Heavy metal pollution evaluation and spatial influence range analysis for main roads within the Fifth Ring Road of Beijing urban

Abstract

以北京市城區五環內為研究區域,共采集34個土壤樣品,采樣點皆位于市區主道路兩側,測定了Cd、Cu、Zn、Pb、V、Mn、Ti、Al和Fe 9種金屬元素含量,由地積累指數污染評價分析表明北京城區主道路土壤環境總體處于輕度污染。土樣中Cd、Cu、Zn、Pb、V和Mn含量均值為1.28、26.45、79.7、32.86、79.11、531.4 mg/kg,Ti、Al和Fe均值為3.76、56.59和21.78μg/kg。其中Cd污染最為嚴重,超過背景值10.67倍,重金屬的污染程度由強至弱依次為Cd>Cu>Pb>Zn>V>Mn。通過GIS空間插值和緩沖區分析表明,二環、三環和四環的外側影響范圍分別為0.3、0.36、0.32 km,其中三環和四環主道路相比于二環更能影響重金屬濃度的分布。 Heavy metals including Cd,Cu,Zn,Pb,V,Mn,Ti,Al and Fe collected from 34 samplings within both sides of road at the fifth ring in Beijing urban were determined. By index of geoaccumulation and clustering analysis,their results showed that soil environment of Beijing urban were in a null-mild pollution level. Content mean value of samplings for Cd, Cu,Zn,Pb,V and Mn were 1.28,26.45,79.7,32.86,79.11 and 531.4 mg/kg,while Ti,Al and Fe were 3.76,56.59 and 21.78 μg/kg,in which the most serious pollution was Cd which was more than 10.67 times of background value. Pollution levels of heavy metal elements were ranked as Cd,Cu,Pb,Zn,V,Mn from strong to weak. GIS interpolation and buffer analysis indicated that outside influence ranges of the second,the third and the fourth ring road were 0.3,0.36 and 0.32 km. Compared with the second ring road, the third and the fourth ring road had a more obvious influence for concentration of heavy metal distribution.