IDENTIFICATION OF AQUIFER USING RESISTIVITY GEOELECTRIC METHOD IN REGIONAL OF BEBANDEM, KARANG ASEM, BALI

2018 ◽  
Vol 19 (1) ◽  
pp. 24-34
Author(s):  
Budy Santoso

Bungaya Kangin Village, Bebandem District, Karangasem Regency, Bali Province consists of paddy fields and settlements, required therefore a water source / aquifer  that can meet all these needs. One of the Geophysical Methods that can identify the aquifer is the Geoelectric Method. Geoelectric method used in this research is Resistivity Method. Data acquisition using Vertical Electrical Sounding (VES) and Electrical Resistivity Tomography (ERT) Methods. VES method is a method of measurement to determine the variation of resistivity vertically at one point. Electrical Resistivity Tomography (ERT) method is a method of measuring resistivity on soil surface / rock by using many electrode (51 electrode), to obtain sub-surface resistivity variation  lateraly and verticaly, to obtain sub-surface image. The equipment used for geoelectric measurements is  Resistivity Meter of Naniura NRD 300 Hf which has been equipped with a switchbox to adjust the displacement of 51 electrodes. Based on the resistivity modeling results, the aquifers in the study area were found in rough sandstones with resistivity values : (49 - 100) Ohm.m.  

2020 ◽  
Vol 30 (1) ◽  
pp. 55
Author(s):  
Asep Mulyono ◽  
Ilham Arisbaya ◽  
Yayat Sudrajat

Root zone geometry research is usually done in a conventional way which is destructive, time-consuming, and requires a considerable cost. Several non-destructive measurements used geophysical methods have been developed, one of which is the Electrical Resistivity Tomography (ERT) method. Tree root zone determination using ERT has been carried out in Kiara Payung area, Sumedang, West Java, with Maesopsis eminii tree as the object study. A total of 29 ERT lines were measured using dipoledipole configuration with electrodes spacing of 50 cm. The results of two-dimensional (2D) and three-dimensional (3D) inversion modeling show that the ERT method has been successfully imaging the tree root zone. The root zone is characterized as 100-700 Ωm with an elliptical shape geometry of the root plate. The root radius is estimated to be 4-5 m from the stem, the root zone diameter reaches 8-9 m at the shallow soil surface and the root zone depth is approximately 2-2.5 m. ABSTRAK Pencitraan geometri zona perakaran pohon menggunakan electrical resistivity tomography. Penelitian geometri zona perakaran biasa dilakukan dengan cara konvensional yang destruktif, memakan waktu, dan membutuhkan biaya yang tidak sedikit. Beberapa pengukuran non-destruktif menggunakan metode geofisika telah dikembangkan, salah satunya adalah metode Electrical Resistivity Tomography (ERT). Penentuan zona perakaran pohon menggunakan metode ERT telah dilakukan di daerah Kiara Payung, Sumedang, Jawa Barat, dengan pohon Maesopsis eminii sebagai objek studi. Sebanyak 29 lintasan ERT diukur menggunakan konfigurasi dipole-dipole pada dengan jarak antar elektroda 50 cm. Hasil pemodelan inversi dua dimensi (2D) dan tiga dimensi (3D) menunjukkan bahwa metode ERT telah berhasil mencitrakan zona perakaran pohon. Zona perakaran teridentifikasi berada pada nilai resistivitas 100-700 Ωm dengan root plate dan root cross-sections berbentuk elips. Radius akar diperkirakan sejauh 4-5 m dari pangkal batang, sedangkan diameter zona perakaran mencapai sekitar 8-9 m di permukaan tanah dangkal dan kedalaman zona perakaran diperkirakan antara ~2-2.5 m. 


2021 ◽  
Vol 54 (2E) ◽  
pp. 122-133
Author(s):  
Raad Eissa

Maintenance of existing structures and development or reuse of brownfield sites need to determine buried foundations, in terms of location and dimensions, as accurately as possible. Geophysical methods provide an indirect way to look in the ground and provide information about the subsurface that the traditional methods might be unable to. In particular, the electrical resistivity method has been performed in the context of buried foundation surveys. This review spots the light on the main results obtained from utilizing the electrical resistivity method and the most affecting parameters that can influence the obtained resistivity models, and also, focuses on published case studies to merge their findings to understand the interaction among the method, the foundation and the hosting background for buried foundations surveys. The case studies mentioned in this review show the resistivity method's success and highlight the most important parameters that can control the method’s applicability and data interpretation. The integration of the geophysical-traditional methods has appreciable potential for more accurate findings.


2021 ◽  
Vol 11 (6) ◽  
pp. 2448
Author(s):  
Alex Sendrós ◽  
Aritz Urruela ◽  
Mahjoub Himi ◽  
Carlos Alonso ◽  
Raúl Lovera ◽  
...  

Water percolation through infiltration ponds is creating significant synergies for the broad adoption of water reuse as an additional non-conventional water supply. Despite the apparent simplicity of the soil aquifer treatment (SAT) approaches, the complexity of site-specific hydrogeological conditions and the processes occurring at various scales require an exhaustive understanding of the system’s response. The non-saturated zone and underlying aquifers cannot be considered as a black box, nor accept its characterization from few boreholes not well distributed over the area to be investigated. Electrical resistivity tomography (ERT) is a non-invasive technology, highly responsive to geological heterogeneities that has demonstrated useful to provide the detailed subsurface information required for groundwater modeling. The relationships between the electrical resistivity of the alluvial sediments and the bedrock and the difference in salinity of groundwater highlight the potential of geophysical methods over other more costly subsurface exploration techniques. The results of our research show that ERT coupled with implicit modeling tools provides information that can significantly help to identify aquifer geometry and characterize the saltwater intrusion of shallow alluvial aquifers. The proposed approaches could improve the reliability of groundwater models and the commitment of stakeholders to the benefits of SAT procedures.


2017 ◽  
Vol 43 (4) ◽  
pp. 1962
Author(s):  
G. Vargemezis ◽  
P. Tsourlos ◽  
I. Mertzanides

The most common geophysical method widely used in hydrogeological surveys concerning deep investigations (150-300m of depth) is the resistivity method and particularly the Vertical Electric Sounding (VES) using the Schlumberger array. VES interpretations assume 1D geoelectrical structure yet it is obvious that such an interpretation assumption is not valid in many cases where 2D and 3D geological features exist. In such cases the application of geoelectrical techniques which can provide both vertical and lateral information concerning the resistivity variations is required. Techniques such as the electrical resistivity tomography, mostly used for the 2D and 3D geoelectrical mapping of near surface applications can be adapted to be used for larger investigation depths provided that modified equipment (viz. cables) is used. In the present paper, the application of deep electrical resistivity tomography (ERT) techniques is applied. ERT array of 21 electrodes, at a distance of 50 meters between them (total length 1000 meters) has been used in several studied areas located in the prefecture of Kavala (North Greece). In several cases near surface structure has been compared with VLF data. The aim of the survey was to study in detail the geological-hydrogeological structure the area of interest in order to suggest the best location for the construction of hydrowells with the most promising results. The 2D images of the geological structure down to the depth of at least 200 meters allowed the better understanding of the behaviour of layered geological formations, since in several cases resistivity values have been calibrated with data from pre-existing boreholes.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
César Moreira ◽  
Marcus Castro ◽  
Ana Gonsalez ◽  
Fernanda Cavallari ◽  
Thais Munhoz ◽  
...  

The biogas originated from anaerobic degradation of organic matter in landfills consists basically in CH4, CO2, and H2O. The landfills represent an important depository of organic matter with high energetic potential in Brazil, although with inexpressive use in the present. The estimation of production of the productive rate of biogas represents one of the major difficulties of technical order to the planning of capture system for rational consumption of this resource. The applied geophysics consists in a set of methods and techniques with wide use in environmental and hydrogeological studies. The DC resistivity method is largely applied in environmental diagnosis of the contamination in soil and groundwater, due to the contrast of electrical properties frequent between contaminated areas and the natural environment. This paper aims to evaluate eventual relationships between biogas flows quantified in drains located in the landfill, with characteristic patterns of electrical resistivity in depth. The drain of higher flow (117 m3/h) in depth was characterized for values between 8000 Ω·m and 100.000 Ω·m, in contrast with values below 2000 Ω·m, which characterize in subsurface the drain with less flow (37 m3/h), besides intermediary flow and electrical resistivity values, attributed to the predominance of areas with accumulation or generation of biogas.


Author(s):  
O. F. Ogunlana ◽  
O. M. Alile ◽  
O. J. Airen

The Electrical Resistivity Tomography (ERT) data was acquired within the area suspected to have high potential for bitumen occurrence using the Wenner-Schlumberger configuration in Agbabu, southwestern Nigeria. PASI 16GL-N Earth resistivity meter instrument was used to acquire data along five (5) traverses with 5m electrode spacing and traverses length of 150m. The apparent resistivity values obtained was processed using RES2DINV software which helped to automatically obtain the 2D inversion model of the subsurface. This study has shown the occurrence of bitumen between the depth of 13.4m and 9.93m for Traverses 1, 2, 3 and Traverses 4, 5 respectively in a 2-Dimensional electrical resistivity images for boreholes with a depth of about 18m. The results indicate that the bitumen is characterized by good lateral continuity and is sufficiently thick for commercial exploitation.


Water ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2400
Author(s):  
Alex Sendrós ◽  
Mahjoub Himi ◽  
Esmeralda Estévez ◽  
Raúl Lovera ◽  
M. Pino Palacios-Diaz ◽  
...  

The geometry and the hydraulic properties of the unsaturated zone is often difficult to evaluate from traditional soil sampling techniques. Soil samples typically provide only data of the upper layers and boreholes are expensive and only provide spotted information. Non-destructive geophysical methods and among them, electrical resistivity tomography can be applied in complex geological environments such as volcanic areas, where lavas and unconsolidated pyroclastic deposits dominate. They have a wide variability of hydraulic properties due to textural characteristics and modification processes suh as compaction, fracturation and weathering. To characterize the subsurface geology below the golf course of Bandama (Gran Canaria) a detailed electrical resistivity tomography survey has been conducted. This technique allowed us to define the geometry of the geological formations because of their high electrical resistivity contrasts. Subsequently, undisturbed soil and pyroclastic deposits samples were taken in representative outcrops for quantifying the hydraulic conductivity in the laboratory where the parametric electrical resistivity was measured in the field. A statistical correlation between the two variables has been obtained and a 3D model transit time of water infiltration through the vadose zone has been built to assess the vulnerability of the aquifers located below the golf course irrigated with reclaimed water.


Author(s):  
Syazwan Aiman Sufiyanussuari ◽  
◽  
Saiful Azhar Ahmad Tajudin ◽  
Mohammad Izzat Shaffiq Azmi ◽  
Muhammad Nur Hidayat Zahari ◽  
...  

Geophysical electrical resistivity method has been one of the more popular non-destructive method to explore the subsurface. Geophysical electrical resistivity tomography (ERT) subsurface profiling was conducted to map the groundwater path along the embankment. The groundwater path able to decrease the slope stability, thus its need to locate the position for conduct the slope remediation via subsoil drainage. In this study, Terrameter LS2 model, electrodes, cables, battery, and cable connectors were the equipment used for measurement. This study uses cable spread line at 200m with 2.5m spacing between electrodes by using gradient protocol. The resistivity data was analyzed using RES2DINV software. The interpretation of groundwater path is based on the resistivity values less than 100 ohm.m, which is interpreted as saturated materials. This study demonstrates the efficiency of application of electrical resistivity tomography (ERT) in detecting the groundwater pathways. This investigation will help in sustaining the slope stability via indicating the position of groundwater pathways, and thus implementing the slope remediation work.


2017 ◽  
Vol 11 (6) ◽  
pp. 2957-2974 ◽  
Author(s):  
Benjamin Mewes ◽  
Christin Hilbich ◽  
Reynald Delaloye ◽  
Christian Hauck

Abstract. Geophysical methods are often used to characterize and monitor the subsurface composition of permafrost. The resolution capacity of standard methods, i.e. electrical resistivity tomography and refraction seismic tomography, depends not only on static parameters such as measurement geometry, but also on the temporal variability in the contrast of the geophysical target variables (electrical resistivity and P-wave velocity). Our study analyses the resolution capacity of electrical resistivity tomography and refraction seismic tomography for typical processes in the context of permafrost degradation using synthetic and field data sets of mountain permafrost terrain. In addition, we tested the resolution capacity of a petrophysically based quantitative combination of both methods, the so-called 4-phase model, and through this analysed the expected changes in water and ice content upon permafrost thaw. The results from the synthetic data experiments suggest a higher sensitivity regarding an increase in water content compared to a decrease in ice content. A potentially larger uncertainty originates from the individual geophysical methods than from the combined evaluation with the 4-phase model. In the latter, a loss of ground ice can be detected quite reliably, whereas artefacts occur in the case of increased horizontal or vertical water flow. Analysis of field data from a well-investigated rock glacier in the Swiss Alps successfully visualized the seasonal ice loss in summer and the complex spatially variable ice, water and air content changes in an interannual comparison.


2014 ◽  
Vol 31 (2) ◽  
pp. 91-99 ◽  
Author(s):  
Grzegorz Pacanowski ◽  
Paweł Czarniak ◽  
Anna Bąkowska ◽  
Radosław Mieszkowski ◽  
Fabian Welc

Abstract This paper addresses the problem of assessing the leakproofness of the bottom of a deep foundation trench, secured by cavity wall, using geophysical methods of electrical resistivity tomography. The study was conducted on a large construction project in Lublin, in a place where there are complicated soil-water conditions: the groundwater level is above the proposed depth of foundation trench, the subsoil is heterogeneous, and there are karsted and weathered carbonate sediments with confined aquifer below the bottom of the trench. A hydraulic fracture occurred at the bottom of the trench during the engineering works, which caused the water flow into the trench. In order to recognize the soil-water conditions the first stage of geophysical measurements of electrical resistivity tomography (ERT) was made. The applied methodology allowed to determine the extent of the hydraulic fracture zone within the bottom of foundation trench. In order to assess the leakproofness of Diaphragm Wall the geophysical ERT measurements were repeated (stage 2) A clear reduction in the value of the electrical resistivity of soils in the area of hydraulic fracture was caused by clay injection. The results of ERT measurements are discussed and graphically presented.


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