Monitoring of an Infiltration Experiment Using the Self-Potential Method
Abstract
The flow of ground water in a porous soil generates an electrical field which can be measured at the ground surface with a set of non-polarizable electrodes connected to a multimeter. These so-called self-potential signals can be used to determine the pattern of the ground water flow in the subsurface. A field experiment was carried out to monitor the piezometric level and the dynamics of self-potential signals during a water infiltration test from a ditch using a set of 18 piezometers and a network of 41 (Pb/PbCl2) non-polarizable electrodes placed at the ground surface. The variations of the self-potential signals and the piezometric levels are linearly correlated with an apparent coupling coefficient of -5.5 +/- 0.9 mV.m-1. The intrinsic streaming potential coupling coefficient, measured on soil samples extracted from the test site, is in the range -4.0 to -5.9 mV.m-1 depending on the conductivity of the pore water. The hydraulic heads and the self-potential signals are jointly modelled using the 2D-finite-difference software GWFGEM (Ground Water Flow Geo-Electrical Mapping). This model reproduces fairly well the observed results with independent evaluation of the material properties entering the field equations. These results show the ability of the self-potential method to monitor ground water flow in a non-intrusive way.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2005
- Bibcode:
- 2005AGUFM.H24C..02S
- Keywords:
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- 1829 Groundwater hydrology;
- 1832 Groundwater transport;
- 1866 Soil moisture;
- 1875 Vadose zone;
- 1884 Water supply