scholarly journals Application K-Means, Fuzzy C-Means and Gustafson-Kessel FCM Methods in Integration of Refraction Seismic Tomography and Electrical Resistivity Data Inversion Results for Evaluation of the Alluvium and Bedrock

2018 ◽  
Vol 3 (2) ◽  
pp. 183-198
Author(s):  
Bahman Mohammadi ◽  
Abolghasem Kamkar Rouhani ◽  
◽  
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.


2016 ◽  
Author(s):  
Benjamin Mewes ◽  
Christin Hilbich ◽  
Reynald Delaloye ◽  
Christian Hauck

Abstract. Geophysical methods are often used to characterise and monitor the subsurface composition of permafrost. The resolution capacity of standard methods, i.e. Electrical Resistivity Tomography and Refraction Seismic Tomography, depends hereby not only on static parameters such as measurement geometry, but also on the temporal variability in the contrast of the geophysical 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 especially the resolution capacity of a petrophysically-based quantitative combination of both methods, the so-called 4-phase model, and by 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 increasing water content compared to decreased ice content, and potentially larger uncertainty for the individual geophysical methods than for the combined evaluation with the 4-phase model. In the latter, ground ice loss 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 visualised the seasonal ice loss in summer, and the complex spatially variable ice-, water- and air content changes in an interannual comparison.


2021 ◽  
Vol 14 (12) ◽  
Author(s):  
Hamad H. AlQahtani ◽  
Mohammed S. Fnais ◽  
Sattam A. Almadani ◽  
Mansour S. Alhumimidi ◽  
Kamal Abdelrahman

2020 ◽  
Author(s):  
Giulia de Pasquale ◽  
Rémi Valois ◽  
Nicole Schaffer ◽  
Shelley MacDonell

Abstract. In semi-arid Chile, rock glaciers cover a surface area that is four-times larger than that occupied by glaciers. For this reason, their role in freshwater production, transfer and storage is likely to be of primary importance, especially in this area of increasing human pressure and high rainfall variability. To understand their hydrological role now and in the future it is necessary to characterize their internal structure (e.g., internal boundaries, ice, air, water and rock content). In this paper, we present the results and interpretations of electrical resistivity and refraction seismic tomography profiles on an active (El Ternero) and inactive (El Jote) rock glacier in the Chilean Andes. These are the first in situ measurements in Estero Derecho: a natural reserve at the headwaters of the Elqui River, where the two rock glaciers are located. Within our study, we highlight the strong differences in the geophysical responses between active and inactive rock glaciers through the analysis and comparison of three different inversion schemes: individual dataset inversion, structural and petrophysical joint inversion. Moreover, we propose a diagnostic model representation for the differentiation between active and inactive rock glaciers.


2015 ◽  
Vol 2015 ◽  
pp. 1-11
Author(s):  
A. Stanley Raj ◽  
D. Hudson Oliver ◽  
Y. Srinivas

Soft computing based geoelectrical data inversion differs from conventional computing in fixing the uncertainty problems. It is tractable, robust, efficient, and inexpensive. In this paper, fuzzy logic clustering methods are used in the inversion of geoelectrical resistivity data. In order to characterize the subsurface features of the earth one should rely on the true field oriented data validation. This paper supports the field data obtained from the published results and also plays a crucial role in making an interdisciplinary approach to solve complex problems. Three clustering algorithms of fuzzy logic, namely, fuzzyC-means clustering, fuzzyK-means clustering, and fuzzy subtractive clustering, were analyzed with the help of fuzzy inference system (FIS) training on synthetic data. Here in this approach, graphical user interface (GUI) was developed with the integration of three algorithms and the input data (AB/2 and apparent resistivity), while importing will process each algorithm and interpret the layer model parameters (true resistivity and depth). A complete overview on the three above said algorithms is presented in the text. It is understood from the results that fuzzy logic subtractive clustering algorithm gives more reliable results and shows efficacy of soft computing tools in the inversion of geoelectrical resistivity data.


Author(s):  
Jian Sun ◽  
Lin Fu ◽  
Shigang Zhang ◽  
Wei Hou

Absorption chillers have currently become an important device in saving energy because of its effectiveness in utilizing low grade heat. Lithium bromide is widely used as absorbent in this system. But there were few outstanding concentration measurement methods in practice before. In this paper, complete electrical resistivity data of lithium bromide aqueous solution for concentration measurement was given. The electrical resistivity of lithium bromide aqueous solution was measured at concentrations of 35–70 wt% of lithium bromide and temperatures of 10–100°C. Results of this work can meet the requirement of concentration measurement of lithium bromide in absorption chillers without extracting samples.


2017 ◽  
Vol 22 (4) ◽  
pp. 411-420
Author(s):  
Adam F. Majzoub ◽  
Kevin W. Stafford ◽  
Wesley A. Brown ◽  
Jon T. Ehrhart

The Delaware Basin of W Texas and SE New Mexico is the western subdivision of the Permian Basin and a northern extension of the Chihuahuan Desert. The major evaporite unit within the Delaware Basin is the Castile Formation, which consists of gypsum/anhydrite and is highly susceptible to dissolution and karstification. Manifestations of karst within the Castile outcrop are abundant and include sinkholes, subsidence features and caves, both epigene and hypogene in origin. Land reconnaissance surveys conducted during 2015 and 2016 documented abundant karst landforms near major thoroughfares in Culberson County, Texas. Two dimensional (2D) electrical resistivity surveys were conducted at four sites to characterize and delineate karst related hazards, both laterally and vertically, associated with the road. The electrical resistivity data were collected with a multi-electrode earth resistivity meter using a dipole-dipole array configuration. The resistivity data were then processed using EarthImager2D to produce inverted profile sections of each site. Two-dimensional electrical resistivity tomography was shown to be an effective non-invasive method in detecting solution conduits, soil filled voids, and fractured bedrock in the shallow subsurface in addition to those directly observed on the surface.


2004 ◽  
Vol 3 (4) ◽  
pp. 1215-1229 ◽  
Author(s):  
D. Cornacchiulo ◽  
A. C. Bagtzoglou

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