Hydrogeophysical investigation for the aquifers in part of Ilorin, Central Nigeria: Implication on groundwater prospect

2021 ◽  
Vol 47 (2) ◽  
pp. 520-534
Author(s):  
Ayodele Kehinde Olawuyi
Keyword(s):  
Groundwater Resources ◽  
Groundwater Potential ◽  
Mean Value ◽  
Groundwater Prospect ◽  
Basement Complex ◽  
Type Curves ◽  
Lateritic Clay ◽  
Overburden Thickness ◽  
Weathered Layer ◽  
Electrical Sounding

Hydrogeophysical study involving the use of Vertical Electrical Sounding (VES) was carried out in part of the basement complex rocks of Ilorin, central Nigeria, with the aim of determining its geoelectric parameters and groundwater potential. A total of thirty (30) VES were carried out using Schlumberger electrode configuration, with half electrode separation (AB/2) varying from 1m to 100m. Information on the subsurface lithologies, overburden thickness and aquiferous layers were obtained from the different VES locations in the study area. From the quantitative interpretations of the data collected, using the method of curve matching with the Orellana-Mooney master curves and 1-D forward modeling with WinResist 1.0 version software, three to five lithologic units were identified in the study. These include: the topsoil, sandy/lateritic clay/laterite, the weathered basement, the fractured basement and the fresh bedrock which are predominantly of the ‘KH’ curve type (30%), followed by ‘H’ type (26.7%), other type curves include ‘QH’ (16.7%), ‘HKH’, ‘HA’ and ‘A’ (6.7% each) and KQ and KQH (3.3% each). The weathered layer and the fractured basement constitute the main aquifer units. The aquifers are of generally low resistivity values (mostly below 100 Ω-m). The depths to dry bedrock at the chosen VES locations vary from 2.7 to 62.7 m with a mean value of 13.02 m in the study area. The geoelectrical interpretations of data obtained in these areas have permitted the delineation of the study area into low and moderate groundwater potential zones. This study is expected to assist in future planning for groundwater resources. Keywords: Hydrogeophysical, Basement Complex, Groundwater, Electrical Soundings, Weathered, Fractured

scholarly journals Geoelectric Investigation of the Groundwater Potential of the Federal Housing Estate, Eastern Part of Ado-Ekiti, Southwestern Nigeria

2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Olayiwola G Olaseeni ◽  
Ajibola Oyebamiji ◽  
Oluwaseun Olaoye ◽  
Bosede Ojo ◽  
Ayokunle Akinlalu
Keyword(s):  
Subsurface Layer ◽  
Groundwater Potential ◽  
Vertical Electrical Sounding ◽  
Southeastern Part ◽  
Southwestern Nigeria ◽  
Type Curves ◽  
Overburden Thickness ◽  
Weathered Layer ◽  
Electrical Sounding ◽  
Matching Techniques

This study aimed at evaluating the potential for groundwater development in the eastern part of Ado-Ekiti, Southwestern Nigeria using Vertical Electrical Sounding (VES). Data were acquired with ABEM SAS 300 and processed through partial curve matching techniques and assisted with 1-D forward modelling. Geoelectric parameters were determined from the VES interpreted result. Seven (7) different VES type curves (H, A, HA, KH, HK, QH and HKH) indicating inhomogeneity of the subsurface layer beneath the study area were observed. Weathered layer resistivity map having values ranging from 3.2 – 272 Ωm, overburden thickness of value vary between 0 and 28m and  bedrock relief values range from 360 – 480 m were delineated. It was estimated from the result that the northwestern and southeastern part which constituted about 15%of the study area possess high groundwater potential while the remaining 85% of the study area exhibit low/moderate potentials for yielding substantial water. Hence, the groundwater potential rating of the area was considered generally low.Keywords- Geoelectric, Groundwater potential, Overburden thickness, Vertical Electrical Sounding

scholarly journals Geoelectric evaluation of groundwater potential within sunshine garden estate, akure southwestern Nigeria

2019 ◽  
Vol 7 (2) ◽  
pp. 61
Author(s):  
Rereloluwa Bello ◽  
Toluwaleke Ajayi
Keyword(s):  
Electrode Array ◽  
Groundwater Potential ◽  
Basement Complex ◽  
Southwestern Nigeria ◽  
Overburden Thickness ◽  
Weathered Layer ◽  
Valley Fills ◽  
Electrical Sounding ◽  
Thick Overburden ◽  
Potential Area

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.  

Identification of lithological units using geo-electrical method, Olabisi Onabanjo University Campus, Southwestern Nigeria

2021 ◽  
Vol 20 (1) ◽  
pp. 171-182
Author(s):  
S.A. Adekoya ◽  
H.T. Oladunjoye ◽  
J.O. Coker ◽  
O.A. Adenuga
Keyword(s):  
Subsurface Layer ◽  
Groundwater Potential ◽  
Imaging Data ◽  
Southwestern Nigeria ◽  
Electrical Method ◽  
Type Curves ◽  
Overburden Thickness ◽  
Weathered Layer ◽  
Porosity And Permeability ◽  
Subsurface Resistivity

The study presented the results obtained from estimation of the depth to the bsement bedrock (overburden thickness) in Olabisi Onabanjo University, Ago-Iwoye using two configurations of electrical resistivity methods. The study was aimed to delineate the stratigraphy and thicknesses of the subsurface layer present in the study area for comprehensive study of the lithostratigraphic information of the area. Vertical Electrical Sounding (VES) and 2-D Horizontal Electrical Profiling (HEP) techniques were used to obtain 1-D and 2-D subsurface resistivity images of the study area. The VES data were plotted manually on the Bi-log graph. The curve obtained was partially curve – matched to obtain the layer resistivities and thicknesses for further iteration. The 2-D resistivity imaging data were analyzed and processed to obtain the inverted (true) resistivity image. From the results, five (5) VES type curves weredelineated. These includes H, HA, QH and KH type. The geoelectric sections and 2-D resistivity images showed three to four geoelectric layers. These layers are topsoil/laterite, weathered basement, partly weathered/fractured basement and fresh basement. The study showed that materials with resistivity values that ranged between 10 and 298 Ωm and 152 and 589 Ωm representing clayey weathered layer and partly weathered/fractured basement were delineated beneath some sounding points. The clayey and weathered layer are indicative of soil formations that are inimical to foundation of civil engineering structure. Likewise, they can serve as reservoir for groundwater potential (if the porosity and permeability are high). Due to this, detailed lithostratigraphic evaluation through petrophysical analysis is encouraged for the purpose of mapping and correlation of the rock units before embarking on any engineering construction in the study area. The study concludes in providing assistance to subsequent research on the stratigraphic related studies in the area. Keywords: Geo-electric , Stratigraphy, Lithology, Layer,

scholarly journals Hydrogeophysical Implication of Geoelectric Sounding at Igarra Comprehensive High School, Akoko Edo Local Government, Nigeria

2021 ◽  
Vol 8 (12) ◽  
pp. 411-417
Author(s):  
Adediran Olanrewaju Adegoke ◽  
E. Rotimi Olafisoye ◽  
Oluwatoyin Ologe
Keyword(s):  
High School ◽  
Electrical Resistivity ◽  
Local Government ◽  
Electrode Array ◽  
Groundwater Potential ◽  
Comprehensive High School ◽  
Resistivity Method ◽  
Overburden Thickness ◽  
Weathered Layer ◽  
Electrical Sounding

Electrical resistivity method was used to carry out hydrogeophysical study in order to evaluate the groundwater potential of Igarra Comprehensive High School, Akoko Edo Local Government, Nigeria. The vertical electrical sounding technique (VES) was adopted for the resistivity method. A total of eighteen electrical soundings were conducted across the area using the Schlumberger electrode array with AB/2 varying from 1 to 65 m. After the data acquisition, interpretation was carried out qualitatively and quantitatively and the results were presented as sounding curves, tables, charts, maps and geoelectric sections. The generated geoelectric layers from the sounding curves revealed four geologic layers: the topsoil, the weathered layer, the partially weathered/fractured basement and the fresh basement with their resistivity values ranging from 129.1 to 956.4 -m, 6.8 to 1491.1 -m, 261.3 to 776.6 -m and 1515.6 to 2653.5 -m respectively. The overburden thickness in the study area varies from 5.5 to 23.5 m. The groundwater potential map enabled in the classification of the study area into: low, medium and high groundwater potential area. About 85% of the study area falls within the low groundwater potential rating while about 10% constitutes the medium groundwater potential rating and the remaining 5% constitutes high groundwater potential rating. Keywords: Groundwater, overburden, electrical resistivity, basement, geoelectric sounding.

scholarly journals Investigation of Geology and Hydro-geophysical Features Using Electromagnetic and Vertical Sounding Methods for Abu Zabad Area, Western Kordofan State, Sudan

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Ahmed Babeker Elhag
Keyword(s):  
Geophysical Methods ◽  
Structural Features ◽  
Groundwater Potential ◽  
Crystalline Basement ◽  
Metamorphic Rocks ◽  
Basement Rock ◽  
Basement Complex ◽  
Groundwater Aquifers ◽  
Electrical Sounding ◽  
Geophysical Features

The geology and hydro-geophysical features can aid in identifying borehole location. The study aims to investigate groundwater aquifers and best location of boreholes in the crystalline basement area of Abu Zabad near El Obeid Southwest, Sudan. The study area is underlain by two aquifers formations from Precambrian age. The oldest units of basement complex of area under investigation consist of metamorphic rocks including gneiss, schist, and quartzite.The geophysical methods electromagnetic (EM) and vertical electrical sounding (VES) surveys showed that best aquifers yield for construction of boreholes are in weathering and fractures formation. The EM results revealed that structural features are significant for groundwater potential and interpretation of the VES data also revealed four geo-electric layers, but generally two distinct lithologic layers, which include Superficial deposit and bedrock-basement respectively. The curves generated from the data revealed H curve and HK curve, and thickness of these layers varies from 15 m to 50 m in the area. The aquifer thickness range from 20 m to 30 m. The study concludes that these techniques are suitable for identifying borehole location in the basement rock in Abu Zabad Area Sudan.

scholarly journals Evaluation of Topsoil Competence, Aquifer Types, Groundwater Prospect and Flow Pattern using Geoelectric Characterization for Part of Ogbomoso, Nigeria

2021 ◽  
Vol 7 (2) ◽  
Author(s):  
O. G. Bayowa
Keyword(s):  
Groundwater Flow ◽  
Flow Pattern ◽  
Flow Direction ◽  
Groundwater Potential ◽  
Water Levels ◽  
Groundwater Prospect ◽  
Southwestern Nigeria ◽  
Fractured Bedrock ◽  
Resistivity Method ◽  
Weathered Layer

Part of Ogbomoso Southwestern Nigeria was assessed using electrical resistivity method with a view to obtaining the subsurface geoelectric parameters (resistivities and thicknesses), categorizes the topsoil into different competence zones and evaluates the aquifer types, groundwater prospect and flow pattern. Fifty-four Vertical Electrical Sounding (VES) data were quantitatively interpreted using the partial curve matching technique to obtain the preliminary layer parameters which were further refined through 1-D forward modelling WinResist software package. The resulting final layer parameters were used to generate 2D geoelectric sections, isopach and isoresistivity maps and subsequently used to categorize the study area into different topsoil Competence, Aquifer types and Groundwater Potential zones. Static water levels of hand-dug wells in the area were used to generate the groundwater flow pattern. Four subsurface geoelectric layers were delineated. These were the topsoil, laterite, weathered/partly weathered layer (main aquifer) and fractured/fresh bedrock. The resistivities and thicknesses of the layers were 76-1858, 649-2021, 17-880 and 260-33385 Ωm and 0.4-4, 0.7-1.9 and 1.9-25.2 m respectively. The groundwater flow pattern in the area was NE-SW. The study concluded that incompetent to highly competent topsoil, weathered bedrock (main) aquifer unit/partly weathered/fractured bedrock aquifer and generally low groundwater potential with NE-SW flow direction underlay the study area.

scholarly journals Magnetic and Restivity Investigation of Geologic Structures in the Basement Complex of Aran-Orin, Kwara-State, Nigeria.

2021 ◽  
Author(s):  
'Muyiwa Adekunle Adeyanju ◽  
Oluwaseun Victoria Fatoye ◽  
O.E Oyanameh
Keyword(s):  
Electrode Configuration ◽  
Vertical Electrical Sounding ◽  
Electrode Spacing ◽  
Basement Complex ◽  
Current Electrode ◽  
Weathered Rock ◽  
Overburden Thickness ◽  
Electrical Survey ◽  
Electrical Sounding ◽  
Depth Ranges

Abstract The study aims to integrate magnetic and vertical electrical sounding (VES) resistivity methods to determine groundwater prospective in part of Aran-orin Sheet 224. A total of three traverses were established in the study area for the vertical electrical sounding using the Schlumberger electrode configuration. A total of 17 VES points was established using the ABEM Terrameter SAS 1000C model with maximum half-current electrode spacing (AB/2) of 120m. A total of eight traverses were established for the magnetics survey with station intervals of 10 m and inter-profile spacing of 100 m. The magnetic and VES data were qualitatively and quantitatively interpreted using IPI2WIN and OASIS MONTAJ package respectively. The geo-electric sections reveal a maximum of 3-4 layers beneath the sub-surface an overburden thickness ranges from 8.2 m to 64.9 m and the corresponding lithology inferred are topsoil, weathered Rock, fractured basement and fresh basement. The depth to basement using half-width method showed that the depth ranges from 8.4-56.04 m, which corresponds with the electrical survey.

scholarly journals Aeromagnetic and electrical resistivity mapping for groundwater development around Ilesha schist belt, southwestern Nigeria

2021 ◽  
Author(s):  
Cyril Chibueze Okpoli ◽  
Blessing omobolanle Akinbulejo
Keyword(s):  
Data Interpretation ◽  
Groundwater Potential ◽  
Vertical Electrical Sounding ◽  
Groundwater Prospect ◽  
Lineament Density ◽  
Geological Structures ◽  
Southwestern Nigeria ◽  
High Tendency ◽  
Electrical Sounding ◽  
Image Enhancing

AbstractAeromagnetic and vertical electrical sounding around Ijano, southwestern Nigeria, was investigated for groundwater potential. Aeromagnetic dataset and vertical electrical sounding were acquired and used to investigate the study area. Oasis Montaj, Microsoft Excel and Arc GIS were used to present the results in maps, images and profiles. In order to map out the geological structures of the study area, magnetic image enhancing filters applied to the total magnetic intensity using Geosoft (Oasis Montaj) are reduction to equator, vertical derivative, total horizontal derivative and upward continuation. These filters helped define the lithological boundaries, geological structures, faults, folds and contacts. The lineament of aeromagnetic map was generated from derived field intensity gradients and solutions of Euler deconvolution carried out on the aeromagnetic data using structural index of 0.5 and 1. The processed image shows the lineaments trends majorly towards NE–SW directions. From these combined results of the study area, consistent aeromagnetic lineament map was generated showing the probable positions and trends of the suspected fractured/faulted zone as well as other basement structures. Hydro-lineament density maps based on lineament were produced from the generalized structure trends in the area. The result from the depth sounding data interpretation indicates three curve types which are H, HA and KH, where curve type H has the highest occurrence. The results from the vertical electrical sounding data revealed that the areas with the highest hydro-lineament density are good for groundwater prospect and development. The study has led to the delineation of areas where groundwater occurrences are most promising for sustainable supply, suggesting that an area with high concentrations of lineament density has a high tendency for groundwater prospecting. The results from the study show that the aeromagnetic technique is capable of extracting lineament trends in an inaccessible tropical forest.

scholarly journals Modeling of Groundwater Potential Using Vertical Electrical Sounding (VES) and Multi-caterial Analysis at Omitogun Housing Estate, Akure, Southwestern Nigeria

2018 ◽  
pp. 1-11
Author(s):  
Adebo A. Babatunde ◽  
Ilugbo Stephen Olubusola ◽  
Oladetan Folorunso Emmanuel
Keyword(s):  
Structural Features ◽  
Groundwater Potential ◽  
Vertical Electrical Sounding ◽  
Groundwater Prospect ◽  
Groundwater Potential Zones ◽  
Southwestern Nigeria ◽  
Entire Study ◽  
Potential Map ◽  
Electrical Sounding ◽  
Groundwater Potential Map

A geoelectric investigation of groundwater prospect at Omitogun Estate, along Benin/Ilesha express way Akure, within the basement complex of southwestern Nigeria was carried out with a view to providing information on the geoelectric characteristic of the subsurface sequence, bedrock topography, subsurface structural features and their hydrogeologic significance, in order to identify aquifer units and determine possible areas for groundwater potential zones. The study involved the use of Schlumberger vertical electrical sounding data at thirty (30) stations. The vertical electrical sounding data presented as field curves were interpreted quantitatively by partial curve matching method and computer iteration technique. Fracture resistivity map, aquifer resistivity map, aquifer thickness map and overburden thickness map were generated from the results. Groundwater potential map was also generated from the integration of these maps using multi-criteria decision analysis (MCDA). The study area has been classified into low, medium, high groundwater potential zones and the results from well data across the entire study area were used to validate the accuracy of the groundwater potential map. From the results obtained, it could be concluded that the study area is generalized to be of low groundwater potential.  

scholarly journals Evaluation of groundwater potential of bedrock aquifers in Geological Sheet 223 Ilorin, Nigeria, using geo-electric sounding

2020 ◽  
Vol 10 (10) ◽  
Author(s):  
W. O. Raji ◽  
K. A. Abdulkadir
Keyword(s):  
Mathematical Model ◽  
Hydraulic Conductivity ◽  
Reflection Coefficient ◽  
Fractured Rock ◽  
Groundwater Potential ◽  
Rock Layer ◽  
Basement Complex ◽  
Weathered Rock ◽  
Electrical Sounding ◽  
Bedrock Aquifers

Abstract Electrical resistivity data acquired in one hundred and ten (110) locations using vertical electrical sounding method of Schlumberger array have been used to study the hydrogeological properties and groundwater storage potential of bedrock aquifers in an area covered by Geological Sheet 223 Ilorin, Nigeria. The aim of the study was to identify productive aquifer zones for citing boreholes for community water supply. The data acquired were processed and interpreted using auxiliary curve matching and computer automation method to delineate the different geo-electric layers, their resistivities, thicknesses, and depths. Geo-electrical layers were interpreted to their equivalent geological layers using borehole lithological logs from the study area. Then, the hydraulic conductivity, transmissivity, fracture contrast, reflection coefficient were estimated and plotted in the form of 2D maps to describe the spatial variations of these parameters in the area. The results of the study revealed the presence of three to five geo-electric layers. The geo-electric layers, from top to the bottom, corresponds to the topsoil layer, lateritic layer, weathered rock layer, fractured rock layer, and the fresh basement rock. Lateritic and/or fractured rock layers were not delineated in some places. The weathered and fractured rock layers, where present, correspond to the aquifer units. The thickness of the fracture aquifer ranges from 0.6 to 33.6 m while the thickness of the weathered aquifer ranges from 1.4 to 49.3 m. The transmissivity, $$ T $$ T , and hydraulic conductivity, $$ K $$ K , range from 3 to 1200 m2/day and 1 to 48 m/day, respectively. The reflection coefficient and fracture contrast map showed the presence of water-bearing fractures and shared some similarities with T and K maps. A mathematical model for predicting groundwater potential, $$ {\text{GW}}_{\text{P}} $$ GW P , of weathered aquifer in the basement complex terrain was proposed in this study. The consistencies between the overall groundwater potential map and aquifers parameters distributions maps suggest the appropriateness of the proposed mathematical model for predicting groundwater potential of weathered rock in the basement complex area of Nigeria. The western, northwestern, and central parts of the study area, having $$ {\text{GW}}_{\text{P}} $$ GW P greater than 0.6 (60%), were recommended for groundwater development through boreholes drilled to a depth ranging between 75 and 100 m.

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