This document summarizes a study on using geophysical methods like electrical resistivity surveys to identify groundwater prospective zones. The study was conducted in areas with thick alluvium geology. Vertical electrical sounding (VES) and 2D electrical resistivity tomography were used to map subsurface resistivity variations. Resistivity is dependent on factors like porosity, water content, and mineral composition. Aquifers were identified in saturated sand, sandy clay, and silt based on their resistivity values relative to surrounding materials. The study concluded electrical resistivity methods are well-suited for mapping aquifers, bedrock topography, and fractured zones to aid groundwater exploration programs.
Resistivity Imaging of Shallow Sediments within University of Maiduguri Campu...iosrjce
Electrical resistivity imaging within University of Maiduguri campus shows varying resistivity values
and thicknesses for shallow sediments from one profile line to another. Sequence stratigraphy of the sediments
indicates they were deposited at different times and varying conditions. Structure of the medium of deposition
conditioned the lithological structures of the sediments. Basin or bowl-shapes of some resistivity structures are
characteristics of some gravelly and clayey sediments. In most cases where such structures are encountered,
gravels seem to host sands; while clays are located at the central parts. This situation may suggest that the
sediments were deposited at the same time, where heavier ones settled to the bottom of the stratigraphy.
Sometimes clayey sediments host sandy sediments; a situation that may be associated with different times of
deposition. Some sediments were laid horizontally, some inclined and others nosed into overlying ones.
Majority of the resistivity images indicate clayey sediments occupying the basal resistivity units. Lower
resistivity values associated with some clayey sediment suggest high degree of saturation. The water might have
been derived through infiltration of the overlying porous sediments. The clays may be followed upwardly by
sands, while gravels sometimes form the capping sediments. Few resistivity profiles host the three sediments at
the bottom of the resistivity structures. Stratigraphic thicknesses for the sediments vary both laterally and
vertically. These are associated with the structure of the medium and prevailing conditions at the time of
deposition
Exploring the Relationship between Moisture Content and Electrical Resistivit...inventionjournals
Conventional borehole sampling and its subsequent geotechnical testing is the most precise and direct method of soil characterization, but conversely it is time-consuming and expensive simultaneously. Electrical resistivity surveys can provide a non-destructive and less expensive way of determining soil properties, if reliable correlations could be established through extensive testing. The main objective of this research work is to establish quantitative relationship of resistivity with moisture content of sandy and silty soils that can be used in geotechnical appraisal of soil slopes. A non-linear relationship trend is observed between moisture content and electrical resistivity values obtained in field and laboratory conditions.
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
Determination of Thickness of Overburden in Basement Area Using Schlumberger ...iosrjce
The overburden thickness of Abuja (Lat. 70
12´N – 9
0 30´ N and Long. 50
24´E- 7
0
19´E)
has been estimated. The geophysical method used was the electrical resistivity and the electrodes
array was Schlumberger type. The equipment utilized were four electrodes, hammer, four reels of
wires, crocodile clips, measuring tape, global positioning systems(GPS) and a terrameter. The survey
was carried out in two locations and the average resistivity values of the first four geoelectrical layers
were from the surface, 590 Ωm, 1800 Ωm, 1900 Ωm and 760 Ωm. These layers were interpreted as
probably top soil, laterite, weathered basement rock and fairly weathered basement rock. The
average thickness of the overburden was found to be 5.43m
Resistivity Imaging of Shallow Sediments within University of Maiduguri Campu...iosrjce
Electrical resistivity imaging within University of Maiduguri campus shows varying resistivity values
and thicknesses for shallow sediments from one profile line to another. Sequence stratigraphy of the sediments
indicates they were deposited at different times and varying conditions. Structure of the medium of deposition
conditioned the lithological structures of the sediments. Basin or bowl-shapes of some resistivity structures are
characteristics of some gravelly and clayey sediments. In most cases where such structures are encountered,
gravels seem to host sands; while clays are located at the central parts. This situation may suggest that the
sediments were deposited at the same time, where heavier ones settled to the bottom of the stratigraphy.
Sometimes clayey sediments host sandy sediments; a situation that may be associated with different times of
deposition. Some sediments were laid horizontally, some inclined and others nosed into overlying ones.
Majority of the resistivity images indicate clayey sediments occupying the basal resistivity units. Lower
resistivity values associated with some clayey sediment suggest high degree of saturation. The water might have
been derived through infiltration of the overlying porous sediments. The clays may be followed upwardly by
sands, while gravels sometimes form the capping sediments. Few resistivity profiles host the three sediments at
the bottom of the resistivity structures. Stratigraphic thicknesses for the sediments vary both laterally and
vertically. These are associated with the structure of the medium and prevailing conditions at the time of
deposition
Exploring the Relationship between Moisture Content and Electrical Resistivit...inventionjournals
Conventional borehole sampling and its subsequent geotechnical testing is the most precise and direct method of soil characterization, but conversely it is time-consuming and expensive simultaneously. Electrical resistivity surveys can provide a non-destructive and less expensive way of determining soil properties, if reliable correlations could be established through extensive testing. The main objective of this research work is to establish quantitative relationship of resistivity with moisture content of sandy and silty soils that can be used in geotechnical appraisal of soil slopes. A non-linear relationship trend is observed between moisture content and electrical resistivity values obtained in field and laboratory conditions.
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
Determination of Thickness of Overburden in Basement Area Using Schlumberger ...iosrjce
The overburden thickness of Abuja (Lat. 70
12´N – 9
0 30´ N and Long. 50
24´E- 7
0
19´E)
has been estimated. The geophysical method used was the electrical resistivity and the electrodes
array was Schlumberger type. The equipment utilized were four electrodes, hammer, four reels of
wires, crocodile clips, measuring tape, global positioning systems(GPS) and a terrameter. The survey
was carried out in two locations and the average resistivity values of the first four geoelectrical layers
were from the surface, 590 Ωm, 1800 Ωm, 1900 Ωm and 760 Ωm. These layers were interpreted as
probably top soil, laterite, weathered basement rock and fairly weathered basement rock. The
average thickness of the overburden was found to be 5.43m
Evaluation of sub-soil geo-electric properties in a proposed power sub-statio...IJERA Editor
Electrical resistivity survey was carried out in a site proposed for the construction and installation of a Power sub-station. The project will involve subsurface installation of cables and other objects that easily conduct electricity. Extant laws including EIA also require knowledge of subsurface distribution of resistivity in construction projects that would involve burial of steel pipes and cables. The imperative of this is emphasized by the location of the project in an area of shallow groundwater conditions. Field resistivity measurements were undertaken using ABEM Terrameter SAS 1000, adopting Schlumberger configuration in vertical electric sounding at 12 locations within the study site. The results were used to generate geo-electric log models. Three geo-electric profile models (pseudo- profiles) were also taken NE-SW of the site. Interpretation of the models shows that the area is characterized by two geo-electric layers to the depth of 30m. The upper layer of lower resistivity occurs to a depth of 2-3m. This layer consists of lateritic to silty sands. The lower layer has a resistivity of between 900 - >2000 Ωm and represents fine to coarse sands and gravels. On the Soil Electrical Resistivity Classification (BS 1377), the subsoil falls within non-corrosive class. Objects installed in the soil are not likely to suffer corrosion soon. Similarly, subsurface electrical installations will pose minimal hazards and would require basic precautions to avoid electrical accidents.
Geoelectrical and Hydrochemical Assessment of Groundwater for Potability in E...Premier Publishers
Geoelectrical and hydrochemical investigations were carried in order to determine the potentials and quality of groundwater in Ebonyi North, Southeastern Nigeria. These methods were also selected to determine their economy and accuracy compared to seismic method. Fifteen (15) vertical electric sounding (VES) survey were conducted using the Schlumberger configuration in order to evaluate the character of the aquifers in the studied locations while twelve (12) groundwater samples were collected from boreholes for hydrochemical analysis. Geoelectric sections derived from modelling of the VES data with the interpex IX1D software reveal 3 to 5 subsurface layers. The lithologic succession comprises of topsoil, lateritic clay, partially weathered, weathered and fractured Asu River shale. The weathered and fractured layers constituted the productive water bearing or aquiferous zones of good groundwater potentials. Hydrochemical analysis of groundwater samples reveals that the pH range from 7.8 to 8.8, electrical conductivity from 10.0 to 1754.00 μS/cm, total dissolved solid from 10.0 to 786.0 mg/l and total hardness from 14.0 to 271.0 mg/l. The analytical results present the concentration of the ions in the following order: Mg > Ca > Na > K and Cl > SO4 >HCO3> NO3 > CO3. Piper trilinear diagram reveals only one water type, with Ca and Cl as the major dominant ions. The major ions concentrations are within recommended standard for drinking, hence the groundwater from the area is suitable for drinking and domestic purposes.
Subsurface 2D Image Analyses of the Uyangha Basement Area, South-Eastern NigeriaIOSR Journals
Geo-electric soundings were made in Stella Maris Secondary School, in Uyangha, Nigeria to image
the subsurface and obtain thicknesses and resistivities of different layers. A quantitative interpretation of the
data obtained clearly reveals the presence of four (4) geo-electric sections which are interpreted to be dry
laterite, moist laterite, weathered basement, and saturated basement. The depth probed is about 100m. The
saturated basement is the aquifer unit. Depth to aquifer unit in the area is at about 65m to 80m.The thickness of
the aquifer unit ranges from 20m to 35m. For ground water exploitation, boreholes in the area should therefore
be drilled to the depth of 91m, for reasonable groundwater yield. The lateritic layer makes the study area
suitable for building construction in the area.
Research Inventy : International Journal of Engineering and Scienceinventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
In order to solve the water scarcity problem in South Malang, East Java,
Indonesia, we have attempted to investigate groundwater by assessing the subsurface
geology and groundwater potential zones. An attempt had been made to identify the
subsurface lithology and aquifer zones by VES (Vertical Electrical Sounding) method
in Pagak, Kepanjen, Kromengan and Gondanglegi district. The study area consists of
major subsurface litho units like sand, silt, clay, tuff, limestone and andesit. In order
to explore the groundwater resources of the study area with an aerial extent of 100
km2, electrical soundings have been conducted by adopting Schlumberger technique
in 12 locations with AB/2 200 m and 5 resistivity profiles were acquired. The field
data were interpreted and processed qualitatively and quantitatively by using
computer software. Considering the geological, geomorphology and hydrogeological
conditions the VES interpretation was done. The study has shown that the region is
underlain by 5 geoelectric layers within the depth penetrated. The groundwater
potential in South Malang reveals four distinct classes (zones) representing ‘Very
good’, ‘good’, ‘moderate’ and ‘poor’ groundwater potential in the area. From the
interpretation result the VES no. 7 (Pagak), and VES no. 9 (Kepanjen) are found to be
prospective for groundwater. It’s also identified that Groundwater occurs under
water table conditions the depth of water table ranges from 5 to 30 m.
Determination of Thickness of Aquifer with Vertical Electrical Sounding iosrjce
IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of mechanical and civil engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in mechanical and civil engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Application of Electrical Resistivity Tomography for Soil Competence Study in...IIJSRJournal
This study was carried out to determine soil competence around University of Benin Teaching Hospital and its environs using electrical resistivity tomography method. The Wenner Schlumberger Array Profiling method was used to give information of the subsurface resistivity. The result of the study showed that in ERT 1, highly competent soil were observed with resistivity values between 725Ωm and greater than 6546Ωm, which means that the area is underlain by clay sand at the top and sand/laterite/bedrock at the bottom. ERT 2 is characterized by highly competent soils with high resistivity values between 899Ωm to greater than 7851 Ωm, which indicates that the soil is underlain by sand/laterite/bedrocks. Furthermore, ERT 3 is group as highly competent soils, with resistivity values between762Ωm and greater than 6980 Ωm; this shows that the profile 3 is underlain by sand/laterite/bed rock. The study shows that though most part of the area contains soils that are competent, because of the presence of clay which on most occasion in the Niger Delta are expandable, detailed Geophysical and Civil engineering studies should be carried out before the erection of high rising engineering structures such as network masts, buildings and water tanks within the study area.
Aquifer polution vulnerability assessment for abi paperEbong Dickson
The geophysical-based integrated electrical
conductivity (IEC) and the groundwater hydraulic confinement–
overlying strata–depth to water table (GOD)
techniques were used to assess vulnerability levels of
aquifers and the extent of aquifer protection in Abi,
Nigeria. The IEC indices was generated from
constrained one dimensional (1D) inversion of vertical
electrical sounding (VES) and two dimensional (2D)
electrical resistivity tomography (ERT) data, acquired
randomly in the area. The GOD indices were sourced
from existing geologic data within the area. Results
showed that IEC values vary from <0.1>2.0 S in the strongly protected areas.
The GOD indices vary from <0.3 in the lowly vulnerable
areas to 0.6 in the highly vulnerable areas. Thus, the
groundwater resources in the area need to be properly
managed for sustainability and such management practices
have been suggested.
Keywords Electrical resistivity. Contamination .
Vulnerability. IEC . GOD . Abi, Nigeria
Corrosion is a mechanism that degrades materials and causes structural failures in infrastructures, which can lead to severe effects on the environment and have direct impact on the population health. In addition, corrosion is extremely complex in the underground environment due to the variability of the local conditions. The delineation and assessment of possible areas of corrosion along Obama-Kolo Creek, in the Niger Delta region was carried out using Earth resistivity measurement. The aim of this study is to evaluate the influence of soil resistivity upon metals buried underground. In this investigation, an Abem SAS 300B meter was used and 20 sounding points were carried out using the Schlumberger array along the pipeline route. A total spread (AB) of 45m was adopted with the assumption that the depth of penetration is th of the total current electrode spread (AB). The results obtained showed that subsoil resistivity values for depths of 2 – 12m required for the underground pipe laying with resistivities in the range of 8 Ohm-m to 78 Ohm-m along Obama – Kolo Creek with a mean of 43 Ohm-m. The low resistivity encountered throughout the study has been attributed to the influence of saline water intrusion in the area. The average thickness of this area is 7m. Basically, most of the geoelectric graphs showed three layers, H-type curves. Generally, the subsurface soil is made up of subsoil lithology of mainly clayey/sandy clay material with different degree of saturation. This is an indication that any underground metallic material will be exposed to high corrosivity environment, hence appropriate cathodic protection will be required.
Measurement of Salinity and Electrical Conductivity of Land Forms in Akwa Ibo...iosrjce
IOSR Journal of Applied Physics (IOSR-JAP) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Integrated Geophysical and Geotechnical Evaluation of Foundation Failure in P...inventionjournals
Geophysical and geotechnical methods have been integrated with the aim of assessing characteristics of sub-surface layers to identify why structures in some parts of Ikere-Ekiti Southwestern Nigeria are failing or sinking as a result of foundation failure. Eight (8) vertical electrical sounding (VES) were carried out using resistivity meter and six (6) pits were dug to a depth of 1.2m. Six disturbed soil samples were collected from the six dug pits for the study. These samples were subjected to geotechnical tests in the laboratory, which include moisture content, shear test, Atterberg limit and grain size analysis. The acquired VES data were processed and interpreted using partial curve matching technique. The results of the all the mall the eight VES produced H curves. This curve type manifested three layers which are composed of sandy-clay, clayeysand/weathered basement and weathered basement/rock head. The depth o rockhead ranges from 12.1 to 43.2m. VES stations four and five have deeper depth to rock head (i.e. 21.3 to 43.2m) while other locations have lesser depth to rockhead (i.e.1 12.1m to 17.5m). The second layer has the lowest resistivity values meaning that it is somewhat conductive owing to clayey sand deposition and weathered area. Geotechnical test shows that the soils in the study area generally has high moisture content, low plasticity, and from grain size distribution, high concentrations of silt and clay. From the result, it is established that the layer in which the foundations are built upon are rated as poor to fairly competent. This might be as a result of poor drainage system characterised the study area which brought about the local deposition of the supposed subsoil. Therefore, high moisture content made the subsoil to lose its competency thereby causing the structures in the study area to subside
Application Of Resistivity For Groundwater, Hydrogeology and Pollution ResearchOmokpariolaElshalom
It was a group seminar geophysics course presentation in my year 3 of which I was asked to represent the group in giving an oral presentation of how we can apply resistivity in the geophysical investigation of groundwater, pollution ansd hydrogeology.
Evaluation of sub-soil geo-electric properties in a proposed power sub-statio...IJERA Editor
Electrical resistivity survey was carried out in a site proposed for the construction and installation of a Power sub-station. The project will involve subsurface installation of cables and other objects that easily conduct electricity. Extant laws including EIA also require knowledge of subsurface distribution of resistivity in construction projects that would involve burial of steel pipes and cables. The imperative of this is emphasized by the location of the project in an area of shallow groundwater conditions. Field resistivity measurements were undertaken using ABEM Terrameter SAS 1000, adopting Schlumberger configuration in vertical electric sounding at 12 locations within the study site. The results were used to generate geo-electric log models. Three geo-electric profile models (pseudo- profiles) were also taken NE-SW of the site. Interpretation of the models shows that the area is characterized by two geo-electric layers to the depth of 30m. The upper layer of lower resistivity occurs to a depth of 2-3m. This layer consists of lateritic to silty sands. The lower layer has a resistivity of between 900 - >2000 Ωm and represents fine to coarse sands and gravels. On the Soil Electrical Resistivity Classification (BS 1377), the subsoil falls within non-corrosive class. Objects installed in the soil are not likely to suffer corrosion soon. Similarly, subsurface electrical installations will pose minimal hazards and would require basic precautions to avoid electrical accidents.
Geoelectrical and Hydrochemical Assessment of Groundwater for Potability in E...Premier Publishers
Geoelectrical and hydrochemical investigations were carried in order to determine the potentials and quality of groundwater in Ebonyi North, Southeastern Nigeria. These methods were also selected to determine their economy and accuracy compared to seismic method. Fifteen (15) vertical electric sounding (VES) survey were conducted using the Schlumberger configuration in order to evaluate the character of the aquifers in the studied locations while twelve (12) groundwater samples were collected from boreholes for hydrochemical analysis. Geoelectric sections derived from modelling of the VES data with the interpex IX1D software reveal 3 to 5 subsurface layers. The lithologic succession comprises of topsoil, lateritic clay, partially weathered, weathered and fractured Asu River shale. The weathered and fractured layers constituted the productive water bearing or aquiferous zones of good groundwater potentials. Hydrochemical analysis of groundwater samples reveals that the pH range from 7.8 to 8.8, electrical conductivity from 10.0 to 1754.00 μS/cm, total dissolved solid from 10.0 to 786.0 mg/l and total hardness from 14.0 to 271.0 mg/l. The analytical results present the concentration of the ions in the following order: Mg > Ca > Na > K and Cl > SO4 >HCO3> NO3 > CO3. Piper trilinear diagram reveals only one water type, with Ca and Cl as the major dominant ions. The major ions concentrations are within recommended standard for drinking, hence the groundwater from the area is suitable for drinking and domestic purposes.
Subsurface 2D Image Analyses of the Uyangha Basement Area, South-Eastern NigeriaIOSR Journals
Geo-electric soundings were made in Stella Maris Secondary School, in Uyangha, Nigeria to image
the subsurface and obtain thicknesses and resistivities of different layers. A quantitative interpretation of the
data obtained clearly reveals the presence of four (4) geo-electric sections which are interpreted to be dry
laterite, moist laterite, weathered basement, and saturated basement. The depth probed is about 100m. The
saturated basement is the aquifer unit. Depth to aquifer unit in the area is at about 65m to 80m.The thickness of
the aquifer unit ranges from 20m to 35m. For ground water exploitation, boreholes in the area should therefore
be drilled to the depth of 91m, for reasonable groundwater yield. The lateritic layer makes the study area
suitable for building construction in the area.
Research Inventy : International Journal of Engineering and Scienceinventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
In order to solve the water scarcity problem in South Malang, East Java,
Indonesia, we have attempted to investigate groundwater by assessing the subsurface
geology and groundwater potential zones. An attempt had been made to identify the
subsurface lithology and aquifer zones by VES (Vertical Electrical Sounding) method
in Pagak, Kepanjen, Kromengan and Gondanglegi district. The study area consists of
major subsurface litho units like sand, silt, clay, tuff, limestone and andesit. In order
to explore the groundwater resources of the study area with an aerial extent of 100
km2, electrical soundings have been conducted by adopting Schlumberger technique
in 12 locations with AB/2 200 m and 5 resistivity profiles were acquired. The field
data were interpreted and processed qualitatively and quantitatively by using
computer software. Considering the geological, geomorphology and hydrogeological
conditions the VES interpretation was done. The study has shown that the region is
underlain by 5 geoelectric layers within the depth penetrated. The groundwater
potential in South Malang reveals four distinct classes (zones) representing ‘Very
good’, ‘good’, ‘moderate’ and ‘poor’ groundwater potential in the area. From the
interpretation result the VES no. 7 (Pagak), and VES no. 9 (Kepanjen) are found to be
prospective for groundwater. It’s also identified that Groundwater occurs under
water table conditions the depth of water table ranges from 5 to 30 m.
Determination of Thickness of Aquifer with Vertical Electrical Sounding iosrjce
IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of mechanical and civil engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in mechanical and civil engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Application of Electrical Resistivity Tomography for Soil Competence Study in...IIJSRJournal
This study was carried out to determine soil competence around University of Benin Teaching Hospital and its environs using electrical resistivity tomography method. The Wenner Schlumberger Array Profiling method was used to give information of the subsurface resistivity. The result of the study showed that in ERT 1, highly competent soil were observed with resistivity values between 725Ωm and greater than 6546Ωm, which means that the area is underlain by clay sand at the top and sand/laterite/bedrock at the bottom. ERT 2 is characterized by highly competent soils with high resistivity values between 899Ωm to greater than 7851 Ωm, which indicates that the soil is underlain by sand/laterite/bedrocks. Furthermore, ERT 3 is group as highly competent soils, with resistivity values between762Ωm and greater than 6980 Ωm; this shows that the profile 3 is underlain by sand/laterite/bed rock. The study shows that though most part of the area contains soils that are competent, because of the presence of clay which on most occasion in the Niger Delta are expandable, detailed Geophysical and Civil engineering studies should be carried out before the erection of high rising engineering structures such as network masts, buildings and water tanks within the study area.
Aquifer polution vulnerability assessment for abi paperEbong Dickson
The geophysical-based integrated electrical
conductivity (IEC) and the groundwater hydraulic confinement–
overlying strata–depth to water table (GOD)
techniques were used to assess vulnerability levels of
aquifers and the extent of aquifer protection in Abi,
Nigeria. The IEC indices was generated from
constrained one dimensional (1D) inversion of vertical
electrical sounding (VES) and two dimensional (2D)
electrical resistivity tomography (ERT) data, acquired
randomly in the area. The GOD indices were sourced
from existing geologic data within the area. Results
showed that IEC values vary from <0.1>2.0 S in the strongly protected areas.
The GOD indices vary from <0.3 in the lowly vulnerable
areas to 0.6 in the highly vulnerable areas. Thus, the
groundwater resources in the area need to be properly
managed for sustainability and such management practices
have been suggested.
Keywords Electrical resistivity. Contamination .
Vulnerability. IEC . GOD . Abi, Nigeria
Corrosion is a mechanism that degrades materials and causes structural failures in infrastructures, which can lead to severe effects on the environment and have direct impact on the population health. In addition, corrosion is extremely complex in the underground environment due to the variability of the local conditions. The delineation and assessment of possible areas of corrosion along Obama-Kolo Creek, in the Niger Delta region was carried out using Earth resistivity measurement. The aim of this study is to evaluate the influence of soil resistivity upon metals buried underground. In this investigation, an Abem SAS 300B meter was used and 20 sounding points were carried out using the Schlumberger array along the pipeline route. A total spread (AB) of 45m was adopted with the assumption that the depth of penetration is th of the total current electrode spread (AB). The results obtained showed that subsoil resistivity values for depths of 2 – 12m required for the underground pipe laying with resistivities in the range of 8 Ohm-m to 78 Ohm-m along Obama – Kolo Creek with a mean of 43 Ohm-m. The low resistivity encountered throughout the study has been attributed to the influence of saline water intrusion in the area. The average thickness of this area is 7m. Basically, most of the geoelectric graphs showed three layers, H-type curves. Generally, the subsurface soil is made up of subsoil lithology of mainly clayey/sandy clay material with different degree of saturation. This is an indication that any underground metallic material will be exposed to high corrosivity environment, hence appropriate cathodic protection will be required.
Measurement of Salinity and Electrical Conductivity of Land Forms in Akwa Ibo...iosrjce
IOSR Journal of Applied Physics (IOSR-JAP) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Integrated Geophysical and Geotechnical Evaluation of Foundation Failure in P...inventionjournals
Geophysical and geotechnical methods have been integrated with the aim of assessing characteristics of sub-surface layers to identify why structures in some parts of Ikere-Ekiti Southwestern Nigeria are failing or sinking as a result of foundation failure. Eight (8) vertical electrical sounding (VES) were carried out using resistivity meter and six (6) pits were dug to a depth of 1.2m. Six disturbed soil samples were collected from the six dug pits for the study. These samples were subjected to geotechnical tests in the laboratory, which include moisture content, shear test, Atterberg limit and grain size analysis. The acquired VES data were processed and interpreted using partial curve matching technique. The results of the all the mall the eight VES produced H curves. This curve type manifested three layers which are composed of sandy-clay, clayeysand/weathered basement and weathered basement/rock head. The depth o rockhead ranges from 12.1 to 43.2m. VES stations four and five have deeper depth to rock head (i.e. 21.3 to 43.2m) while other locations have lesser depth to rockhead (i.e.1 12.1m to 17.5m). The second layer has the lowest resistivity values meaning that it is somewhat conductive owing to clayey sand deposition and weathered area. Geotechnical test shows that the soils in the study area generally has high moisture content, low plasticity, and from grain size distribution, high concentrations of silt and clay. From the result, it is established that the layer in which the foundations are built upon are rated as poor to fairly competent. This might be as a result of poor drainage system characterised the study area which brought about the local deposition of the supposed subsoil. Therefore, high moisture content made the subsoil to lose its competency thereby causing the structures in the study area to subside
Application Of Resistivity For Groundwater, Hydrogeology and Pollution ResearchOmokpariolaElshalom
It was a group seminar geophysics course presentation in my year 3 of which I was asked to represent the group in giving an oral presentation of how we can apply resistivity in the geophysical investigation of groundwater, pollution ansd hydrogeology.
Exploring the Relationship between Moisture Content and Electrical Resistivit...inventionjournals
Conventional borehole sampling and its subsequent geotechnical testing is the most precise and direct method of soil characterization, but conversely it is time-consuming and expensive simultaneously. Electrical resistivity surveys can provide a non-destructive and less expensive way of determining soil properties, if reliable correlations could be established through extensive testing. The main objective of this research work is to establish quantitative relationship of resistivity with moisture content of sandy and silty soils that can be used in geotechnical appraisal of soil slopes. A non-linear relationship trend is observed between moisture content and electrical resistivity values obtained in field and laboratory conditions.
Electrical Resistivity Survey Forground Water At Eye Zheba Village, Off Bida ...iosrjce
The paper titled “Electrical Resistivity survey for ground water” at EL-HALAL Farms, covered an
area of about 10km2
, located at Eye Zheba village along Minna-Bida Road, located on latitude 60
.001
and 6
0
7
1
West and longitude 90
3
1
and 9.101 North. As a result of water problem in Bida and its environs, the people living
in this environment suffered a lot due to lack of portable drinking water and water for domestic use. A
Geophysical survey carried out, employed the schlumberger Array method in which current were sent beneath
the earth surfaces, this was done at various points and the data collected. The area revealed three lithological
formations in some places while in some place five. With the lowest resistivty found to be 6.85 Ωm and the
highest resistivity was 12,774.46 Ωm. The lithotogical formation includes the sandstones, clayey sandstones,
sandy clay and ferruginised sandstone. Since this is a sedimentary area drilling is expected to be deep down to a
depth of about 70-75m
Geo Environmental Investigation of Abuad Dumpsite, Southwestern NigeriaIJERA Editor
Geoenvironmental study of ABUAD female dumpsite was conducted to investigate the suitability of its location
and potential impact on groundwater in the environment. Profiling and Vertical electrical sounding methods
were employed using Dipole - Dipole and Schlumberger configuration respectively. Five points were sounded
and one profile was occupied. Three heterogeneous subsurface lithologic units were established namely; lateritic
topsoil, clayey-sand, and, fresh basement. The curve types are simple H and HA. The topsoil and clayey-sand
materials are characterized with relatively low resistivity values while the fresh basement materials are
characterized with high resistivity values. The average resistivity and thickness values for the topsoil are
280.0Ωm and.2.3m respectively. Clayey-sand was encountered in all the locations with average resistivity and
thickness values of 32.0Ωm and 7.3m respectively. Basement is relatively shallow in the study area, it was
encountered in all the locations with an average resistivity and depth values to the top of basement of 674Ωm,
and 9.6m respectively. Overburden materials are relatively thin within the area with an average resistivity and
thickness values of 156Ωm, and 9.6m respectively. The overburden materials constituting the aquiferous units
within the study area are porous, vulnerable, and good paths for leachate migration. The relatively low
resistivity values within the clayey-sand layers (14 - 61Ωm) are suggestive of leachate intrusion, while relatively
high resistivity values of the impervious basement are due to their crystalline nature. The proximity of the
dumpsite to both the cafeteria and residential halls is a cause for concern.
Subsurface Determination Of Cavities In Limestone Rock Area By Geoelectric Me...IJERA Editor
Two Dimensional of geoelectric method can be used to find out the conductive formation in the earth surface. The purpose of this research is to give the description about the geological subsurface formation, that the high resistivity value is indicate the potential area of cave and void in the limestone rocks. The dipole dipolegeoelectric method is used in this research with the path of lines is 250 m with 10 m electrode spacing. The total lines is 7 and the azimuth is from east to west. Resistivity method is started with inject the electrical current into the earth by current electrode, then potential difference will arise and measured by potential electrode. Variation value of resistance for each layer rock can calculated by divided potential defference with current value. The existence of the cavity is known by the resistivity value is more than 2500 ohm-m, while the cracks have a resistivity of 1500 to 2500 ohm-m.
Groundwater Studies in Abakaliki Using Electrical Resistivity Methodiosrjce
Electrical resistivity survey was carried out to investigate the groundwater potential of Abakaliki
urban, a sedimentary area with the oldest Cretaceous rocks (sandstones and shales) which are of Albian age.
The equipment used for the survey include, ABEM terrameter (SAS, 300C), four electrodes, hammer, four reels
of wires, connecting cords, measuring tapes and global positioning system. The survey was carried out in three
different locations. The field layout employed was the schlumberger array. The result of the survey shows that
the average resistivities are 1337.06m for the first layer, 5914. 34m for the second layer, 1277. 59m for
the third layer, 189. 65m for the fourth layer and 695.78m for the fifth layer with probable lithologic
interpretations as lateritic over-burden for the first layer, ferruginised and highly compact clay stone (dry) for
second layer, fissile dry shale, splintery shale(wet) and saturated and pyritised silty shale (wet) for the other
three layers, respectively. The result indicates that potential groundwater would likely be located in the fourth
layer in the study area.
Eight Vertical Electrical Sounding surveys were carried out in Abua town in Rivers State, Nigeria to determine the depth to shallow aquifers suitable for borehole drilling for groundwater use in the town. The Schlumberger array method was employed with current electrode spread of 200 m to 600 m and the corresponding electric current and voltage measured. The apparent resistivity was obtained and plotted against half the current electrode spread with the aid of an IPWIN 12 software to obtain the field curves which were interpreted in terms of resistivity, thickness and depth of occurrence. The results revealed two to four geoelectric sections with resistivity values of 8.29 Ω to 777 Ω. The maximum depth penetrated was 56.5 m with the maximum current electrode spread used. A shallow aquifer close to the surface at Omelema waterside was observed with a thickness of 49 m. The abnormal resistivity value of this zone indicates that it was probably contaminated by saline water intrusion. At Abua LGA site, a shallow aquifer was also observed at a depth of 7.86 m. At the dump site, the shallow aquifer was contaminated by leachates while at Omelema primary school site the result revealed unconsolidated sediments. The results for Abua Amp site and Rghom site also revealed shallow aquifers at depths of 4 m and 6 m respectively.
Delineation of Groundwater Potential Zones through Electrical Resistivity Par...iosrjce
This study motivated to determine electrical resistivity parameters of Osmania University campus
area which is underlain by granitic terrain. A total 103 Vertical Electrical Soundings were conducted with
maximum electrode spacing of 150m, the results reveals four subsurface geoelectrical layers, the top soil layer
of variable resisitivity value between 11.2 Ωm to 599 Ωm whose maximum thickness is 0.75 m to 8.46 m. The
highly weathered second layer resistivity value varing from 1.72 Ωm to 1800 Ωm, thickness is 0.12 m to 36.6m.
The third fractured layer indicated by resistivity value of 16.3 to 460 Ωm and thickness is 4.9 m to 87.4 m. The
groundwater potentials of the area are evalueted based on the Longitudinal Conductance (S), Transverse
Resistance (T), Coefficient of Electrical Anisotropy (λ), Resistivity for the Formation ( ), Reflection
Coefficient ( ) and Resistivity Contrast ( ), Locations where weathered layer thickness > 25 m and of a low
clay content as indicated by the resistivity range < 60 Ωm value is categorized to be the area of highs
groundwater potentials
Similar to Identification of Groundwater Prospective Zones Using Geoelectrical and Electromagnetic Surveys (20)
Essentials of Automations: The Art of Triggers and Actions in FMESafe Software
In this second installment of our Essentials of Automations webinar series, we’ll explore the landscape of triggers and actions, guiding you through the nuances of authoring and adapting workspaces for seamless automations. Gain an understanding of the full spectrum of triggers and actions available in FME, empowering you to enhance your workspaces for efficient automation.
We’ll kick things off by showcasing the most commonly used event-based triggers, introducing you to various automation workflows like manual triggers, schedules, directory watchers, and more. Plus, see how these elements play out in real scenarios.
Whether you’re tweaking your current setup or building from the ground up, this session will arm you with the tools and insights needed to transform your FME usage into a powerhouse of productivity. Join us to discover effective strategies that simplify complex processes, enhancing your productivity and transforming your data management practices with FME. Let’s turn complexity into clarity and make your workspaces work wonders!
Dr. Sean Tan, Head of Data Science, Changi Airport Group
Discover how Changi Airport Group (CAG) leverages graph technologies and generative AI to revolutionize their search capabilities. This session delves into the unique search needs of CAG’s diverse passengers and customers, showcasing how graph data structures enhance the accuracy and relevance of AI-generated search results, mitigating the risk of “hallucinations” and improving the overall customer journey.
GridMate - End to end testing is a critical piece to ensure quality and avoid...ThomasParaiso2
End to end testing is a critical piece to ensure quality and avoid regressions. In this session, we share our journey building an E2E testing pipeline for GridMate components (LWC and Aura) using Cypress, JSForce, FakerJS…
Enchancing adoption of Open Source Libraries. A case study on Albumentations.AIVladimir Iglovikov, Ph.D.
Presented by Vladimir Iglovikov:
- https://www.linkedin.com/in/iglovikov/
- https://x.com/viglovikov
- https://www.instagram.com/ternaus/
This presentation delves into the journey of Albumentations.ai, a highly successful open-source library for data augmentation.
Created out of a necessity for superior performance in Kaggle competitions, Albumentations has grown to become a widely used tool among data scientists and machine learning practitioners.
This case study covers various aspects, including:
People: The contributors and community that have supported Albumentations.
Metrics: The success indicators such as downloads, daily active users, GitHub stars, and financial contributions.
Challenges: The hurdles in monetizing open-source projects and measuring user engagement.
Development Practices: Best practices for creating, maintaining, and scaling open-source libraries, including code hygiene, CI/CD, and fast iteration.
Community Building: Strategies for making adoption easy, iterating quickly, and fostering a vibrant, engaged community.
Marketing: Both online and offline marketing tactics, focusing on real, impactful interactions and collaborations.
Mental Health: Maintaining balance and not feeling pressured by user demands.
Key insights include the importance of automation, making the adoption process seamless, and leveraging offline interactions for marketing. The presentation also emphasizes the need for continuous small improvements and building a friendly, inclusive community that contributes to the project's growth.
Vladimir Iglovikov brings his extensive experience as a Kaggle Grandmaster, ex-Staff ML Engineer at Lyft, sharing valuable lessons and practical advice for anyone looking to enhance the adoption of their open-source projects.
Explore more about Albumentations and join the community at:
GitHub: https://github.com/albumentations-team/albumentations
Website: https://albumentations.ai/
LinkedIn: https://www.linkedin.com/company/100504475
Twitter: https://x.com/albumentations
DevOps and Testing slides at DASA ConnectKari Kakkonen
My and Rik Marselis slides at 30.5.2024 DASA Connect conference. We discuss about what is testing, then what is agile testing and finally what is Testing in DevOps. Finally we had lovely workshop with the participants trying to find out different ways to think about quality and testing in different parts of the DevOps infinity loop.
Sudheer Mechineni, Head of Application Frameworks, Standard Chartered Bank
Discover how Standard Chartered Bank harnessed the power of Neo4j to transform complex data access challenges into a dynamic, scalable graph database solution. This keynote will cover their journey from initial adoption to deploying a fully automated, enterprise-grade causal cluster, highlighting key strategies for modelling organisational changes and ensuring robust disaster recovery. Learn how these innovations have not only enhanced Standard Chartered Bank’s data infrastructure but also positioned them as pioneers in the banking sector’s adoption of graph technology.
Alt. GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using ...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
UiPath Test Automation using UiPath Test Suite series, part 6DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 6. In this session, we will cover Test Automation with generative AI and Open AI.
UiPath Test Automation with generative AI and Open AI webinar offers an in-depth exploration of leveraging cutting-edge technologies for test automation within the UiPath platform. Attendees will delve into the integration of generative AI, a test automation solution, with Open AI advanced natural language processing capabilities.
Throughout the session, participants will discover how this synergy empowers testers to automate repetitive tasks, enhance testing accuracy, and expedite the software testing life cycle. Topics covered include the seamless integration process, practical use cases, and the benefits of harnessing AI-driven automation for UiPath testing initiatives. By attending this webinar, testers, and automation professionals can gain valuable insights into harnessing the power of AI to optimize their test automation workflows within the UiPath ecosystem, ultimately driving efficiency and quality in software development processes.
What will you get from this session?
1. Insights into integrating generative AI.
2. Understanding how this integration enhances test automation within the UiPath platform
3. Practical demonstrations
4. Exploration of real-world use cases illustrating the benefits of AI-driven test automation for UiPath
Topics covered:
What is generative AI
Test Automation with generative AI and Open AI.
UiPath integration with generative AI
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Generative AI Deep Dive: Advancing from Proof of Concept to ProductionAggregage
Join Maher Hanafi, VP of Engineering at Betterworks, in this new session where he'll share a practical framework to transform Gen AI prototypes into impactful products! He'll delve into the complexities of data collection and management, model selection and optimization, and ensuring security, scalability, and responsible use.
A tale of scale & speed: How the US Navy is enabling software delivery from l...sonjaschweigert1
Rapid and secure feature delivery is a goal across every application team and every branch of the DoD. The Navy’s DevSecOps platform, Party Barge, has achieved:
- Reduction in onboarding time from 5 weeks to 1 day
- Improved developer experience and productivity through actionable findings and reduction of false positives
- Maintenance of superior security standards and inherent policy enforcement with Authorization to Operate (ATO)
Development teams can ship efficiently and ensure applications are cyber ready for Navy Authorizing Officials (AOs). In this webinar, Sigma Defense and Anchore will give attendees a look behind the scenes and demo secure pipeline automation and security artifacts that speed up application ATO and time to production.
We will cover:
- How to remove silos in DevSecOps
- How to build efficient development pipeline roles and component templates
- How to deliver security artifacts that matter for ATO’s (SBOMs, vulnerability reports, and policy evidence)
- How to streamline operations with automated policy checks on container images
In the rapidly evolving landscape of technologies, XML continues to play a vital role in structuring, storing, and transporting data across diverse systems. The recent advancements in artificial intelligence (AI) present new methodologies for enhancing XML development workflows, introducing efficiency, automation, and intelligent capabilities. This presentation will outline the scope and perspective of utilizing AI in XML development. The potential benefits and the possible pitfalls will be highlighted, providing a balanced view of the subject.
We will explore the capabilities of AI in understanding XML markup languages and autonomously creating structured XML content. Additionally, we will examine the capacity of AI to enrich plain text with appropriate XML markup. Practical examples and methodological guidelines will be provided to elucidate how AI can be effectively prompted to interpret and generate accurate XML markup.
Further emphasis will be placed on the role of AI in developing XSLT, or schemas such as XSD and Schematron. We will address the techniques and strategies adopted to create prompts for generating code, explaining code, or refactoring the code, and the results achieved.
The discussion will extend to how AI can be used to transform XML content. In particular, the focus will be on the use of AI XPath extension functions in XSLT, Schematron, Schematron Quick Fixes, or for XML content refactoring.
The presentation aims to deliver a comprehensive overview of AI usage in XML development, providing attendees with the necessary knowledge to make informed decisions. Whether you’re at the early stages of adopting AI or considering integrating it in advanced XML development, this presentation will cover all levels of expertise.
By highlighting the potential advantages and challenges of integrating AI with XML development tools and languages, the presentation seeks to inspire thoughtful conversation around the future of XML development. We’ll not only delve into the technical aspects of AI-powered XML development but also discuss practical implications and possible future directions.
The Art of the Pitch: WordPress Relationships and SalesLaura Byrne
Clients don’t know what they don’t know. What web solutions are right for them? How does WordPress come into the picture? How do you make sure you understand scope and timeline? What do you do if sometime changes?
All these questions and more will be explored as we talk about matching clients’ needs with what your agency offers without pulling teeth or pulling your hair out. Practical tips, and strategies for successful relationship building that leads to closing the deal.
Observability Concepts EVERY Developer Should Know -- DeveloperWeek Europe.pdfPaige Cruz
Monitoring and observability aren’t traditionally found in software curriculums and many of us cobble this knowledge together from whatever vendor or ecosystem we were first introduced to and whatever is a part of your current company’s observability stack.
While the dev and ops silo continues to crumble….many organizations still relegate monitoring & observability as the purview of ops, infra and SRE teams. This is a mistake - achieving a highly observable system requires collaboration up and down the stack.
I, a former op, would like to extend an invitation to all application developers to join the observability party will share these foundational concepts to build on:
How to Get CNIC Information System with Paksim Ga.pptxdanishmna97
Pakdata Cf is a groundbreaking system designed to streamline and facilitate access to CNIC information. This innovative platform leverages advanced technology to provide users with efficient and secure access to their CNIC details.
How to Get CNIC Information System with Paksim Ga.pptx
Identification of Groundwater Prospective Zones Using Geoelectrical and Electromagnetic Surveys
1. International Journal of Engineering Inventions
e-ISSN: 2278-7461, p-ISSN: 2319-6491
Volume 3, Issue 6 (January 2014) PP: 17-21
Identification of Groundwater Prospective Zones Using
Geoelectrical and Electromagnetic Surveys
Sajeena, S., Abdul Hakkim, V. M., and Kurien, E. K.
Kelappaji College of Agricultural Engineering and Technology, Tavanur P.O. Malappuram, Kerala
I. INTRODUCTION
Groundwater resources play a major role in ensuring livelihood security across the world. Utilization of
groundwater reservoir as a viable source for meeting drinking and domestic water needs is safer and economical
than surface water, as groundwater is available everywhere and is generally uncontaminated. As a result
groundwater investigation has assumed top priority in recent years. Groundwater is usually held within porous
soils or rock materials. People all around the world face serious water shortage because of the over exploitation
of groundwater for domestic, industrial and agricultural purposes. It is estimated that (2003) around seven
billion people out of the projected 9.3 billion in the entire world will face water shortage and out of these, 40%
will face acute water crisis. The annual replenishable groundwater resources in India is estimated as 432 BCM
out of which 398 BCM is available for utilization leaving aside 34 BCM for natural discharge. Groundwater
contributes 60% of the total irrigated area of the country and plays a significant role in irrigation development.
Presently the overall stage of groundwater development is 58%, however there exists a significant regional
variation in its development.
In many parts of the world, groundwater is the only source of water to meet domestic, industrial or
agricultural demand (Komatina, 1994). Electrical geophysical methods have been applied in groundwater
exploration for decades (Chapellier et al., 1991). The methods used were electromagnetic and electrical
resistivity (namely vertical electrical sounding). Geophysical methods are used to obtain more accurate
information about subsurface conditions, such as type and depth of materials (consolidated or unconsolidated),
depth of weathered or fractured zone, depth to groundwater, depth to bedrock and salt content of groundwater (
Bouwer, 1978)).
II. GEOPHYSICAL METHODS OF GROUND WATER INVESTIGATIONS
The role of geophysical methods in groundwater exploration is vital. The aim is to understand the
hidden subsurface hydro-geological conditions adequately and accurately. The basis of any geophysical method
is measuring a contrast between physical properties of the target and the environs. The better the contrast or
anomaly, the better the geophysical response and hence the identification. So, the efficacy of any geophysical
technique lies in its ability to sense and resolve the hidden subsurface hydro-geological heterogeneities or
variation. Hence for groundwater exploration, a judicious application or integration of techniques is most
essential for success in exploration, technologically as well as economically (Rosli et. al., 2012).
Electrical Resistivity method has the widest adoption among the various geophysical methods of
groundwater investigation. (Olorunfemi, 1999; Ariyo, 2007; and Afolayan et al., 2004). This is due to the fact
that the field operation is easy, the equipment is portable, less filled pressure is required, it has greater depth of
penetration and it is accessible to modern computers. The Electrical Resistivity method has helped in the
identification and better understanding of aquifer dimensions (Stephen and Gabriel O., 2009).
In geophysical investigations for water exploration, depth to bedrock determinations, sand and gravel
exploration etc, the Electrical Resistivity Meter (ERM) method can be used to obtain quickly and economically
the details about the location, depth and resistivity of subsurface formations. Emenike (2001) tested the
groundwater potential and a correlation of the curves with the lithologic log from a nearby borehole and
suggested that the major lithologic units penetrated by the sounding curves were laterite clay sandstone and clay.
The sandstone unit, which was the aquiferous zone, had a resistivity range between 500 ohm-m and 960 ohm-m
and thickness in excess of 200 m.
ERM uses an artificial source of energy, rather than the natural fields of force, such as in gravity
surveying, hence the source detector separation can be altered to achieve the optimum separation, which
effectively controls the depth of measurement. The water exploration survey with the help of ERM is low cost,
easy for operation, speedy and accurate. Liu (2004) used ERM method for imaging changes of moisture content
in the vadose zone. The ability of the integrative approach was tested by directly estimating moisture
distributions in three-dimensional, heterogeneous vadose zones. This survey can also be used for geotechnical
and environmental purposes. ERM is generally employed for groundwater studies, such as quality, quantity,
www.ijeijournal.com
Page | 17
2. Identification of Groundwater Prospective Zones Using Geoelectrical…
mapping fresh water lenses, investigation of salt water intrusion and determination of the extent of
contaminants.
2.1 Vertical Electrical Sounding (VES)
The Vertical Electrical Sounding (VES) method is a depth sounding galvanic method and has proved
very useful in ground water studies due to simplicity and reliability of the method. The electrical resistivity of
rock is a property which depends on lithology and fluid contents. For example, the resistivity of coarse- grained,
well consolidated sandstone saturated with fresh water for example is higher than that of unconsolidated silt of
the same porosity, saturated with the same water. Similarly, the resistivities of identical porous rock samples
vary according to the salinity of the saturated water. The instrumentation of this method is simple, field logistics
are easy and straight forward while the analysis of data is less tedious and economical (Zhody et al., 1974;
Ekine and Osobonye, 1996; Ako and Olorunfemi, 1989). With this method, depth and thickness of various
subsurface layers and their water yielding capabilities can be inferred. These measurements have been used to
solve ground water and its related problems; notably in determining suitable site for drilling of boreholes and in
studying ground water contamination. This can also be used for the estimation of dynamic and static
groundwater reserves (Paliwal and Khilnani, 2001).
2.2 2-D Electrical Resistivity Tomography
2-D Electrical Resistivity Tomography (ERT) has been extensively used for many years for
groundwater exploration. The technique is employed together with drilling for determination of resistivity value
of alluvium and the effect of groundwater. 2-D Electrical Resistivity Tomography (ERT) is now mainly carried
out with a multi-electrode resistivity meter system (Figure 1). Such surveys use a number (usually 25 to 100) of
electrodes laid out in a straight line with a constant spacing. A computer-controlled system is then used to
automatically select the active electrodes for each measure (Griffith and Barker, 1993).
Fig. 1. The arrangement of electrodes for a 2-D electrical survey and the sequence of measurements used to
build up a pseudosection
The resistivity method basically measures the resistivity distribution of the subsurface materials. Table
1 and 2 shows the resistivity value of some typical rocks, soil materials and water (Keller and Frischknecht
1996). Igneous and metamorphic rocks typically have high resistivity values. The resistivity of these rocks is
mainly dependent on the degree of fracturing. Since the water table is generally shallow, the fractures are
commonly filled with ground water. The greater the fracturing, the lower is the resistivity value of the rock. As
an example, the resistivity of granite varies from 5000 m in wet condition to 10,000 m when it is dry. When
these rocks are saturated with ground water, the resistivity values are low to moderate, from a few m to a less
than a hundred m. Soils above the water table are drier and have a higher resistivity value of several hundred
to several thousand m, while soils below the water table generally have resistivity values of less than 100 m.
Also clay has a significantly lower resistivity than sand (Rosli et. al., 2012). The study was conducted in areas
which have a geology record of thick alluvium. The result show that groundwater will lower the resistivity value
and silt also will bring down the resistivity value lower then groundwater effect. Groundwater reservoirs are
found in saturated sand, saturated sandy clay and saturated silt, clay and sand.
www.ijeijournal.com
Page | 18
3. Identification of Groundwater Prospective Zones Using Geoelectrical…
Table 1. Resistivity values of common rocks and soil materials in survey area
Material
Resistivity (m)
Alluvium
10 to 800
Sand
Clay
Groundwater (fresh)
Sandstone
Shale
Limestone
Granite
60 to 1000
1 to 100
10 to 100
8 – 4 x103
20 -2 x103
50 – 4 x 103
5000 to 1,000,000
(Keller and Frischknecht 1996)
Table 2.]= Resistivity values of some types of water
Types of water
Precipitation
Surface water, in areas of igneous rock
Surface water, in area of sedimentary rock
Ground water, in areas of igneous rock
Ground water, in area of sedimentary rock
Sea water
Drinking water (max. salt content 0.25%)
Water for irrigation and stock watering
(max. salt content 0.25%)
Resistivity (m)
30-1000
30-500
10-100
30-150
>1
= 0.2
>1.8
>0.65
(Keller and Frischknecht 1996)
2.3 Direct Current (DC) resistivity method
Direct Current (DC) resistivity method is used to determine the electrical resistivity structure of the
subsurface. Resistivity is defined as a measure of the opposition to the flow of electric current in a material. The
resistivity of a soil or rock is dependent on several factors that include amount of interconnected pore water,
porosity, amount of total dissolved solid such as salts and mineral composition (clays) (Rosli et. al.,2012). From
various electrical methods, the Direct Current (DC) resistivity method for conducting a vertical electrical
sounding (i.e. Schlumberger sounding) is effectively used for groundwater studies due to the simplicity of the
technique, easy interpretation and rugged nature of the associated instrumentation. The technique is widely used
in soft and hard rock areas (e.g. Van Overmeeren, 1989; Urish and Frohlich, 1990; Ebraheem et al., 1997).
However, groundwater investigations in hard rock areas are often more difficult as tube-wells must be located
exactly to be successful. Tube-wells drilled without proper geophysical and hydro-geological study often fail to
yield groundwater. In hard rock areas, groundwater is found in the cracks and fractures of the local rock.
Groundwater yield depends on the size of fractures and their interconnectivity. Use of Schlumberger sounding is
well known for determining the resistivity variation with depth. However, it is very difficult to perform
resistivity soundings everywhere without prior information.
2.4 Electrical resistivity method using a terrameter SAS 4000
SAS stands for Signal Averaging Systems, a method whereby consecutive readings are taken
automatically and the results are averaged continuously. The Terrameter SAS/4000 can operate in different
modes (resistivity, self potential & induced polarization). A useful facility of the SAS/4000 is its ability to
measure in four channels simultaneously. This implies that well resistivity and induced potential measurements
as voltage measurements can be performed up to four times faster. Resistivity measurements with ERM are one
of the simplest methods to be used in geophysics. By putting two electrodes into the ground and inducing an
electric current through the ground, a potential field is created. Two additional electrodes are used to measure
the potential at some location. Increasingly deeper measurements are achieved by using a bigger separation
between the current electrodes. Moving the current electrode and having the potential electrode fixed is named
the “Schlumberger” method (Fig. 2).
www.ijeijournal.com
Page | 19
4. Identification of Groundwater Prospective Zones Using Geoelectrical…
Fig. 2. Geometric arrangement of the Schlumberger array configuration
For this setup, a direct current is introduced into the ground through two current electrodes A and B.
The potential electrodes M and N are inserted in the ground between the outer current electrodes A and B, to
measure the potential difference. By measuring the current (I) between the two current electrodes A and B and
the associated potential difference (V) between the potential electrodes M and N, the apparent resistivity (ρa) is
computed by the Eq1 as given below:
a = K (V/I)
---------------------- (1)
Where,
K is the geometric factor of the electrode arrangement in case of Schlumberger electrode
configuration, which is given by Eq 2:
(AB/2)2 – (MN/2) 2
----------- (2)
MN
By repeating the Schlumberger measurements with the entire setup moved one step to the side, vertical electrical
soundings (VES) are performed continuously and the resistivities along a profile are measured.
K=
2.5 VLF electromagnetic method
The VLF (Very Low Frequency) method has been applied successfully to map the resistivity contrast at
boundaries of fractured zones having a high degree of connectivity (Parasnis, 1973). Further, the VLF method
yields a higher depth of penetration in hard rock areas because of their high resistivity (McNeill et al., 1991).
Therefore, a combined study of VLF and DC resistivity has potential to be successful (Benson et al., 1997,
Bernard and Valla, 1991). VLF data are also useful in determining the appropriate strike direction to perform
resistivity soundings (i.e. parallel to strike), again improving the likelihood of success. The radio signals
transmitted from worldwide transmitters, used for navigation purposes in the frequency range of 5-30 kHz are
used as a source for the primary field in a VLF survey. Such type of transmitting source makes VLF instrument
very light and portable, and can be useful to survey a large area quite quickly. VLF magnetic field measurement
makes use of E-polarization in which a transmitter is selected in the direction of strike and measuring profiles
are taken perpendicular to the strike direction. Generally, the horizontal and vertical components of magnetic
fields are measured and real and imaginary anomalies are computed using the expression given by Smith and
Ward (1974)
2(Hz –Hx ) cos
tan 2 = + -------------------------1-(Hz –Hx ) 2
And
Hz Hx sin
e = ------------------H12
Where is dip angle, e is ellipticity, Hz and Hx are the amplitudes, the phase difference
- x, in which z is the phase of Hz and x is the phase of Hx, and H1 = Hx e i sin+ Hz cos.
= z
The tangent of the tilt angle is a good approximation of the ratio of the real component of the vertical secondary
magnetic field to the horizontal primary magnetic field. The ellipticity is a good approximation of the ratio of
the quadrature component of the vertical secondary magnetic field to the horizontal primary field (Paterson and
Ronka, 1971). These quantities are called the real (= tan a × 100 %) and imaginary (= e × 100 %) anomalies,
respectively and they are normally expressed as percentage.
VLF data were collected using an ABEM-WADI instrument. Since the strike of the formation was
approximately in the E-W direction, a transmitter in this direction with a frequency of 19.8 kHz was used.
www.ijeijournal.com
Page | 20
5. Identification of Groundwater Prospective Zones Using Geoelectrical…
III. CONCLUSION
ERM solves the problems of groundwater exploration in the alluvium formation aquifer by serving as
an inexpensive and useful method. The Electrical Resistivity Method helps in the identification and better
understanding of aquifer dimensions. It has been concluded from this study that electrical resistivity methods are
suited for estimating thickness of weathered mantle and mapping of bedrock topography and fractured zones. It
is therefore suggested that geophysical methods, especially the electrical resistivity method, along with
geological methods should form an integral part of groundwater exploration programs in solving complex
geohydrological problems associated with ground water occurrence and resource development. Some uses of
this method in groundwater are: determination of depth, thickness and boundary of an aquifer, determination of
interface saline water and fresh water porosity of aquifer, hydraulic conductivity of aquifer, transmissivity of
aquifer, specific yield of aquifer, contamination of groundwater (Choudhury et al., 2001). Contamination
usually reduces the electrical resistivity of pure water due to increase of the ion concentration (Frohlich & Urish,
2002). However, when resistivity methods are used, limitations can be expected if ground in homogeneties and
anisotropy are present (Matias, 2002). However, the use of geophysics for both groundwater resource mapping
and for water quality evaluations has increased drastically during last 10 years in large part due to the rapid
advances in microprocessors and associated numerical modelling solutions.
The Vertical Electrical Sounding (VES) methods have proved to be very reliable for ground water
studies and therefore the method can effectively be used for shallow and deep underground water geophysical
resistivity investigation.
REFERENCES
[1].
[2].
[3].
[4].
[5].
[6].
[7].
[8].
[9].
[10].
[11].
[12].
[13].
[14].
Babiker, I.S., Mohamed, A.M. and Hiyama, T. 2007. Assessing groundwater quality using GIS, Water
Resources Managemen., 21(4) : 699 –715.
Balakrishnan, P., Saleem, A. and Mallikarjun, N. D. 2011. Groundwater quality mapping using
Geographic Information System (GIS): A case study of Gulbarga City, Karnataka, India. African
Journal of Environmental Science and Technology. 5(12) : 1069-1084.
Herman, R. 2001. An introduction to electrical resistivity in geophysics. American Journal of Physis.
69 (9) : 943-952.
ICAR. 2010. Annual Report, AICRP on Groundwater Utilization 2009 – 2010.
Directorate
of Water Management, Bhubaneswar, Orissa, pp: 1-80.
Israil, M., Mufid, A. Singhal, D. C. and Kumar, B. 2006. Groundwater recharge estimation using a
surface electrical resistivity method in the Himalayan foothill region, India. Hydrogeology Journal. 14:
44-50.
Jain, S. K., Singh, A. K. and Thakur, A.K. 2008. Assessment of quality of gound water pollution
arising from various sources. Journal of Indian Water Resources. 28 (3) : 9-13.
Kavitha , M.M., Mohana, P. and Naidu, K. B. 2011. Delineating groundwater potential zones in
Thurinjapuram watershed using geospatial techniques. Indian Journal of Science and Technology.
4(11) : 23-27.
Kumar, A. 2011. ICAR Vision 2030, Directorate of Water Management, Bhubaneswar, Orissa : pp:130.
Muhammed A. J. M., Cheema and Shafique A. 2007. Determination of Lithology and Groundwater
Quality Using Electrical Resistivity Survey. International Journal of Agriculture & Bioligy. 9(11) : 43–
146
Rosli, S. Nawawi, M.N.M. and Mohamad, E. T. 2012. Groundwater Detection in Alluvium Using 2-D
Electrical Resistivity Tomography (ERT), EJGE, Vol. 17 [2012].
Selvam, S. and Sivasubramanian, P. 2012. Groundwater potential zone identification using
geoelectrical survey: A case study from Medakdistrict, Andhra Pradesh, India., International Journal of
Geomatics and Geosciences. 3(1): 55-62.
Sharma, S.P. and Baranwal, V. C. 2005. Delineation of groundwater-bearing fracture zones in a
hardrock area integrating Very Low Frequency Electromagnetic and Resistivity data, Geophysics.
57:155-166
Sitender. and Rajeshwari. (2011). Delineation of groundwater potential zones in Mewat District,
Haryana, India. International Journal of Geomatics and Geosciences. 2(1): 18-22.
Stephen, O. A and Gabriel, O. A. 2009. Role of Electrical Resistivity Method for Groundwater
Exploration in Hard Rock Areas: A Case Study from Fidiwo/Ajebo Areas of Southwestern Nigeria,
The Pacific Journal of Science and Technology, 10(1) : 483–486
www.ijeijournal.com
Page | 21