Spatial variability of Cu, Zn and Mn contents in Non-anthropized soils in the Santa Catarina state

Abstract

The aim of this study was to evaluate the spatial variability of Cu, Zn and Mn in non-anthropic soils in the Santa Catarina state, using ordinary kriging and ordinary cokriging models. The Cu, Mn and Zn contents were taken from the database of the Department of Soils and Natural Resources of the State University of Santa Catarina. The geostatistical methods of ordinary kriging and ordinary cokriging were applied to fit the theoretical models to the experimental semivariograms. The model choice with the best fit was based on the parameters of Average Square Root, Average Standard Error, Akaike Criterion and Spatial Dependency Index. For ordinary kriging the Gaussian model (R² 0.998) explains the spatial variability of Cu, while the circular model describes the variations of Mn (R² 0.894) and Zn (R² 0.991). For ordinary cokriging, the exponential model describes the behavior of trace elements versus land elevation. Geostatistical methods are effective in the spatializing of Cu, Mn and Zn contents in non-anthropic soils in the Santa Catarina state. Finally, land elevation does not show a linear relationship with the trace elements levels, which are concentrated in the western region, correlating with the source material.