Spatial Variability And Source Analysis Of Soil Heavy Metals In Pingtan

Soil heavy metals are the important indexes of soil environmental quality. The development of "Pingtan Comprehensive Experimental Zone" aggravates the pressure on the environment of soil. Currently, there are few studies on the spatial distribution of soil heavy metals in Pingtan island. It is essential to investigate soil heavy metals contents, to analyse their spatial distribution and the source. Combining traditional statistics with GIS spatial analysis, the paper focused on the spatial variability and influencing factors of soil heavy metals in Pingtan Island. Results are proposed to be benefit for assessing the cumulative environmental effect of development on local environment, maintaining the soil environmental quality, and preventing pollution of heavy metals during construction.The characteristics of spatial variability of soil heavy metals shows that the spatial variability of Cd is medium, while the spatial vaiaibilities of Cr?Co?Zn?As?and Pb are high.. All soil heavy metals are spatially autocorrelated, and for semivariance analysis, the isotropy was the best. For V, The best interpolation model is the simple kriging-removing the second order-Gaussian model-interpolation. For Cr?As?Pb, the best interpolation methods are the simple kriging-exponential model-interpolation. For Co, the best interpolation method is simple kriging-spherical model-interpolation. For Zn, the best interpolation method is ordinary kriging-remove the second order-Gaussian model-interpolation. For Cd, the best interpolation method is tension spline interpolation.The spatial distribution of soil heavy metals shows that V?Co and Cr are similar, in the centerl and northwest Pingtan, their contents are high. As and Cd are considered the pollutant elements, their contents in most places are higher than the national standard. In northeast and southwest of Pingtan, soil As content is high. In the northwest, middle and east of Pingtan, soil Cd is high. In the northwest, part of middle, and east of Pingtan, soil Zn is high.The soil Pb is low in the whole area, in the west, middle of Pingtan, soil Pb is relatively higher than other parts.The source analysis of soil heave metals shows that Pb, Cd, Cr contents are significantly different in various soil classes, particularly for As and V, with a high value in red soil and latosol. Elevation has significantly positive correlation with Cr, Co contents. Slope has significantly positive correlation with Pb. Slope aspect had significantly impact on As, with a high value on the shaded slope and a low value on the sunny. Land use patterns is an important factor affected soil heavy metal elements except Pb. Soil erosion has obviously impact on Cd content change, the greater the amount of soil erosion area, the lower the content of Cd. Road traffic distribution has great impact on spatial variability of Zn, Pb. Distribution of traffic arteries has great impact on spatial variability of Cd. Residential location also has great impact on spatial variability of As, Cd and Pb. The road pollution range is approximately 120m, and the residential areas pollution range is approximately 225m.Heavy metal pollution research of studied area shows that As and Cd mean values exceed the background value of Fujian province coastal area. Zn is a potential contaminated element; For As, pollution comes from pesticides and fertilizers, residential wastewater and waste residue emissions. For Cd, pollution is mainly from traffic pollution emissions, residential domestic wastewater, and pesticides and fertilizers. For Zn, pollution is due to road traffic emission.