农牧交错区路域表层土壤重金属污染评价—以省道104武川-召河段为例

Pollution Assessment of Heavy Metals in Farming-Pastoral Ecotone of Roadside Soils—A Case Study of S104 from Wuchuan to Zhaohe

随着经济的发展,道路交通在一定程度上导致了农牧交错带道路周边土壤重金属污染。本文以北方农牧交错区内省道104武川-召河段路旁0~200 m土壤表层为研究对象,采集农地、林地、草地土壤样品192个,进行重金属Cd、Zn、Cr、Ni、Cu、Pb含量测定。以此为基础用地累积指数评价及潜在生态危害评价方法评价了研究区的污染状况。研究表明:距路基5~30 m范围内个别重金属含量的地累积指数达到轻度污染状态值,其他距离范围内为无污染状态。从潜在生态危害评价结果来看,三种土地类型土壤重金属生态风险都属于低生态风险等级,但是RI指数在5~10 m内都大于其他区域,随着离路基距离越远,生态风险指数逐渐降低。生态风险等级最高为农地,其次为林地,最后为草地。

With the development of economy, conduct of road traffic to an extent has resulted in soil metals pollution along the road in farming-pastoral ecotone. Selecting 0 - 200 m surface soil along the 104 road from Wuchuan to Zhaohe in farming-pastoral ecotone North China, we took 192 samples in farmland, forest, grassland and gauge the content of soil metals such as Cd, Zn, Cr, Ni, Cu, Pb. Based on the content of soil heavy metals, the research assessed the pollution situation with method of geoaccumulation index and potential ecological index. Pollution assessment showed that some in-dividual kinds of heavy metals contaminated soil in 5 - 50 m area to road, and other areas were not contaminated. The rate of ecology risk was low, but with the distance towards road increasing, the RI index decreased. The highest degree of land use is farmland;the second is forest;the degree of grassland is the lowest.