Pollution assessment and spatial distribution of soil Hg and Cr in the Taiyuan area of the Fenhe River

Soil samples were collected from the Taiyuan area of the Fenhe River and analyzed to determine Hg and Cr concentrations. The spatial distribution of Hg and Cr in soils in this area was explored using the technologies of Geographic Information System and Geostatistic. Single Factor index was used to assess the pollution of Hg and Cr in urban soils of this area. The results show that the concentration of soil Hg in this area is higher than background concentration of that in Shanxi Province and China, while the concentration of soil Cr equals to the background concentration of that in Shanxi Province and China. The semi-variance model of Hg, Cr is Gauss model. The spatial self-correlations of Hg and Cr in soils in this area are moderately dependent and their spatial interpolation map revealed high concentration of Hg and Cr in the north-central and south parts of the region. The results of single factor index assessment show that Hg pollution is much more serious than that of Cr, however, the content of Hg is in the range of the second grade of the national standard for soil environmental quality (GB15618-1995). Various spatial distributions suggested that Hg and Cr pollution control should focus on their spatial character and local condition.