Figure 1.
Location of sampling sites in the Laizhou Bay and the coastal Zhangzi Island.
Table 1.
The metal guideline values of two different criteria used to distinguish marine sediment quality and the average upper continental crust (UCC) values.
Figure 2.
Information of the total concentrations of the studied metals.
The spatial variations of studied metals in total concentrations of the surface sediments from the Laizhou Bay and the coastal Zhangzi Island. The horizontal dash lines represent their corresponding TEL or PEL concentrations; the horizontal solid lines represent their corresponding higher boundary values of Class I sediment category of China.
Table 2.
Heavy metal concentrations in the surface sediments of the Laizhou Bay and the coastal Zhangzi Island; and the related values reported for the surface sediments of other marine areas of China are shown for comparison.
Table 3.
Pearson correlation matrix for the sediment components.
Figure 3.
Geochemical phases of the studied metals.
The distributions of studied metals in different geochemical phases of the surface sediments from the Laizhou Bay and the coastal Zhangzi Island.
Table 4.
Pearson correlation matrix for metal fractionations with grain size and TOC.
Figure 4.
The spatial distribution of mean PEL quotient values.
The histogram shows spatial distribution of mean PEL quotient values in the surface sediments of the Laizhou Bay and the coastal Zhangzi Island.
Figure 5.
Dendrogram showing clustering of sampling sites in the two studied areas.
Figure 6.
The spatial distributions of EF values.
The histogram shows spatial distributions of EF values for heavy metals in the surface sediments of the Laizhou Bay and the coastal Zhangzi Island. The horizontal lines represent EF value of 1.5.
Figure 7.
The spatial distributions of Igeo values.
The histogram shows the spatial distributions of Igeo values for heavy metals in the surface sediments of the Laizhou Bay and the coastal Zhangzi Island. The horizontal dash and solid lines represent Igeo values of 0 and 1, respectively.
Figure 8.
The spatial distributions of RAC values.
The histogram shows the spatial distributions of RAC values (%) for heavy metals in the surface sediments of the Laizhou Bay and the coastal Zhangzi Island. The horizontal dash lines represent RAC values (%) of 1 or 10. The horizontal solid lines represent RAC values (%) of 30 or 50.
Figure 9.
The spatial distributions of ER values.
The histogram shows the spatial distributions of ER values for heavy metals in the surface sediments of the Laizhou Bay and the coastal Zhangzi Island. The horizontal dash and solid lines represent ER values of 40 and 80, respectively.
Figure 10.
The mean values of EF, Igeo, RAC, ER and total concentration for metals.
Figure 11.
Loading plots of the principal components obtained for the data set.
Table 5.
Loadings of experimental variables on significant principal components for the data sets of the Laizhou Bay and the coastal Zhangzi Island.