陕西省泾惠渠灌区土壤重金属环境质量现状及评价

Current Situation and Evaluation of Soil Environmental Quality for HeavyMetals in Jinghuiqu Irrigation District of Shaanxi Province

在调查收集泾惠渠灌区农业生态环境状况资料的基础上,通过采集土壤样品,分析了灌区土壤中重金属含量,并通过单因子指数法对其土壤重金属环境质量现状作出了评价。结果表明,灌区土壤中Pb,Cd,Hg,As,Cu,Zn平均值与陕西省土壤背景值的平均值相比,分别超出46.0%,105.7%,90.6%,47.8%,12.6%和178.6%,只有Cr基本接近;从各元素的变异系数看,Cd的最大,为1.547,As的最小,为0.105;土壤中Pb,Cd,Hg,As,Cu,Zn以及Cr相互之间的相关性都不显著;重金属元素与肥力指标的相关性不具有任何规律性;单因子评价结果表明,灌区土壤中Zn污染最严重,平均单因子污染指数1.48,为轻度污染。As的平均单因子污染指数1.11,也达到轻度污染。Cd的平均评价结果为非污染。灌区土壤中Cr,Pb,Cu,Hg含量基本未达到土壤污染积累的起始值。

Based on investigating and collecting information on the present situation of agro-ecological environment in Jinghuiqu irrigation district of Shaanxi Province,soil samples are collected and the contents of heavy metals are analyzed.Meanwhile,soil environmental quality for heavy metals is evaluated by single factor index.Results show the average contents of Pb,Cd,Hg,As,Cu,and Zn in soils are 46.0%,105.7%,90.6%,47.8%,12.6%,and 178.6%,respectively,higher than soil background values of Shaanxi Province.Only the content of Cr is similar basically.The variation coefficient of Cd is the biggest（1.547） and that of As is the smallest（0.105）.There are no significant correlations among Pb,Cd,Hg,As,Cu,Zn,and Cr.The correlation between heavy metals and soil fertility index is not significant.The pollution degree of Zn is the highest and the average single factor index is 1.48,which means pollution degree is at a light level.The average single factor index of As is 1.11 and it is also at a light level.The average single factor index of Cd is at no pollution level.The contents of Cr,Pb,Cu,and Hg are lower than the initial values of soil pollution accumulation basically.