Electrical resistivity imaging has been validated as a technique that can show the two dimensional movement of water through the soil profile after the application of irrigation water.

Water movement can be inferred in the resistivity section by comparing resistivity images recorded before and after the application of irrigation water. As the water migrates through the soil profile the resistivity decreases (electrical conductivity increases). The movement of the water through the vadose zone has been shown to be via preferential paths, possibly related to cracks or sandier zones within the profile. Time-lapse sequences of deep drainage show that irrigation water reaches depths of 5 to 10 meters within the first few hours after watering.

Electrical images comparing the moisture content throughout the soil profile to 10 metres in October and then in February show that a substantial quantity of water is added to the profile to a depth of 6 metres throughout the growing season. Resistivity images recorded just prior to irrigation show that the roots of the cotton plants have removed significant quantities of water immediately surrounding the roots, but have little influence on the moistures content of the soil profile immediately below the root zone. The drier soil around the root zone shows up as semi-circles of higher resistivity in the resistivity images.

At some locations, after watering there is an increase in the resistivity of the soil profile between 1 to 1.5 metres. This is interpreted as fresher irrigation water flushing out more saline pore water.