scholarly journals Application of Electrical Resistivity and Hydrochemistry Methods for Mapping Groundwater Contamination around Okun Ilashe Island Area, Lagos State, Southwestern Nigeria

2019 ◽  
pp. 1-15
Author(s):  
T. O. Alabi ◽  
S. O. Ilugbo ◽  
O. E. Akinmoye ◽  
M. A. Ibitomi ◽  
I. Aigbedion ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Groundwater Contamination ◽  
Water Samples ◽  
Vertical Electrical Sounding ◽  
Quality Analysis ◽  
High Resistivity ◽  
Southwestern Nigeria ◽  
Island Area ◽  
Lagos State ◽  
Electrical Sounding

An application of Electrical Resistivity and hydrochemistry investigation involving Vertical Electrical Sounding (VES) and water quality analysis was conducted around Okun Ilashe Island area of Lagos state, southwestern Nigeria where there have been reported cases of groundwater contamination. The hydrochemical analysis was performed on five water samples in the area; two from boreholes and others from hand dug wells. Present study investigation showed that the groundwater had been contaminated by hydrocarbon arising from pipeline leakages in the studied area. The hydrocarbon contaminated plumes are specially characterized by relatively high resistivity values (> 800 Ω-m) and were delineated to a depth of about 12 m. Hydrochemical results showed that three of the sampled water have higher total dissolved solids (TDS) (>400 ppm) in compared to the remaining water samples. The major ions identified includes Na+, K+, Cl, Mg2+, Ca2+ and NO3-. Total Dissolved Solid (TDS) and Electrical Conductivity (EC) showed values not in agreement with WHO standards values. Ten (10) Vertical Electrical Sounding (VES) stations were occupied along four traverse lines trending E-W direction. The vertical electrical sounding results indicate maximum of four subsurface layers; Top soil, hydrocarbon contaminated sand, clay/clayey sand and sand/sandy clay. The contaminant plume has migrated to a significant depth of 12 m thus posing an inherent danger to the inhabitant of the area.

scholarly journals Surface DC resistivity survey of contamination Beneath Ido-Osun dumpsite, southwestern Nigeria

2015 ◽  
Vol 54 (4) ◽  
Author(s):  
Gabriel Oyelowo Bayowa ◽  
Dele Ebenezer Falebita ◽  
Raheem Olajide Adegboyesga
Keyword(s):  
Groundwater Contamination ◽  
Groundwater Pollution ◽  
Vertical Electrical Sounding ◽  
Dc Resistivity ◽  
Southwestern Nigeria ◽  
Fractured Bedrock ◽  
Resistivity Survey ◽  
Groundwater Reservoir ◽  
Electrical Sounding ◽  
Resistivity Profiling

Surface DC resistivity techniques have been used to investigate the subsoil characteristics around an abandoned dumpsite in Ido Osun, Southwestern Nigeria. The aim was to delineate groundwater contamination, identify lithologic layers, locate possible leachate plumes, and assess the risk of groundwater pollution. Schlumberger vertical electrical sounding (VES) and Dipole-dipole resistivity profiling data were acquired at 20 m and 10 m intervals respectively along three northwest-southeast geophysical traverses. The geoelectric sections revealed four probable subsurface geoelectric layers which were considered to be topsoil, laterite, weathered/fractured bedrock and competent/fresh bedrock based on previous works. The weathered/fractured bedrock forms the groundwater reservoir in the area as interpreted from the over 98% occurrence of H, KH geoelectric curve types. The dipole-dipole sections showed several distinct low resistivity zones which extends into the weathered/fractured bedrock. These were interpreted as probable contamination plumes beneath the dumpsite.

scholarly journals Geophysical Assessment of Groundwater Vulnerability to Diesel Contamination at a Telecommunication Mast in Adebayo Area, Ado-Ekiti, Southwestern Nigeria

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Olaseeni Olayiwola ◽  
Fagbemigun Tokunbo ◽  
Ojo Bosede ◽  
Amosun Joel ◽  
Oyebamiji Ajibola
Keyword(s):  
Electrical Resistivity ◽  
Groundwater Vulnerability ◽  
Diesel Oil ◽  
Vertical Electrical Sounding ◽  
Geophysical Investigation ◽  
Southwestern Nigeria ◽  
Geoelectric Section ◽  
Resistivity Method ◽  
Electrical Sounding ◽  
Electrical Resistivity Method

Abstract An appraisal of the groundwater vulnerability to contamination risk at Adebayo in Ado-Ekiti, Southwestern Nigeria, was carried out using the electrical resistivity method of geophysical prospecting. Two traverses of length 100 m each were established for both vertical electrical sounding (VES) and dipole-dipole. Six (6) Vertical Electrical Sounding (VES) and 2-D dipole-dipole profiling techniques of the electrical resistivity method were adopted for the geophysical investigation. The results show variations in resistivity values, depicting four to five geologic layers: the topsoil, laterite, weathered layer, fractured, and the fresh basement. It was observed from the correlation of the geoelectric section and 2-D resistivity image along traverse 1 (TR1) that the groundwater in the study area flows towards the southwestern part, and the fractured basement serves as a migration pathway to the diesel oil in the same direction as groundwater flow. The fractured basement (Well 2) with no lateritic cover has higher resistivity values compare to the fracture zone that was found directly under the mast which was overlain by the laterite. Comparing the resistivity values of Well 1 and 2, Well 2 that was drilled into the fractured basement has more traces of the contaminant than Well 1.

A LOW-COST RESISTIVIMETER FOR USE IN PRACTICAL LECTURES OF APPLIED GEOPHYSICS

2016 ◽  
Vol 34 (1) ◽  
Author(s):  
Walter Sydney Dutra Folly ◽  
Aracy Sousa Senra
Keyword(s):  
Electrical Resistivity ◽  
Low Cost ◽  
Test Area ◽  
Vertical Electrical Sounding ◽  
Applied Geophysics ◽  
Resistivity Profile ◽  
Electrical Sounding ◽  
Good Agreement

ABSTRACT. We describe the construction and testing of a simple and efficient low-cost resistivimeter designed for use in practical classes in Applied Geophysics. The equipment was successfully tested in a vertical electrical sounding (VES) performed on sandy terrain within the campus of the Universidade Federal de Sergipe, Brazil. The VES results were in good agreement with the profiles obtained from two boreholes located approximately 500 m from the test area, clearly demonstrating the efficiency of the equipment and the adopted methodology.Keywords: vertical electrical sounding, electrical resistivity, resistivity profile. RESUMO. Neste artigo, descrevemos a construção e o teste de um resistivímetro de baixo custo, simples e eficiente, concebido para ser utilizado em aulas práticas de Geofísica Aplicada. O equipamento foi testado com a realização de uma sondagem elétrica vertical (SEV) em um terreno arenoso localizado no campus da Universidade Federal de Sergipe, Brasil. Os resultados obtidos nesta SEV apresentaram boa concordância com os perfis observados em dois poços de sondagem localizados a 500 m da área de teste, fato que comprovou a eficiência do equipamento e da metodologia adotada.Palavras-chave: sondagem elétrica vertical, resistividade elétrica, perfil de resistividade. 

scholarly journals Evaluation of Salt-water Intrusion in the Coastal Area of Igbokoda, Southwestern Nigeria

2018 ◽  
Vol 6 (01) ◽  
Author(s):  
Talabi A. O ◽  
Ajayi C. A ◽  
Afolagboye L. O ◽  
Oyedele A. A ◽  
Ojo O. F ◽  
...  
Keyword(s):  
Coastal Area ◽  
Salt Water ◽  
Silty Sand ◽  
High Resistivity ◽  
Salt Water Intrusion ◽  
Southwestern Nigeria ◽  
Major Threat ◽  
Sandy Clay ◽  
The World ◽  
Electrical Sounding

Saltwater intrusion into the coastal aquifer has long been recognized as a major threat to groundwater quality around the world. Groundwater evaluation of salt water intrusions in Igbokoda coastal area, southwestern Nigeria was carried out employing combined Horizontal Profiling and Vertical electrical sounding. Two traverses each with two sounding points were occupied. The result from the survey revealed 4 to 5 major layers comprising the unconsolidated silty sand and sandy clay (overburden), clayey zone, consolidated sand zone, partly intruded salt water intruded sandy clay zone and salt water intruded clay zone. The curves were the complex types KQH, KHA, QH and HKH curves. The overburden has resistivity that ranged from 253 to 1316.7Ω-m, thickness that ranged from 0.2 m to 7m. The clayey zone had resistivity of 846.0 Ω-m and thickness of 4m. The consolidated sand zone had resistivity that ranged from 2848.7 to 2865.7Ω-m and thickness that ranged between 4 and 21m. The partly intruded salt water zone is characterized by resistivity that varies between 18.4Ω-m and 93.0Ω-m and thickness of about 7-25m. The salt water intruded zone is characterized by resistivity that ranges between 4.1Ω-m and 9.7Ω-m and thickness of 4-48m. The partly-salt water intruded zones and salt water intruded zone were characterized with low resistivity while the high resistivity zones of consolidated sand layer constitute fresh water bearing zone that could serve as boreholes in the study area.

scholarly journals An Investigation of Groundwater Contamination around Nsukka Municipality Dumpsite using the Resistivity Method

2020 ◽  
Author(s):  
Olisah Nzemeka
Keyword(s):  
Electrical Resistivity ◽  
Groundwater Contamination ◽  
Low Resistivity ◽  
Electrical Resistivity Survey ◽  
Resistivity Method ◽  
Electrical Sounding ◽  
On Line ◽  
2D Resistivity Imaging ◽  
Resistivity Meter ◽  
2D Resistivity

An investigation using electrical resistivity method was conducted around a solid waste dumpsite at Nsukka in Nsukka L.G.A of Enugu State, Nigeria to investigate the level of groundwater contamination. Electrical Sounding (VES) and 2D resistivity imaging were used with a digital read out resistivity meter (ABEM SAS 1000) to acquire data in the area. A total of eight (8) sounding and six (6) 2D resistivity imagings were carried out in the area. A contaminant leachate plume was delineated in 2D resistivity sections as low resistivity zones while the VES shows the depth of aquifer. In 2D pseudosections where bluish colours with low resistivities (less than 20.80Ωm) with the depth ranging from 1.28m to 17.1m in the Line 1 and 2 are seen as contaminated zones. The rest of the lines are not contaminated because of their high resistivities (greater than 20.80Ωm). The result of the electrical resistivity survey also showed 4 - 5 layers geo-electric sections and an AA and AK type sounding curves. The VES result shows that VES 1A, 1B, 2A and 2B which are carried out on line 1 & 2 of the wenner lines showed signs of contamination with low resistivity values less than 20.80Ωm complementing the wenner results. The contamination has not yet got to where the aquifer is located on the lines. Since the depth to the aquifer ranges from 30.26m to 155.43m while maximum depth of contamination is 17.1m. It is believed that the leachate has not percolated down to the aquiferous zones as such aquifers are presumed to be free.

scholarly journals DELINEATION OF CONCENTRATION OF FERRUGINOUS MINERALS IN AQUIFERS IN YENAGOA, BAYELSA STATE, NIGERIA, USING GEOELECTRIC VERTICAL ELECTRICAL SOUNDING (VES) AND PHYSICOCHEMICAL TECHNIQUES

2020 ◽  
Vol 4 (2) ◽  
pp. 90-101
Author(s):  
Okorobia E. Mark ◽  
Etim D. Uko ◽  
Amechi Bright ◽  
Onengiyeofori A. Davies
Keyword(s):  
Water Samples ◽  
Ph Value ◽  
Physicochemical Analysis ◽  
Vertical Electrical Sounding ◽  
World Health ◽  
Physical Parameters ◽  
Chemical Parameters ◽  
Flame Atomic Absorption ◽  
Flame Atomic Absorption Spectrophotometer ◽  
Electrical Sounding

A total of sixteen Vertical Electrical Sounding (VES) surveys and five physicochemical analyses were carried out in selected locations within the Yenagoa Metropolis, in Bayelsa State, Nigeria, to delineate the concentration of ferruginous minerals in freshwater aquifers in the area. For the geophysical survey, the Schlumberger electrode configuration was employed. The resulting data obtained was processed and interpreted using Excel suite, IPI2WIN resistivity, Surfer-11 and Rockworks software. The results revealed four to six geologic layers across the area, and were used to generate geoelectric maps which showed that in most part of the study area, there were uneven distributions of shallow aquifers (4 – 10m), and uneven layers of clay and sandy-silt at varying depths up to 20m. The physicochemical analysis of raw water samples collected from five boreholes located in close proximity to the VES sounding locations were analysed for physical and chemical parameters. Physical parameters tested include colour, conductivity, turbidity, and temperature. Chemical parameters analysed are pH, Dissolved Oxygen (DO), Total Dissolved Solids (TDS) Alkalinity, Total Iron, Carbonate, Chloride, Sulphate, and heavy metals such as copper, chromium, nickel, cadmium, manganese, zinc and lead. The pH was determined using a Mettler Toledo (GmbH 8603 Schwerzenbach) pH meter by direct measurement. An analogue mercury thermometer was used for temperature measurements and a Hach 2100A turbidimeter for turbidity determination. Also, the concentrations of Zinc, Lead, and Copper in the water samples were obtained using the flame atomic absorption spectrophotometer. It was observed that the values SO42- , Cl-, Na2+, Mg2+, Ca2+, F- have values below World Health Organization (WHO) standard in all boreholes tested while Mn2+, NH3, PO3−and Fe2+, K+, and Cu2+ have values above WHO standard in some boreholes. The pH values all showed that the water was slightly basic as the values all exceeded the neutral limit 7, with only station showing slightly elevated pH value 9, suggesting the presence of iron bacteria. F-, K+, Fe2+ and Mn2+ have values that exceeded the WHO standard. The results from Physicochemical and geophysical analysis suggest that at depths of 20 – 45m, the concentration of ferruginous minerals is high especially towards the north eastern section of the study area and so drilling should be made to approximate depths of 50 – 80m for minimal iron contamination in the aquifers.

scholarly journals Seepage investigations of heterogeneous soils beneath some buildings using geophysical approaches: example from southwestern Nigeria

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Adebayo Olayinka Salako ◽  
Abayomi Gaius Osotuyi ◽  
Adekunle Abraham Adepelumi
Keyword(s):  
Electrical Resistivity ◽  
Ground Penetrating Radar ◽  
Flood Plain ◽  
High Resistivity ◽  
Safe Haven ◽  
Southwestern Nigeria ◽  
Heterogeneous Soils ◽  
Ground Conditions ◽  
Southwest Nigeria ◽  
Ground Penetrating

AbstractBuildings along the flood plain of River Osun, southwest Nigeria, are usually thought of as been a safe haven for residence over the years. But in recent times with vast (increasing) population and growing urbanization, some of the buildings currently experience structural damages not related to constructional designs but rather ground conditions around building foundations. The ground conditions (seepages in this case) and how it influences properties of soils (water moisture, permeability etc.) to support the foundation of buildings. This paper attempts to map out seepages in heterogeneous soils around buildings in Erinle, southwest Nigeria where building cracks probably as a result of water seepages from subsurface through fissures and fractures where noticed. These cracks are a probable manifestation of a weakened foundation that could overtime result to a collapse, hence the need to investigate seepage prone zones. To achieve this, electrical resistivity (ER) and Electromagnetic Ground Penetrating Radar (EM-GPR) surveys were made along affected buildings to map out possible causes of deterioration. Geo-sections (analyzed ER data) shows high resistivity layer (topsoil) underlain by low resistivity layer (weathered basement) confirmed by planer reflections (topsoil) and fairly smooth to smooth reflections (weathered basement) in Radargrams (analyzed GPR data). An integration of the geo-section and radargram produced from ER and GPR data shows that buildings along traverses 1, 2, 3 and 5 is most prone to seepages especially as it exhibits very low anomalously resistivity values (< 25 Ωm) but this is not the case for buildings along traverses 4, 6, 7 and 8.

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