scholarly journals On the Application of Coefficient of Anisotropy as an Index of Groundwater Potential in a Typical Basement Complex of Ado Ekiti, Southwest, Nigeria

2019 ◽  
pp. 1-10
Author(s):  
A. I. Olayinka ◽  
E. A. A. Oyedele
Keyword(s):  
Electrode Array ◽  
Groundwater Potential ◽  
Geographical Information ◽  
Depth Image ◽  
Basement Complex ◽  
Fractured Bedrock ◽  
Southwest Nigeria ◽  
Porosity And Permeability ◽  
Thick Overburden ◽  
Depth Sounding

This paper examines the application of the Dar Zarrouk parameter, the Coefficient of Anisotropy to Groundwater Potential Evaluation in a typical Basement Complex Terrain of Ado-Ekiti Southwest, Nigeria. A regional Geoelectric Depth sounding was carried out across the metropolis using the Schlumberger electrode array. Resistivity-depth image in terms of layer thickness and resistivity was used to compute the Coefficients of Anisotropy for the VES locations occupied. Thematic maps of the geoelectric parameters were generated using the Concept of Geographical Information System (GIS). Comparative Map Analysis revealed that a range of 1.3 to 1.6 Anisotropy values was observed across the zones characterized by thick overburden, Weathered Basement Thickness in excess of 25m, low weathered basement resistivity, fractured bedrock and basement depressions in the study area. Anisotropy values ranging from 1.8 to 2.8 were observed across the basement ridges and zones characterized by thin overburden, Weathered Basement Thickness of generally less than 15m and Weathered Basement resistivity greater than 1500 Ω-m with least groundwater potential. The regions of Anisotropy values ranging from 1.3 to 1.6 are demarcated as high groundwater potential zones. Areas characterized by higher Anisotropy values can be associated with low porosity and permeability with less hydro geological appeal.

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.  

scholarly journals Groundwater Potentiality Prediction Using AHP-MCDA and GBT Model in a Typical Basement Complex, Nigeria: Insights From Remote Sensing and Geophysical Datasets

2022 ◽  
Author(s):  
Balogun Olabode Olumide ◽  
Akintorinwa Olaoluwa James ◽  
Mogaji Kehinde Anthony
Keyword(s):  
Drainage Density ◽  
Groundwater Potential ◽  
Data Driven ◽  
Groundwater Potential Zone ◽  
Gradient Boosting ◽  
Potential Zone ◽  
Basement Complex ◽  
True Nature ◽  
Groundwater Potentiality ◽  
Depth Sounding

Abstract Delineation of geologic features that are capable of hosting water in economic quantity in the Basement Complex has been a major concern because they are usually localized due to restricted fractured and weathered rock. To effectively evaluate the groundwater potentiality prediction index (GPPI) accuracy of an area, solely depends on the groundwater potentiality predictors (GPPs) considered and the statistical model used in analyzing the data. Therefore, the acquired remotely sensed and geophysical depth sounding database processed using autopartial curve matching software and computer aided iteration to determine was analyzed using the conventional Analytical Hierarchy Process (AHP) model and the machine learning Gradient Boosting Tree (GBT) data driven model. Such a data driven model (GBT) is efficient in solving complex and cognitive problems in high uncertainty and complex environments. Twelve (12) groundwater potentiality predictors (GPPs) namely: Digital Elevation Model (DEM), Slope (S), Drainage Density (Dd), Land Use (Lu), Aquifer Resistivity (ρa), Aquifer Thickness (h), Overburden Thickness (b), Aquifer Hydraulic Conductivity (k), Aquifer Transmissivity (Tr), Aquifer Storativity (St), Aquifer Diffusivity (D), Aquifer Reflection Coefficient (Rc). The efficacy of GBT model was applied using the Salford Predictive Modeler 8.0 software. The data were partitioned into training and test dataset in ratio 90:10 using k-10 cross validation techniques. Their prediction importance was determined and the groundwater potentiality prediction index calculated and processed in the ArcGIS environment to produce the groundwater potential prediction index (GPPI) map of the investigated area. The investigated area was classed into three (3) zonations of low, moderate and high groundwater potential with about 56% classed within the low groundwater potential zone. Fifteen (15) water column measurement from wells was used to validate the developed model by calculating the predictive correlation accuracy (PCA) using the spearman's correlation analysis. The AHP-GPPI and GBT-GPPI model gave a correlation of (rs = 0.66; p = .007) and (rs = 0.74; p = .002) respectively. In conclusion, the model has proven that the drop in aquifer resistivity doesn't necessitate the presence of groundwater but rather several parameter should be integrated together to better understand the true nature of the aquifer.

scholarly journals The Use of Combined Geophysical Survey Methods for Groundwater Investigation in a Typical Basement Complex Terrain: Case Study of Erunmu, Ibadan, Southwest Nigeria

2019 ◽  
pp. 1-16
Author(s):  
Abudulawal, Lukuman
Keyword(s):  
Water Saturation ◽  
Survey Methods ◽  
Low Frequency ◽  
Groundwater Potential ◽  
Future Research ◽  
Basement Complex ◽  
Southwest Nigeria ◽  
Subsurface Layers ◽  
Basement Layer ◽  
Geophysical Survey Methods

A combined Survey involving the very low frequency electromagnetic (VLF – EM) and Electrical resistivity surveys were carried out in order to appraise the groundwater potential, and locate appropriate positions for sighting boreholes in Erunmu Community, Egbeda local government area, Oyo State, Nigeria. VLF data were obtained along five traverses as the first step in order to locate suitable vertical electrical sounding (VES) stations. Vertical Electrical Soundings using Schlumberger array were thereafter carried out at twenty 20) locations. The integrated interpretation of both data confirms the presence of aquifers, which includes, weathered zone and basement transition/fractures beneath the area, which prior to this investigation have a history of failed boreholes and wells. The resistivity curve types obtained includes H and A which revealed the presence of 3 to 4 subsurface layers consisting of topsoil, the clay, the sandy clay, fractured zone and the highly resistive bedrock. The resulting geo-electric section from the interpretation revealed the Reflection coefficient which ranges from 0.45 – 0.98. The dominated curve type in the area investigated is the H which is typical of basement complex while the A-type is about 20% of the total curves. Hydrogeological, the topsoil is not important because the degree of water saturation in this layer is very low and cannot be utilized for groundwater. The fractured basement layer (which is present in less than 15% of the study area is very relevant in groundwater prospecting; when it is thick enough the layer could support borehole drilling. Areas identified as geological interfaces in the VLF anomaly charts were also confirmed by the interpreted VES data as poor and intermediate zones for groundwater potential in the study area. The significance of this study is such that it will serve as a useful reference for future research efforts in the aspect of basement complex groundwater studies.

scholarly journals Mapping Groundwater Potential for Irrigation, by Geographical Information System and Remote Sensing Techniques: A Case Study of District Lower Dir, Pakistan

Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 669
Author(s):  
Abid Sarwar ◽  
Sajid Rashid Ahmad ◽  
Muhammad Ishaq Asif Rehmani ◽  
Muhammad Asif Javid ◽  
Shazia Gulzar ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Water Table ◽  
Groundwater Potential ◽  
Geographical Information ◽  
Groundwater Potential Zone ◽  
Potential Zone ◽  
Relative Significance ◽  
High Good ◽  
Groundwater Potentiality ◽  
Very High

The changing climate and global warming have rendered existing surface water insufficient, which is projected to adversely influence the irrigated farming systems globally. Consequently, groundwater demand has increased significantly owing to increasing population and demand for plant-based foods especially in South Asia and Pakistan. This study aimed to determine the potential areas for groundwater use for agriculture sector development in the study area Lower Dir District. ArcGIS 10.4 was utilized for geospatial analysis, which is referred to as Multi Influencing Factor (MIF) methodology. Seven parameters including land cover, geology, soil, rainfall, underground faults (liniment) density, drainage density, and slope, were utilized for delineation purpose. Considering relative significance and influence of each parameter in the groundwater recharge rating and weightage was given and potential groundwater areas were classified into very high, high, good, and poor. The result of classification disclosed that the areas of 113.10, 659.38, 674.68, and 124.17 km2 had very high, high, good, and poor potential for groundwater agricultural uses, respectively. Field surveys for water table indicated groundwater potentiality, which was high for Kotkay and Lalqila union councils having shallow water table. However, groundwater potentiality was poor in Zimdara, Khal, and Talash, characterized with a very deep water table. Moreover, the study effectively revealed that remote sensing and GIS could be developed as potent tools for mapping potential sites for groundwater utilization. Furthermore, MIF technique could be a suitable approach for delineation of groundwater potential zone, which can be applied for further research in different areas.

GIS and RS intelligence in delineating the groundwater potential zones in Arid Regions: a case study of southern Aseer, southwestern Saudi Arabia

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Mohd Yawar Ali Khan ◽  
Mohamed ElKashouty ◽  
Ali Mohammad Subyani ◽  
Fuqiang Tian ◽  
Waleed Gusti
Keyword(s):  
Saudi Arabia ◽  
Primary Source ◽  
Groundwater Potential ◽  
Integrated Analysis ◽  
Groundwater Potential Zones ◽  
Geospatial Tools ◽  
Porosity And Permeability ◽  
Proterozoic Basement ◽  
Dug Well ◽  
Very High

AbstractProterozoic basement aquifers are the primary source of water supply for the local populations in the Aseer (also spelled “Asir” or “Assir”) province located in the southwest of Saudi Arabia (SA) since high evaporation rates and low rainfall are experienced in the region. Groundwater assets are receiving a lot of attention as a result of the growing need for water due to increased urbanization, population, and agricultural expansion. People have been pushed to seek groundwater from less reliable sources, such as fracture bedrocks. This study is centered on identifying the essential contributing parameters utilizing an integrated multi-criteria analysis and geospatial tools to map groundwater potential zones (GWPZs). The outcome of the GWPZs map was divided into five categories, ranging from very high to negligible potential. The results concluded that 57% of the investigated area (southwestern parts) showed moderate to very high potentials, attributed to Wadi deposits, low topography, good water quality, and presence of porosity and permeability. In contrast, the remaining 43% (northeastern and southeastern parts) showed negligible aquifer potential zones. The computed GWPZs were validated using dug well sites in moderate to very high aquifer potentials. Total dissolved solids (TDS) and nitrate (NO32−) concentrations were highest and lowest in aquifers, mainly in negligible and moderate to very high potential zones, respectively. The results were promising and highlighted that such integrated analysis is decisive and can be implemented in any region facing similar groundwater expectations and management.

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.

Mapping of Groundwater potential zones in Lingasugur Taluk in North-eastern part of Karnataka, India using Remote Sensing, GIS and multi-criteria data analysis

2021 ◽  
Vol 14 (12) ◽  
pp. 13-22
Author(s):  
Ajgaonkar Swanand ◽  
S. Manjunatha
Keyword(s):  
Remote Sensing ◽  
Groundwater Resources ◽  
Drainage Density ◽  
Groundwater Potential ◽  
Groundwater Exploration ◽  
Geographical Information ◽  
Groundwater Potential Zones ◽  
Thematic Maps ◽  
North Eastern

Groundwater research has evolved tremendously as presently it is the need of society. Remote Sensing (RS) and Geographical Information System (GIS) are the main methods in finding the potential zones for the groundwater. They help in assessing, exploring, monitoring and conserving groundwater resources. A case study was conducted to find the groundwater potential zones in Lingasugur taluk, Raichur District, Karnataka State, India. Ten thematic maps were prepared for the study area such as geology, hydrogeomorphology, land use/ land cover, soil type, NDVI, NDWI, slope map, lineament density, rainfall and drainage density. A weighted overlay superimposed method was used after converting all the thematic maps in raster format. Thus from analysis, the classes in groundwater potential were made as very good, moderate, poor and very poor zones covering an area of 10.1 sq.km., 169.25 sq.km., 1732.31 sq.km. and 53.66 sq.km. respectively. By taking the present study into consideration, the future plans for urbanization, recharge structures and groundwater exploration sites can be decided.

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,

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