IPI2WIN Software Research Articles

Aquifer delineation using Vertical Electrical Sounding (VES) and correlation of borehole logs in Opolo-Epie, Yenagoa Bayelsa State, Nigeria

This study investigates the groundwater potential in Opolo-Epie, Yenagoa, Bayelsa State, Nigeria, deploying electrical sounding (VES) surveys and borehole log data analysis. Utilizing the Schlumberger electrode configuration and Terrameter SAS 1000 instrument, coupled with the Global Positioning System (GPS), three VES profiles were conducted and processed using IPI2win software and Starter 5. Key findings from the study reveal promising subsurface features and groundwater prospects. VES 1 identified distinct zones of fine to medium sand with resistivity value of 0.62-28.7 Ωm with a depth of (17.4–47.2 m) and coarse sand with resistivity value of 359 Ωm and a depth of (47.2–56.2 m). VES 2 indicated potential aquifers in the medium sand with resistivity value of 368.4 Ωm with a depth of (5.48–11.45 m) and coarse sand with resistivity value of 1089 Ωm and a depth (11.45-23.92 m), while VES 3 delineated a shallow aquifer in the fine sand layer with a resistivity of 117.4 Ωm and depth zone of (1.92–5.19 m) and a deeper, more promising aquifer in the coarse sand zone with resistivity value of 1680 Ωm and depth of (11.13–22.66 m). Borehole logging confirmed significant sand layers (3–30 meters) with potential for water storage and flow, along with a clay layer (27.1–30 meters) acting as a confining unit for underlying groundwater. The correlation between VES and borehole data revealed consistency in identifying clay layers but discrepancies in interpreting deeper aquifer zones, underscoring VES limitations in resolving thin layers. The study underscores the importance of integrating VES surveys with borehole data for a comprehensive evaluation of groundwater resources. Notably, the borehole logging-identified coarse sand layer (33.3–42.4 meters) appears to be an attractive prospect for a productive aquifer; therefore, additional research is necessary to resolve interpretational differences and determine whether clay layers exist and how thick they are in this zone.

Determination of Clay and Sand Volume Using Vertical Electrical Sounding

This study presents the results of an electrical resistivity survey conducted in Agudama Epie, Yenagoa local government area, Bayelsa State, Nigeria. The primary objective of the survey was to estimate the volume of clay and sand within a rectangular land parcel measuring 100 m by 200m in the study area. The survey employed the Schlumberger electrode configuration and utilized nine vertical electrode sounding (VES) points.Data was collected using a Terrameter SAS 1000 and was processed using IPI2win software. The geophysical analysis revealed the presence of four distinct geoelectric layers across the study area, identified as layers 1 to 4 in the VES profiles. Layer 2, characterized by clay, exhibited an average thickness of 21.2 meters, while layer 3, consisting of sand, had an average thickness of 8.15 meters. The apparent resistivity values ranged from 8.45 to 79.43 ohm-meter to a depth of 10.14 meters for the clay layer and 8499.86 to 15013.11 ohm-meter to a depth of 33.5 meters for the sand layer. The study estimated a substantial presence of approximately 746,240 tonnes of clay and approximately 261,126 tonnes of sand in Agudama Epie. This discovery offers significant economic potential, including job creation, the establishment of small and medium-sized enterprises, and opportunities within the construction industry. The local extraction and processing of clay can drive economic growth and facilitate the production of concrete and building materials. Additionally, the availability of sand in the region can reduce transportation costs and stimulate local construction projects, thereby fostering economic activity and infrastructure development.

Groundwater Potential of the East and North Sides of Gunungmasigit Village: A Case Study

The purpose of this research is to conduct a groundwater survei by analyzing the availability of groundwater on the east and north sides of Gunungmasigit Village, Kec. cipatat, kab. west bandung (case study: PPSDM Geominerba field campus KESDM). The aim of this study was to determine the potential for groundwater in the northern area of the PPSDM Geominerba Field Campus and to find information regarding the absence of groundwater after drilling was carried out in 2019 in the area on the east side of the PPSDM Geominerba Field Campus. The research administrative area is located in Gunungmasigit Village, Kec. Cipatat, Kab. West Bandung (PPSDM Geominerba field campus KESDM). The author will focus more on the end of Cipatat-1 (north side) on the map, where it is located in the gate area of the Geominerba PPSDM Field Campus. This study uses the geoelectrical measurement method. One of the geoelectrical methods is the resistivity or resistivity method. This method studies the subsurface structure based on the different resistivity values in the rock with depth. Data analysis used IPI2WIN Software with track 1 having a length of 200 meters and track 3 having a length of 400 meters. In the results of Cipatat-1 it is suspected that there is a water-carrying layer at a depth of 11.9 – 45.9 m. Meanwhile, the results of Cipatat-3 suggest that there is a water-carrying layer at a depth of 26.3 m.

PRELIMINARY ASSESSMENT OF GROUNDWATER POTENTIAL ZONES IN AYEDE-EKITI, EKITI STATE, SOUTHWESTERN NIGERIA USING ELECTRICAL METHODS

An electrical resistivity survey was conducted at different locations within Ayede Ekiti, Ekiti State, Southwestern Nigeria. This is aimed at evaluating groundwater potential zones and aquifer properties within the study area. Data were acquired at four (4) different locations using the vertical electrical sounding method by employing the Schlumberger array configuration. This study utilizes resistivity data processed with IPI2win software to analyze the subsurface geology of a basement complex region. The result of the study showed that qualitatively, three major curve types (A, HA, and H) were observed. Varying curve types, predominantly A curves, were observed across the research area, with notable groundwater potential indicated by H and HA curve types at select points. Through curve matching techniques, three to four distinct geo-electric layers were identified, while the quantitative interpretation resulted in deducing layers with different resistivity and thickness values for each VES(s) of the study area. It was deduced that the VES 2 and 3 zones are connected to a high output of groundwater. However, VES 1 and 4 are characterized by low groundwater potential. This research contributes valuable insights for geological mapping and groundwater resource assessment in complex basement terrains of the study area.

Geoelectric Method for Groundwater Identification in Pangkalarang

Meeting the need for clean water is one of the supporting conditions for creating good public health. Clean water can be obtained from several sources, including ground water, river water, dug well water, and so on. Likewise, people in the Pangkalarang area are experiencing a clean water crisis. They have difficulty getting clean water and can only rely on dug well water which is brownish red in color, similar to tea water and has a slight metallic smell. And of course this water is not suitable for consumption and can only be used for watering plants, washing clothes and bathing. The condition of clean water may be influenced by the condition of the Pangkalarang area which has swamps and is a coastal area, so it is possible that water pollution from dug wells may occur. The Pangkalarang area has a source of clean water in the form of groundwater whose existence needs to be known to make it easier for the community to determine the position of the drilled well. Therefore, researchers consider it necessary to investigate the existence of groundwater which is a source of clean water using Geoelectric methods in the Pangkalarang area. This Geoelectric method uses a Schlumberger electrode configuration to obtain information on the position and depth of the aquifer. This electrode configuration has the advantage of good vertical resolution so that it can represent groundwater depth conditions in detail along with information on the types of silt or rock layers in or around the aquifer. The results of observations and research data processing using IPI2Win software show that there is a very Geoelectric point position that can be used as a reference for determining the drilled well point, namely at a depth of 87 m it is estimated that water can be found, but it is still very likely to be mixed with sea water. Therefore, researchers recommend that groundwater drilling be carried out to a depth of 87 - 164 meters.

Exploration of Ground Water Potential of Federal University of Technology, Owerri and Its Environs Using Resistivity Survey

The research focused on evaluating the groundwater potential in the vicinity of Federal University of Technology Owerri (FUTO) using a resistivity survey method. The investigation involved the utilization of eleven Schlumberger vertical electrical soundings (VES). The data collection was conducted using an ABEM Terrameter SAS4000 and then processed with IPI2Win Software, which relies on the conventional theory of curve matching. This process aimed to determine the depth, quality, and subsurface formations of the groundwater. The VES interpretation results revealed the presence of 3-5 geoelectric layers above the aquiferous layers. Various curve types were identified in the study area, including monotonically ascending (AA), bowed-ascending (HA), bowl-bell (HK), and ascending-bell (AK) curves. The majority of the field curves were found to be of the A-shaped type, signifying specific aquifer characteristics. The study indicated that the depth to the water table is relatively shallow in the Ihiagwa area, with an average depth of 7.26 meters. In contrast, the aquifer's depth is deeper around Avu, Nekede, and Eziobodo areas, with a mean depth of 32.33 meters. Obinze had very deep aquifers, with an average depth of 57.75 meters. Furthermore, the study established a relationship between aquifer characteristics and geoelectric parameters, allowing for the estimation of hydraulic conductivity and transmissivity values at all the sounding locations, even in areas lacking boreholes. These hydraulic characteristics showed that the aquifer had protective capacities ranging from 0.036 to 0.509 mhos, transmissivity values ranging from 11856.32 to 28661.28 m2/day, and hydraulic conductivity ranging from 13.47 to 1009.2 m/day. These values suggested that the aquifer materials are highly permeable, facilitating fluid movement within the aquifer. This research demonstrated the effectiveness of surface geophysics in estimating aquifer hydraulic characteristics, particularly in situations where pumping test data are unavailable. It also highlighted the vulnerability of the aquifer to surface contaminants. The findings are expected to be valuable for the long-term planning of groundwater exploitation projects in the study area.

Geophysical investigation of the effects of refuse dumpsites on the quality of groundwater in some major towns in Niger state, Nigeria

<p>This study was carried out to investigate the effects of refuse dumpsites on the quality of groundwater in some major towns in Niger State, Nigeria. A total of sixty (60) Vertical Electrical Soundings (VES) was conducted across fifteen (15) dumpsites within the study areas; twenty (20) VES at each of the three (3) dumpsites of Lapai, Bida and Paiko using Schlumberger configuration to investigate the possibility of contamination of groundwater in the areas. The resistivity data were collected using G41 Resistivity Meter and interpreted using IPI2Win Software. The results revealed four geo-electrical layers. The resistivity values of the Aquifer layers of Lapai dumpsites ranged from 136 Ωm to 681 Ωm, with the thickness ranging between 2.82 - 8.77 m at the depth of 4.21 – 10.90 m at Engr. A. A. Kure dumpsite. At Malle dumpsite, the thickness range was (1.10 – 4.39) m and the depth at 5.27 – 12.70 m. The resistivity values of the aquifer layers at Bida dumpsites ranged from 161.10 Ωm to 223 Ωm, with the thickness ranging between 4.86 and 11.00 m at the depths of 7.65 – 12.70 m while at Mayaki Ndajiya dumpsite, the thickness range was 4.91 – 23.46 m at the depth of 6.84 – 25.57 m. Also the resistivity values of the aquifer layers of Paiko dumpsites ranged from 20.90 Ωm to 110 Ωm with thicknesses ranging from 2.33 to 14.00 m at the depth range of between 3.85 and 15.50 m at Gidan Marafa dumpsite while the thickness range was from 3.19 – 9.04 m at the depth of 6.70 – 14.14 m at Angwan Akimi dumpsite. These values were used to compute the Dar Zarrouk parameters which indicate aquifer protectivity. The protective capacity of the over burden rock materials at Lapai dumpsites ranged from 0.010 – 0.076 Siemens, while at Bida dumpsites it ranged 0.009 – 0.152 Siemens and at Paiko dumpsites it ranged between 0.025 – 0.046 Siemens. The low protective features observed in the Aquifer zones of Lapai, Bida and Paiko dumpsites indicated the possibility of leachate migration from the waste dumpsites infiltrating into the aquifers and polluting the groundwater. It is evident, from the results of this geophysical survey that the water in the study areas of Lapai, Bida and Paiko could be polluted leading to water related diseases.</p>

Estimasi Kedalaman Batuan Dasar di Kampung Yabaso Kabupaten Jayapura Menggunakan Metode Vertical Electrical Sounding Konfigurasi Schlumberger dan Metode HVSR

Research on the estimation of bedrock depth in Yabaso village, Jayapura district using the Schlumberger configuration Vertical Electrical Sounding (VES) method and the HVSR method has been carried out. The total observation points are three points where VES is one point and VHSR are two observation points. VES measurements used a set of resistivity meter model AK HV 500 with a maximum spread length of the current electrode is 100 m. HVSR measurements use a portable seismograph set and the measurement time for ambient seismic waves is 60 minutes. VES and HVSR data processing respectively using IPI2Win and Geopsy software. The model parameters resulting from the inversion of the VES data show that there are nine layers with a resistivity range between 18 – 25,260 Ωm. Layer 1 is a heap of sandy gravel with a resistivity value of 92 Ωm. Layers 2 to 7 are part of alluvium formations and coastal deposits (Qa) with resistivity values of 18 – 264 Ωm. While layers 8 and 9 are fragments of weathered ultramafic rock (um) and compact and dry ultramafic rock respectively. The source rock (bedrock) is layer 9 which is at a depth of 42 m. The results of HVSR data processing show that the natural frequencies at the two observation points are very small (<2.5 Hz), namely 0.85 Hz and 0.83 Hz. According to Kanai's classification, this frequency value is type I, class IV, namely alluvial rock. The depths of source rock based on the HVSR method at measurement points 1 and 2 are 43 m and 44 m, respectively. There is agreement in the estimation of the depth of the source rock obtained from the VES and HVSR methods even though the two methods utilize two different physical parameters.
 Keywords: HVSR; VES configuration Schlumberger; Resistivity; Jayapura

Investigation of subsurface contaminants leachate within Ansaru-Islam Secondary School, Ilorin, Nigeria

This study adopts the use of Vertical Electrical Sounding (VES) and 2-D resistivity imaging (employing Schlumberger and Wenner array configurations) to investigate and map the extent of leachate’s migration and its possible impacts on groundwater within Abata Asunkere dumpsite, Ilorin, Kwara State. This study was inspired by the unrestrained manner of garbage dumping in the area over time, which poses great threat to the availability of clean water for the increasing populace. To delineate the subsurface, 2-D resistivity imaging data were acquired along two traverses, while the VES data were randomly acquired along the established traverses. The 2-D resistivity imaging and VES data were processed using Res2D and IPI2Win software respectively. The results of the 2-D and VES revealed five (5) geoelectric sections, which correspond to the topsoil, clayey sand, weathered basement, fractured basement and fresh basement rocks with H, QH and KH sounding signature curve types. The topsoil has layer thickness of 0.5 - 1.7 m and resistivity values ranging from 11.9 - 165 Ωm. The clayey sand has layer thicknesses between 0.7 - 2.8 m and resistivity values ranging from 20.1 - 56 Ωm. The weathered basement has thickness of 0.9 - 16.3 m and resistivity values ranging from 2.09 - 5.25 Ωm. The fractured to fresh basement has resistivity values ranging from 26.8 - 3000 Ωm with thickness ranging from 5.3 m to infinity. The third layer with low resistivity values of 2.09 - 3.52 Ωm at depth range 0.9 - 10 m is suggestive of leachate contamination. The outcome of this study indicates that some regions around the dumpsite are susceptible to leachate’s contamination, which has tendencies to permeate the unconfined aquifers in the study area if not properly monitored and controlled.

Exploring the Geological Formation and Sub-Surface Lithology Modelling of Hadejia, Jigawa State Nigeria

This research aims to explore the geological formation and sub-surface lithology modelling of Hadejia, Jigawa State using the VES (vertical electrical sounding) method. The VES method is a geophysical technique that measures the electrical resistivity of the subsurface, which is related to the lithology of the rock units. The study area is located in the north-western part of Nigeria, on latitudes 12025’23.73‘‘N and longitudes 10°04’06.74‘‘E, and is characterized by a chad formation geological setting with a variety of rock units, including sandstones, shales, and limestone. The research was conducted using a total of 50 VES stations, which were distributed over the study area in a grid pattern. The data collected from the VES stations were analyzed using the IPI2WIN software. The results were used to create a subsurface electrical resistivity model, which was then used to infer the lithology units present in the subsurface. The results showed that the study area is characterized by a complex subsurface structure, with several rock units present, including sandstones, silt, and clay. The subsurface electrical resistivity model revealed that the sandstone units are located at shallow depths, while the silt units are found at deeper depths. The clay is present at intermediate depths and is interbedded with sandstones and clay. The results provide valuable information for hydro-geological and mineral exploration in the area.

Sedimentary characteristics and geophysical architecture of the Cretaceous Bambalo claystone formation (Mayo Oulo-Lere Basin, North Cameroon)

• Depth and spatial development of Bambalo sedimentary sequences during the Cretaceous. • The Bambalo Formation described in terms of lithostratigraphy, VES and ERT. • Fluvio-lacustrine deposits including claystone, siltstone and limestone. • Sequences dominated by retrogradational sequences in a lacustrine environment. The Mayo-Oulo-Lere Basin, with an overall surface area of 122 km 2 is located in northern Cameroon between the western extension of the Doba Basin and the eastern edge of the Benue Trough. This study maps the depth and spatial development of Bambalo sedimentary sequences in the Mayo Oulo-Lere Basin that were deposited during the Cretaceous. The depositional sequences present an exposure of crocodile fossils and plants evidenced by superficial alteration. The Bambalo Formation is described in terms of lithostratigraphy, vertical electrical sounding (VES) and electrical resistivity tomography (ERT) to provide a better understanding of stratigraphic evolution and setting conditions during sedimentation. Sedimentary deposits in the Mayo Oulo-Lere Basin are mainly fluvio-lacustrine deposits consisting of alternating claystone, siltstone and limestone. The lithostratigraphic log of Bambalo for the subsurface geology up to 25 m presents three main depositional sequences named S1, S2 and S3. S1 presents ripples marks and desiccation cracks that are directly observed on the surface outcrop. The separation between S1-S2 and S2-S3 is marked by unconformity surfaces. The sedimentary sequences are dominated by retrogradational depositional trends that describe short sequences of fining-upwards successions. The ERT image results obtained from geophysical analysis using Res2Dinv display local features associated with folding in the aforementioned sedimentary thickness of approximately 30 m. Additionally, the VES analyses using ipi2win software show that the upper 78 m part of the Bambalo formations is composed of four layers (L1, L2, L3 and L4) distinct by resistivity. L4 Layer correlated with the top of lithostratigraphic log S3, while L3 is a semiresistive set of 78 Ω·m layering S1 and S2 lithostratigraphy sequences. Layer L2 corresponds to a conductive set with resistivity of approximately 27 Ω·m above the lower layer L1, a resistive sequence with resistivity greater than 1000 Ω·m. The combination between the major rifting faults (N70°, N110° and N130°E), syntectonic sedimentation and Barremian-Aptian age attributed to sediments of Bambalo demonstrate clearly that the sediments were deposited during or few time after the rifting phases. The sediments are resulting from a rapid filling of the basin characterised with retrogradational sequences that are controlled by the evolution between accommodation space created after each tectonic phase and the base water level rise within the basin. The rapid elevation of water and sedimentation might be one of the reasons of the massive death of crocodilians. The results of this study demonstrate that the combination of ERT and lithostratigraphic analysis is a powerful tool for a better understanding of the Bambalo sedimentary process and basin evolution. The lateral and vertical evolution of the layers being proven, a future deep excavation will certainly make it possible to bring to light new types of fossils from these deposits and in the neighbouring basins.

The Application of Vertical Electrical Sounding for the Geophysical and Hydrogeological Investigation in University of Benin Area, Nigeria

The occurrence and distribution of groundwater in a sedimentary basin are localized and confined to the weathered sandy layer/zone. The study was carried out with the aim of demonstrating the vertical electrical sounding method of investigation in the exploration of groundwater at the University of Benin, around VC’s lodge. A total of six VES points were probed using the ABEM SAS 300C terrameter which was used to generate field data applying the Schlumberger Array with AB/2 of 1.5 m, 215 m. The results were simulated using IPI2WIN software. The results show an average of four geo-electric layers per VES point; superficial layer, duricrust, clay layer, alluvium, sand layer and the weathered sandy layer. For VES 1-6, the thicknesses of the water table are 11.6 m. 16.6 m, 22.5m, 30.5 m 51.4 m and 27.8 m respectively and the depth to the water table is 124.4 m, 124.6 m, 78.4m, 55.2 m, 38.5 m, and 29.4 m accordingly. Going by the results, VES 1 & 5 ranked the highest water prospect due to the thickness of the water table layer, the depth to the water table and most importantly the weathered/fractured layers with resistivity as high as 15,188 Ω and 76,432 Ω for VES 1 & 5 respectively, which also increases the permeability and storage of the groundwater. VES 2, 3, 4, and 6 are also wet reservoirs but for their shallow thicknesses and depth to the water table which will influence the purity of the water. However, further investigation is needed to ascertain the suitability of the water as portable drinking water by examining the physicochemical and hydrogeological characteristics of the existing Boreholes drilled in the vicinity of the study area. The findings of this study are a reminder of the essence of a geophysical survey prior to drilling exercises and the suitability of electrical resistivity as a tool for aquifer delineation.

Application of Vertical Electrical Sounding for the Investigation of Groundwater potentials at Umaru Musa Yar'adua University, Katsina

The population of Umaru Musa Yar’adua University, Katsina (the study area) is increasing every session and therefore, sources of safe water in the area is need to be improved; more importantly groundwater. Recently, water supply from Zobe Dam is connected to the study area but still it does not solve the water supply problem; hence other alternative is needed in order to supplement for existing. Various groundwater exploration programs that have been carried out in the study area have not yielded the required results. However, there was no academic research on groundwater in the study area. VES has been carried out in order to investigate groundwater potential, to determine the lithology, the resistivity value associated with the groundwater and prospect locations for groundwater exploration. The ABEM Terrameter SAS 4000 was used and a Schlumberger array was employed to accomplish this task by obtaining resistance of 7 VES points in the study area with a maximum current electrode spacing (AB) of 240 m. The VES data obtained were processed using IPI2Win software. The VES results in correlation with the and borehole log data have revealed that the near-surface materials with resistivity value between about 1 Ωm to 7,985 Ωm is representing 4 to 5 layers consisting of first layer mostly top soil and laterite, having resistivity values between 403 Ωm to 7,985 Ωm with thickness from 0.498 m to 1.21 m; second layer with resistivity values from 43.6 Ωm to 114.4 Ωm having thickness from 1.34 m to 4.71 m interpreted commonly as sandy clay and sandy soil; third layer showing resistivity values between about 1 Ωm to 38.4 Ωm is found to be a saturated layer with water; fourth layer generally indicating weathered basement with resistivity values from about 1 Ωm to 7.57 Ωm having thickness of 36.1 m and or infinite thickness, and fifth layer showing vary low resistivity value with infinite thickness. The result shows that the groundwater exploration should be conducted at VES 1, 2, 3, 4, and 5 at a depth from about 30 m to 50 m revealing low resistivity values ranging from 2 Ωm to 391 Ωm however, VES 6 and 7 indicates high resistivity value and therefore poor groundwater potentials.

Spatial and temporal variation of aquifer vulnerability in Miri coastal region of NW Borneo using resistivity survey and GIS

In this research, Vertical Electrical Soundings (VES) were conducted along the coastal region of Miri City, East Malaysia for two different seasons to determine the spatial and temporal variation of aquifer vulnerability through Geographic Information System (GIS). VES data was processed in IPI2Win software and curve matching method was adopted to determine the predominance curve types in the study area. The corrected data were used to create spatial maps for resistivity and thickness for each layer through ArcGIS software. Pseudo cross-sections were produced to identity the lithological variance and the movement of saline groundwater plumes. Dar Zarrouk parameters such as longitudinal conductance (S) and transverse resistance (T) were also calculated and spatial maps were prepared to differentiate freshwater and saline water aquifers in the study area. From the results, it was found that the dominant curve types identified in the study area are Q type (24%) and QH type (28%) during the Northeast monsoon (NEM); whereas QH type (19%) and QHKH type (18%) are identified during the Southwest monsoon (SWM). The significant resistivity values that indicate the saline water intrusion (SWI) are 0.49–47.6 ohm.m and 4.34–40.2 ohm.m, which was identified from the northern and southern parallel pseudo cross-sections. Overall, the study reveals that the intensive SWI occurred during SWM, compared to NEM. SWI was observed with low resistivity at a deeper depth of 20 m on the northern side of the study area. The southern urban area of Miri City is continuously prone to infiltration of brackish water at shallow depth caused by anthropogenic activities.

Characterization of Crystalline Aquifers in Ouaddaï Division (East of Chad) Using Electrical Resistivity Method: A Case Study of Waguiré and Anourchi

This study aimed to locate suitable aquifers that can be exploited with their structural and hydraulic characteristics. So for this aim, combination of geoelectrical and drilling techniques was used. Eight electrical trailing and Vertical Electrical Soundings (VES) were carried out with Syscal R1 - Plus resistivimeter, using Schlumberger array. VES data were interpreted using the Ipi2win software, and geohydraulic parameters (conductivity, transmissivity, and porosity) were estimated based on geoelectric parameters computed. Results show four favorable shapes of electrical trailing (W, U, V, and H -shapes) and four types of VES curves (H, HA, QH and HKH). Three to five geoelectric layers were delineated from analysis of VES curves with aquifer resistivity influenced by clay content, varying from 6.09 to 33.84 Ω.m and thickness from 5.54 to 17.35 m. Computed hydraulic conductivity, transmissivity, and porosity vary from 14.19 to 70.93 m/day, 92.36 to 429.13 m²/day, and 37.44 to 44.68% respectively. The groundwater potential of the area ranges from moderate to high potential. Based on these geohydraulic parameters, two points (VES4 and VES7) were chosen to drill a hole. Drillings were a success and yield ranging from 2.72 m3/h to 3.12 m3/h. This study reveals that geohydraulic parameters could be an alternative to choose where to drill a positive borehole in the area with a similar geological context.

Composite Geoelectrical Investigation to Delineate Groundwater Feasibility in Hard Rock Area of Raipur, Chhattisgarh, India

In hard rock terrains, groundwater movement, migration, and storage occur through subsurface fractures. To assess the fractures and associated water, the authors carried integrated geophysical investigation with Wenner, GRP, Schlumberger, and Pole-Dipole array in the Indian state. The resistivity survey was carried out using a CRM-500 resistivity meter. The analyzed results are also re-verified with the help of IPI2WIN software. Initially, lateral and surface variations of resistivity were plotted by using Wenner and gradient resistivity profiling array. Then the low resistivity points were investigated with Schlumberger and Pole-Dipole array. In interpretation, low resistive zones identified correspond to the possible fractured zones. The results allowed mapping of the weathering zone at depth 12 to 15 m, and deep fracture lies below depth 55.0 m depth. The present study validates that the integrated geophysical survey is a powerful exploration technique to scrutinize and identify water-bearing fractures in the hard rock area.

Investigation of groundwater resources using electrical resistivity sounding and Dar Zarrouk parameters for Uthal Balochistan, Pakistan

Uthal is a small town in the Balochistan province of Pakistan. It has an arid to semi-arid climate and groundwater is the primary source of freshwater for domestic and agricultural uses. To evaluate groundwater's nature, an electrical resistivity survey (ERS) was conducted in Uthal. Groundwater investigation for 25-point data was carried out with the PASI Electrical Resistivity Imaging System, using the Schlumberger array. The data was acquired with a maximum current electrode spacing of 300 m. The geoelectrical parameters measured were analyzed by IPI2win software by curve matching, and five geoelectrical layers were identified, and the Dar Zarrouk parameters were calculated. The top thinnest layer of unconsolidated material had a resistivity between 600 and 2600 Ωm. The second layer was of unconsolidated sand and gravel with a resistivity of 50–11,500 Ωm; the third with dry sand and clay had a resistivity of up to 200 Ωm; the fourth showed a thick freshwater zone with a resistivity between 75 and 100 Ωm followed by a thick layer of sand and clay with fresh water had resistivity between 48 Ωm and 90 Ωm. The Dar Zarrouk parameters, longitudinal unit conductance S is from 0.1 to 1.65 mho; transverse unit resistance T greater than 25,000 Ωm2; longitudinal resistance RS is from 50 to 1350 Ωm and transverse resistivity RT from 22 to 1150 Ωm. ERS data and Dar Zarrouk parameters showed that the study area has freshwater resources in the subsurface. Saline water is present in isolated locations in small pockets, resulting from dry surface conditions. The results of ERS data and Dar Zarrouk parameters show no occurrence of seawater intrusion.

GROUNDWATER POTENTIAL INVESTIGATION USING 1-D ELECTRICAL RESISTIVITY TECHNIQUE AT NIGER STATE POLYTECHNIC ZUNGERU, ZUNGERU MAIN CAMPUS, NIGER STATE, NIGERIA

Electrical resistivity method employing vertical electrical sounding was carried out with aim to investigate groundwater potential at Niger State Polytechnic, Zungeru, Niger State. Ten points were selected at different locations within the campus for vertical electrical sounding (VES), using Schlumberger protocol. Maximum current electrodes separation (AB) of 120m was used. The investigation was carried out using Terrameter PE 02 SAS 300 system. The survey was able to investigate groundwater potential of the area. The IPI2win software was used for data analysis. The geologic section derived from geoelectric parameters revealed three subsurface layers. The first layer is interpreted as topsoil, the second layer is inferred to be weathered rock, while the third layer probably could be fresh basement rock. The thickness of the superficial cover is averagely 2.49m, and the depth to the basement is between 5.2m to 22.9m, the aquifer thickness ranges between 1.67 to 21.1m. The laterite in the second layer shown in some locations is of great importance as it reduces surface run off and aids infiltration into the underlying aquifer. The thickness of the aquifer component in the north-southern half of the study area is large enough to harbour substantial quantity of water. Areas around ZUN 01 and ZUN 05 could be potential areas for groundwater exploration. In this research, the depth to bedrock and aquifer thickness were determined, lithological formations within the overburden were delineated and approximate depths

Assessment of effects of a Cemetery leachate on Groundwater Quality using an Integrated Approach

The dependency of residents in the vicinity of cemeteries on groundwater from hand-dug wells as an alternative source of water supply for their domestic use without cognisance of the quality of such water has been a concern. So, this research assesses the effects of a cemetery on groundwater quality using an integrated approach in Edunabon, South-western Nigeria. Thirty groundwater samples from available hand-dug wells were collected and analysed for various physicochemical parameters. GIS cloud data collection server and Mobile Data Collector (MDC) were used to obtain these hand-dug wells' locations and spatial distributions. The determination in variation in physicochemical concentration parameters was obtained using the curve fitting technique of ARCVIEW GIS software and digital map. Physicochemical results were used to calculate Water Quality Index (WQI) of each sample. Two Schlumberger Vertical Electrical Soundings (VES) of 130.0m long were conducted at 10.0m intervals to the wall and the next VES, on each side of the cemetery. Current spacing (AB/2) and apparent resistivity (ρa) data were plotted on a double logarithm paper, curved matched and iterated using IPI2Win software for qualitative and quantitative interpretation. WQI results ranged from (107.37–173.64), (76.60–93.37), (54.94–71.53), (31.29–48.01), and (10.84–25.31) for fourteen, seven, three, four and two hand-dug wells respectively, an indication that the water from these wells was unfit for drinking, very poor, poor, good, and excellent respectively. VES results revealed that first, second and third layers were mainly clayey topsoil (46.7–96.8Ωm), lateritic soil (169.0–551.3Ωm), and weathered layer (3.21–27.4Ωm), which favourably enhances the migration of leachate from the cemetery to the surrounding soils and groundwater. The lowest resistivity values recorded in the second and third layers indicated leachate presence at these hand-dug wells. The integration of GIS and electrical resistivity methods would be useful tools to assess groundwater quality around cemeteries. Keywords: Groundwater quality, Mobile Data Collection, unfit for drinking, Vertical Electrical Sounding, Water Quality index

Groundwater Potential Assessment Using Vertical Electrical Sounding and Magnetic Methods: A Case of Adilo Catchment, South Nations, Nationalities and Peoples Regional Government, Ethiopia

Vertical electrical sounding and magnetic methods were carried out to assess groundwater potential in Adilo catchment, Kembata Tembaro Zone, South Nations, Nationalities and Peoples Regional Government, Main Ethiopian Rift. The data were acquired from eight VES points using Schlumberger electrode arrays with maximum half current electrode spacing ( AB / 2 = 500 ) and 253 magnetic data points were analyzed. The qualitative analysis of VES data was accomplished by using curves, apparent resistivity, and pseudodepths, and the quantitative interpretations of the VES data were constructed by the VES data using IPI-Res3, IPI2Win, and surfer software and constructing geoelectric section along with profiles and lithological information from the borehole and Geosoft interpretation was used for magnetic data. The VES results of the data revealed five geoelectric layers which differ in degree of fracturing, weathering, and formation. The upward continued magnetic field map anomaly to 560 m illustrated northwestern to the southwest; areas have a low magnetic anomaly. Examining the potential aquifer of profile one’s geoelectric section, the horizons of layer four were better potential aquifers as the highly fractured and weathered ignimbrite zone of layer five of VES13 was 219 m deeper than the depths of the other VES points, and along with profile two geoelectric sections, the horizon of layer four VES23 layer five has the lowest resistivity with large thickness at a depth of 253 m. Thus, the low resistivity and the large thickness of these formations are an indication of the high yield of groundwater potential in the study area.