摘要
城市土壤重金属污染是城市化后噬待解决的一个重要问题。传统的土壤重金属污染分析方法——克里格方法,通过满足未采样点局部方差最小而获得土壤污染状况预测结果,算法本身会给估值结果带来光滑作用,并只能提供未采样点的局部不确定性。文章提出利用空间统计学的模拟方法,对土壤重金属污染状况进行研究,通过获取多幅模拟结果之间的差异来揭示研究区域土壤重金属污染的整体空间分布形态。文章以上海某区域6种重金属(Cu、Pb、Cd、Cr、Hg和As)为研究对象,利用空间统计学模拟方法对其空间分布予以研究,给出每种重金属空间分布模拟结果。最后,文章以研究区域土壤环境背景上限值为标准,给出研究区域不同土壤重金属空间分布相应级别的不确定性分析结果。
The pollution of surface soils caused by heavy metals was a focus problem appeared in the process of urbanization. Instead of the acquisition of the smoothed and ＂best＂ estimation of unsampled points, the paper paid much attention to describe the detail of contamination and assess the spatial uncertainty about unsampled values. The simulation method in Geostatistics was applied to the study of heavy metal contamination. Based on the statistics （histogram, Variogram） of sampled points, the simulation method can generate a set of equally-probable realizations. They represented the different situation of contamination possibly, which was particularly helpful for uncertainty assessment. The case study was from an Urban-Rural transition zone of Shanghai, China. Six kinds of heavy metals （Cu, Pb, Cd, Cr, Hg and As） in agricultural surface soils were analyzed in the paper. Based on the sequential simulation methods, the author got the different realizations of the six kinds of heavy metals respectively. At last, the author drew the conclusion that Cu, Cd and Cr were the dominant elements that influenced soil quality in the study area. Meanwhile, the author gave the uncertainty map of the six heave metals with the standards values of background as the threthold.
出处
《生态环境》
CSCD
北大核心
2008年第5期1898-1902,共5页
Ecology and Environmnet
基金
建设部研究开发项目(06-K9-8)
关键词
模拟
地统计学
空间变异
重金属
不确定性
simulation
geostatistics
spatial variability
heavy metals
uncertainty
