『Abstract
Soil map units taken into account in geostatistical prediction
of heavy metals concentrations in a contaminated site of Fuyang
Valley, Zhejiang Province, China. To compare the spatial variabilities
of Cu, Zn, Pb and Cd concentrations in different soil map unit
or combination of soil map units, a total of 94 samples distributed
in three map units (Yellowish-red soil, Gravelly-yellowish-red
soil and Gritty-yellowish-red soil) were collected in this area.
The values of Cu, Zn, Pb and Cd concentrations were natural logarithm
transformed to fit normal distribution. The variations of four
heavy metal concentrations in Gravelly-yellowish-red soil was
similar to that in Gritty-yellowish-red soil, but they were different
to that in Yellowish-red soil. Then, the 94 soil samples were
grouped into two classes (samples of Yellowish-red soil, and samples
of Gravelly-yellowish-red soil or Gritty-yellowish-red soil).
Semivariogram analysis revealed that all the four heavy metal
concentrations in the study area showed moderate to strong spatial
dependency, and local spatial variability (i.e. the variance between
soil map units) played an important role in their spatial prediction.
The spatial distribution maps of the four heavy metals were drawn
by using only the measured data and by using the measured data
plus taking into account soil map units, respectively. The results
showed that spatial prediction by taking into account soil map
units could reveal the huge spatial variability of the heavy metals,
much better than the prediction without using soil map information
in this contaminated site.
Keywords: Contamination; Heavy metals; Semivariogram; Soil map
unit; Spatial variability』
1. Introduction
2. Materials and methods
2.1. Descriptions of study area
2.2. Sample collection and analyses
2.3. Data transformation and methods
2.4. Coefficient of variation
2.5. One-way analysis of variance
2.6. Semivariance analysis and kriging interpolation
3. Results and discussion
3.1. Pollution status of the four heavy metals
3.2. Comparison of heavy metal concentration in different map
units
3.3. Semivariograms and spatial prediction comparison
4. Summary
Acknowledgements
References