Characterizing three-dimensional hydraulic conductivity distributions using qualitative and quantitative geologic borehole data: Application to a field site

The focus of this paper is the characterization of three-dimensional hydraulic conductivity distributions using qualitative and quantitative geologic borehole data. We illustrate an approach that entails a three-step procedure, where lithologic information reported in the borehole logs is first classified into texture classes. Representative hydraulic conductivity values are then calculated for each texture class using a correlation relating measured lithologic and hydraulic data from core samples. The generalized kernel estimator method, which can take full advantage of the characteristics of borehole log data and is applicable to statistically nonstationary systems, is used thereafter to generate the three-dimensional distributions of hydraulic conductivity. An application using borehole data from a trichloroethene (TCE)-contaminated Superfund site in Tucson, Arizona, is presented and used to test the proposed methodology. The simulated hydraulic conductivity distributions appear reasonable and the simulated permeability distributions for several cross sections agree well with the hydrogeologic cross-sectional maps. The use of mean permeability indicators for differentiating zones of high and low permeability is also investigated.