Spatial Heterogeneity and Distribution of Lead in Topsoil of Lower Reaches of Minjiang River,Wutongqiao

The application of spatial heterogeneity analysis based on geographical information system(GIS) to environmental geochemistry was studied.Spatial analysis methods,including geostatistics and spatial autocorrelation,were used for lead content in 93 topsoil samples from Wutongqiao county at the lower reaches of Minjiang River,for analyzing the lead spatial heterogeneity in topsoil and its pollution characteristic.The results of geostatistics showed that the lead content had good spatial structure and its semi-variogram can be fitted by exponential model.The distribution characteristics of Pb in soil was shown obviously anisotropy and had significant spatial autocorrelation at the Minjiang River's azimuth,deduced the lead in soil had a migration tendency along the Minjing River.The map of classification of soil Pb content by Kriging method showed the bank and urban-rural marginal area were the mainly contaminative area,preliminary result indicated there had Non-point source pollution of lead at these areas.