Advances in interpretation of subsurface processes with time‐lapse electrical imaging

Abstract

Electrical geophysical methods, including electrical resistivity, time‐domain induced polarization, and complex resistivity, have become commonly used to image the near subsurface. Here, we outline their utility for time‐lapse imaging of hydrological, geochemical, and biogeochemical processes, focusing on new instrumentation, processing, and analysis techniques specific to monitoring. We review data collection procedures, parameters measured, and petrophysical relationships and then outline the state of the science with respect to inversion methodologies, including coupled inversion. We conclude by highlighting recent research focused on innovative applications of time‐lapse imaging in hydrology, biology, ecology, and geochemistry, among other areas of interest. Copyright © 2014 John Wiley & Sons, Ltd.

Quantifying spatiotemporal dynamics of root-zone soil water in a mixed forest on subtropical coastal sand dune using surface ERT and spatial TDR

“…To obtain the ''true'' subsurface resistivity distribution, we inverted the apparent resistivity data using the iterative tomographic inversion scheme of the RES2DINV software (Loke and Barker, 1995). To minimize artefacts produced by numerical inaccuracies from inverting each dataset separately, the time-lapse inversion method was applied which uses a common reference model to jointly invert datasets from different dates (Loke, 2013;Singha et al, 2014). We inverted the first dataset collected on 8 November 2012 to produce the starting and reference model for the subsequent time-lapse inversions, i.e.…”

Uniform and lateral preferential flows under flood irrigation at field scale

“…The physics behind the two measurement techniques are different. NMR measurements are mainly dominated by the water content in the subsurface, whereas ERT data are dependent on different subsurface state variables (Singha et al, ). Although an Archie's type conversion from resistivity to water content is an empirical approximation (Singha & Gorelick, ), this method is an accepted standard method in hydrogeophysical analyses, especially with time‐lapse ERT (Singha et al, ).…”

Electrical resistivity imaging of hydrologic flow through surface coal mine valley fills with comparison to other landforms

“…The maximum possible temporal resolution of time‐lapse tomograms is the time it takes to complete one survey, which is 35 min for the Supersting R8. Time‐lapse tomograms have been found to be more accurate than individual resistivity tomograms because systematic errors are minimized and physical properties of the subsurface, such as lithology, and porosity, are held constant (Kemna et al, ; Samouёlian, Cousin, Tabbagh, Bruand, & Richard, , Miller, Routh, Brosten, & McNamara, , Singha et al, ).…”