Evaluation of aquifer contamination sources by using directional variography: a case study

The a posteriori identification of the main features of a contamination source is relevant to modeling, managing, and monitoring of polluted aquifers. This paper proposes a geostatistical application, in particular, directional variography, to detennine groundwater contamination source types. By using the experimental values of different solute concentrations sampled in 36 wells located in 76 km2 area, directional variography produces results of interest. In particular, radar plots of sills (Le, the variances of concentration measurements computed along different directions) show peculiar shapes which have been compared with the ones obtained from controlled computer simulations using simplified assumptions. We conclude that the analysis of directional variography has practical uses in the screening of field measurements aimed at the classification of contamination sources.