Wenner-Schlumberger Configuration Research Articles

Identification of Seawater Intrusion in Groundwater using The Wenner-Schlumberger Configuration (2D) Geoelectric Resistivity Method on Balu Island, Santiri Village, Tiworo Utara Sub-District, West Muna Regency

This research aims to identify sea water intrusion in groundwater using the Wenner-Schlumberger configuration (2D) resistivity geolectric method on Balu Island, Santiri village, Tiworo Utara sub-District, West Muna Regency. This research uses primary data which is resistivty measurement data measured in the field aimed at identifying groundwater aquifers. The interpretation data is then reconstructed into 2D cross-sectional profile using Res2Dinv software. The results obtained in the research area show that sea water intrusion has occurred in groundwater at an average surface depth of up to 39.6 meters with low resistivity values ​​between 0.06 – 807 Ohm-meters

2D and 3D Modelling Electrical Resistivity Tomography (ERT) of Landslide Sliding and Weak Bedding Plane Along Mountain Road North Bengkulu-Lebong, Indonesia

The North Bengkulu-Lebong Mountain Road is prone to landslide disasters due to its geological susceptibility to land movement. This study aims to measure and assess the sliding plane on the mountain road, particularly in the layer with a soft rock structure, such as clay rock. The study utilizes 2D and 3D Electrical Resistivity Tomography (ERT) methods with the Wenner-Schlumberger configuration to measure the resistivity of the rock layers.The research includes one 2D measurement point and one 3D ERT measurement point, estimating actual resistivity values in each rock layer. Our results identify triggering and controlling factors for landslide disasters in the research area. The geological conditions consist of layers of clay (200-500 Ωm), wet clay (500-900 Ωm), dry clay (1000-3000 Ωm), weathering clay (500-1000 Ωm), aquifer (10-65 Ωm), perched aquifer (100-200 Ωm), weathering igneous rock (>10000 Ωm), and massive intrusive rock (>20000 Ωm). These geological conditions significantly influence the strength of landslide materials, with the sliding of the soft rock layer causing landslides and resulting in a large volume of landslide material. Other contributing factors to landslides in this location include slope, topography, and hydrology, with extreme slopes ranging from 33° to 55°, making it a very steep area with high potential for landslides.

Studi Keandalan Geolistrik Dalam Identifikasi Kebocoran Embung: Studi Kasus Embung Wolo, Sulawesi Tenggara

Small dams are vital for supporting water resource conservation. The reservoir stores water from several water sources, especially in the rainy season, so that it remains available in the dry season. Some reservoir infrastructures were built using earthen fill materials located around it. This condition is very vulnerable to disasters, ranging from seepage to collapse. It is important to evaluate the safety of all potential dangers to minimize the risk of disasters. One method that can be used is the geoelectric method, which allows us to analyze the resistivity properties of the soil, but the reliability of this method needs to be further evaluated. This research aims to determine the reliability of geoelectric in identifying potential leaks in reservoirs. Geoelectric measurements were carried out at Wolo Small Dam using the Wenner-Schlumberger configuration with 32 electrodes at 2.5 m. Data collection was carried out at the top of the small dam so that it could provide the condition of the soil layer of the embankment material in the longitudinal direction. Validate the measurement using the results of previous research. The results of the analysis show that there are differences in lithology in the body of the reservoir, which indicates differences in the quality of work during construction. The interface between these two surfaces can lead to leaks. Apart from that, the analysis results also show the potential for piping in the reservoir. The location of the potential piping area is not far from the results obtained in previous research at the same location. This shows that geoelectric is quite capable of being a tool that can be used to identify leaks in reservoirs or other water structures. Of course, the combination of geoelectric and other soil testing will provide better results in anticipating disasters caused by small dam leaks

Electrical Resistivity Tomography (ERT) for investigating subsurface structures in the karst area of the Ek Leuntie Cave, Aceh Province

Ek Leuntie Cave, in the southern city of Banda Aceh, Aceh Province, is recognized as an educational media based on geopark sites because it holds a 7400-year paleotsunami track record. As a karst area, Ek Leuntie Cave is vulnerable to the impact of geological disasters such as earthquakes, sinkholes and subsidence. As an effort to reduce the negative impact of geological disasters, geophysical studies have been applied in the Ek Leuntie Cave Karst area. The study aims to identify the subsurface geological structure of the Karst area. The identification was carried out using the Electrical Resistivity Tomography (ERT) method of Wenner-Schlumberger configuration applied to two measurement trajectories that have South-North and West-East directions in front of the Ek Leuntie Cave door. ERT data acquisition results were then modeled in inversion using Res2Dinv software to produce a 2D model of the subsurface geological structure of the Ek Leuntie Cave karst area based on variations in rock resistivity values. Interpretation of subsurface geological structure modeling is validated with shallow drilling data (Hand Auger). The inversion modeling results show that the rock resistivity value in the Ek Leuntie Cave area reaches a depth of 30 m which has a resistivity value of 0 - 1000 Ωm. The results of the interpretation of resistivity values and validation of drill data show that the Ek Leuntie Cave area is covered by a layer of sand with fine to coarse texture and the layer below is a layer of limestone at a depth of ± 0.4 meters with a resistivity value of 50 - 250 Ωm. Limestone generally shows porosity with the possibility of caves or pores in the rock formation at Ek Leuntie Cave, making it vulnerable to damage from earthquakes, landslides, and subsidence. The results of the study are expected to provide updated information in efforts to develop the Ek Leuntie Cave geopark area.

Landslide Potential Zone Identification Using Electrical Resistivity Tomography Modeling

The Pidada area, Panjang sub-district, Bandar Lampung City, is located on the physiography of Bukit Barisan and is also influenced by the movement of the Sumatran fault and the Lampung-Panjang fault, so the morphological condition is hilly with steep slopes which cause natural disasters such as landslides. In this study, the knowledge of subsurface rock lithology and slip-slide-prone zones was carried out using the Wenner-Schlumberger geoelectric method. Based on the Wenner-Schlumberger configuration, the top layer consists of weathered rock associated with clay tuff and sandy tuff with a resistivity of 7.2 ?m - 135 ?m. Coarse-grained tuff and fine-grained tuff with resistivity values ??of 135 ?m - 437 ?m, and the third layer combines breccia and igneous rock from the Tarahan Formation with resistivity values ??of more than 437 ?m. The clay sand layer acts as a slip plane. The type of landslide developed in the research area is a crawling soil landslide.

Identifikasi Sebaran Dan Volume Pasir Besi Menggunakan Metode Geolistrik Konfigurasi Wenner-Schulumberger Dan Analisis Kandungan Fe Didalamnya Menggunakan X-Ray Fluorescence Di Desa Paca Bagian Selatan

This research uses the Naniura NRD300 HF tool to apply the Wenner-Schlumberger configuration geoelectric method which aims to determine the direction of distribution of iron sand, the volume of iron sand, and the Fe2O3 concentration of iron sand in the southern Paca beach area. The collected measurement results are then processed by RES2DINV software into a 2 Dimensional (2D) cross section which shows the distribution value of the subsurface layer as shown by a color image. After being saved in (.xyz) format, the RES2DINV software results are processed in RockWork software to create a pseudo-3D cross section. The RES2DINV software results show a resistivity value between 0,0761 – 3,59 Ωm which is identified as iron sand with a volume of 13,304 m3 at a depth of 2,50 – 9 meters from the surface of the datum point, while on track 2, the resistivity value ranges between 0,414 – 3,13 Ωm, and at a depth of 2,50 – 7 meters from the surface of the datum point with a volume reaching 12,883 m3 based on the results of the RockWork software. The distribution of iron sand deposits in the study area is from south to north. The method used to determine the composition of minerals present in a sample is called X-ray fluorescence (XRF). The results of the analysis of the Fe2O3 content in the first pass were 36,704% and in pass 2 it was 35,500%.

Seismic Vulnerability Evaluation in Western Bandar Lampung's Quarter Formation using the ERT Technique

Western Bandar Lampung is rapidly evolving into a sought-after residential locale and a scenic mountainous tourist spot. Notably, this region sits atop multiple fault structures, signaling potential seismic threats. This study aims to gauge the susceptibility of superficial layers by analyzing the resistivity properties of the underlying rock. Using the ERT geoelectric method across three lines, following the Wenner-Schlumberger configuration, a length of 140 m was mapped with electrodes spaced at intervals of 5 m. The subsurface materials in the examined area displayed a resistivity range between 4 and 1050 Ohm m, characterized by a blend of weathered constituents and igneous lenses. The dominant presence of extensively weathered material, especially given its thickness, highlights possible seismic dangers, including amplification, liquefaction, and potential landslides. To mitigate the repercussions of seismic hazards stemming from these fault lines, there is an imperative need for stringent adherence to construction guidelines tailored for seismically active regions.Top of Form

Remedial Measures to Protect Transmission Tower from Excessive Soil Movement : A Case Study

The research background focused on investigating deformation in the T.73 Nonohonis-Kefamenanu transmission tower structure that was suspected to be caused by soil movement due to the tower’s location on a sloped area. To analyze this, various tests were conducted to examine the soil properties and slope stability considered the impact of intense rainfall. The Cone Penetration Test (CPT) results revealed hard soil at depths of 6.8 meters (S1), 8.4 meters (S2), and 7.4 meters (S3), falling within the Silty Sand to Sandy Silt - Sand zone, with qc > 200 kg/cm2. Boring & N-SPT tests indicated hard soil with N-SPT values > 50 at depths of 18 meters (BH-1) and 8 meters (BH-2). The geoelectrical survey using the Wenner-Schlumberger configuration found a groundwater layer at 3-5 meters and suggested the presence of a slip plane. Janbu’s method was used to analyze slope stability, taking into account the complex profiles, layers, and soil characteristics. Modeling results showed minimum safety factors after rainfall (SF 1 = 1.827) and after 30 days (SF 3 = 3.302) following the installation of a 15-meter bored pile foundation with a 50-ton load at the chimney.

Engineering Geology and Slope Stability Analysis in Kendari-Andoolo Road Section, Wolasi District, South Konawe Regency, Southeast Sulawesi

This research presents the engineering geological features of the Kendari-Andoolo road section, Wolasi Sub-district, South Konawe Regency, Southeast Sulawesi, a vulnerable area for landslides. The slope factor of safety (FoS) was also determined using the limit equilibrium method on a single and overall slope. Hand auger drilling and Wenner-Schlumberger configuration geoelectric surveys were conducted to estimate the slope failure plane. The study area is composed of phyllite, mudstone, and sandstone. Discontinuities at the face of the slope are N45ºE and N105ºE shear fractures, N280ºE foliation, and N310ºE fault brecciation. The overburden is low plasticity organic silt (OL) with a density range of 16.92 kN/m3-18.01kN/m3 and a plasticity index of 8.64-10.57 (medium). The FoS values of the slopes assumed rotational and nonrotational slip failures. On a single slope assuming rotational failures, the FoS value was lower than the nonrotational plane but still above the threshold value. The critical FoS is on the rotational sliding plane on the overall slope model. The slope's landslide failure plane is the clay's boundary layers and weathered phyllite.

Integration of Electrical Resistivity Tomography (ERT) and Induced Polarization (IP) methods to observe seawater intrusion in Sungai Nipah Village, Mempawah Regency

Sungai Nipah Village is one of the coastal areas of Mempawah Regency, where most people utilize dug wells to meet their clean water needs. The problem faced by the community is that the clean water from the drilled well still has a brackish to salty taste. This study aims to observe seawater intrusion that is estimated to cause the problem based on the distribution of resistivity and chargeability values in the subsurface. The methods used are electrical resistivity tomography (ERT) and induced polarization (IP). The field measurements used a Wenner-Schlumberger configuration with three lines that have a length of 200 m each. The resulting research showed that the study area in Sungai Nipah village is prone to seawater intrusion. The seawater intruding the shallow unconfined aquifer is indicated by resistivity and chargeability values of less than 1 Ωm and 5 ms – 25 ms, respectively. The aquifer layer is composed of sand and clay at a depth of about 13 to 17 m. The seawater intrusion extended from the southern part of the study area to the north and covered about half of the study area.

Identification of Iron Ore Deposit in Sub-Surface using Resistivity and Induced Polarization Methods at Sarakaman, Sebuku Island, South Kalimantan

Iron is the second most abundant metal on earth. Sebuku Island is one of the areas in Indonesia that has potential for laterite iron ore. This study aims to detect the presence of mineralized zones and estimate the volume of iron ore. Therefore, geophysical research was carried out using the resistivity method and the Induced Polarization methods with the Wenner-Schlumberger configuration. The research was carried out in 4 paths along 475 m with a space between the electrodes of 5 meters. Based on modeling, 20 iron ore deposits were found in the study area on all trajectories characterized by high chargeability values ranging from 251,55 – 810,55 ms which correlated with low resistivity values of 4,02 – 124,41 m. Then it was found that the direction of the distribution of iron ore deposits in the study area was north-south and there was no continuous zone of iron ore deposits due to the long distance of the path. The volume of iron ore deposits in the study area in an area of ±39 hectares is estimated to be around 1.807.614 m3 with total reserves of iron ore deposits of 7.230.456 tons.

Identification of Rock Resistivity and Slip Surface in the Ambon Volcanic Rock in the Kayu Putih Area of Ambon City

Research on rock resistivity and slip surface in the Ambon Volcanic Rock formation has been carried out through geoelectric mapping with the Wenner-Schlumberger configuration in the Kayu Putih area, Ambon City as one of the areas prone to landslides. Measurement of rock resistivity by Mapping was carried out on two tracks each 120 m long and 70 m long intersecting each other. The results showed that the resistivity values ​​of the rocks ranged from 185 Ωm to 4,128 Ωm consisting of Top Soil, Unsaturated Landfill, and Loose Sand as the cover layer followed by Dry Sandy Soil and Gravel, and Breccia Dacite and Tuff at the bottom layer. Breccia Dacite rocks with a resistivity of greater than 2,000 Ωm are found at a depth of 11 – 13 m below the soil surface functioning as slip surface for the sand layer above them. The movement of the soil mass over the slip surface causes cracks in the surface of the road and houses.

Integrated Geophysical and Geotechnical Approaches for Evaluating Dam Seepage in Lesser Himalayan Region of Pakistan

Dam leakage is a major problem in earth-filled reservoir dams. The present research is aimed at detecting the seepage zones in an earth-filled reservoir dam in the vicinity of Sarobi village, North Waziristan, Pakistan. The objective was achieved by integrating geological, geotechnical, and geophysical datasets. Geological survey was carried out in the area to identify the surface exposures. Geotechnical data involved was used to estimation of permeability and Lugeon values to identify network of joints/fractures whereas electrical resistivity tomography (ERT) technique (utilizing Wenner-Schlumberger configuration) was applied for the identification of the leakage zones. Geological data revealed highly deformed alluvium towards the right abutment underlain by compressed shale and highly fractured limestone beds. Geotechnical data indicated high permeability, Lugeon values, and concentration of sand and gravel towards the right abutment whereas low permeability, Lugeon values, and higher concentration of silt and clay were observed towards the left abutment. ERT data identified a conductive zone embedded between impermeable lithologies having resistivity between 10 and 60 Ω·m. This conductive zone was observed in parallel profiles acquired in upstream, dam crest, and downstream parts of the dam. The integration of all the datasets revealed a network of joints that are interconnected and provide a path for water at the upstream side to pass through right abutment of dam and leak towards the downstream.

Application of Resistivity Geoelectric to Determine the Seawater Intrusion Zone in the Sungai Kakap District

The application of the resistivity geoelectric method has been carried out in a study to determine the seawater intrusion zone in Sungai Kakap District, Kuburaya Regency using the Wenner-Schlumberger configuration. This research used Automatic Resistivity System Multielectrode (ARES). The research was carried out by arranging the 5 tracks. The first, second, fourth and fifth tracks have a track length of 117 m. While the third track has a track length of 93 m. The distance between the electrodes is 3 m. The results showed that seawater intrusion that occurred in each track had resistivity value range between 0.2 Ωm to 2.77 Ωm. Seawater intrusion found in layers with sand material. Keyword : sea water intrusion, geoelectrical, resistivity, Wenner-Schlumberger

Joint Analysis of InSAR, ERT, and in-Situ Geological Survey in Landslide Prone Area: A Case in Laeya Village, North Buton Regency, Indonesia

Landslide investigation in Laeya Village of North Buton Regency, Indonesia, is necessary since this area is frequently experiencing landslides. In this study, we applied a joint analysis of interferometric synthetic aperture radar (InSAR), electrical resistivity tomography (ERT), and in-situ geology observation. The objectives of this multidisciplinary study are: a) to estimate ground deformation through the InSAR method, b) estimation of subsurface characteristics based on the electrical resistivity of rocks, as well as estimation of the shape of the slip plane and the type of landslide that resulted; and c) to identify the surface geology conditions of the site from an in-situ geology survey. The InSAR data of the Sentinel-1A acquired from 2015 to 2017 were processed using the Sentinel toolbox. The resistivity data collected utilizing the electrodes array of the Wenner-Schlumberger configuration were processed employing the RES2DINV. The in-situ geology survey involving the observation of elevation, slope, and soil and rock type was also carried out in the landslide area. The InSAR method may estimate the deformation of slope material of the investigated sites with a magnitude ranging from -53 mm to +55 mm. The negative mark of the magnitude means that the ground deformation is ground subsidence and the positive means ground uplift. The ERT method has successfully estimated the existence of the saturated zones, the clay layer that acts as a slip plane, and the slip surface type. There are at least two types of slip planes estimated, namely the planar and uneven curvature slip planes that generate the translational and the complex landslides, respectively. In-situ observations of geological conditions support the results obtained from the InSAR and ERT methods.

Geoelectrical resistivity and geochemical method for groundwater investigation in the coastal sediment

This research presents new investigations on the identification and mapping of heavy metals in aquifer systems using geoelectrical methods, water samples, and geochemical analyses. The subsurface was investigated using a total of three geoelectrical survey lines in the Wenner Schlumberger configuration. Six samples—three from bore wells, two from rivers, and one from the sea—were collected for additional laboratory examination in order to observe the quality of the water samples and variations in hadrochemical water samples in the research area. Soil samples collected from three different places were geochemically analysed. Cd concentration (0.94-2.42 mg/kg) was found to be higher in the northern portion of the study site, and Cr concentration (4.39-72.98 mg/kg), Ni concentration (12.11-47.69 mg/kg), and Co concentration (7,19-12,86) were found to be higher in the southern section. While Cd, Cr, Ni, and Co distribution of heavy metals are quite high in the northern and southern areas of Galesong beach, they are relatively low in the middle. A geochemical study of soil samples reveals that Cd and Cr concentrations are significantly high in the resistivity zone (<20 Ωm). The environmental resistivity value is low from the center zone to the northwest. The heavy metal zone in the aquifer system can be simply represented by the geoelectrical resistivity distribution presented in the form of a depth section, even though the resistivity value of more than 40 Ωm can be regarded as an aquifer zone.

Identifikasi Zona Rawan Longsor Menggunakan Metode Geolistrik Resistivitas Di Desa Pao Kecamatan Tombolo Pao Kabupaten Gowa

This research aims to identify landslide-prone zones using the geoelectric resistivity method in Pao Village, Tombolo Pao District, Gowa Regency. The configuration used for data collection in the field is the Wenner-Schlumberger configuration using four the number of lines. The result of research indicates that the first line average is founded in each layer which is suspected to occur in a layer of soil and igneous rock in the form of lava with 2.10 Ωm- 12.7 Ωm in resistivity value. In the second line, the average is founded wet soil, dry soil and igneous rock with 1.26 Ωm – 11.1 Ωm in resistivity value. The third line average is an established layer of soil and lava with 2.18 Ωm – 6.51 Ωm in resistivity value. The fourth line is suspected to occur layer of soil and lava with 1.59 Ωm – 8.50 Ωm in resistivity value and 1.25 m – 15.9 m in depth. It can be concluded that the first and fourth lines, based on the resistivity value, are generated to occur in a layer of soil. Igneous rocks are supported by topography, slup reaching 30o – 35o. Meanwhile, the second and third lines do not happen landslide potential because the resistivity results contain igneous rock. Still, the topography, vegetation, and slup are not the landslide-prone category.

A geoelectrical study of aquifers in the Natar, South Lampung

The conditions for the development of population growth and development in the area around the City of Bandar Lampung are very fast and starting to get crowded, as happened in the District of Natar South Lampung, especially in the Village of Pemanggilan. This condition causes an increase in the need for clean water resources in line with the increase in groundwater exploitation. Therefore it is necessary to map the potential of groundwater through aquifer mapping and aquifer rock layers through geoelectrical measurements. This study aims to determine the potential of groundwater from volcanic aquifer systems based on geoelectrical measurements. The method used in this study is geoelectric resistivity using the Wenner-Schlumberger configuration with 3 measurement points. The results of the study show that using the geoelectrical resistivity method, layers with a resistivity value of ? 30.3 ?m are interpreted as shallow aquifers at depths varying from 1 to more than 24 meters with lithology suspected to be tuff and tuff sandstones, which according to geological data are included in the Lampung Formation. Using the 2D geoelectric method, the distribution of shallow aquifers in the study area to a depth of 24 meters can also be determined. The data obtained is expected to be used as supporting data for the sustainable use of water sources.

SLIP SURFACE IDENTIFICATION FOR LANDSLIDE HAZARD MITIGATION WITH ELECTRICAL RESISTIVITY TOMOGRAPHY

Pidada area, Panjang sub-district, Bandar Lampung city, located on Barisan Hill complex, has been affected by the Sumatran fault movement and the Lampung-Panjang fault so that the morphological condition is hilly with steep slopes, which causes the risk of natural disasters such as landslides. In this article, the identification of subsurface rock lithology and sliding plane in the landslide-prone zone is carried out using the Wenner-Schlumberger configuration geoelectric method. Based on the Wenner-Schlumberger configuration, the top layer has lithology clay tuff and sandy tuff, which predicted a weathered rock with a resistivity of 1 - 133 ohm.m. Coarse-grained tuff and fine-grained tuff with resistivity values of 135 - 250 ohm.m in the middle. The bottom layer has a resistivity of more than 250 ohm.m, that predicted to have a lithology breccia (igneous rock) Tarahan Formation. The sandy clay layer (81 - 90 ohm.m) predict as a sliding plane in this area at depths of 8.2 to 16 m. The type of landslide developed in the research area is a crawling soil landslide with very steep slope characteristics (80 – 350).

How to Identify the Subsurface Layer of Bangkam Hill - Mempawah Regency? Application of the Geoelectrical Resistivity Method

Mapping the subsurface is essential in rock exploration for construction to minimize costs and guide adequate mining planning. This study aims to identify the subsurface layer of Bangkam Hill, a depot of various rocks for construction materials located in Sungai Kunyit District, Mempawah Regency. A resistivity method was applied to map the sub-surface using the Wenner-Schlumberger configuration. Data acquisition was performed at six measurement lines to cover the hill. The results show that the subsurface layers of the hill from the ground to 40 m in depth are composed of sand, laterite soil, gravel, and igneous rock, with resistivity varying from about 30 to 693,055 Ωm. Using the subsurface map, the stakeholder can assess shallow rock reserves in the study area and create a proper mining strategy.