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| Titel |
Forward Modeling and validation of a new formulation to compute self-potential signals associated with ground water flow |
| VerfasserIn |
A. Bolève, A. Revil, F. Janod, J. L. Mattiuzzo, A. Jardani |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1027-5606
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| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 11, no. 5 ; Nr. 11, no. 5 (2007-10-16), S.1661-1671 |
| Datensatznummer |
250009475
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| Publikation (Nr.) |
 copernicus.org/hess-11-1661-2007.pdf |
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| Zusammenfassung |
| The classical formulation of the coupled hydroelectrical
flow in porous media is based on a linear formulation of two coupled
constitutive equations for the electrical current density and the seepage
velocity of the water phase and obeying Onsager's reciprocity. This
formulation shows that the streaming current density is controlled by the
gradient of the fluid pressure of the water phase and a streaming current
coupling coefficient that depends on the so-called zeta potential. Recently
a new formulation has been introduced in which the streaming current density
is directly connected to the seepage velocity of the water phase and to the
excess of electrical charge per unit pore volume in the porous material. The
advantages of this formulation are numerous. First this new formulation is
more intuitive not only in terms of establishing a constitutive equation for
the generalized Ohm's law but also in specifying boundary conditions for the
influence of the flow field upon the streaming potential. With the new
formulation, the streaming potential coupling coefficient shows a decrease
of its magnitude with permeability in agreement with published results. The
new formulation has been extended in the inertial laminar flow regime and to
unsaturated conditions with applications to the vadose zone. This
formulation is suitable to model self-potential signals in the field. We
investigate infiltration of water from an agricultural ditch, vertical
infiltration of water into a sinkhole, and preferential horizontal flow of
ground water in a paleochannel. For the three cases reported in the present
study, a good match is obtained between finite element simulations performed
and field observations. Thus, this formulation could be useful for the
inverse mapping of the geometry of groundwater flow from self-potential
field measurements. |
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