scholarly journals HYDROGEOPHYSICAL AND AQUIFER PROTECTIVE CAPACITY OF ABAKALIKI/AFIKPO AREA AND ENVIRONS, SOUTHEASTERN NIGERIA USING GEO-SOUNDING DATA

Author(s):  
I Osi-Okeke ◽  
◽  
AI Opara ◽  
IC Oli ◽  
HM Udeh ◽  
...  

This work was carried out to evaluate the hydrogeological and geophysical properties of Abakaliki and Afikpo environs. Forty-seven (47) Vertical Electrical Sounding data were acquired with electrode spacing (AB/2) of 500m using Schlumberger electrode configuration. Conventional curve matching techniques were used to interpret the data and obtain initial model parameters. Results of the study showed 3-7 electric layers which indicate multiple aquifer system. QQH, QHK, KHK and QQHK models were the Vertical Sounding curves obtained. The aquiferous layers make up the third and fourth layers. The resistivity of the aquifer varies from 10.74Ωm to 13201Ωm with an average of 1013.58 Ωm. Aquifer depth ranges from 6.2m to 92.5m with an average aquifer depth of 27.07m, while the aquifer thickness varies from 2.3m to 55.87m with an average of 15.61m. Transverse resistance varies from 65.34Ωm2to 7079.14 Ωm2 with an average of 9966.29 Ωm2; and the longitudinal conductance varies from 0.00018Ω-1 to 1.65 Ω-1 with an average of 0.026 Ω-1. From the study, 49% of the study area falls under the poor protective rating while 21% falls under the weak rating with 25% and 5% which makes up the moderate and good ratings respectively. Using the average longitudinal conductance, it is observed that the study area is moderately protected.

2020 ◽  
Vol 4 (2) ◽  
pp. 99-102
Author(s):  
Johnson C. Ibuot ◽  
Moses M. M. Ekpa ◽  
Doris O. Okoroh ◽  
Aniefiok S. Akpan Emmanuel T. Omeje

Geoelectric survey employing Vertical Electrical Sounding (VES) was carried out in order to assess the groundwater repositories. A total of seven soundings were obtained with their layer resistivity, thickness and depth within the maximum electrode separation. The geoelectric parameters obtained were used to estimate the Dar-Zarrouk parameters (longitudinal conductance and transverse resistance), hydraulic conductivity and transmissivity. The result shows the aquifer resistivity ranging from 77.14 to 784.76 Ωm, with thickness ranging from 28.78 to 80.04 m. The longitudinal conductance have values ranging from 0.071 to 0.825 Ω-1 while the values of hydraulic conductivity and transmissivity range from 1.087 to 5.881 m/day and 60.180 to 374.031 𝑚2/day respectively. The contour maps generated show the variation of these parameters across the subsurface, and areas with poor protective capacity were delineated. The results also delineate the groundwater potential of the study area as moderate, while the corrosivity rating indicates non-corrosive and slightly corrosive.


2020 ◽  
Vol 4 (2) ◽  
pp. 102-104
Author(s):  
Johnson C. Ibuot ◽  
Moses M. M. Ekpa ◽  
Doris O. Okoroh ◽  
Aniefiok S. Akpan Emmanuel T. Omeje

Geoelectric survey employing Vertical Electrical Sounding (VES) was carried out in order to assess the groundwater repositories. A total of seven soundings were obtained with their layer resistivity, thickness and depth within the maximum electrode separation. The geoelectric parameters obtained were used to estimate the Dar-Zarrouk parameters (longitudinal conductance and transverse resistance), hydraulic conductivity and transmissivity. The result shows the aquifer resistivity ranging from 77.14 to 784.76 Ωm, with thickness ranging from 28.78 to 80.04 m. The longitudinal conductance have values ranging from 0.071 to 0.825 Ω-1 while the values of hydraulic conductivity and transmissivity range from 1.087 to 5.881 m/day and 60.180 to 374.031 𝑚2/day respectively. The contour maps generated show the variation of these parameters across the subsurface, and areas with poor protective capacity were delineated. The results also delineate the groundwater potential of the study area as moderate, while the corrosivity rating indicates non-corrosive and slightly corrosive.


2018 ◽  
Vol 65 (6) ◽  
pp. 637-645
Author(s):  
Amobi C. Ekwe ◽  
Alexander I. Opara ◽  
Obialo S. Onwuka

Purpose The corrosivity and competence of soils within Uburu and Okposi areas of the Southern Benue Trough, Nigeria, were evaluated using the electrical resistivity method. This paper aims to provide information that will aid pre-design of subsurface iron/steel pipe networks for distribution of pipe-borne water and construction of subsurface structures for agricultural and environmental purposes. Design/methodology/approach In total, 22 vertical electrical soundings (VES) in the Schlumberger configuration were acquired with Allied Ohmega™ Terrameter with a maximum half current (AB/2) electrode spacing of 200 m. Layer parameters were determined using partial curve matching techniques, using the Schlumberger master curves, while processing and modelling were done with the IPI2win™ software. The VES results were interpreted qualitatively and quantitatively to obtain various curve types and layer parameters, respectively, which were used to categorize the area into different competence and corrosivity zones. The first layer isoresistivity and competence maps were used to delineate four zones (A,B,C and D) with varying apparent resistivities and competences. Findings Incompetent soils with resistivity values ranging from 24.3-88.7 Om are found in Zone A. The soils in Zone A are mainly expansive clays which swell on absorption of water. Zone B contains moderately competent soils with resistivity values ranging from 273-308.6 Om, while Zones C and D are underlain by sandstones and contain competent to highly competent soils with resistivity values ranging from 511-750 Om and 835-1,525 Om, respectively. Zone E contains highly corrosive (24.3 Om) to mildly corrosive (102 Om) soils; Zone F contains soils that are essentially non-corrosive with resistivity values ranging from 271-1,525 Om, while the corrosivity of soils within Zone G varies from corrosive to mildly corrosive, with resistivity values ranging from 44.3-114 Om. Research limitations/implications Some of the areas are not accessible because of community restrictions. Practical implications These findings are essentially very significant and should be taken into consideration when materials that are susceptible to corrosion are being considered for engineering, agricultural and environmental purposes in the area. Social implications The findings will aid water resource planners and developers on how to protect metal pipes from corrosion, when used for water reticulation and agricultural purposes. Originality/value This paper fulfils an identified need to study the corrosivity of soils in the study area with a view to providing adequate protection to metal objects when being considered for water reticulation for domestic and agricultural purposes in the area.


2018 ◽  
Vol 65 (1) ◽  
pp. 45-58
Author(s):  
A.A. Oyedele ◽  
G.M. Olayanju ◽  
A.O. Talabi ◽  
S.N. Ogunyebi ◽  
O.F. Ojo

AbstractVertical electrical sounding, well inventory and physicochemical analysis were conducted to evaluate soil corrosivity and aquifer protective capacity of overburden units in the basement complex terrain of Ado-Ekiti, southwestern Nigeria. The topsoil is composed of slightly corrosive materials at the eastern, southern and northeastern flanks and the central portion with resistivity values ranging from 60 to 180 Ωm. Moderately corrosive/slightly corrosive materials (with resistivity values of 10 < ρ < 60 Ωm) constitute the second layer around the eastern, southern and north-eastern flanks. Pockets of areas in the northwestern, southeastern, eastern and central parts of the metropolis are practically non-corrosive with resistivity values in excess of 200 Ωm. Zones of good, moderate, weak and poor overburden protective capacity were delineated, with longitudinal conductance (S) values of 0.7 < S < 4.9, 0.2 < S < 0.69, 0.1 < S < 0.19 and S < 0.1 mhos, respectively. On a regional consideration, 23.31%, 18.80% and 57.9% of the study area is characterised by overburden materials of poor, weak and moderate protective capacity, respectively. Only 6.02% of the area indicates good overburden protective capacity.


Author(s):  
Dian Darisma ◽  
Ferdy Fernanda ◽  
Muhammad Syukri

Lam Apeng is a village with a majority of people living as farmers, which causes the need of water for agriculture is increasing. The water demand in this area continues to increase as the population increases, for various purposes. The objective of this study is to determine the distribution of the groundwater layer using the electrical resistivity method and to determine groundwater potential using hydraulic parameters. This research is conducted using 2 measurement line with a length of each line is 112 meters and distances of each electrode is 2 meters. The data invert using Res2Dinv software to obtain 2D subsurface lithology subsurface. At line 1, the aquifer (sand) layer is located in the second layer with a rock resistivity value of 12 Ωm - 18.6 Ωm at a depth of 8 m - 18 m. At line 2, the aquifer (sand) layer is also located in the second layer with a resistivity value of 4.6 Ωm - 18 Ωm at a depth of 5 m – 12 m. Based on the interpretation of the two measurement lines, it can be concluded that the type of aquifer in the research site is a semi unconfined aquifer. In this study, hydraulic parameters (hydraulic conductivity, longitudinal conductance, transverse resistance, and transmissivity) was calculated based on the resistivity value and the thickness of the aquifer layer. The average resistivity of the aquifer layer used is 15.3 Ωm and 11.3 Ωm, respectively for line 1 and line 2, indicating that the aquifer was moderately corrosive. Longitudinal conductance values are 0.65 Ω-1 and 0.62 Ω-1 which indicated moderate protective capacity. The transmissivity values are 6.78 m2/dayand 4.77 m2/day, which indicates that the designation in this area is low and the groundwater potential is local or only for personal consumption.


2021 ◽  
Vol 30 (1) ◽  
pp. 43-52
Author(s):  
Kenechukwu A. Ifeanyichukwu ◽  
Elizabeth Okeyeh ◽  
Okechukwu E. Agbasi ◽  
Onwe I. Moses ◽  
Ogechukwu Ben-Owope

In Nnewi, Anambra State Nigeria, twenty vertical electrical sounding (VES) were performed to delineate vulnerability and transmissivity of identified aquifer within the study area. Hydraulic parameters (transverse resistance, longitudinal conductivity, hydraulic conductivity and transmissivity) were delineated from geoelectrical parameters (depth, thickness, and apparent resistance). The geo- parameters of the aquifer: apparent resistance from 1000.590 to 1914.480, thickness from 42.850 – 66.490 m and 65.530 to 100.400 m of depth. The estimated hydraulic parameters of the aquifers are transverse resistance 54264.383 - 104568.898 Ωm, longitudinal conductance 0.029 – 0.062 mho, hydraulic conductivity 0.664 – 2.015 m/day and transmis- sivity between 4.167 and 13.963 m2/day. All aquifers have poor protective capacity, 40 percent of the aquifers have low classification with smaller withdrawal potential for local groundwater supply, while 60 percent of the delineated aquifer has intermediate classification and withdrawal potential for local groundwater supply. Due to its groundwater supply potential and protective capacity, the eastern part of the study area has stronger groundwater potential.


Author(s):  
A. Olajide ◽  
S. Bayode ◽  
T. Fagbemigun ◽  
A. Oyebamiji ◽  
J. Amosun ◽  
...  

Groundwater potential and aquifer protective capacity of the overburden unit was evaluated in part of Iju, Akure North, Ondo State using integrated geophysical methods involving Very Low Frequency Electromagnetic (VLF-EM) profiling and Vertical Electrical Sounding (VES). Four major traverses were established of varying length extents. The VLF-EM measurements were taken along the four major profiles of 10 m station interval.Forty two (42) Vertical Electrical Soundings were also conducted with half electrode spacing varying between 1 and 100 m and interpretation was done using the partial curve matching techniques and computer aided iteration. Five subsurface geological units were identified from geoelectric sections, consisting of the top soil, lateritic, weathered, partly weathered and fresh basement layers consecutively. For the first layer, resistivityranges between 23 and 323 Ωm with values of thickness ranging between 0.5 and 2.2 m. The resistivity and thickness of the second (lateritic) layer range from 132 to 430 Ωm and 1.6 to 4 m respectively. The resistivity of the weathered layer ranges from 4 to 94 Ωm and variable thickness between 10 and 24.4 m. The fourth layer has a resistivity value range of 65 to 120 Ωm and thicknesses between 20 and 30 m. The basement bedrock (fifth layer) has resistivity values between 770 and 820 Ωm. The depth to bedrock ranges from 1.8 to 31 m. The geophysical data and the basement aquifer delineated were then used to evaluate the hydrogeological setting and aquifer protective capacity of the study area. The observation from the results shows that close to 70 % of the study area falls within the zones of low groundwater potential, 25 % falls within medium potential zones while only 5 % make up the high potential zones. 75 % of the study area constituted the weak to poor protective capacity zones.  


2021 ◽  
Vol 2 (5) ◽  
pp. 18-23
Author(s):  
A. Nur ◽  
A. Taiyib ◽  
I. S. Nggada

Twenty-two Vertical Electrical Sounding (VES) were carried out to evaluate groundwater potential and aquifer protective capacity of the overburden units using Schlumberger configuration. It was observed that H-curve is the dominant curve type in the study area. The Geo-electro stratigraphic section revealed that the geologic sequence beneath the study area is composed of topsoil, highly weather basement, partly fractured basement and fresh basement. The first layer has an average thickness and resistivity of 1 m and 130 Ωm, respectively. The second layer has an average thickness of 14 m and an average resistivity of 53 Ωm. The third layer is partly fracture basement with an average resistivity of 747 Ωm while at some VES point represents fresh basement. The highly weathered basement and partly fracture basement layer make up the water bearing formation of the area. Dar-Zarrouk parameter revealed that the area under study has protective capacity range from weak to good capacity of the overburden material. Areas that are classified as poor and weak are indicative areas are thus vulnerable to infiltration of leachate and other surface contaminations. The groundwater potential of the area ranges from low to moderate potential; the moderate zone constitutes 86% while the low potential constitutes 14% of the study area. The transverse resistance within the study area ranges from 119.6 to 6983.7 ohms-m2 with an average value of 1024.59 ohms-m2. Hydraulic conductivity values determined from geoelectrical technique range from 3.05 to 38.04 m/day with an average value of 14.86 m/day.


2021 ◽  
Author(s):  
'Muyiwa Adekunle Adeyanju ◽  
Oluwaseun Victoria Fatoye ◽  
O.E Oyanameh

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.


2020 ◽  
Vol 10 (10) ◽  
Author(s):  
Joy O. Eugene-Okorie ◽  
Daniel N. Obiora ◽  
Johnson C. Ibuot ◽  
Desmond O. Ugbor

Abstract Electrical resistivity survey employing vertical electrical sounding was carried out in Oraifite, Southeastern Nigeria, involving a total of twenty soundings across, in order to assess the groundwater potential and the aquifer vulnerability in Oraifite. The field data were interpreted using the WINRESIST software, and the resulting geoelectric curves give the resistivities, depths and thicknesses of each geoelectrical layer. Dar Zarrouk parameters and aquifer transmissivity were computed using the values of aquifer resistivity and thickness. From the results, variations of the computed parameters were observed. Aquifer resistivity ranges from 420.1 to 27,585.8 Ωm having an average value of 4906.3 Ωm, while its thickness varies from 13.4 to 93. 9 m. Longitudinal conductance varies from 0.0015 to 0.2136 Ω−1, transverse resistance ranges from 29,388.88 to 1,158,604.0 Ωm2, while the transmissivity varies from 1.1692 to 123.7905m2/day. The contour maps reveal the distributions of these parameters, which help in delineating zones with different layer characteristics. The result from this study can be a reference for decision making in the abstraction and management of groundwater repositories.


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