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Prediction of soil solution electrical conductivity by the permittivity corrected linear model using a dielectric sensor

Kargas, George; Persson, Magnus LU ; Kanelis, George; Markopoulou, Ioanna and Kerkides, Petros (2017) In Journal of Irrigation and Drainage Engineering 143(8).
Abstract

In the present study, the electrical conductivity of the soil solution (σp) was predicted using a linear model in which the bulk soilelectrical conductivity (σb) effect on the apparent dielectric permittivity (εs) was considered. The performance of the proposed model wasevaluated by measurements with a dielectric sensor (the WET sensor) in four porous media at four different levels of electrical conductivity ofthe moistening KCl solution (σw). It was found that the relationship between the square root of the permittivity (εs) and soil volumetric watercontent (θ) was dependent on soil type, which is consistent with the low operating frequency of the sensor. Establishing a soil... (More)

In the present study, the electrical conductivity of the soil solution (σp) was predicted using a linear model in which the bulk soilelectrical conductivity (σb) effect on the apparent dielectric permittivity (εs) was considered. The performance of the proposed model wasevaluated by measurements with a dielectric sensor (the WET sensor) in four porous media at four different levels of electrical conductivity ofthe moistening KCl solution (σw). It was found that the relationship between the square root of the permittivity (εs) and soil volumetric watercontent (θ) was dependent on soil type, which is consistent with the low operating frequency of the sensor. Establishing a soil specific θm-√εsrelationship substantially increased the θ measurement accuracy compared to the factory calibration. It was shown that the new approach forthe σp prediction gave reasonably accurate results in sands irrespective of the σp values. For the finer porous media, it improved the predictionof σp only for the higher salinity levels, but the σp values appear to be underestimated. The relationship between the corrected dielectricpermittivity εR and σb is strongly linear for σw and σb values up to 6 and 1.7 dS · m-1, respectively.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Bulk electrical conductivity, Linear model, Permittivity, Salinity
in
Journal of Irrigation and Drainage Engineering
volume
143
issue
8
external identifiers
  • scopus:85020671012
  • wos:000408355300015
ISSN
0733-9437
DOI
10.1061/(ASCE)IR.1943-4774.0001210
language
English
LU publication?
yes
id
f84cc95f-85d3-4e41-a656-a27cf59e5dd7
date added to LUP
2017-07-04 08:03:36
date last changed
2017-09-18 11:37:33
@article{f84cc95f-85d3-4e41-a656-a27cf59e5dd7,
  abstract     = {<p>In the present study, the electrical conductivity of the soil solution (σ<sub>p</sub>) was predicted using a linear model in which the bulk soilelectrical conductivity (σ<sub>b</sub>) effect on the apparent dielectric permittivity (ε<sub>s</sub>) was considered. The performance of the proposed model wasevaluated by measurements with a dielectric sensor (the WET sensor) in four porous media at four different levels of electrical conductivity ofthe moistening KCl solution (σ<sub>w</sub>). It was found that the relationship between the square root of the permittivity (ε<sub>s</sub>) and soil volumetric watercontent (θ) was dependent on soil type, which is consistent with the low operating frequency of the sensor. Establishing a soil specific θ<sub>m</sub>-√ε<sub>s</sub>relationship substantially increased the θ measurement accuracy compared to the factory calibration. It was shown that the new approach forthe σ<sub>p</sub> prediction gave reasonably accurate results in sands irrespective of the σ<sub>p</sub> values. For the finer porous media, it improved the predictionof σ<sub>p</sub> only for the higher salinity levels, but the σ<sub>p</sub> values appear to be underestimated. The relationship between the corrected dielectricpermittivity ε<sub>R</sub> and σ<sub>b</sub> is strongly linear for σ<sub>w</sub> and σ<sub>b</sub> values up to 6 and 1.7 dS · m<sup>-1</sup>, respectively.</p>},
  articleno    = {04017030},
  author       = {Kargas, George and Persson, Magnus and Kanelis, George and Markopoulou, Ioanna and Kerkides, Petros},
  issn         = {0733-9437},
  keyword      = {Bulk electrical conductivity,Linear model,Permittivity,Salinity},
  language     = {eng},
  month        = {08},
  number       = {8},
  series       = {Journal of Irrigation and Drainage Engineering},
  title        = {Prediction of soil solution electrical conductivity by the permittivity corrected linear model using a dielectric sensor},
  url          = {http://dx.doi.org/10.1061/(ASCE)IR.1943-4774.0001210},
  volume       = {143},
  year         = {2017},
}