| 摘要: |
| ［目的］通过对土壤重金属含量的空间分布和和合理采样数量研究，可为农用地土壤环境质量调查提供帮助。［方法］在江苏省宜兴市农用地共布设1 139个采样点，测定了土壤重金属As、Cd、Cu、Hg、Pb、Zn的含量，利用经典统计法和地统计分析对土壤重金属的空间变异性进行了研究，并采用克里格法（Kriging）确定土壤重金属合理采样数目，相比于普通克里格法（Ordinary Kriging），协克里格法（Co-Kriging）插值利用与目标变量相关性较好的辅助变量，可以更合理地确定采样数量。［结果］县域尺度研究区土壤中6种重金属元素空间变异系数范围为3066％～12537％，其变异系数由大至小为Cd>Cu>Hg>Pb>Zn>As，且这些土壤重金属均在一定范围内存在中等空间自相关，空间相关距排列为Cu=Pb>Cd>As>Hg>Zn； 6种土壤重金属与Fe2O3、OM间相关性极显著，且土壤Zn和Cd与土壤pH间相关性极显著，以此作为协同克里格插值的基础。为保证土壤重金属协同克里格的插值精度，土壤Cd的合理的采样点数量应该在1 139个以上，土壤As、Cu、Hg、Pb、Zn可减少至1 025个。［结论］研究可为县域尺度农用地土壤重金属空间变异和采样调查研究提供参考，为制定农用地重金属防治决策提供科学依据。 |
| 关键词: 土壤重金属空间变异性合理采样数地统计分析普通克里格协同克里格 |
| DOI： |
| 分类号:S1519+3 |
| 基金项目:国土资源部公益性行业专项经费项目“重金属超标农用地安全利用管控技术研究”（201511082） |
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| SPATIAL VARIABILITY AND REASONABLE SAMPLING NUMBER OF SOIL HEAVY METALS IN AGRICULTURE LAND |
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Li Junying1,2, Wu Kening1,2※, Song Wen3
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1. School of Land Science and Technology, China University of Geosciences, Beijing 100083, China; 2. Key Laboratory of Land Consolidation and Rehabilitation, Ministry of Land and Resources, Beijing 100035, China; 3. College of Resources and Environment, Shandong Agricultural University, Tai′an 271018, Shandong，China
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| Abstract: |
| Study on spatial variability and reasonable sampling number of soil heavy metals can provide help for investigation of soil environmental quality of agricultural land. A total of 1 139 sampling points were collected and the content of As, Cd, Cu, Hg, Pb and Zn was determined to investigate the heavy metal pollution situation in Yixing city of Jiangsu province. The spatial variability of soil heavy metals was studied by classical statistical method and geostatistical analysis, and the reasonable sampling number of heavy metals in soils was determined by Kriging method. Compared with the ordinary Kriging method, the Co kriging method could determine the number of samples more reasonably by using the auxiliary variables which had better correlation with the target variables. The results showed that the spatial variability coefficient of the determined heavy metals in the soil of researched area was 30.66%~125.37% and the variation degree was Cd>Cu>Hg>Pb>Zn>As. These heavy metals had the medium spatial relevance in certain scope and the space correlation was Cu=Pb>Cd>As>Hg>Zn. The correlation between 6 kinds of heavy metals and Fe2O3, OM was very significant, and the correlation between Zn and Cd and soil pH was very significant, which was the basis of Co kriging interpolation. In order to ensure the interpolation accuracy of Co kriging method for soil heavy metals, the reasonable number of sampling points of soil Cd should be over 1 139, and soil As, Cu, Hg, Pb and Zn could be reduced to 1 025. The study can provide reference for the spatial variability and sampling investigation of heavy metals in agricultural land at county scale, and provide scientific basis for the decision making of heavy metals control in agricultural land. |
| Key words: soil heavy metal spatial variability reasonable sampling number geostatistical analysis ordinary Kriging Co kriging |
