Γo resistivity monitoring for environmental and engineering applications

Resistivity imaging has become widely used in engineering and environmental applications thanks to enhanced capabilities in the past couple of decades. A problem is ambiguities in the geological interpretation due to similar resistivity or insufficient contrast between different materials. Monitoring, or time-lapse, resistivity investigations can overcome some of these problems, as it makes it possible to separate change in resistivity due to for example chemical composition of pore fluid from the spatial variation due to the geology. The presented results demonstrate that resistivity monitoring is a powerful tool to trace changes in the ground that occur as a result of variation in water, ion or gas content, or temperature. The results show a strong potential for resistivity monitoring in 2D and 3D for engineering and environmental applications. This includes natural or man-induced movement of fluids or gas in natural ground as well as man-made structures, and change in material properties by for example internal erosion. The method can be used not only to monitor transport of water and solutes in the ground, but also to study e.g. the development of plant root systems.