Three-Dimensional Electrical Resistivity Tomography to Monitor Root Zone Water Dynamics

Root zone geometry research is usually done in a conventional way which is destructive, time-consuming, and requires a considerable cost. Several non-destructive measurements used geophysical methods have been developed, one of which is the Electrical Resistivity Tomography (ERT) method. Tree root zone determination using ERT has been carried out in Kiara Payung area, Sumedang, West Java, with Maesopsis eminii tree as the object study. A total of 29 ERT lines were measured using dipoledipole configuration with electrodes spacing of 50 cm. The results of two-dimensional (2D) and three-dimensional (3D) inversion modeling show that the ERT method has been successfully imaging the tree root zone. The root zone is characterized as 100-700 Ωm with an elliptical shape geometry of the root plate. The root radius is estimated to be 4-5 m from the stem, the root zone diameter reaches 8-9 m at the shallow soil surface and the root zone depth is approximately 2-2.5 m. ABSTRAK Pencitraan geometri zona perakaran pohon menggunakan electrical resistivity tomography. Penelitian geometri zona perakaran biasa dilakukan dengan cara konvensional yang destruktif, memakan waktu, dan membutuhkan biaya yang tidak sedikit. Beberapa pengukuran non-destruktif menggunakan metode geofisika telah dikembangkan, salah satunya adalah metode Electrical Resistivity Tomography (ERT). Penentuan zona perakaran pohon menggunakan metode ERT telah dilakukan di daerah Kiara Payung, Sumedang, Jawa Barat, dengan pohon Maesopsis eminii sebagai objek studi. Sebanyak 29 lintasan ERT diukur menggunakan konfigurasi dipole-dipole pada dengan jarak antar elektroda 50 cm. Hasil pemodelan inversi dua dimensi (2D) dan tiga dimensi (3D) menunjukkan bahwa metode ERT telah berhasil mencitrakan zona perakaran pohon. Zona perakaran teridentifikasi berada pada nilai resistivitas 100-700 Ωm dengan root plate dan root cross-sections berbentuk elips. Radius akar diperkirakan sejauh 4-5 m dari pangkal batang, sedangkan diameter zona perakaran mencapai sekitar 8-9 m di permukaan tanah dangkal dan kedalaman zona perakaran diperkirakan antara ~2-2.5 m.

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Electrical Resistivity Tomography of the Root Zone

SSSA Special Publications - Soil-Water-Root Processes: Advances in Tomography and Imaging ◽

10.2136/sssaspecpub61.c11 ◽

2015 ◽

pp. 223-245 ◽

Cited By ~ 1

Author(s):

Alex Furman ◽

Ali Arnon-Zur ◽

Shmuel Assouline

Keyword(s):

Electrical Resistivity ◽

Electrical Resistivity Tomography ◽

Root Zone ◽

Resistivity Tomography

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

Hydrology and Earth System Sciences ◽

10.5194/hess-22-5427-2018 ◽

2018 ◽

Vol 22 (10) ◽

pp. 5427-5444 ◽

Cited By ~ 13

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.

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Assessment of the Efficiency of Consolidation Treatment through Injections of Expanding Resins by Geotechnical Tests and 3D Electrical Resistivity Tomography

The Scientific World JOURNAL ◽

10.1155/2015/237930 ◽

2015 ◽

Vol 2015 ◽

pp. 1-13 ◽

Cited By ~ 5

Author(s):

T. Apuani ◽

G. P. Giani ◽

M. d’Attoli ◽

F. Fischanger ◽

G. Morelli ◽

...

Keyword(s):

Electrical Resistivity ◽

Electrical Resistivity Tomography ◽

Three Dimensional ◽

Test Site ◽

Mechanical Stiffness ◽

Foundation Soil ◽

Resistivity Tomography ◽

Consolidation Treatment ◽

Injection Process ◽

Geotechnical Tests

The design and execution of consolidation treatment of settled foundations by means of injection of polyurethane expanding resins require a proper investigation of the state of the foundation soil, in order to better identify anomalies responsible for the instability. To monitor the injection process, a procedure has been developed, which involves, in combination with traditional geotechnical tests, the application of a noninvasive, geophysical technique based on the electrical resistivity, which is strongly sensitive to presence of water or voids. Three-dimensional electrical resistivity tomography is a useful tool to produce effective 3D images of the foundation soils before, during, and after the injections. The achieved information allows designing the consolidation scheme and monitoring its effects on the treated volumes in real time. To better understand the complex processes induced by the treatment and to learn how variations of resistivity accompany increase of stiffness, an experiment was carried out in a full-scale test site. Injections of polyurethane expanding resin were performed as in real worksite conditions. Results confirm that the experimented approach by means of 3D resistivity imaging allows a reliable procedure of consolidation, and geotechnical tests demonstrate the increase of mechanical stiffness.

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Bedrock detection beneath river terrace deposits using three-dimensional electrical resistivity tomography

Geomorphology ◽

10.1016/j.geomorph.2012.03.034 ◽

2012 ◽

Vol 177-178 ◽

pp. 17-25 ◽

Cited By ~ 36

Author(s):

J.E. Chambers ◽

P.B. Wilkinson ◽

D. Wardrop ◽

A. Hameed ◽

I. Hill ◽

...

Keyword(s):

Electrical Resistivity ◽

Electrical Resistivity Tomography ◽

Three Dimensional ◽

River Terrace ◽

Resistivity Tomography

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Application of Two Dimensional Electrical Resistivity Tomography (ERT) For Moisture Detection in Thessaloniki’s Rotunda Pillars and Three-Dimensional ERT Modeling Using Optimized Electrode Arrays

ArchéoSciences ◽

10.4000/archeosciences.9443 ◽

2021 ◽

pp. 179-181

Author(s):

Prodromos Louvaris ◽

Panagiotis Tsourlos ◽

Gregory Tsokas ◽

George Vargemezis ◽

Nectaria Diamanti ◽

...

Keyword(s):

Electrical Resistivity ◽

Electrical Resistivity Tomography ◽

Three Dimensional ◽

Two Dimensional ◽

Electrode Arrays ◽

Resistivity Tomography ◽

Moisture Detection

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Preliminary use of ground-penetrating radar and electrical resistivity tomography to study tree roots in pine forests and poplar plantations

Functional Plant Biology ◽

10.1071/fp08062 ◽

2008 ◽

Vol 35 (10) ◽

pp. 1047 ◽

Cited By ~ 68

Author(s):

Terenzio Zenone ◽

Gianfranco Morelli ◽

Maurizio Teobaldelli ◽

Federico Fischanger ◽

Marco Matteucci ◽

...

Keyword(s):

Electrical Resistivity ◽

Ground Penetrating Radar ◽

Electrical Resistivity Tomography ◽

Water Saturation ◽

Three Dimensional ◽

Tree Roots ◽

Resistivity Tomography ◽

Shape Distribution ◽

Geophysical Surveys ◽

Ground Penetrating

In this study, we assess the possibility of using ground penetrating radar (GPR) and electrical resistivity tomography (ERT) as indirect non-destructive techniques for root detection. Two experimental sites were investigated: a poplar plantation [mean height of plants 25.7 m, diameter at breast height (dbh) 33 cm] and a pinewood forest mainly composed of Pinus pinea L. and Pinus pinaster Ait. (mean height 17 m, dbh 29 cm). GPR measures were taken using antennas of 900 and 1500 MHz applied in square and circular grids. ERT was previously tested along 2-D lines, compared with GPR sections and direct observation of the roots, and then using a complete 3-D acquisition technique. Three-dimensional reconstructions using grids of electrodes centred and evenly spaced around the tree were used in all cases (poplar and pine), and repeated in different periods in the pine forest (April, June and September) to investigate the influence of water saturation on the results obtainable. The investigated roots systems were entirely excavated using AIR-SPADE Series 2000. In order to acquire morphological information on the root system, to be compared with the GPR and ERT, poplar and pine roots were scanned using a portable on ground scanning LIDAR. In test sections analysed around the poplar trees, GPR with a high frequency antenna proved to be able to detect roots with very small diameters and different angles, with the geometry of survey lines ruling the intensity of individual reflectors. The comparison between 3-D images of the extracted roots obtained with a laser scan data point cloud and the GPR profile proved the potential of high density 3-D GPR in mapping the entire system in unsaturated soil, with a preference for sandy and silty terrain, with problems arising when clay is predominant. Clutter produced by gravel and pebbles, mixed with the presence of roots, can also be sources of noise for the GPR signals. The work performed on the pine trees shows that the shape, distribution and volume of roots system, can be coupled to the 3-D electrical resistivity variation of the soil model map. Geophysical surveys can be a useful approach to root investigation in describing both the shape and behaviour of the roots in the subsoil.

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