scholarly journals Reconstruction of former channel systems in the northwestern Nile Delta (Egypt) based on corings and electrical resistivity tomography (ERT)

2021 ◽  
Vol 70 (1) ◽  
pp. 151-164
Author(s):  
Marina Altmeyer ◽  
Martin Seeliger ◽  
Andreas Ginau ◽  
Robert Schiestl ◽  
Jürgen Wunderlich
Keyword(s):  
Electrical Resistivity ◽  
Electrical Resistivity Tomography ◽  
Nile Delta ◽  
Small Scale ◽  
Resistivity Tomography ◽  
Channel System ◽  
Sedimentary Environments ◽  
Current State ◽  
State Of Research ◽  
Fluvial Network

Abstract. The current state of research about ancient settlements within the Nile Delta allows the hypothesizing of fluvial connections to ancient settlements all over the Nile Delta. Previous studies suggest a larger Nile branch close to Kom el-Gir, an ancient settlement hill in the northwestern Nile Delta. To contribute new knowledge to this little-known site and prove this hypothesis, this study aims at using small-scale paleogeographic investigations to reconstruct an ancient channel system in the surroundings of Kom el-Gir. The study pursues the following: (1) the identification of sedimentary environments via stratigraphic and portable X-ray fluorescence (pXRF) analyses of the sediments, (2) the detection of fluvial elements via electrical resistivity tomography (ERT), and (3) the synthesis of all results to provide a comprehensive reconstruction of a former fluvial network in the surroundings of Kom el-Gir. Therefore, auger core drillings, pXRF analyses, and ERT were conducted to examine the sediments within the study area. Based on the evaluation of the results, the study presents clear evidence of a former channel system in the surroundings of Kom el-Gir. Thereby, it is the combination of both methods, 1-D corings and 2-D ERT profiles, that derives a more detailed illustration of previous environmental conditions which other studies can adopt. Especially within the Nile Delta which comprises a large number of smaller and larger ancient settlement hills, this study's approach can contribute to paleogeographic investigations to improve the general understanding of the former fluvial landscape.

scholarly journals Small-scale characterization of vine plant root water uptake via 3-D electrical resistivity tomography and mise-à-la-masse method

2018 ◽  
Vol 22 (10) ◽  
pp. 5427-5444 ◽  
Author(s):  
Benjamin Mary ◽  
Luca Peruzzo ◽  
Jacopo Boaga ◽  
Myriam Schmutz ◽  
Yuxin Wu ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Root System ◽  
Field Data ◽  
Electrical Resistivity Tomography ◽  
Root Zone ◽  
Plant Root ◽  
Root Water Uptake ◽  
Small Scale ◽  
Noninvasive Methods ◽  
Resistivity Tomography

Abstract. The investigation of plant roots is inherently difficult and often neglected. Being out of sight, roots are often out of mind. Nevertheless, roots play a key role in the exchange of mass and energy between soil and the atmosphere, in addition to the many practical applications in agriculture. In this paper, we propose a method for roots imaging based on the joint use of two electrical noninvasive methods: electrical resistivity tomography (ERT) and mise-à-la-masse (MALM). The approach is based on the key assumption that the plant root system acts as an electrically conductive body, so that injecting electrical current into the plant stem will ultimately result in the injection of current into the subsoil through the root system, and particularly through the root terminations via hair roots. Evidence from field data, showing that voltage distribution is very different whether current is injected into the tree stem or in the ground, strongly supports this hypothesis. The proposed procedure involves a stepwise inversion of both ERT and MALM data that ultimately leads to the identification of electrical resistivity (ER) distribution and of the current injection root distribution in the three-dimensional soil space. This, in turn, is a proxy to the active (hair) root density in the ground. We tested the proposed procedure on synthetic data and, more importantly, on field data collected in a vineyard, where the estimated depth of the root zone proved to be in agreement with literature on similar crops. The proposed noninvasive approach is a step forward towards a better quantification of root structure and functioning.

scholarly journals Quasi-3-D resistivity imaging – mapping of heterogeneous frozen ground conditions using electrical resistivity tomography

2009 ◽  
Vol 3 (3) ◽  
pp. 895-918 ◽  
Author(s):  
C. Kneisel ◽  
A. Bast ◽  
D. Schwindt
Keyword(s):  
Electrical Resistivity ◽  
Electrical Resistivity Tomography ◽  
Swiss Alps ◽  
Small Scale ◽  
Frozen Ground ◽  
Resistivity Tomography ◽  
Near Surface ◽  
Glacier Forefield ◽  
Mountain Permafrost ◽  
Ground Conditions

Abstract. Up to now an efficient 3-D geophysical mapping of the subsurface in mountainous environments with rough terrain has not been possible. A merging approach of several closely spaced 2-D electrical resistivity tomography (ERT) surveys to build up a quasi-3-D model of the electrical resistivity is presented herein as a practical compromise for inferring subsurface characteristics and lithology. The ERT measurements were realised in a small glacier forefield in the Swiss Alps with complex terrain exhibiting a small scale spatial variability of surface substrate. To build up the grid for the quasi-3-D measurements the ERT surveys were arranged as parallel profiles and perpendicular tie lines. The measured 2-D datasets were collated into one quasi-3-D file. A forward modelling approach – based on studies at a permafrost site below timberline – was used to optimize the geophysical survey design for the mapping of the mountain permafrost distribution in the investigated glacier forefield. Quasi-3-D geoelectrical imaging is a useful method for mapping of heterogeneous frozen ground conditions and can be considered as a further milestone in the application of near surface geophysics in mountain permafrost environments.

scholarly journals Small scale characterization of vine plant root water uptake via 3D electrical resistivity tomography and Mise-à-la-Masse method

2018 ◽  
Author(s):  
Benjamin Mary ◽  
Luca Peruzzo ◽  
Jacopo Boaga ◽  
Myriam Schmutz ◽  
Yuxin Wu ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Root System ◽  
Field Data ◽  
Electrical Resistivity Tomography ◽  
Root Zone ◽  
Plant Root ◽  
Small Scale ◽  
Resistivity Tomography ◽  
Invasive Approach ◽  
Non Invasive

Abstract. The investigation of plant roots is inherently difficult and often neglected. Being out of sight, roots are often out of mind. Still, roots play a key role in the exchange of mass and energy between soil and the atmosphere, let alone the many practical applications in agriculture. In this paper, we propose a method for roots imaging based on the joint use of two electrical non-invasive methods, Electrical Resistivity Tomography (ERT) and Mise-a-la-Masse (MALM). The approach is based on the key assumption that the plant root system acts as an electrically conductive body, so that injecting electrical current in the plant stem will ultimately result in the injection of current in the subsoil through the root system, and particularly through the root terminations via hair roots. Evidence from field data, showing that voltage distribution is very different whether current is injected in the tree stem or in the ground, strongly supports this hypothesis. The proposed procedure involves a stepwise inversion of both ERT and MALM data that ultimately leads to the identification of electrical resistivity distribution, and of the current-injection root distribution in the three-dimensional soil space. This, in turn, is a proxy to the active (hair) root density in the ground. We tested the proposed procedure on synthetic data and, more importantly, on field data collected in vineyard, where the estimated depth of the root zone proved to be in agreement with literature on similar crops. The proposed non-invasive approach is a step forward towards a better quantification of roots structure and functioning.

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