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 ◽  
...  

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.    

2017 ◽  
Vol 15 (1) ◽  
pp. 70-81
Author(s):  
V MAKINDE ◽  
A O ERUOLA ◽  
S A GANIYU ◽  
O T OLURIN ◽  
O O ADELEKE ◽  
...  

Evaluation of groundwater potential in Odeda Local Government Area, Ogun State, Southwestern Nigeria, has been carried out in this study using Vertical Electrical Sounding method. The study area is underlain by Precambrian Basement Complex rocks of Southwestern Nigeria. These rocks are inher-ently characterized by low porosity and permeability. The interpretation of thirty (30) vertical electrical sounding (VES) conducted using the Schlumberger electrode array shows four geo-electric layers in the subsurface within the study area. The overburden thickness varies from 5.9 to 39 m across the study area. This was used to prepare the groundwater potential map which assisted in the zoning of the area into low, medium and high groundwater potential zones. The study showed that about 60% of the study area falls within the low/medium rated groundwater potential zone while the remaining 40% constituted the high groundwater potential zone. Hence, the groundwater potential rating of the area is generally low.


Author(s):  
O. E. Odeyemi ◽  
O. M. Odeyemi ◽  
S. A. Owolabi ◽  
E. A. Mamukuyomi ◽  
R. A. Salako

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.


2020 ◽  
Vol 66 (3) ◽  
pp. 199-209
Author(s):  
J.O. Aina ◽  
O.O. Adeleke ◽  
V. Makinde ◽  
H.A. Egunjobi ◽  
P.E. Biere

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.


2019 ◽  
Vol 7 (2) ◽  
pp. 61
Author(s):  
Rereloluwa Bello ◽  
Toluwaleke Ajayi

The Vertical Electrical Resistivity surveys in the Sunshine Garden Estate have contributed to a better understanding of the basement complex of Southwestern Nigeria. Nine (9) vertical electrical sounding (VES) using the Schlumberger electrode array were interpreted and the results shows three (3) subsurface geoelectric layers within the study area. These are the weathered layer, topsoil, fresh/fractured basement. Groundwater pockets such as fractured zones, valley fills/basement depressions, and weathered zones were delineated in the study area. Weathered/partially weathered layer and weathered basement/fractured basement were the two major aquifer mapped out and these aquifers are characterized by thick overburden, found within basement depressions. The groundwater potential of the study area was zoned into low, medium and high potentials. Zones where the overburden thickness (which constitutes the main aquifer unit) is greater than 13m and of low clay composition (average resistivity value between 200 - 400Ωm) are considered zones of high groundwater potential. Area where the thickness of the aquifer ranges from 11-13m with less clay composition are considered to have medium groundwater potential and the areas where the thickness of the aquifer is less than 11m are considered to have a low groundwater. The VES station underlained by high and medium groundwater potential zones are envisaged to be viable for groundwater development within the area.  


Author(s):  
I. A. Adeyemo ◽  
V. O. Iwuala ◽  
T. S. Fadare ◽  
E. O. Otayemi

Aim: Groundwater potential evaluation, corrosivity and geotechnical competence investigations of the subsurface layers were carried at FUTA Cooperative Housing Estate, Ilaramokin near Akure Southwestern Nigeria in order to facilitate proper positioning of facilities within the estate. Methodology: A total of 14 vertical electrical sounding (VES) data was acquired across the estate using Schlumberger array. Results: The VES survey results delineated 3 - 5 geoelectric layers across the estate which corresponds to the topsoil, weathered layer, partially weathered basement, partially fractured basement and the presumed fresh bedrock. The groundwater potential map of the estate revealed that the groundwater potential is moderate (GWP of 0.5 - 0.75) to high (GWP of 0.75 - 1.0) in the western and southeastern parts of the estate. The depth slice corrosivity maps (1.0, 2.0 and 3.0 m) of the estate indicated that the corrosivity of the subsurface layers within the estate reduces with depth. The 0.5 m depth slice isoresistivity map of the estate indicates that the central and a segment of the southwestern parts of the estate are characterized with low resistivity (50 - 100 Ωm) indicating incompetence, while the estate flanks (west and east) are considered to be moderately competent (100 - 350 Ωm). Likewise, the 1.0 m depth slice isoresistivity map of the estate reveals that the central and western parts of the estate are characterized with low resistivity (50 - 100 Ωm) suggesting incompetent layer, while the northern, southern and eastern parts of the estate are moderately competent (100 - 350 Ωm). Conclusion: These results suggested that structural failures can be expected on any engineering structures sited at the central, northern, southern and eastern parts of the estate. Groundwater efforts should be concentrated at the western and southeastern parts of the estate.


2019 ◽  
Vol 9 (3) ◽  
Author(s):  
H. I. Bello ◽  
U. D. Alhassan ◽  
K. A. Salako ◽  
A. A. Rafiu ◽  
A. A. Adetona ◽  
...  

2017 ◽  
Vol 10 (6) ◽  
Author(s):  
H.I. Kuforiji ◽  
O.D. Akinyemi ◽  
M.A. Busari ◽  
R. Bello

2021 ◽  
Vol 20 (2) ◽  
pp. 99-106
Author(s):  
O.I. Popoola ◽  
O.A. Adenuga ◽  
E.O. Joshua

The geological map of the old western region of Nigeria indicates the presence of iron ore deposit at Iboro village Ogun state (7.9983o - 7.99933o N, 3.5790o - 3.5890o E). Hence a ground magnetic survey was carried out at a location at Iboro village so as to delineate the subsurface magnetic anomalies and to know whether the anomalies favour accumulation of magnetic minerals. The survey was carried out using high resolution proton precession magnetometer model G-856X. Eight traverses were run at 5m separations and earth magnetic intensity values were measured at 10m intervals along each traverse; the acquired data were corrected for drift. The residual anomalies obtained by removal of regional gradient from observed data using trend analysis were presented as profiles and maps. The treated data were qualitatively and quantitatively interpreted and the results gave values for the total ground magnetic anomalies that varied between a minimum and maximum peak values of about -33.0 and 30.6nT respectively. Depth to the basement rock was estimated using Peter’s half slope method which gave a maximum depth of about 13m. The contour maps and the total relative graphs present the subsurface picture of the geological structure that is assumed to harbour the metallic minerals through the action of the field towards the concentration of anomalies. It was suspected that the overburden was relatively thin in the study area and the minerals were at a shallow depth.


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