Using the kriging spatial interpolation method, Cd sediment contamination in Lake Erie from 1971 (263 samples) and 1997/1998 (55 samples) were mapped as continuous data surfaces. Although the most recent data set is two decades old, the roughly 25 year period between the two comprehensive lake-wide surveys represents a period of intense binational management action to reduce sources of contamination. To improve interpolation accuracy between two different sampling densities, auxiliary variables including lake-wide sediment substrate types were integrated into spatial analysis of Cd contamination patterns. The potential for adverse biological impacts posed by Cd sediment contamination to humans and aquatic life was measured by the threshold identified contamination along the Long Point Erie Sill and the south-western Ontario shoreline (composed predominately of glacial till) to be in the range of “practically unpolluted” by anthropogenic sources. The highest degree of anthropogenic pollution was found in regions of fine-grained materials (mud and silt). By combining Cd contamination surfaces with sediment substrate categories for analysis of anthropogenically-derived pollution, regions of the lake at higher risk for long-term sediment contamination can be targeted for continued monitoring.
Mitchell, Danielle E.; Forsythe, K. Wayne; Marvin, Chris H.; and Burniston, Debbie A.
"Temporal Trends and Origins of Lake Erie Cadmium Contamination in Relation to Sediment Substrate Type Using Multivariate Kriging Analyses,"
International Journal of Geospatial and Environmental Research: Vol. 6
, Article 3.
Available at: https://dc.uwm.edu/ijger/vol6/iss1/3