Hydrogeophysical Methods at the Laboratory Scale

Abstract

Hydrogeophysics relies on the inference of hydrologically important properties based on the measurement of other properties that are more easily obtained. This inference requires, first, the definition of petrophysical relationships such as the dependence of the bulk dielectric permittivity of a medium on its volumetric water content (see Chapters 4 and 9 of this volume). Second, confounding effects must be defined or controlled to allow for appropriate corrections. For example, if electrical resistance tomography (ERT) is to be used to infer water-content changes, the change in measured electrical conductivity as a function of temperature must be accounted for, or measurements must be made under isothermal conditions. Third, if the measured property or the property of interest varies within the measurement sample volume, then the manner in which the measurement method averages these heterogeneous values must be considered.