Determination of shear surface of landslides using electrical resistivity tomography

Abstract

Geophysical methods offer a broad spectrum of information by dealing with slope deformations. The electrical resistivity tomography (ERT) method is mainly applied for spatial localization of the landslide body and depicting the shear zone position. This article presents the application of the ERT method for the landslide hazardous areas by means of numerical modelling. Four different synthetic models with very small resistivity contrast (30 Ohm.m/50 Ohm.m), where each model represents a different type of slope deformation, were tested by several factors affecting the final inverse model: measurement point density, L1 and L2 norm and L-norm roughness filter components. The higher measurement points density helps mainly to detect the boundaries at greater depths. Inverse models computed using the L1 norm bring satisfactory results for compact anomalous bodies, i.e. water saturated landslide body. In the case of subtle conductive zones, i.e. shear planes, the L2 norm based inversion is recommended. For enhanced reconstruction of skewed anomalous objects, roughness filter including a diagonal component produces more accurate inverse image. The article also demonstrates the ability of the ERT method to detect and describe the shape of the slope deformation even by a relative subtle resistivity contrast.

Geophysical and geotechnical approach to a landslide stability assessment: a case study

“…This method is widely used in evaluating slope deformations and in predicting the surface mass movements (Friedel et al 2006;Jongmans and Garambois 2007;Constantin et al 2011;Pasierb 2015;Bellanova et al 2018;Šilhán et al 2019). In particular, this method is applied for recognitions of lithostratigraphic sequences and the geometry of the landslide's body, identifying the sliding surfaces between the slide material and the underlying bedrock and the location high-water content areas (Panek et al 2008;Dardé et al 2013;Holec et al 2013;Dostál et al 2014;Tomecka-Suchoń et al 2017;Crawford and Bryson 2018). It is also used for the building and monitoring of high-resolution geological models (both 2D and 3D) and presenting results in a 4D system (Lebourg et al 2005;Jomard et al 2010;Chambers et al 2011;Merritt et al 2014;Uhlemann et al 2017;Boyle et al 2018;Břežný et al 2018).…”

Characterization of Sobradinho landslide in fluvial valley using MASW and ERT methods

“…For example, the Electrical Resistivity Tomography (ERT) and the Multi-channel Analysis of Surface Waves (MASW) (which were adopted in this study) are based on the electrical and seismic properties of materials, respectively. ERT has been extensively used for the determination of landslide slip surface and its hydrological characteristics (Kneisel, 2006;Panek et al, 2008;Burda et al, 2013;Dostál et al, 2014;Szalai et al, 2014;Ling et al, 2016;Bran et al, 2017;Kristyanto et al, 2017;Qiao et al, 2017;Carlini et al, 2018;Mita et al, 2018;Kasprzak et al, 2019).…”

Complex geophysical investigation of the Kapušany landslide (Eastern Slovakia)

“…As an input for the inversion a collated dataset from both field datasets was created. A standard least-squares constraint inversion (L 2 norm) with topography was used because it gives optimal results where subsurface geology exhibits a smooth variation, such as the shear zone shape (Dostál et al, 2014).…”