Characterizing Scale Dependent Hydraulic Properties with Measurement of Dielectric Properties

摘要

The objective of this research project was to develop ways to obtain information about the hydraulic properties of the subsurface from measurement of dielectric properties. The focus of the research was the use of ground penetrating radar (GPR), a high resolution geophysical technique that images changes in dielectric properties of the subsurface. Geostatistical analysis of GPR images was found to provide a non-invasive means of characterizing the spatial heterogeneity of the subsurface. Results from a field experiment, which involved the collection of GPR data across a cliff face, showed that the spatial variability seen in the GPR image was representative of the spatial variability seen in the grain size of the sediments in the cliff. Dielectric measurements can be used to obtain estimates of the magnitude of hydraulic properties, if the relationship between dielectric properties and hydraulic properties is known. Theoretical and numerical modeling, and laboratory measurements on layered materials investigated the effect of layer thickness and frequency or wavelength of the measurement. By taking these parameters into account the accuracy with which hydraulic properties are obtained from dielectric measurements can be significantly improved.