Vertical Electrical Sounding Technique Research Articles

Vertical electrical sounding technique for evaluating and characterizing weathered Neogene basaltic aquifer in Jbab area, Southern Syria

ABSTRACT Vertical electrical sounding (VES) technique with Schlumberger array is used to characterize the subsurface basaltic aquifers in Jbab area, Southern Syria. The Dar-Zarrouk (D-Z) parameters of 18 VES points allow to characterize the subsurface basaltic environment and the weathered Neogene basalt aquifer in the study region. The Neogene basaltic aquifer exists at a depth varying between 12.40 and 291.8 m, its thickness varies between 32.3 and 244.4 m. Its resistivity is between 12.53 and 53.40 Ω.m. The hydraulic conductivity (K) varies between 0.64 and 0.68 m/day, while the transmissivity (T) ranges between 21.94 and 162.68 m2/day. The overburden protective capacity (OPC) is evaluated through modeling the longitudinal conductance of the layers above the Neogene basaltic aquifer. OPC varies between 0.064 Ω-1 and 2.90 Ω-1, reflecting that more than 83% of the study region is identified by relatively moderate to good aquifer protective capacity. The use of the VES technology with its related D-Z parameters provides a vital information about the subsurface weathered basaltic aquifer in the study area, and can be practiced worldwide to characterize areas with similar geological context.

Geometric Characterization of the Mateur Plain in Northern Tunisia Using Vertical Electrical Sounding and Remote Sensing Techniques

The Mateur aquifer system in Northern Tunisia was examined using data from 19 water boreholes, 69 vertical electrical sounding (VES) stations, and a Sentinel-2 satellite image. Available boreholes and their corresponding logs were compared to define precisely the multi-layer aquifer system, including the Quaternary and Campanian aquifers of the Mateur plain. Quantitative interpretation and qualitative evaluation of VES data were conducted to define the geometry of these reservoirs. These interpretations were enhanced by remote sensing imagery processing, which enabled the identification of the Mateur plain’s superficial lineaments. Based on well log information, the lithological columns show that the Quaternary series in the Ras El Ain region contains a layer of clayey, pebbly, and gravelly limestone. Additionally, in the Oued El Tine area, a clayey lithological unit has been identified as a multi-layer aquifer. The study area, exhibiting apparent resistivity values ranging between 20 and 170 Ohm·m, appears to be rich in groundwater resources. The correlation between the lithological columns and the interpreted VES data, presented as geoelectrical cross-sections, revealed variations in depth (8–106 m), thickness (10 to 55 m), and resistivity (20–98 Ohm·m) of a coarse unit corresponding to the Mateur aquifer. Twenty-three superficial lineaments were extracted from the Sentinel-2 image. Their common superposition indicated that both of them are in a good coincidence; these could be the result of normal faults, creating an aquifer system divided into raised and sunken blocks.

Assessment of groundwater resources from geophysical and remote sensing data in a basement complex environment using fuzzy-topsis algorithm

This study addresses the pressing global water challenge by focusing on a typical basement complex area experiencing acute water shortage. Indiscriminate well siting without reliable hydrogeological maps has resulted in failed attempts to address water shortages. To overcome these challenges, this research aims to enhance the accuracy and reliability of groundwater potential assessments by incorporating crucial groundwater-related factors.The Fuzzy Technique for Order Preference by Similarity to Ideal Solution (FTOPSIS) method was adopted due to its ability to improve multi-criteria decision-making (MCDM) techniques for effective groundwater resource management. Unlike TOPSIS, FTOPSIS better reflects decision-makers' intentions, especially concerning geological boundaries and natural phenomena. To achieve the objectives of the study, geophysical and remote sensing datasets were utilized. The study employed the electrical resistivity method, utilising the Vertical Electrical Sounding (VES) technique with the Schlumberger array while the remote sensing data used were the Digital Elevation Model (DEM) image and Landsat ETM image which were processed to generate key groundwater conditioning factors. These factors were integrated using the FTOPSIS algorithm. This algorithm facilitated the calculation of the groundwater potential indices by assigning weights based on their level of significance to influencing groundwater potential in order to generate the groundwater potential map (GPM). The GPM was classified into five zones of varying groundwater potential, with very low and low potential occupying 74 % of the total area. Validation with well data yielded an impressive 79 % accuracy, showcasing the model's enhanced precision. Beyond improved accuracy, the study's implications extend to practical applications in groundwater resource management. By providing a clearer understanding of groundwater potentiality, the research can inform more robust decision-making frameworks, promoting sustainable water use not only in the study area but also in similar geological settings of the world.

Ingress of municipal solid waste into water resources: an environmental assessment and monitoring tool near dumpsites in Akwa Ibom State, Nigeria

ABSTRACT Municipal solid waste (MSW) dumping sites are only used for trash discarding. Beyond the reek that the dumpsites generate, which defiles the milieu, the primary issue is the spreading of fluid from the landfills. The thrust of this research is to utilize the contiguous data from geophysics and laboratory analysis of groundwater samples to decipher the influence of MSW on aquifer systems in Uyo and Eket Counties. Geo-electrical studies featured vertical electrical sounding (VES) and constant electrode separation techniques to generate 1D and 2D electrical resistivity models. The analyzed field data were integrated with water sample analysis to deduce the influence of leachate on groundwater. The VES curve types conformed to A (7.1%), HK (21.4%), Q (21.4%), and K (50.0%). The created 2D image maps for MSW locations lay bare the fact that leachate dispersal between source and sink obeys the inverse square rule. The heavy ions, which were all higher than the approved standards have, chromium as the highest and nickel as the least. The anionic average relative abundance has hydrogen trioxocarbonate ion concentration as the highest and fluoride ions as the least. The survey demonstrates that leachate has a considerable impact on groundwater.

Vertical electrical sounding method and Dar Zarrouk analysis to identify the distribution of seawater intrusion in Pelauw Village, Maluku

Groundwater is one of the essential resources that support human life. Excessive exploitation activities can cause groundwater problems such as seawater intrusion, especially in coastal areas. Groundwater salination must be a concern and measured to determine the condition and level of distribution. One of the non-invasive, inexpensive, and efficient methods to see seawater intrusion phenomena is the vertical electrical sounding (VES) technique of electrical resistivity method. This research aimed to analyze the distribution of seawater intrusion in Pelauw Village, Maluku, Indonesia, using the VES and Dar-Zarrouk parameters S and T. The S and T are longitudinal conductance and transversal resistance, respectively. This study collected 16 VES stations spread across residential areas near the coast of Pelauw Village. Groundwater affected by seawater intrusion in the study area has S>1.00 mho and T<1,000 ohm m2. Three VES stations are suspected to have experienced seawater intrusion, namely V7, V8 and V12. These three stations are located near the shoreline and densely populated areas. Based on the 2D cross-section, the spread of seawater intrusion toward the land is about 200 meters. This seawater intrusion event is thought to have occurred due to groundwater exploitation by communities around the coast and active tectonic activity. The VES method and Dar Zarrouk Analysis proved compelling enough to delineate the spread of seawater intrusion, so based on these results, it can be a reference for mitigating groundwater pollution.

Investigation of Aquifer Vulnerability under some Protective Measures in Ehime Mbano, South-Eastern Nigeria for Sustainable Groundwater Development

This study focuses on assessing aquifer vulnerability to contamination in Ehime Mbano South-Eastern Nigeria by applying the DRASTIC model. The data was obtained using (VES) vertical electrical sounding technique by applying Schlumberger configurations with AB/2 = 400 m. The VES data were interpreted using state of the art soft wares e.g. IP12WIN and Surfer 12 to obtain the final model for each VES, groundwater vulnerability map was also developed while aquifer media was gotten by taking into account, the depth at which water was struck and correlating those depths with the lithological description of the VES results obtained. The hydraulic conductivity was calculated from apparent resistivity of the aquifer. However, the net recharge, soil media, and topography was obtained from research documentaries. Aquifer vulnerability assessment carried out revealed areas with high, low and moderate vulnerability based on the DRASTIC Index. Locations with high vulnerability rating of 126 -165 includes: Umuokiri Umunumo and Ikperejere. Locations with moderate vulnerability rating of 86-125 includes: Ikpem, Ikweii Nzerem while locations with low vulnerability rating of 70-85 includes: Umuokara Uzinomi and areas close to Umueze II. The findings of the study can be used to identify regions of contamination of groundwater in the study area.

Vertical Electrical Sounding Technique as an Efficient and Rapid Tool for Groundwater Investigation in a Basaltic Environment at Kodana Station for the Shami goats. Case Study from Southern Syria

Geoelectrical survey was conducted by using vertical electrical sounding technique (VES) with adapting Schlumberger configuration, to locate and drill a borehole for groundwater extraction in the Kodana station for the Shami goats, Southern Syria. An integrated approach is proposed to increase the efficacy of the VES technique and to reduce the uncertainties and the high failures in locating and drilling a successful groundwater borehole. The approach is essentially based on analyzing the Dar-Zarrouk (D-Z) parameters with constraining several conditions to obtain the optimum hydro-geophysical model.The 1D inversion quantitative interpretation of twelve VES sounding points and the (D-Z) parameters allowed the characterization of the study area in terms of depth and the Neogene pyroclastic basalt aquifer. The result showed that VES point (V6) has the optimum and favorable properties for drilling a successful borehole in the area. The V6 has GPS coordinates of E: 3589614, N: 3301961 and Z: 770835m. The Neogene (fractured pyroclastic layer with rocks of basaltic composition) aquifer at this V6 point is characterized by a thickness (h) of 217m, a resistivity (ρ) of 227Ωm, a transverse resistance (R) of 49259 Ωm2, and an anisotropy parameter (λ) of 1.15. The advantages of the proposed approach are well proven and documented, in comparing with other techniques that require the combination of VES technique with other available geophysical techniques. The VES technique within the proposed approach is therefore recommended to be easily applied for groundwater investigations, and locating the suitable positions for drilling boreholes in similar worldwide basaltic environments.

Near surface resistivity investigation of regolith of Middle Benue Trough: implications on road pavement along Lafia-Shendam Axis, North Central Nigeria

ABSTRACT Electrical characteristics and subsurface structures associated with the regolith of Middle Benue Trough have been investigated. Vertical electrical sounding (VES) and constant separation traversing (CST) techniques were employed for data acquisition along Lafia-Shendam Road, Lafia, North Central Nigeria. Forty (40) Schlumberger sounding stations and four (4) Wenner resistivity profiles were occupied along opposite sides of the road to delineate and decipher the subsurface geological structures. Second-order Dar Zarrouk parameters (longitudinal and transverse resistivities, mean resistivity and coefficient of anisotropy) computed from VES parameters were also used to evaluate the pseudo-anisotropy characteristics of the regolith cover. Geoelectric sequences delineated within the study area include thin topsoil, alluvium deposit, weathered layer (laterite and saprolite) and fresh basement. The regolith is hosted by a weathered sedimentary rock at an average depth which varies from 10.2 to 37.3 m. The regolith structure is not complex and has a greater proportion of conductive laterite. The saprolite associated with the host sedimentary rock, masked in the VES technique, is revealed as a very thin zone with moderate resistivity in the CST 2-D structures. The predominance of laterite in the regolith is also corroborated by the range of values of the coefficient of anisotropy and mean resistivity.

Using VES and GIS-Based DRASTIC Analysis to Evaluate Groundwater Aquifer Contamination Vulnerability in Owerri, Southeastern Nigeria

This study assesses groundwater vulnerability in Owerri, Nigeria, using Vertical Electrical Sounding (VES) and Geographic Information System (GIS)-based DRASTIC modeling. The research methodology includes literature review, field survey, geological feature mapping, hydrogeological assessment, geo-electrical sounding, and data interpretation. Owerri, a rapidly developing city with flat topography and a growing population, uses the DRASTIC model to construct a groundwater vulnerability map. The model evaluates the risk of groundwater contamination using seven critical criteria, including depth to water table, net recharge, aquifer media, soil media, topography, vadose zone impact, and hydraulic conductivity. Each parameter was given a weight and rating, and the DRASTIC Index (DI) was calculated by summing the products of the weights and ratings for each factor. The results of the vulnerability assessment indicated that approximately 49% of the study area falls into the high vulnerability category, around 45% is classified as moderate vulnerability, and the remaining 6% is labeled as low vulnerability. The study reveals moderate to high vulnerability zones in Owerri, Nigeria, due to factors like lower slope terrain, permeable aquifer media, and vadose zone impact. The use of VES and GIS-based DRASTIC mapping techniques provides insights into groundwater vulnerability, aiding in sustainable resource management and environmental protection. The findings emphasize the importance of understanding potential risks and the need for effective management strategies to safeguard clean water supplies. Further research and mitigation efforts should focus on highly vulnerable areas.

Multi-well clustering and inverse modeling-based approaches for exploring geometry, petrophysical, and hydrogeological parameters of the Quaternary aquifer system around Debrecen area, Hungary.

This research aims to explore the application of an unsupervised machine learning and inverse modeling-based methods to map the aquifers geometry and investigate the petrophysical and hydrogeological parameters of the Quaternary aquifer system around the Debrecen area, Eastern Hungary. The study utilized a limited well-logs, including spontaneous potential, natural gamma ray, and normal resistivity logs. The k-means clustering technique is applied to identify the distribution of lithological facies within the formerly identified basin-scale hydrostratigraphical units of coarsening upward, alluvial, valley incision, and Late Miocene deposits. Based on the mathematical and geological considerations, the analysis revealed three main clusters (C1, C2, and C3), representing different lithofacies of shale, shaly sand, and sand and gravel. The result of the cluster analysis is further validated with a surface geophysical survey using the vertical electrical sounding (VES) technique. Furthermore, an inverse-modeling-based approach using Csókás method is employed to detect the vertical and horizontal distribution of the hydraulic conductivity along these units. Csókás model is empirically modified from the Kozeny-Carman equation that suites the unconsolidated freshwater-bearing units. The results indicated that the petrophysical and hydrogeological parameters widely ranged with the hydraulic conductivity between almost zero in the shaly layers to more than 21.5 m/d in the sandy and gravely layers. However, the valley incision unit aquifers showed a more uniform distribution of hydraulic conductivity. Based on these results, the Quaternary aquifers in the Debrecen area are classified as moderate to highly productive and ideal for groundwater development. The applied methodology contributed to understanding the complexity of the hydrogeological conditions, providing a robust approach to characterize the heterogeneous groundwater systems.

Combination of Vertical Electrical Sounding (VES) and Electrical Resistivity Tomography (ERT) techniques for hydrogeological reconnaissance in the Guigou plain, Tabular Middle Atlas, Morocco

The study site is located in the Guigou plain, which is situated on the south-eastern edge of the Tabular Middle Atlas and is characterised by a particular geology within the mountainous region. Unlike the Tabular Middle Atlas, which is generally covered by Lias carbonate formations, the Guigou plain is characterised by the presence of a different type of cover formed by basaltic flows of plioquaternary age, forming a surface layer that is used extensively for agricultural activities. The main objective of our study is to detect the different geoelectric levels both at the surface and at depth, thus providing indications of the specific aquifer formations in the region studied. The analysis of the results obtained highlighted the presence of a superficial resistant level, attributed to basalts of Plio-Quaternary age, with an estimated thickness of between 30 and 100 m, forming the superficial aquifer of the plain. Next, a conductive level was identified, associated with alternating marl and marl-limestone of Pliocene age, in keeping with the local geology. Finally, at a depth of 225 m, a very resistant level was identified, corresponding to Lias limestone, which becomes a deep aquifer on the Guigou plain. This study provides essential vertical hydrogeological reconnaissance and highlights the need to carry out numerous tomographic profiles as well as electrical boreholes. These combined approaches are crucial to enriching our understanding of the particular geological and hydrogeological characteristics of this region, which forms a transition zone between the MAT and the MAP.

Vertical electrical sounding techniques training on frozen multilayer soils in a cold laboratory

This paper presents a comprehensive plan for teaching the method of Vertical Electrical Sounding in the cold laboratory of the Geography Department of MSU on model-prepared frozen multilayer soils. Vertical electrical sounding (VES) is the definitive method for studying the structure of the Earth's crust. It does this by measuring the electrical resistance of rocks at different depths. A four-electrode setup is used for VES (AB is the supply electrode, and MN is the receiving electrode). The process involves measuring the current in AB and the potential difference at MN, calculating the apparent resistivity, and increasing the AB differences. The results are presented in the form of a RES curve and a transect. We will consider typical transects and VES curves (two-layer curves with ρ1 < ρ2 and ρ1 > ρ2). We will now interpret the bilayer section (sediment-granites). This allows you to master both the theory and practice of the VES method under conditions that mirror those in the field. VES, model soils, frozen soils, multilayer soils, training

Evaluation of geohydraulic response properties of hydrogeological units in Littoral hydro-lithofacies in Uyo, Southern Nigeria

Aquifer geohydraulic response properties are important parameters in groundwater resource management and exploitation. However, geohydraulic properties in the study area is sketchy and due to wildcat drilling. This practice, which leads to inadequate inventory of groundwater parameters, deprived the area of efficient exploitation, monitoring and management of groundwater resources. This study is aimed at evaluating the geo-hydraulic response properties of hydrogeological units in littoral hydro-lithofacies in Uyo, Southern Nigeria. Vertical electrical sounding (VES) technique was carried out, and a total of fifteen geoelectric soundings were obtained using IGIS Resistivity metre model SSR-MP-ATS and its accessories employing Schlumberger electrode configuration. The interpreted data give sets of geoelectric curves from which the aquifer resistivity and thickness were determined. The results reveal the aquifer bulk resistivity ranging from 23.4 to 1306.2 Ωm with an average of 347.99 Ωm, while aquifer thickness spanned from 7.4 to 56.3 m. The formation factor, fractional porosity and transmissivity ranged from 2.41 to 12.52, 0.20 to 0.46, and 0.001 to 0.037m2/s, respectively. The formation tortuosity also ranged from 1.05 to 1.58; longitudinal conductance ranged from 0.020 to 1.004 Ω−1; and transverse resistance ranged from 549.90 to 69,097.98 Ωm2. These parameters were contoured, and their variations are displayed on the contour maps generated. The graphs plotted showed strong correlation coefficient and earth response function that can be used in modelling the aquifer repositories in areas with similar geomaterials. The results of this study indicate that the survey area has a good prospect for groundwater accumulation, and the results can be useful in installing matching hydraulic pumps in boreholes in the survey area.

Delineating of Groundwater Aquifer Potential Using Vertical Electrical Sounding (VES) Methods in Giriloyo, Wukirsari Village, Imogiri District, Bantul Regency, Special Region of Yogyakarta

The geophysical investigation in Giriloyo, Wukirsari Village, has defined the groundwater potential zones. The research region underwent a geophysical examination utilizing the electrical resistance method, which comprised the vertical electrical sounding (VES) technique and the Schlumberger array system. The study area is surrounded by common rock types such as lava, tuff, agglomerate, and alluvial. In the study region, five lines were explored. Data for subsurface resistivity were gathered with an Oyo McOhm type 2115. IPI2win, a piece of computer software that analyzes data and automatically interprets apparent resistivity, was used to examine the data. The VES data showed the varied nature of the subsurface geological sequence. The geoelectrical cross-sections along the profile of (VES 2-3-4-1) show an aquifer, which stretches from the southeast towards the northwest part of the basin. Tuff is seen to have formed shallow aquifers due to the top weathered part at VES-2 and 3, while Quartz chlorite calcite (VES-4) and Plagioclases (VES-1) are devoid of shallow aquifers. The higher-elevation lithological areas recharge the low-elevation aquifer zones. At VES 2 and 3, relatively low resistivity values (< about 100 Ωm) have been observed. A field observation at these locations reveals that these lithologies are highly fractured with a weathering profile of up to 10 m. Thus, these are the sites where groundwater potential zones can be marked (figure 4). The high resistivity (about 3162 Ωm regions is observed extending at the VES-4; this may be due to the least weathered Quartz chlorite calcite at high elevation. VES-1 is also located on the plagioclase and shows a slight resistivity zone, which could be considered a groundwater recharge zone. This profile shows the high possibility of groundwater potential due to the zone of lineaments.

Application of Electrical Resistivity Method to Decipher Groundwater Occurrence Status at Isikuku, Southern Nigeria

Electrical resistivity method is a type of geophysical survey employed for groundwater investigation, conducted in Isikuku Community in Benin City, Edo state with the aim of delineating groundwater occurrence. Schlumberger electrode array configuration was employed in this study. Six (6) VES points were surveyed with linearised inversion technique used for the interpretation of sounding taken at various locations in the area. The data collected were interpreted by curved matching and computer iteration using Interpex Ix1D v 2 software. From the geoelectric section, VES 1 possess the AK curve with four layers ρ1˂ρ2˂ρ3˃ρ4, VES 2 possess the KQ curve with four layers ρ1˂ρ2˃ρ3˃ρ4, VES 3 possess the A curve with three layers ρ1˂ρ2˂ρ3, VES 4 possess the AK curve with four layers ρ1˂ρ2˂ρ3˃ρ4, VES 5 possess the A curve with three layers ρ1˂ρ2˂ρ3, VES 6 possess the K curve with three layers ρ1˂ρ2˃ρ3. Geo-electrical layers identified in the study area included topsoil, sandy clay, clay basement and sandstone. The VES study revealed the layer which constitute the productive water-bearing zones referred to as good groundwater potential aquifers. The analysis of the interpretation of the field data showed that the area under investigation delineated four layers earth in each of the vertical electrical sounding point. Generally, the geoelectric survey conducted in the study area revealed the subsurface lithologies: Clay, Clayey Sandstone, Sand stone, Coarse Sand, Lateritic soil and Top soil. Thus, vertical electrical sounding techniques employed in this study has proved useful and successful in delineating subsurface lithology in the study area.

Assessment of Potential Potable Water Reserves in Islamabad, Pakistan Using Vertical Electrical Sounding Technique

This study aimed to investigate the potential reserves of potable water in Islamabad, Pakistan, considering the alarming depletion of water resources. A detailed vertical electrical sounding (VES) survey was conducted in two main localities: Bara Kahu (Area 1) and Aabpara to G-13 (Area 2), based on accessibility, time, and budget constraints. A total of 23 VES measurements were performed, with 13 in Area 1 and 10 in Area 2, reaching a maximum depth of 500 m. Geologs and pseudosections were generated to assess lithological variations, aquifer conditions, and resistivity trends with depth. Statistical distribution of resistivity (SDR), hydraulic parameters, true resistivity, macroanisotropy, aquifer depth and thickness, and linear regression (R2) curves were calculated for both areas, providing insights into the aquifer conditions. The results revealed that the study areas predominantly consisted of sandy lithology as the aquifer horizon, encompassing sandstone, sandy clay, and clayey sand formations. Area 2 exhibited a higher presence of clayey horizons, and aquifers were generally deeper compared to Area 1. The aquifer thickness ranged from 10 m to 200 m, with shallow depths ranging from 10 m to 60 m and deeper aquifers exceeding 200 m. Aquifers in Area 1 were mostly semi-confined, while those in Area 2 were predominantly unconfined and susceptible to recharge and potential contamination. The northwest–southeast side of Area 1 exhibited the highest probability for ground resource estimation, while in Area 2, the northeast–southwest side displayed a dominant probability. The study identified a probable shear zone in Area 2, indicating lithological differences between the northeast and southwest sides with a reverse sequence. Based on the findings, it is recommended that the shallow aquifers in Area 1 be considered the best potential reservoir for water supply. In contrast, deeper drilling is advised in Area 2 to ensure a long-lasting, high-quality water supply. These results provide valuable information for water resource management and facilitate sustainable water supply planning and decision making in Islamabad, Pakistan.

Evaluation of sedimentary aquifer in tehsil Zehri area using VES technique, Balochistan Pakistan

A geophysical resistivity survey was conducted in Zehri tehsil in the district of Khuzdar for the metering of subsurface hydrogeological properties of aquifers. The Schlumberger electrode arrangement was employed with the vertical electrical sounding (VES) method for subsurface exploration. Two profile lines were designated for the survey. The distance between the two profile lines was about 1500 ​m and each profile contained four VES stations. The results of profile one show the aquifers were encountered in fractured limestone of the Jamburo Formation of Paleocene age at an average depth of 127 ​m, with an average resistivity of 39.7 ​Ωm, and the average aquifer thickness was 54.025 ​m. The result of profile two shows the aquifers were encountered only in VES four in the sandstone lithology of the Ziddi Formation with a resistivity of 79.9 ​Ωm, at a depth of 120 ​m with, and a thickness of 40 ​m. There was no aquifer encountered in the remaining all VES. The main lithology of these VES is thick impervious compacted limestone, shale, and clay of Jurassic age from the Ziddi Formation. The current tube wells were also rapidly depleting in the study area. The main factor behind the decline of aquifers in the study area is an uncontrolled installation of tube wells and continuous pumping of tube wells for agricultural purposes badly puts stress on aquifers and directly deteriorates the quality and quantity of groundwater.

Deployment of Geophysical Technique in Groundwater Search at Guinueaworm Endermic areas in Obubra local government area of cross river state, Nigeria

This study was conducted in the Guineaworm prone areas in Obubra Local Government Area, the study entails the deployment of vertical electrical sounding technique in the search for groundwater. In doing this, measurement was made in 14 profiles of 500m long each, using the IGIS resistivity meter model SSR-MP-ATS. Resist software was used for analysis. The Geoelectric sounding data interpretation revealed characteristic curves with two to six geoelectric layer thicknesses. The predominant curve types in the area were the KH, HKH, and HK. The electrical resistivity of the first layer ranged between 15.8to1626Ωm, which was indicative of clay, shale, or sandy silt, three to six geoelectric layers were obtained from the interpretation of the sounding data. The resistivity of the second layer ranged from 52.3 to 370.7Ωm. This was assumed to be shalestone/shale, and it was overlain by the third layer, which had resistivity values between 121 m to 1491.9Ωm, which was assumed to be sandstone (sandstone materials make good aquifers).The fourth layer, had values between 12.3Ωm. m to 1052.7Ωm, the fifth layer, had values between 11.21Ωm. to 2277.2Ωm, and the last layer, which had a value of32Ωm.The Transmissivity measurements ranged from 16 m2/day to 171 m2/day, Porosities were high with strong storactivity which show that the studied area contains thick and abundant aquiferous zone. Protective capacities (PC) values of (0.01-1.260 seimens) were obtained from the VES data. Borehole depths were recommended for each profile for borehole development. The study was identified to have confine aquifer terrain because of the confining clay layer which had a large vertical extend in the adjacent layers that enclosed the aquifer layer.

Examining tunnel erosion using vertical electrical sounding and ground magnetic geophysical techniques in Awka, Nigeria

Examining tunnel erosion using vertical electrical sounding and ground magnetic geophysical techniques in Awka, Nigeria

Lithologic characterization of Iguosa erosion site using geoelectrical techniques

Considering the devastating menace of gully erosion for which lithology is one amongst several other agents that drives soil loss and gully erosion, Vertical Electrical Sounding (VES) and Electrical Resistivity (ERT) techniques were adopted to investigate subsurface lithology in Iguosa gully erosion site. PASI 16GL model resistivity meter was used in acquiring data for VES and ERT in the area under investigation. VES data acquired were processed both qualitatively and quantitatively, and geoelectric sections were generated using AUTOCAD software by combination of two or more interpreted VES results along a profile. ERT data were processed using Res2dinv software to an inverse model resistivity section. The geoelectric image generated were interpreted to obtain lithology of the subsurface. The analysis and interpretation of the subsurface image reveals presence of topsoil, sand, dry sand, clayey sand and coarse sand. The subsurface lithology within the study location is predominantly sandy. The result obtained from the resistivity of all profiles shows that erodibility increases with depth within this study area with corresponding high resistivity values. Due to the fact that sand within the study area is loose coarse and silty, which can give rise to high resistivity and causes erosion.