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Communication dans un congrès

Can electrical resistivity tomography describe soil structure evolution?

Abstract : Variations of soil structure is significant for the understanding of water and gas transfer in soil profiles. In the context of arable land, soil structure can be compacted due to either agriculture operation (wheel tracks), or hardsetting and crusting processes. As a consequence, soil porosity is reduced which may lead to decrease water infiltration and to anoxic conditions. Porosity can be increased by cracks formation due to swelling and shrinking phenomenon. We present here a laboratory experiment based on soil electrical characteristics. Electrical resistivity allows a non destructive three dimensional and dynamical analysis of the soil structure. Our main objective is to detect cracks in the soil. Cracks form an electrical resistant object and the contrast of resistivity between air and soil is large enough to be detected. Our sample is an undisturbed soil block 240mm*170mm*160mm with an initial structure compacted by wheel traffic. Successive artificial cracks are generated. Electrodes built with 2 mm ceramic cups permit a good electrical contact at the soil surface whatever its water content. They are installed 15 mm apart and the electrical resistivity is monitored using a dipole-dipole and wenner multi-electrodes 2D imaging method which gives a picture of the subsurface resistivity. The interpreted resistivity sections show the major soil structure. The electrical response changes with the cracks formation. The structure information extracted from the electrical map is in good agreement with the artificially man-made cracks. These first results demonstrate the relevance of high resolution electrical imaging of the soil profile. Further experiments need to be carried out in order to monitor natural soil structure evolution during wetting-drying cycles.
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Communication dans un congrès
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https://hal-insu.archives-ouvertes.fr/hal-00079716
Déposant : Nathalie Pothier <>
Soumis le : mardi 13 juin 2006 - 14:50:27
Dernière modification le : jeudi 24 septembre 2020 - 16:00:35
Archivage à long terme le : : lundi 5 avril 2010 - 22:44:11

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  • HAL Id : hal-00079716, version 1
  • PRODINRA : 252490

Citation

Anatja Samouëlian, Guy Richard, Isabelle Cousin, Alain Tabbagh, Ary Bruand. Can electrical resistivity tomography describe soil structure evolution?. 16th Triennial Conference of the ISTRO, 2003, Brisbane, Australia. ⟨hal-00079716⟩

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