scholarly journals 2D inversion of electrical resistivity investigation of contaminant plume around a dumpsite near Onitsha expressway in southeastern Nigeria

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Charles Chibueze Ugbor ◽  
Ifeanyi Emmanuel Ikwuagwu ◽  
Osim Jethro Ogboke
Keyword(s):  
Flow Direction ◽  
Southeastern Nigeria ◽  
Resistivity Tomography ◽  
2D Inversion ◽  
Low Resistivity ◽  
Leachate Plume ◽  
Electrical Sounding ◽  
Resistivity Meter ◽  
2D Resistivity ◽  
Borehole Log

AbstractThe study tries to utilize vertical electrical sounding (VES) and 2D resistivity tomography to evaluate the region of influence of the leachate plume on the groundwater around a dumpsite at Onitsha expressway, southeastern Nigeria. The borehole log data were acquired and their respective geoposition logged with Garmin GPS device. In addition, four 1D (VES) soundings and 2D electrical profile data were acquired in the field utilizing the Schlumberger and Wenner profiles respectively. Petrozenith PZ-03 Resistivity meter was used to acquire the electrical data, while RES2DINV and WinResist software were used to interpret the 2D and 1D data respectively. The resulting geoelectic layers were correlated with the borehole logs and were interpreted according to their resistivity distribution. Results of the 2D inversion at profiles 1 and 3 showed low resistivity zones indicating influence from the leachate plume. Profiles 2 and 4 gave low resistivity zone within 14.6 and 44.3 Ωm from surface to between 0.375 and 3.60 m depths indicating influence from leachate plume. Likewise, profiles 1 and 3, which penetrated groundwater, also showed very low resistivity with resistivity ranging from 3.12 to 8.7 Ωm, from surface to few meters depths. This indicates that it has been polluted by the leachate. In contrast, Profiles 2 and 4, from the 2D inversion, has no leachate influence on the groundwater. The VES result showed that the depth to the water table at location 1, 2, 3 and 4 are 21.7 m, 17.9 m, 15.9 m and 12.2 m respectively, with the leachate plume flowing in the southeast direction in line with the groundwater flow direction.

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 Two-dimensional Electrical Resistivity Tomography of Bitumen Occurrence in Agbabu, Southwest Nigeria

2019 ◽  
pp. 1-9
Author(s):  
O. F. Ogunlana ◽  
O. M. Alile ◽  
O. J. Airen
Keyword(s):  
Electrical Resistivity ◽  
Apparent Resistivity ◽  
Electrical Resistivity Tomography ◽  
Electrode Spacing ◽  
Southwestern Nigeria ◽  
Resistivity Tomography ◽  
2D Inversion ◽  
Earth Resistivity ◽  
Southwest Nigeria ◽  
Resistivity Meter

The Electrical Resistivity Tomography (ERT) data was acquired within the area suspected to have high potential for bitumen occurrence using the Wenner-Schlumberger configuration in Agbabu, southwestern Nigeria. PASI 16GL-N Earth resistivity meter instrument was used to acquire data along five (5) traverses with 5m electrode spacing and traverses length of 150m. The apparent resistivity values obtained was processed using RES2DINV software which helped to automatically obtain the 2D inversion model of the subsurface. This study has shown the occurrence of bitumen between the depth of 13.4m and 9.93m for Traverses 1, 2, 3 and Traverses 4, 5 respectively in a 2-Dimensional electrical resistivity images for boreholes with a depth of about 18m. The results indicate that the bitumen is characterized by good lateral continuity and is sufficiently thick for commercial exploitation.

scholarly journals 2D Resistivity Tomography Survey for Leachate Plume from Isundunrin Poultry Disposal Pits

2019 ◽  
Vol 8 (2) ◽  
Author(s):  
Fakunle Mutiu Alani ◽  
Alabi Olusegun Olalekan ◽  
Olatona Gbadebo Ismaila ◽  
Oladejo Oubusayo Felix ◽  
Adeleke Joshua Toyin
Keyword(s):  
Alternative Methods ◽  
Horizontal Distance ◽  
Poultry Farm ◽  
Chemical Parameters ◽  
Resistivity Tomography ◽  
North East ◽  
The North ◽  
Leachate Plume ◽  
Dug Wells ◽  
2D Resistivity

Management of dead birds in poultry farms has been a major problem in Nigeria. This study aimed at using 2D resistivity tomography to outline leachate plume from disposal pits in a poultry farm. 2D electrical resistivity tomography were conducted along three profiles, two of which were 3.0 m and 25.0 m respectively to the two available mortality pits (Pit1 and Pit 2) while the third was 300.0 m away from the mortality Pit 1. Profile length of 100.0 m each and interspaced 5.0 m oriented in the North-East (Profile 1), South-East (Profile 2) and North-East (Profile 3) directions respectively was covered. 2D resistivity data inversions were performed on the obtained converted apparent resistivity using DIPROWIN software. Five water samples collected from five different hand dug wells available within the poultry farm were analysed for hydro chemical parameters. 2D results showed conductive paths occurrence in transverse one at the depth of 5.0 m, a horizontal distance of 45.0 m to 55.0 m, and had migrated down to the depth of 10.0 m. The second traverse showed varying resistivity values ranged 7.0 Ω m to 31.0 Ω m up to a depth of 15.0 m, an indication of the presence of clay soil. Low resistivity values ranged 14.0 Ω m to 49.0 Ω m were recorded in traverse 3. The extent of the contaminant is prominent at the topmost part of the soil and to almost 10.0 m depth. This was attributable to the contaminant from the deposit site of faeces of the poultry. Hydro chemical analysis indicated high values of Conductivity and Total Dissolved Solids (TDS). This confirms the migration of leachate from the disposal pits to the surrounding soils and groundwater and the 2D results obtained from disposal Pit 1. Other alternative methods of disposing dead birds are hereby recommended.

Assessment of groundwater repositories in Edem, Southeastern Nigeria, using vertical electrical sounding

2021 ◽  
Vol 14 (6) ◽  
Author(s):  
Emmanuel Tochukwu Omeje ◽  
Desmond Onyeka Ugbor ◽  
Johnson Cletus Ibuot ◽  
Daniel Nnemeka Obiora
Keyword(s):  
Vertical Electrical Sounding ◽  
Southeastern Nigeria ◽  
Electrical Sounding

scholarly journals Assessment of Environmental Geochemistry of Lead-Zinc Mining at Ishiagu Area, Lower Benue Trough, Southeastern Nigeria

2020 ◽  
Vol 9 (1) ◽  
pp. 31 ◽  
Author(s):  
Odika, P.O. ◽  
Anike, O.L. ◽  
Onwuemesi, A.G. ◽  
Odika, N.F. ◽  
Ejeckam, R.B.
Keyword(s):  
Heavy Metals ◽  
Flow Direction ◽  
Environmental Geochemistry ◽  
Zinc Sulphide ◽  
Mining Activities ◽  
Southeastern Nigeria ◽  
Rock Types ◽  
Sulphide Ores ◽  
Lead Zinc ◽  
Concentration Levels

Mining activities have long been recognized as a major source of environmental contamination associated with heavy metals and metalloids. This study evaluated the relationship between the occurrence and mining of lead-zinc sulphide ores at Ishiagu, Nigeria, and heavy metal and metalloid contamination. A comparative study of two zones in the area, with and without mining activities was also made Water, soil, stream sediment and ore samples were analyzed, after acid digestion, using atomic absorption spectrophotometer (AAS).  The concentration levels of seven heavy metals and a metalloid namely Pb, Cu, Ni, Zn, Mn, Co, Cd and as were evaluated. While the highest concentration levels of As, Co and Pb (5.20 mg/l, 0.54 mg/l and 3.40 mg/l respectively) were found in water, those of Ni and Mn (2.26 mg/l and 5.48 mg/l respectively) occurred in soil.  For Cu and Zn, highest levels of concentration (2.80 mg/l and 0.41 mg/l respectively) occurred in stream sediments. The variations in the concentration levels of these elements in varying geologic media (soil, water and sediment) indicate influence of rock types, human activities and media physiochemical characteristics. Geostatistical analyses using QQPlot, semivariogram and kriging showed normal distribution of these elements. Distribution and dispersion patterns of the heavy metals indicated increase in concentration levels in the local stream flow direction. Pb, Cu, As, Cd, Mn, and Ni concentrations had reached pollutant levels in water based on WHO standards, while Zn level is below. Since the local people use untreated surface water and groundwater for drinking and other domestic purposes, soil for farming and lead for cosmetics, long term exposure poses significant health risk for humans, animals and plants.

scholarly journals LWD DATA INVERSION FOR STRUCTURE WITH ANGULAR UNCONFORMITY

2021 ◽  
Vol 2 (1) ◽  
pp. 336-344
Author(s):  
Anna S. Astrakova ◽  
Elena V. Konobriy ◽  
Dmitry Yu. Kushnir ◽  
Nikolay N. Velker ◽  
Gleb V. Dyatlov
Keyword(s):  
Real Time ◽  
Optimization Method ◽  
Parametric Model ◽  
Model Parameters ◽  
Time Inversion ◽  
Water Contact ◽  
2D Inversion ◽  
Angular Unconformity ◽  
Oil Water ◽  
2D Resistivity

Non-structural traps and reservoir flanks are characterized by angular unconformities. Angular unconformity between dipping formation and sub-horizontal oil-water contact is common in the North Sea fields. This paper presents an approach to real-time inversion of LWD resistivity data for the scenario with angular unconformity. The approach utilizes artificial neural networks (ANNs) for calculating the tool responses in parametric surface-based 2D resistivity models. We propose a parametric model with two non-parallel boundaries suitable for scenarios with angular unconformity and pinch-out. Training of ANNs for this parametric model is performed using a database containing samples with the model parameters and corresponding tool responses. ANNs are the kernel of 2D inversion based on the Levenberg-Marquardt optimization method. To demonstrate applicability of our approach and compare with the results of 1D inversion, we analyze Extra Deep Azimuthal Resistivity tool responses in a 2D synthetic model. It is shown that 1D inversion determines either the position of the oil-water contact or dipping layers structure. At the same time, 2D inversion makes it possible to correctly reconstruct the positions of non-parallel boundaries. Performance of 2D inversion based on ANNs is suitable for real-time applications.

scholarly journals On the Use of Electrical Resistivity Method in Mapping Potential Sources and Extent of Pollution of Groundwater Systems in Lapai Town, Niger State, Nigeria.

2021 ◽  
Vol 5 (1) ◽  
pp. 18
Author(s):  
Matthew Tersoo Tsepav ◽  
Aliyu Yahaya Badeggi ◽  
Obaje Nuhu George ◽  
Usman Yusuf Tanko ◽  
Ibrahim Samuel Ibbi
Keyword(s):  
Electrical Resistivity ◽  
Lateritic Soil ◽  
Protective Capacity ◽  
Unconfined Aquifers ◽  
Resistivity Method ◽  
Electrical Sounding ◽  
Groundwater Systems ◽  
Electrical Resistivity Method ◽  
Resistivity Meter ◽  
Confined And Unconfined Aquifers

<p>Electrical resistivity method employing the Schlumberger array was used to occupy forty four (44) vertical electrical sounding points in Lapai town with the aim of determining the depth to aquifers, aquifer thicknesses and aquifer protective capacity. The G41 Geotron resistivity meter was used in obtaining the apparent resistivity data which was processed using Interpex 1XD resistivity interpretation software. The results revealed four lithologic sections which include top lateritic soil, sandy clay, fractured basement and fresh basement. Both confined and unconfined aquifers were identified within the area, with four classes of aquifer proactive capacities as high, moderate, weak and poor. While the aquifer at VES 20 was highly protected, twenty other aquifers were moderately protected, eight others had weak protection and fifteen aquifers were poorly protected. The aquifers were generally of good thicknesses and at varying reasonable depths, making them good reservoirs of water in appreciable quantity. The average aquifer thickness was estimated to be 48.36m while the average depth to aquifers was estimated to be 56.68m.</p>

scholarly journals Electrical resistivity tomography applied to geologic, hydrogeologic, and engineering investigations at a former waste-disposal site

Geophysics ◽  
2006 ◽  
Vol 71 (6) ◽  
pp. B231-B239 ◽  
Author(s):  
Jonathan E. Chambers ◽  
Oliver Kuras ◽  
Philip I. Meldrum ◽  
Richard D. Ogilvy ◽  
Jonathan Hollands
Keyword(s):  
Electrical Resistivity ◽  
Electrical Resistivity Tomography ◽  
Site Investigation ◽  
High Resistivity ◽  
Potential Zone ◽  
Resistivity Tomography ◽  
L2 Norm ◽  
Resistivity Model ◽  
2D And 3D ◽  
2D Resistivity

A former dolerite quarry and landfill site was investigated using 2D and 3D electrical resistivity tomography (ERT), with the aims of determining buried quarry geometry, mapping bedrock contamination arising from the landfill, and characterizing site geology. Resistivity data were collected from a network of intersecting survey lines using a Wenner-based array configuration. Inversion of the data was carried out using 2D and 3D regularized least-squares optimization methods with robust (L1-norm) model constraints. For this site, where high resistivity contrasts were present, robust model constraints produced a more accurate recovery of subsurface structures when compared to the use of smooth (L2-norm) constraints. Integrated 3D spatial analysis of the ERT and conventional site investigation data proved in this case a highly effective means of characterizing the landfill and its environs. The 3D resistivity model was successfully used to confirm the position of the landfill boundaries, which appeared as electrically well-defined features that corresponded extremely closely to both historic maps and intrusive site investigation data. A potential zone of leachate migration from the landfill was identified from the electrical models; the location of this zone was consistent with the predicted direction of groundwater flow across the site. Unquarried areas of a dolerite sill were imaged as a resistive sheet-like feature, while the fault zone appeared in the 2D resistivity model as a dipping structure defined by contrasting bedrock resistivities.

Better placement of soil moisture point measurements guided by 2D resistivity tomography for improved irrigation scheduling

Soil Research ◽  
2011 ◽  
Vol 49 (6) ◽  
pp. 504 ◽  
Author(s):  
B. F. J. Kelly ◽  
R. I. Acworth ◽  
A. K. Greve
Keyword(s):  
Soil Moisture ◽  
Spatial Information ◽  
Root Zone ◽  
Irrigation Scheduling ◽  
Measurement Methods ◽  
Deep Drainage ◽  
Resistivity Tomography ◽  
Point Measurement ◽  
Irrigated Crops ◽  
2D Resistivity

Soil moisture beneath irrigated crops has traditionally been determined using point measurement methods such as neutron probes or capacitance systems. These approaches cannot measure soil moisture at depths beyond the root-zone of plants and have limited lateral coverage. It is shown that surface two-dimensional electrical resistivity tomography (ERT) can be used to map the spatial heterogeneity in soil moisture throughout a field under irrigated cotton. The case study demonstrates that ERT provides a better understanding of the pathways of water migration, and provides spatial information on how water storage changes throughout the growing season. We conclude that ERT should be integrated into farm water management surveys to delineate zones of excessive water loss due to deep drainage and to improve the positioning of point measurement methods for measuring soil moisture, thereby improving irrigation scheduling.

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