scholarly journals Electrical Resistivity Tomography Techniques for Identifying Groundwater Pollution Due To Leachate flows at Putri Cempo Landfill

2017 ◽  
Vol 1 ◽  
pp. 103-109
Author(s):  
Harjito Harjito ◽  
Suntoro Suntoro ◽  
Totok Gunawan ◽  
M. Maskuri
Keyword(s):  
Electrical Resistivity ◽  
Groundwater Pollution ◽  
Land Surface ◽  
Electrical Resistivity Tomography ◽  
Subsurface Layer ◽  
Quality Analysis ◽  
Leachate Treatment ◽  
Resistivity Tomography ◽  
Leachate Management ◽  
Surrounding Areas

Landfill developed with open dumping system and below the adequate standard potentially lead to new problems like those found at Putri Cempo Landfill in Surakarta City. They include leachate, which easily flows in runoff, seeps through soil and land surface, and infiltrate into groundwater that supplies the surrounding residential wells. A research on leachate spread pattern from landfills to their surrounding areas thereby becomes necessary particularly in terms of environmental pollution potential from underground, which is latent and difficult to monitor. The aims of this research were (1) to identify the areas that experienced groundwater pollution due to leachate flows, (2) to identify the distribution of resistivity in these areas, and (3) to develop a model for leachate management. This research used Electrical Resistivity Tomography (ERT) survey for identifying the distribution of resistivity in polluted areas. It also used groundwater quality analysis for validating the interpretation of the ERT survey results. The results of the research showed that there was an anomaly in the subsurface layer. Materials with resistivity values of 0.25-1.20 ohmm were found in various depths within 0-8 m below the surface. These values were much lower than the resistivity of the main materials found at the measurement site, i.e. 4.9-13.1 ohmm. Accordingly, this anomaly signified the existing influence of pollution. The pollution along the geoelectrical sounding line had uneven distribution and centric pattern at several points that indicated the accumulation sites of leachate. The proposed leachate management model included the constructions of base lining (liner), leachate collection channel, geomembrane-composed final cap, and leachate treatment.

scholarly journals Identifying Changes in Sediment Texture along an Ephemeral Gravel-Bed Stream Using Electrical Resistivity Tomography 2D and 3D

2021 ◽  
Vol 11 (7) ◽  
pp. 3030
Author(s):  
Marcos A. Martínez-Segura ◽  
Carmelo Conesa-García ◽  
Pedro Pérez-Cutillas ◽  
Pedro Martínez-Pagán ◽  
Marco D. Vásconez-Maza
Keyword(s):  
Electrical Resistivity ◽  
Cross Sections ◽  
Electrical Resistivity Tomography ◽  
Environmental Changes ◽  
Subsurface Layer ◽  
Sediment Texture ◽  
Borehole Data ◽  
Resistivity Tomography ◽  
Gravel Bed ◽  
Basin Scale

Differences in deposit geometry and texture with depth along ephemeral gravel-bed streams strongly reflect fluctuations in bedload which are due to environmental changes at the basin scale and to morphological channel adjustments. This study combines electrical resistivity tomography (ERT) with datasets from borehole logs to analyse the internal geometry of channel cross-sections in a gravel-bed ephemeral stream (southeast Spain). The survey was performed through longitudinal and transverse profiles in the upper channel stretch, of 14 to 30 m in length and 3 to 6 m in depth, approximately. ERT values were correlated with data on sediment texture as grain size distribution, effective grain sizes, sorting, and particle shape (Zingg’s classification). The alluvial channel-fills showed the superposition of four layers with uneven thickness and arrangement: (1) the softer rocky substrate (<1000 Ω.m); (2) a thicker intermediate layer (1000 to 2000 Ω.m); and (3) an upper set composed of coarse gravel and supported matrix, ranging above 2000 Ω.m, and a narrow subsurface layer, which is the most resistive (>5000 Ω.m), corresponding to the most recent armoured deposits (gravel and pebbles). The ERT results coupled with borehole data allowed for determining the horizontal and vertical behaviour of the materials in a 3D model, facilitating the layer identification.

scholarly journals Exploring the regolith with electrical resistivity tomography in largescale surveys: electrode spacing related issues and possibility

2020 ◽  
Author(s):  
Laurent Gourdol ◽  
Rémi Clément ◽  
Jérôme Juilleret ◽  
Laurent Pfister ◽  
Christophe Hissler
Keyword(s):  
Electrical Resistivity ◽  
Apparent Resistivity ◽  
Large Scale ◽  
Electrical Resistivity Tomography ◽  
Subsurface Layer ◽  
Electrode Spacing ◽  
High Resistivity ◽  
Constant Thickness ◽  
Resistivity Tomography

Abstract. Within the Critical Zone, regolith plays a key role in the fundamental hydrological functions of water collection, storage, mixing and release. Electrical Resistivity Tomography (ERT) is recognized as a remarkable tool for characterizing the geometry and properties of the regolith, overcoming limitations inherent to conventional borehole-based investigations. For exploring shallow layers, a small electrode spacing (ES) will provide a denser set of apparent resistivity measurements of the subsurface. As this option is cumbersome and time-consuming, smaller ES – albeit offering poorer shallow apparent resistivity data – are often preferred for large horizontal ERT surveys. To investigate the negative trade-off between larger ES and reduced accuracy of the inverted ERT images for shallow layers, we use a set of synthetic conductive/resistive/conductive three-layered soil–saprock/saprolite–bedrock models in combination with a reference field dataset. Our results suggest that an increase in ES causes a deterioration of the accuracy of the inverted ERT images in terms of both resistivity distribution and interface delineation and, most importantly, that this degradation increases sharply when the ES exceeds the thickness of the top subsurface layer. This finding, which is obvious for the characterization of shallow layers, is also relevant even when solely aiming for the characterization of deeper layers. We show that an oversized ES leads to overestimations of depth to bedrock and that this overestimation is even more important for subsurface structures with high resistivity contrast. To overcome this limitation, we propose adding interpolated levels of surficial apparent resistivity relying on a limited number of ERT profiles with a smaller ES. We demonstrate that our protocol significantly improves the accuracy of ERT profiles when using large ES, provided that the top layer has a rather constant thickness and resistivity. For the specific case of large-scale ERT surveys the proposed upgrading procedure is cost-effective in comparison to protocols based on small ES.

scholarly journals Underground Leachate Distribution Based on Electrical Resistivity in Piyungan Landfill, Bantul

2018 ◽  
Vol 50 (1) ◽  
pp. 34
Author(s):  
Harjito Harjito ◽  
Suntoro Suntoro ◽  
Totok Gunawan ◽  
M. Maskuri
Keyword(s):  
Electrical Resistivity ◽  
Land Surface ◽  
Overland Flow ◽  
Research Area ◽  
Quality Analysis ◽  
Management Model ◽  
Surrounding Area ◽  
High Concentration ◽  
Leachate Treatment ◽  
Landfill Management

Piyungan Landfill is constructed to accommodate the disposal of wastes from Yogyakarta City, Sleman Regency, and Bantul Regency. Overland flow that passes through landfillsand potentially dissolves organic and anorganic materials in a high concentration is referred to as leachate. Leachate is easily transported by overland flow. It can seep through soil or land surface and, then, infiltrate into groundwater, which is commonly accessed through residential wells. Therefore, a study on leachate distribution pattern from landfill to the surrounding area becomes necessary particularly due to the potential of leachate to contaminate the environment via groundwater whose characters are latent and difficult to monitor. This research aims to (1) identify areas that experience groundwater pollution caused by leachate movement, (2) identify the distribution of electrical resistivity in polluted areas as well as the spread direction of leachateto the surrounding area, and (3) to develop a leachate management model. This research uses Electrical Resistivity Tomography (ERT) survey in order to identify the distribution of electrical resistivity in polluted areas. Groundwater quality analysis is used for validating the interpretation of ERT survey. The spread direction of leachate is identified from stratigraphic Fance model correlated with geologic and hydrologic data. The results show that groundwater contamination has occurred in the research area, as indicated by very low electrical resistivity in aquifer zone, i.e. 3-9 Ωm. Such low electrical resistivity is caused byincreased ions in groundwater as the results of leachate migrating downward into groundwater. The increased ions will trigger an increase in electrical conductivity (EC), i.e. up to 1,284 μmhos/cm, and a decline in electrical resistivity. The leachate spreads westward and northward at a depth of 6-17 m (aquifer) with a thickness of pollution between 4-11 m. The recommended landfill management model, emphasizing on leachate movement, include base lining (liner), leachate collection channel, geomembrane cap, and leachate treatment.

scholarly journals Exploring the regolith with electrical resistivity tomography in large-scale surveys: electrode spacing-related issues and possibility

2021 ◽  
Vol 25 (4) ◽  
pp. 1785-1812
Author(s):  
Laurent Gourdol ◽  
Rémi Clément ◽  
Jérôme Juilleret ◽  
Laurent Pfister ◽  
Christophe Hissler
Keyword(s):  
Electrical Resistivity ◽  
Apparent Resistivity ◽  
Large Scale ◽  
Electrical Resistivity Tomography ◽  
Subsurface Layer ◽  
Electrode Spacing ◽  
High Resistivity ◽  
Constant Thickness ◽  
Resistivity Tomography

Abstract. Within the critical zone, regolith plays a key role in the fundamental hydrological functions of water collection, storage, mixing and release. Electrical resistivity tomography (ERT) is recognized as a remarkable tool for characterizing the geometry and properties of the regolith, overcoming limitations inherent to conventional borehole-based investigations. For exploring shallow layers, a small electrode spacing (ES) will provide a denser set of apparent resistivity measurements of the subsurface. As this option is cumbersome and time-consuming, larger ES – albeit offering poorer shallow apparent resistivity data – is often preferred for large horizontal ERT surveys. To investigate the negative trade-off between larger ES and reduced accuracy of the inverted ERT images for shallow layers, we use a set of synthetic “conductive–resistive–conductive” three-layered soil–saprock/saprolite–bedrock models in combination with a reference field dataset. Our results suggest that an increase in ES causes a deterioration of the accuracy of the inverted ERT images in terms of both resistivity distribution and interface delineation and, most importantly, that this degradation increases sharply when the ES exceeds the thickness of the top subsurface layer. This finding, which is obvious for the characterization of shallow layers, is also relevant even when solely aiming for the characterization of deeper layers. We show that an oversized ES leads to overestimations of depth to bedrock and that this overestimation is even more important for subsurface structures with high resistivity contrast. To overcome this limitation, we propose adding interpolated levels of surficial apparent resistivity relying on a limited number of ERT profiles with a smaller ES. We demonstrate that our protocol significantly improves the accuracy of ERT profiles when using large ES, provided that the top layer has a rather constant thickness and resistivity. For the specific case of large-scale ERT surveys the proposed upgrading procedure is cost-effective in comparison to protocols based on small ES.

scholarly journals Application of Electrical Resistivity Tomography (ERT) in the investigation of quaternary landslide zones, based on the selected regions of Płock slope

2014 ◽  
Vol 31 (2) ◽  
pp. 101-107 ◽  
Author(s):  
Łukasz Kaczmarek ◽  
Radosław Mieszkowski ◽  
Marcin Kołpaczyński ◽  
Grzegorz Pacanowski
Keyword(s):  
Electrical Resistivity ◽  
Safety Factor ◽  
Cross Sections ◽  
Land Surface ◽  
Electrical Resistivity Tomography ◽  
Mass Movement ◽  
Virgin Mary ◽  
Resistivity Tomography ◽  
Vistula River ◽  
Geophysical Surveys

Abstract The article shows the results of geophysical surveys performed by using Electrical Resistivity Tomography (ERT) method on selected region of Płock slope of a Tumski hill near Basilica of Assumption of the Blessed Virgin Mary in Płock and in Maszewo by the Vistula River a few kilometers north of Płock. The above-mentioned sections were selected due to landslide phenomena observed there. Geophysical surveys were conducted in order to verify the state of the distribution of electrical resistivity in the sectors where mass movement was identified. The electrofusion cross-section near Cathedral Basilica shows clays and sands. Also in ERT prospection a zone of loose soils with high resistance is clearly visible. The results of the ERT method from Maszewo, indicates historical land surface of a landslide and that the slope in Maszewo consists of cohesive deposits. In order to describe these particular issues, geological cross-sections and safety factor obtained by calculation are presented for the analyzed parts of the slope. The safety factor shows that probability of landslide activity near Cathedral Basilica is very unlikely and in Maszewo is very high

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