影响城市土壤重金属污染因子的关联度分析

THE CORRELATION ANALYSIS BETWEEN THE CONTENT OF HEAVY METALS AND THE FACTORS INFLUENCING THE POLLUTION OF HEAVY METALS IN URBAN SOILS IN NANJING CITY

城市土壤深受人为活动的影响 ,具有明显的重金属人为富积的特点 ,认识这些土壤重金属丰度、形态与土壤理化性质及周围环境因子的关系 ,有助于更好地保护和修复城市土壤生态系统。本文对南京城市土壤中Pb、Zn、Cu、Cd四种重金属元素的含量和形态特征进行了研究 ,并用灰色系统理论方法对南京城市土壤重金属污染的影响因子进行了灰色关联度分析 ,认为最主要影响因子是距工业区远近 ,其次是土壤粘粒含量、pH值 ,而交通车流量。

The urban soils are affected greatly by human activity and characterized by significantly anthropogenic enhancement of heavy metals. It will be helpful for us to protect and to remedy the ecosystem of urban soils better if we are learn the relation between the abundance and the form of heavy metals in soil with the physical and chemical properties of soils and the factors of surrounding environment. This study was conducted to examine the content and the forms of heavy metals in urban soils in Nanjing, applying the theory of grey system to analyze the factors influencing the pollution of heavy metals. Such factors as soil organic matter content, soil clay content, soil pH, the distance from industrial zone, the automobile flow, and the fraction of residue in soils were concerned in this paper. Grey-relational analysis showed that the most important factor is the distance from industrial zone. The factors such as soil clay content and soil pH are also important. Other factors are relatively unimportant.