Research on Spatial Distribution and Pollution Evaluation of Heavy Metals in Soils Around a Thermal Power Plant

The contents of heavy metals(Cu,Zn,Pb and Cr)in soils around Dawukou thermal power plant which locates in Ningxia Province were investigated to evaluate soil environmental pollution of heavy metals by using different evaluation standards of heavy metal pollution for comparison,furthermore,the spatial distribution of pollution index was analyzed with the aid of geographical information system(GIS)technology and potential sources of heavy metal pollutants in soils were also elucidated.The results showed that the soils were polluted with heavy metals Cu,Zn,Pb and Cr according to natural background values as evaluation standard.While using National Standard(GB 15618—1995)as evaluation standard,soils were not polluted with heavy metals.The pollution of Pb and Cr was more serious.Integrated pollution index of soil heavy metals is less than 0.7 so that the whole studied soils were unpolluted.It was preliminarily concluded that the Dawukou thermal power plant,the traffics and human activities may be the major causes leading to soil heavy metal pollution.