摘要
为了解晋中盆地土壤重金属污染现状及来源,测定了302个土壤样品中Pb、Cr、Cd、As和Hg五种重金属的含量,采用多元统计方法、地统计学方法和随机森林模型,分析了盆地内土壤重金属的污染状况和污染来源。结果表明:五种重金属含量均值都高于山西省背景值含量,其中As和Cr含量均值接近山西省背景值含量,Pb略高于山西土壤背景值、Cd和Hg则存在明显超标,其中Hg和Cd分别有11. 5%和60. 0%的样点超过国家土壤质量二级标准。源解析结果显示:As和Cr主要来源于土壤母质等自然源,Pb、Cd和Hg主要来源于工、农业生产等人为源。随机森林结果显示:影响Cd含量的主要因素重要性排序依次为土壤有机质含量、人均工业产值和土壤全氮含量,说明Cd的积累受工业活动和农业活动中化肥施用的共同影响;影响Hg含量的主要因素重要性排序依次为人均工业产值和污染企业距离,说明Hg主要来源于工业污染活动;影响Pb含量的主要因素重要性排序依次为道路距离、人均工业产值和污染企业距离,说明Pb既受交通运输的影响又受工业活动的影响。
To understand the status and sources of heavy metal pollution in soil in Jinzhong basin,the contents of Pb,Cr,Cd,As,and Hg in 302 soil samples were determined.The pollution status and sources of heavy metals in soil in the basin were analyzed by using multivariate statistical method,geostatistical method,and the random forest model.Results show that the mean contents of five heavy metals are all higher than the corresponding background values for Shanxi.Specifically,As and Cr content averages are close to background values.The content of Pb is slightly higher than that of soil background values in Shanxi.Cd and Hg contents are significantly above the standard,Hg and Cd in 11.5% and 60.0% of sample points,respectively,exceed the levels of national second-level soil quality standard.The results of source analysis show that As and Cr are mainly from natural sources like soil parent materials,whereas Pb,Cd,and Hg are mainly from artificial sources including industrial and agricultural production.The random forest model results show that the importance of the main factors affecting the Cd content follow the order of soil organic matter content,industrial output per capita,and soil total nitrogen content.This indicates that the accumulation of Cd is affected by combined effects of industrial activities and chemical fertilizer application in agricultural activities.The most important factor affecting the Hg content is per capita industrial output value,followed by distance from polluting enterprises,indicating that Hg is mainly from industrial pollution activities.The main factors affecting Pb content are ranked in the order of road distance,per capita industrial output value,and distance from polluting enterprises,indicating that Pb is affected by both transportation and industrial activities.
作者
刘斌
郭星
朱宇恩
LIU Bin;GUO Xing;ZHU Yuen(Shanxi Academy of Social Sciences,Taiyuan 030006,China;College of Environment and Resources,Shanxi University,Taiyuan 030006,China)
出处
《干旱区资源与环境》
CSSCI
CSCD
北大核心
2019年第1期106-111,共6页
Journal of Arid Land Resources and Environment
基金
国家重点研发计划(2017YFD0801300)
山西省软科学研究计划重点项目(2017042014-7)资助
关键词
晋中盆地
土壤重金属
多元统计
随机森林
Jinzhong basin
heavy metals in soil
multivariate statistics
Random Forests
