山东高密胶河土豆产地土壤重金属含量特征及来源解析OA

Taking the core production area of"Jiaohe Potato",a national geographical indication product as the research area,645 surface soil samples have been systematically collected,and the contents of 8 heavy metals,including As,Cd,Cr,Cu,Hg,Ni,Pb,Zn,and pH value of the soil have been determined.By using geo-accumulation index and Nemerow index,the pollution degree has been evaluated.Combining with correlation analysis,systematic clustering,principal component analysis and geostatistics,the sources and spatial distribution of heavy metals have been revealled.It is showed that Hg exhibits the most significant spatial variability,the coefficient of variation is 207.69%.Cd and Cu exceed the risk screening values at 4 sampling points respectively,and no sampling points exceeds the risk intervention values.The median and mean values of geo-accumulation index are both less than 0,indicating an overall low level of pollution,while Hg and Cd show local abnormal enrichment and significant heterogeneity.As revealled by the Nem-erow index,Cd is main contributor of composite pollution.Comprehensive pollution high-value area mainly distribute along the railway lines and Xiajiagou area.The sources of heavy metals can be classified into four categories,they are traffic sources,natural sources,agricultural sources and anthropogenic mixed sources.The four principal components have explained 77.619%of the original information cumu-latively.Regulated by hydrodynamic sorting and supergene geochemical migration,main component factor score of heavy metals in Jiaohe floodplain area is low.Through the coupling of multiple methods,the pol-lution characteristics and sources of soil heavy metals have been analyzed systematically.It will provide a scientific support for comprehensive management of Jiaohe potato production area.