Geostatistics Applied to Groundwater Contamination. I: Methodology

This paper presents an introduction for the nonspecialist to the use of geostatistics to estimate and map contaminant concentrations and estimation errors in a groundwater plume from a set of measured contaminant concentrations. The paper begins with a brief review of the essential elements of geostatistical theory. The remainder of the paper describes the four steps of a geostatistical analysis with special emphasis on the interpolation technique known as point kriging. This procedure can be used to obtain the best (i.e., minimum estimation error), linear (i.e., the estimated concentration at an unmeasured point is given by a linear combination of nearby measured concentrations), unbiased estimate, and the estimation error for any point within the plume. These point values can then be mapped (i.e., contours of equal values of expected contaminant concentration and estimation error can be drawn), e.g., to display the extent and severity of groundwater contamination at a site.