The electrical resistivity of the ground is related to the soils type and its degree of water saturation. Most commonly, resistivity profiling is used to develop a pseudo cross-section of the ground to show the arrangement of strata and groundwater. Where the properties of these change, for example where groundwater becomes contaminated or where strata are faulted against each other, resistivity profiles will reveal the change.
Electrical resistivity data is acquired by placing a series of electrodes along the profile of interest. By applying current to successive pairs of electrodes it is possible to generate a profile of data representing the selected depth. Computerised inversion of the data allows a cross-section model of the ground beneath the profile to be generated.
