MULTIVARIATE-GEOSTATISTICS-AND GIS-BASED APPROACH TO STUDYING RESIDUES AND SPATIAL DISTRIBUTION OF OCPs IN SOILS OF HUIZHOU CITY,CHINA

摘要:

Investigations on residues of organochlorine pesticides(OCPs) in soils in Huizhou,China were conducted.A total of 42 soil samples were collected from sites representative of the region for analysis of contents of OCPs.And with the aid of multi-variate geostatistics and GIS,residue and spatial distribution of 17 types of OCPs were analyzed.Results show that the 17 OCPs were detected,various in content in all the soil samples.HCHs and DDTs residues were detected,but below the criteria of the national standards for soil environment quality.Residue content of beta-HCH was the highest among HCHs,which implied some recent input of HCH to soils,while for DDT,no sign of new input was found.Compared with other regions in the country,Huizhou city was lower in soil HCH and DDT content.Principal component analysis demonstrated that the above-said 17 OCPs in the soil may have 5 major contributors,corresponding respectively to industrial use of HCH,natural factors,use of lindane,use of heptamul and use of Drinox.By means of ordinary Kriging interpolation,spatial distribution of OCPs was studied with results indicating that the 17 OCPs variaed greatly in spatial distribution between types选取位于珠江三角洲的惠州市为研究区域,对该市土壤进行了系统采样分析,测定了42个表层土壤样品中的17种有机氯农药的含量.利用多元地统计和GIS相 结合的方法,研究了17种有机氯农药的残留状况及空间分布情况.结果表明,17种有机氯农药在42个土壤样品中均有不同程度的检出,其中p,p′-DDE 检出率为100%,3种有机氯农药检出率在90%以上,6种有机氯农药的检出率在80%以上.其中六六六和滴滴涕残留较普遍,但并未达到污染水平.分析显 示,近期可能仍有新的六六六输入土壤环境,而滴滴涕则主要来自过去施用农药的残留.与国内其他地区比较,惠州市土壤HCH和DDT含量处于较低水平.主成 分分析显示上述17种有机氯农药可以由5个主成分反映,分别对应于工业HCH的使用,自然因素,林丹的使用以及七氯和艾氏剂等农药的使用.采用克里格插值 法对有机氯农药在研究区的空间分布进行了研究,结果表明不同有机氯农药在研究区分布存在很大差异

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