Spatial Variability And Evaluation Of Heavy Metals In The Wetland Sediments At The Baidu Port Of Taihu Lake

In this study, heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) were measured in the sediment of Baidu port estuary wetlands, Taihu lake. The methods of data fitting functions of geo-statistical analysis and spatial analysis function of GIS were used in the spatial variation analyses of heavy metals. On this basis, heavy metal pollution assessment in Baidu port estuary wetland was carried out by the methods of pollution load index and potential pollution ecological index. The results show that:(1)Cd, Cu, Ni and Zn contents were over the background value in all of the sampling points. And in most of them, Cr, Pb contents were the same. Help with the urbanization and industrialization accelerates on banks of upstream rivers, the trend that the heavy metals in sediment was accumulating was clear.(2)Ni content showed weak spatial correlation. It may be because that the element was affected by pollution, wetland plant species, management of human random factors such as larger. While, the content of the three heavy metals Cd, Pb, Zn showed moderate spatial correlation and similar random effects and structural effects. Cr, Cu showed strong spatial correlation- it showed that the description of parent material, topography, climate and other structural factors on the spatial variability play a dominant role.(3)In the six heavy metals in sediment, Cu and Cd created most serious pollution problem, and loaded the largest contribution to the heavy metal pollution. That made Cu and Cd be the priority pollutants. The order beginning with the largest potential ecological risks of heavy metals is that: Cd>Cu>Ni>Pb>Zn>Cr. Overall, there were 81.25% of total sample points, which the potential ecological risk index (RI) were beyond the moderate risk level. All above showed that heavy metals have been presented against total potential ecological deterioration.