个旧城区土壤中重金属潜在生态危害评价

A STUDY ON THE POTENTIAL ECOLOGICAL RISK OF HEAVY METALS IN SOILS OF GEJIU URBAN AREA

采用Hakanson潜在生态危害指数法对个旧城区土壤重金属的潜在生态危害作出评价,并在此基础上应用Kriging插值方法进行了空间分析,得出了个旧城区土壤各等级生态危害的面积分布以及重金属潜在生态危害的空间变化特征。

Heavy metals are one of the most important factors of environmental pollution in the town of Gejiu, Yunnan. The method of potential ecological risk index, proposed by Hakanson, is used to assess the risk of seven heavy metals in the soil of the town. Based on it, Kriging interplating method is used to analyze the spatial characteristics of the risk. After that, a three-dimensional picture, which shows the areas of different potential risk ranks and their spatial features in Gejiu, is completed. In the whole researched area, the potential ecological risk index of the seven metals is 200.74,which is moderate. And they, one by one, from the maximum to the minimum, rank in the following order: As Pb Cd Cu Zn Cr Hg. For the most of the area studied, the potential ecological risk of heavy metals is soft. The risk of Hg is the minimum, and soft in the whole area. The risk of As is the maximum, and the area ratio of the risk ranks, from the low rank to the high, is 40.5∶41.8∶12.6∶(4.1)∶1.0. Most heavy metals, especially Cu As and Pb, are distributed in the central section and the south-west of the town.