Geospatial Estimation of Mercury Contamination in Buffalo River Sediments

Abstract

The Buffalo River Area of Concern (AOC) is associated with heavy metal pollution. This research utilized sediment core data to model the geographic distribution of mercury within surface and subsurface sediments of a section of the AOC. Using ordinary kriging, a geostatistical interpolation technique, mercury concentration prediction maps were created. Standard maps were created by interpolating a prediction surface for the entire study area. In addition, spliced maps were created by interpolating prediction surfaces for three sections of the study area and merging these together to generate a quasi-continuous surface. The latter type of map was needed in order to account for the pronounced meandering nature of the river and to explore the potential existence of regional and local mercury sedimentation patterns. The surface level results show an increased level of mercury contamination from east to west (the direction of river flow), with peak values found in the mid-region of the study area. Additionally, surface sediments were less polluted with mercury than subsurface sediments. Finally, this study highlighted several mercury contamination hotspots, which could be targeted for future sediment restoration endeavors in the AOC.