scholarly journals Electrical resistivity tomography contribution to the characterization of underground cavities in the region of Safi, Morocco

2020 ◽  
Vol 150 ◽  
pp. 03023
Author(s):  
Toufiq Ait Elfakih ◽  
Lahcen Bahi ◽  
Ahmed Akhssas ◽  
Latifa Ouadif ◽  
Rachid Benkmil
Keyword(s):  
Electrical Resistivity Tomography ◽  
High Salinity ◽  
Controlling Factors ◽  
Site Conditions ◽  
Resistivity Tomography ◽  
Aggressive Environment ◽  
Underground Cavities ◽  
Favorable Conditions ◽  
Hydrogeological Information

Natural underground cavities represent a major risk that compromises the durability of infrastructures and buildings and requires an urgent evaluation in order to be integrated in urban planning and decision-making. Nevertheless, the assessment of the hazard related to them requires a better understanding of the complexity of karst phenomena that may be well-developed in an area even without the presence of any surface indices. Actually, evolutions of karst underground features are controlled by a set of predisposing factors. The present study aims to contribute to the delineation and characterization of underground cavities in the coastal part between Safi and Oualidia. The choice of the study area was based on a preliminary analysis of site conditions and the main controlling factors of superficial karst especially those related to geology, hydrology and geomorphology. In this part of Safi region, The high salinity of seawater enhances the process of dissolution creating so an aggressive environment and favorable conditions for an accelerated extension of karst networks. In order to detect and estimate the approximate extensions of karst networks and features in this area, results of seven electrical profiles were interpreted in correlation with available geological and hydrogeological information.

Characterization Of Complex Archaeological Sites Using 3D Electrical Resistivity Tomography

2004 ◽  
Author(s):  
Annalisa Morelli ◽  
Gianfranco Morelli ◽  
Paolo Chiara ◽  
Alessio Pacchini ◽  
Federico Fischanger
Keyword(s):  
Electrical Resistivity ◽  
Electrical Resistivity Tomography ◽  
Archaeological Sites ◽  
Resistivity Tomography

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.

Application of electrical resistivity tomography (ERT) technique to detect underground cavities in a karst area of South Korea

2013 ◽  
Vol 71 (6) ◽  
pp. 2797-2806 ◽  
Author(s):  
Mi Kyung Park ◽  
Samgyu Park ◽  
Myeong-Jong Yi ◽  
Changryol Kim ◽  
Jung-Sul Son ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
South Korea ◽  
Electrical Resistivity Tomography ◽  
Karst Area ◽  
Resistivity Tomography ◽  
Underground Cavities
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