摘要
随着农牧经济的快速发展,大量重金属进入土壤,使土壤结构和功能发生改变、土壤质量下降,不仅影响农牧业的产量和品质,最终会危及到人类的健康。选取北方农牧典型交错区扎鲁特旗作为研究区,采集62个土壤表层(0—20 cm)样品,测定了铜(Cu)和铅(Pb)两种重金属的含量,采用简单克里金插值分析了重金属Cu和Pb含量的空间分布特征,利用污染指数和潜在生态风险指数评价了重金属的污染及生态风险状况,以及运用反距离权重插值法分析了潜在生态风险的空间分布特征。结果表明:土壤Cu和Pb平均含量分别为24.28和19.54 mg·kg–1。Cu含量呈现由中心向四周辐射状递减,其峰值主要分布于中部偏东位置,低值主要分布于西北部区域;Pb含量呈现由西北向东南地区递增的趋势,其区域变化较明显,北部地区含量较少。农田Cu和Pb含量显著高于草地。土壤重金属含量的空间分布与年平均降水量、土壤有机碳、土壤容重有显著的相关性。Cu污染比较严重,Pb为轻度或中度污染,综合潜在生态风险均在中等及以下,风险区主要分布在中部。
With the rapid development of agriculture and animal husbandry economy,a large amount of heavy metals enter the soil,which changes the structure and function of the soil and decreases the quality of the soil.It not only affects the output and quality of agriculture and animal husbandry,but also ultimately threatens human health.A total of 62 soil surface(0-20 cm)samples were collected from the study area of a typical farming-pastoral region in northern China,namely,Zhalute Banner.The contents of two heavy metals(Cu)and lead(Pb)were collected.The spatial distribution characteristics of heavy metals Cu and Pb were analyzed by simple Kriging interpolation,and the pollution and ecological risk of heavy metals were evaluated by using pollution index and potential ecological risk index.The spatial distribution characteristics of potential ecological risk were analyzed by inverse distance weight interpolation method.The results showed that the average contents of Cu and Pb in soil were 24.28 and 19.54 mg·kg–1,respectively.The content of Cu decreased radially from the center to the surroundings,and its peak value mainly distributed in the east-central region,while the low value mainly distributed in the Northwest region.The content of Pb increased from the northwest to the Southeast region,with obvious regional change and less content in the North region.The contents of Cu and Pb in farmland were significantly higher than that in grassland.The spatial distribution of heavy metals in soil was significantly correlated with annual average precipitation,soil organic carbon and soil bulk density.The pollution of Cu was serious,and the pollution of Pb was mild or moderate.The comprehensive potential ecological risk was moderate or below,and the risk area was mainly in the middle.
作者
师小平
陈银萍
李玉强
王旭洋
余沛东
牛亚毅
SHI Xiaoping;CHEN Yinping;LI Yuqiang;WANG Xuyang;YU Peidong;NIU Yayi(College of Environmental and Municipal Engineering,Lanzhou Jiaotong University,Lanzhou,730070,China;Northwest Institute of Ecological Environment and Resources,Chinese Academy of Sciences,Lanzhou,730000,China)
出处
《生态科学》
CSCD
2020年第6期7-15,共9页
Ecological Science
基金
国家重点研发计划(2017YFA0604803,2016YFC0500901)
国家自然科学基金项目(No.31560161,No.31260089,No.31971466)。
关键词
重金属
空间分布
污染评价
潜在生态风险
heavy metal
spatial distribution
pollution assessment
potential ecological risk
