利州区农产品基地土壤重金属污染评价

运用指数法对利州区农产品基地土壤重金属污染进行分析评价,并尝试运用聚类法对重金属进行了聚类分析和污染源推测。从单项污染指数来看,利州区农产品基地8个采样点中所有点元素均不超标。土壤中重金属元素平均单项污染指数由高到低依次为:AsHgCdCuCrPb,其中最高值为As,其值为0.42,可知农产品基地土壤中重金属平均单项污染指数均小于1。从上可以说明该基地的重金属含量受人为影响已在土壤中有所积累,但是总体状况良好。从综合污染指数来看,土壤中重金属平均内梅罗综合污染指数为0.31,其值小于1,属于清洁水平,适合发展有机食品和发展无公害食品生产。聚类分析法得出Pb和Hg的相关系数最大,其值为0.72。说明两者之间具有强正相关性,它们的含量会同时出现增减变化,而Cd和Cu的相关系数为-0.705,说明两者之间是有此消彼长相互抑制的关系。

Assessment of Heavy Metal Pollution in Soils of Lizhou Agricultural Products Base

The Index Method was adopted to evaluate the soil heavy metal pollution of Lizhou Agricultural Products Base.The Clustering Method was used to analyze the soil heavy metals and speculate the source of pollutants.According to the single contaminant index,heavy metal index from every one of the eight sampling sites was under the standards.The average single pollution indexes of the heavy metals were listed from higher to lower as AsHg CdCuCrPb,in which the maximum index with value of 0.42 was from As.Therefore all of the average single pollution indexes of the heavy metals were less than 1.The discussion above means that the heavy metals had been accumulated in the soils due to human activities,while the overall situation was good.Considering of the integral pollution index,the average Nemerow Pollution Index was 0.31,which was less than 1 belonging to clean level and being suitable to develop organic food and safe food production.According to Cluster Analysis,the correlation coefficient of Pb and Hg was the maximum as 0.72,which meant a strong positive correlation between.Their contents would increase or decrease synchronously.While that between Cd and Cu was-0.705,which meant they inhibited each other.