摘要
在土壤元素异常下限值的确定对环境地球化学评价具有重要意义,传统异常下限值计算方法仅适用于元素含量数据呈正态分布的情况,而事实上土壤元素含量的空间分布极其复杂,很可能具有多重分形分布特征,元素背景和异常有各自独立的幂指数关系。本文探讨利用分形方法确定典型工业区土壤中Cd元素的异常下限值。基于分形的含量-面积方法确定了合肥大兴地区(典型工业区)土壤中污染元素Cd的异常下限值为0.445 mg/kg,并根据该异常下限值圈定了异常范围。同时与传统方法(平均值加两倍标准离差)确定的土壤中Cd元素异常下限值及异常范围进行了对比分析,结果显示,分形方法圈定的异常区域是有效的、合理的,控制了区内主要的导致土壤Cd元素污染的企业。
It is of great significance to determinate the singularity thresholds value of elements in soil for environmental geochemical evaluation, the traditional way of the singularity thresholds value is only suitable to the element data that is normal distribution. Nevertheless, the spatial distribution of chemical elements in soil is extremely complicated, which has the multi -fractal distribution characteristic possibly, and the background and anomaly values of elements usually show independent power index relationship. This paper discusses to use fractal method to determinate the singularity thresholds value of Cd element in soil of typical industrial district. Based on the concentration - area fractal, the singularity thresholds value of Cd element＇s determination in soil of Daxin in Hefei （typical industrial district）is 0. 445 mg/kg, and the anomaly extension is also selected based on this thresholds. Compared with the singularity thresholds value of elements and the anomaly extension in soil which are determined by the traditional methods（X^- ＋ 2S）, the results show that the anomaly extension selected by fractal method which control the main enterprise that leads to Cd element pollution in area is effectively and reasonably.
出处
《环境科学与管理》
CAS
2009年第5期27-30,共4页
Environmental Science and Management
基金
安徽省优秀青年科技基金项目(编号:04045063)
关键词
分形
Cd元素
异常值
土壤
合肥
fractal method
Cd element
the singularity threshold
soil
Hefei
