陕西省泾惠渠灌区土壤重金属地质累积指数评价

通过对陕西省泾惠渠灌区现场调查及土壤样品的采集,分析了灌区土壤中Hg、Cd、Cr、Pb、As、Cu、Zn等7种元素的含量,应用地质累积指数对灌区土壤进行了评价。结果表明：从区域分布看,阎良区、临潼区、高陵县所属采样点污染较严重;Hg污染最严重,地质累积指数为1.007～3.117,58%的采样点级别为3级,属中度污染到强污染,38%的采样点级别为2级,属中度污染;Zn污染程度次之,地质累积指数为-0.407～1.644,71%的采样点级别为1级,属无污染到中污染;Cd污染变异程度最大,地质累积指数为-2.705～3.312,70%的采样点级别0级,属无污染,但个别采样点达到了强污染;Cu的地质累积指数为-0.535～0.421,Pb为-1.119～-0.144,Cr为-1.005～-0.458,As为-0.562～0.077,除个别点外这些重金属污染级别皆为0级,属无污染。

Assessment on Soil Heavy Metals Pollution by Geoaccumulation Index in Jinghuiqu Irrigation District of Shaanxi Province

By investigating field and sampling soil in Jinghuiqu irrigation district of Shaanxi,the contents of Hg、Cd、Cr、Pb、As、Cu and Zn in soil were analyzed,and soil quality was assessed with geoaccumulation index.The results showed that the pollution levels of heavy metals were higher at the sampling sites of Yanliang,Lintong and Gaoling than that at Sanyuan and Jingyang;the pollution level of Hg was highest,geoaccumulation index was 1.007-3.117,the grade of geoaccumulation index was moderate or strong pollution for 58% of sampling sites,and moderate pollution for 38% of sampling sites;the pollution level of Zn was only less than that of Hg,geoaccumulation index was-0.407-1.644,the grade of geoaccumulation index was no pollution or moderate pollution for 71% of sampling sites;the variability of pollution level of Cd was greatest,geoaccumulation index was-2.705-3.312,the grade of geoaccumulation index was no pollution for 70% of sampling sites,but the grade of geoaccumulation index was strong pollution for individual sampling site;geoaccumulation indexes of Cu,Pb,Cr and As were respectively-0.535-0.421,-1.119——0.144,-1.005——0.458 and-0.562-0.077,the grade of geoaccumulation index was no pollution for most sampling sites.