 75 % of the study area constituted the weak to poor protective capacity zones.  

scholarly journals Modeling of Subsurface Integrity Using Dar-Zarrouk Parameters: A Case Study of Ikekogbe UBE Primary School, Ekpoma, Edo State, Nigeria

2019 ◽  
pp. 1-17
Author(s):  
Bawallah Musa Adesola ◽  
Ilugbo Stephen Olubusola ◽  
Aigbedion Isaac ◽  
Aina Adebayo O. ◽  
Oyedele Akindele Akintunde
Keyword(s):  
Electrical Resistivity ◽  
Primary School ◽  
Electrode Array ◽  
Electrode Spacing ◽  
Weak Zone ◽  
Current Electrode ◽  
Resistivity Method ◽  
Edo State ◽  
Structural Failures ◽  
Dar Zarrouk Parameters

In this present study area, most building failures often start with minor/major cracks which widen over time, and it is often followed by post construction remedial measures which fail after sometime, thereby leading to total collapse and sinking of such buildings. The research was carried out in order to be able to unravel the causes of major cracks along the side of a major class room block at Ikekogbe, UBE Primary School, Ekpoma, Edo State, Nigeria in less than five (5) years after it was constructed. The cracks were visible both at the front and at the back of the building along the same axis and almost at this same distance as it was at the front of the building. The investigation involved Electrical Resistivity method using three techniques; Vertical Electrical Sounding (VES), 2-D Electrical Resistivity Tomography (ERT) and Horizontal Profiling (HP). The traverses were established along E-W directions and Eight (8) VES were carried out using Schlumberger array with current electrode spacing varying from 1 to 40 m, with 2-D ERT using Dipole-Dipole electrode array with inter-station separation of 5 m and an expansion factor that varied from 1 to 5 and HP using Wenner array with an electrode spacing of 5 m interval. The VES interpretation results were used to determine the second order parameters for modeling of subsurface integrity/competence. The 2 D imaging (Dipole-Dipole) gave information on the subsurface characteristic and the Wenner profile was characterised by low resistivity at the region of 30 to 45 m considered as the weak zone. Correlating the results with subsurface integrity model along traverses one and three, there was a high degree of correlation as this region coincides with the very low/low integrity/competence with the foundation of the classroom overlying this layers. The research revealed that the problem of structural failures/crack noticed along the building walls and axis was not as a result of human problem alone but mainly the existence of very low/low integrity/competence layers which contributed greatly to the cracks observed on the classroom block. These results reveal that the three Electrical resistivity techniques used for this study are complimentary to each other.

scholarly journals Investigation of groundwater potential using integrated geophysical methods in Moloko-Asipa, Ogun State, Nigeria

2021 ◽  
Vol 11 (4) ◽  
Author(s):  
A. A. Alabi ◽  
S. A. Ganiyu ◽  
O. A. Idowu ◽  
A. F. Ogabi ◽  
O. I. Popoola
Keyword(s):  
Geophysical Methods ◽  
Low Frequency ◽  
Sampling Interval ◽  
Groundwater Potential ◽  
Groundwater Exploration ◽  
Protective Capacity ◽  
Southwestern Nigeria ◽  
Industrial Growth ◽  
Geoelectric Section ◽  
Weathered Layer

AbstractWater is essential for livelihood, development, and industrial growth. Its exploration in sufficient quantity is required where it does not freely occur on the surface. This research was aimed to delineate aquifer regions and provide information on the subsurface lithology of Moloko-Asipa Southwestern Nigeria. A combination of eight traverses investigated with very low frequency electromagnetic (VLF-EM) method at 5 m constant sampling interval and ten vertical electrical sounding (VES) were carried out in the survey. Measurements from the VLF-EM survey were processed with Karous and Hjelt filtering to give the resistivity contrast across the selected profiles. The VES data processing involved an automatic approximation of the initial resistivity and thickness of the geoelectric layers with IPI2Win and further filtering by WinResist iteration. Estimation of Dar-Zarrouk parameters was also employed to investigate the aquifer protective capacity of the area. The processed VLF-EM results showed the geology of the area to an average depth of 25 m. The geoelectric section of the VES data revealed minimum of 3 layers from sandy top soil to weathered layer and fresh basement with an average resistivity values of 1,816, 926 and 17,503 Ωm, respectively. The integration of VLF-EM and VES in the investigation revealed that the potential for groundwater exploration in the study area is poor due to the thin nature of the weathered layer and its shallow depth to basement. The aquifer protective capacity of the area was likewise inferred to be poor.

scholarly journals Integrated Geotechnical and Geophysical Investigation of a Proposed Construction Site at Mowe, Southwestern Nigeria

2018 ◽  
Vol 64 (3) ◽  
pp. 21-29
Author(s):  
Kayode F. Oyedele ◽  
Sunday Oladele ◽  
Adaobi C. Nduka
Keyword(s):  
Standard Penetration Test ◽  
Thin Layers ◽  
Electrode Spacing ◽  
Silty Clay ◽  
Geophysical Investigation ◽  
Clayey Sand ◽  
Deep Foundation ◽  
Southwestern Nigeria ◽  
Lateritic Clay ◽  
Wenner Array

Abstract The subsurface of a proposed site for building development in Mowe, Nigeria, using Standard Penetration Test (SPT), Cone Penetrometer Test (CPT) and Horizontal Electrical Profiling (HEP), was investigated with the aim of evaluating the suitability of the strata for foundation materials. Four SPT and CPT were conducted using 2.5 tonnes hammer. HEP utilizing Wenner array were performed with inter-electrode spacing of 10 – 60 m along four traverses coincident with each of the SPT and CPT. The HEP data were processed using DIPRO software and textural filtering of the resulting resistivity sections was implemented to enable delineation of hidden layers. Sandy lateritic clay, silty lateritic clay, clay, clayey sand and sand horizons were delineated. The SPT “N” value defined very soft to soft sandy lateritic (<4), stiff silty lateritic clay (7 – 12), very stiff silty clay (12 - 15), clayey sand (15-20) and sand (27 – 37). Sandy lateritic clay (5-40 kg/cm2) and silty lateritic clay (25 - 65 kg/cm2) were defined from the CPT response. Sandy lateritic clay (220-750 Ωm), clay (< 50 Ωm) and sand (415-5359 Ωm) were delineated from the resistivity sections with two thin layers of silty lateritic clay and clayey sand defined in the texturally filtered resistivity sections. Incompetent clayey materials that are unsuitable for the foundation of the proposed structure underlain the study area to a depth of about 18m. Deep foundation involving piling through the incompetent shallow layers to the competent sand at 20 m depth was recommended.

scholarly journals Groundwater Prospecting Using Combined Vertical Electrical Sounding and Borehole Performance

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
S.O Oyegoke ◽  
A.S Adebanjo ◽  
O.O Fayomi ◽  
O. Obot
Keyword(s):  
Specific Capacity ◽  
Electrode Array ◽  
Data Interpretation ◽  
Pumping Test ◽  
Vertical Electrical Sounding ◽  
Computer Assisted ◽  
Current Electrode ◽  
Top Soil ◽  
Weathered Layer ◽  
Electrical Sounding

This study aimed to determine the prospect of groundwater in Afe Babalola University, Ado-Ekiti(ABUAD); result of which will inform of the possibility of getting sufficient water underground. Geophysical survey was carried out in the study area and complemented with performance of an existing borehole. The survey involved 1-D Vertical Electrical Sounding (VES) utilizing the Schlumberger electrode array with half-current electrode separation (AB/2) that ranged from 1m to 50m. The VES data interpretation involved partial curve matching and computer assisted 1-D forward modeling using IPI 2 WIN software. The results showed the subsurface to have 3-layer earth strata comprising of sandy-clay top soil up to 3.26m deep, weathered/fractured basement in the next 9.06m depth and then, the fresh basement with the weathered layer constituting the main aquifer unit. The resistivity values of the weathered and fractured basement are 174 and 192 ohmm indicating relatively low potential for groundwater resource. Pumping test on a nearby borehole gave specific capacity of 7.95m2/day which depicts a low to intermediate transmissivity conforming to the VES.

scholarly journals Geoelectrical Assessment of the Impact of the Ilokun Dumpsite, Ado-Ekiti Southwestern Nigeria, on Surrounding Groundwater Aquifers

2015 ◽  
Vol 40 ◽  
pp. 41-47
Author(s):  
T.A. Lateef ◽  
Akinola B. Eluwole ◽  
Dare J. Adewa
Keyword(s):  
Electrode Spacing ◽  
Contaminant Plume ◽  
Southwestern Nigeria ◽  
Geoelectric Section ◽  
Contaminant Plumes ◽  
Low Resistivity ◽  
Resistivity Method ◽  
Weathered Layer ◽  
The Impact ◽  
Aquifer Unit

The area around the Ilokun dumpsite, Ado-Ekiti was investigated with the aim of establishing the possible impact the contaminant plumes emanating from the dumpsite have on the subsurface aquifers. The Vertical Electrical Sounding (VES) field technique of the electrical resistivity method was adopted for the study, and the half-electrode spacing AB/2 varied from 1 to 65 m. A total of eight VES stations were occupied and a control VES point was located on the refuse dump. The VES data were interpreted quantitatively by partial curve matching and computer iteration, after which the geoelectric parameters were used to evolve a 2-Dimensional geoelectric section beneath the study area.The weathered layer beneath the control VES point was identified to be the aquifer unit, but the anomalously low resistivity of 18 ohm-m within the unit was interpreted as an evidence of pollution from conductive contaminant plume. The geoelectric section beneath VES 1 to 7 delineated four layers, these include the topsoil; the weathered layer; the fractured basement and the fresh basement. The resistivity and thickness range of the layers are 177 – 399 ohm-m and 0.7 – 1.2 m; 29 – 842 ohm-m and 1.0 – 3.4 m; 16 – 446 ohm-m and 4.5 – 45.5 m; and 289 – 2144 ohm-m respectively. The fractured layer constitutes the main aquifer unit beneath the seven VES points, but the anomalously low resistivity of 16 – 47 ohm-m within the fractured layer beneath VES 4, 5, 6 and 7 is suspected to be as a result of pollution from conductive contaminant plume emanating from the dumpsite. The fractured layer beneath VES 2 and 3 which does not show any evidence of pollution yet is at a risk of being contaminated, due to its interconnection with the polluted zone.

scholarly journals Electrical Resistivity and Geotechnical Attributes and The Dynamics of Foundation Vulnerability

2021 ◽  
Vol 1 (2) ◽  
pp. 84-97
Author(s):  
Musa Adesola Bawallah ◽  
Stephen Olubusola Ilugbo ◽  
Kesyton Oyamenda Ozegin ◽  
Babatunde A Adebo ◽  
Isaac Aigbedion ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Structural Integrity ◽  
Sedimentary Environment ◽  
Electrode Array ◽  
Electrode Spacing ◽  
Contributing Factors ◽  
Current Electrode ◽  
Lateral Extent ◽  
Indispensable Tool ◽  
Depth Of Investigation

This research evaluates the significance of geotechnical and Electrical Resistivity methods in studying structural integrity as fundamental factors that may account for failure in a typical sedimentary environment of Ukpenu Primary School, Ekpoma, Edo State, Nigeria. Two methods were used in this study such as the Electrical Resistivity approach involving the use of Lateral Horizontal Profiling (LHP), 2D Electrical Resistivity Tomography (ERT), and Vertical Electrical Sounding (VES) techniques. While geotechnical method involved the collection of soil samples from the study locations for the characterization of the soil properties that are very vital to foundation studies. Nine VES were carried out using Schlumberger array with current electrode spacing varying from 1 to 40 m, with 2-D ERT using Dipole-Dipole electrode array with inter-station separation of 5 m and an expansion factor varied from 1 to 5 while LHP involve Wenner array with an electrode spacing of 5 m interval and was used to determine the vulnerability factors for the building sustainability. The VES interpretation results were used to determine the second-order parameters for the determination of vulnerability. The results obtained from the two methods review that both are very fundamental to foundation dynamics. However, electrical attributes were found to give better information in terms of depth, lateral extent, layer stratification, and nature of materials which make it an indispensable tool over geotechnical attributes whose depth of investigation is up to a maximum of 5 m which poses great limitation in the evaluation of structural integrity, against stress, and strain occasion by geodynamic activities that often result into fracture, crack, highly weathered formation that usually goes beyond the shallow depth of investigation. Therefore, it can be stated that resistivity attributes account for 90% of the major contributing factors that affect foundation vulnerability.

GEO-ELECTRIC INVESTIGATION OF GROUNDWATER POTENTIAL IN LADERIN HOUSING ESTATE, ABEOKUTA, SOUTHWESTERN, NIGERIA

2021 ◽  
Vol 19 (1) ◽  
pp. 74-91
Author(s):  
A. A. ALABI ◽  
A. O. ADEWALE ◽  
O.O. ADELEKE ◽  
F. G. AKINBORO ◽  
AYODEJI AFE ◽  
...  
Keyword(s):  
Electrode Array ◽  
Geological Structure ◽  
Groundwater Potential ◽  
Geophysical Survey ◽  
Housing Estate ◽  
Basement Rock ◽  
Southwestern Nigeria ◽  
Ogun State ◽  
Difficult Terrain ◽  
Lithologic Unit

Vertical Electrical Sounding (VES) and 2D Electrical Resistivity Tomography (ERT), with Schlumberger and Wenner electrode array configurations respectively were employed to investigate the groundwater potential of Laderin Housing Estate located at Oke-mosan, Abeokuta, Ogun state, southwestern Nigeria. The area is underlain by the basement complex of the southwestern Nigeria. The research aimed at determining the aquifer/groundwater zone and characterizes the lithology of the study area. The geophysical survey involving nine VES and four profile of 2-D ERT lines with lengths varying from 100 m to 150 m were carried out.  The field data from both the ERT and VES were processed and interpreted using RES2DINV and WINRESIST software respectively. Geometrical effects from the pseudo-section were removed and an image of true depth and true formation resistivity were produced. Three to four geo-electric layers were revealed in all, which are; topsoil, weathered layer, fractured and fresh basement rock. The result of 2 D inversion provide lithologic unit, weathering profile and geological structure favourable for groundwater potential. The results show that the basement rock was delineated with resistivity values that range between 701.3 Ωm and 9459.3 Ωm. The bedrock topography has a variable thickness of overburden between 3 m and above 16.4 m, which is fairly shallow.  The geophysical survey show that VES 2, VES 3, VES 4, VES 5, and VES 6 are possible location for groundwater extraction. The difficult terrain, where thick overburden are located are also promising target for groundwater development.    

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