Non-Invasive 3D Conductivity Measurements During Flow Experiments In Columns With Merit

The non-invasive measurement of physical parameters in soils is an important tool for observation and sustainable management of soils and aquifers so as to preserve or to restore groundwater quantity and quality from natural or anthropogeneous e ects. We present the Magneto-Electrical Resistivity Imaging Technique (MERIT) in theory and application to investigate the variation of the three-dimensional distribution of the electrical conductivity during fluid flow. Numerical experiments were performed to simulate water flow in cylindrical soil columns, the effect of saturation changes on electrical conductivity, and the changes in the resulting electrical potential and magnetic field due to current injection. As result we can state that MERIT is a non-invasive method that is capable of monitoring fluid flow and solute transport processes in soils, if the accuracy of the magnetic eld measurements is 0:1% and the resolution is 50 pT minimum.