Pedosphere 16(5): 545--554, 2006
ISSN 1002-0160/CN 32-1315/P
©2006 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Spatial prediction of heavy metal pollution for soils in peri-urban Beijing, China based on fuzzy set theory |
TAN Man-Zhi1,2 , XU Fang-Ming3, CHEN Jie1, ZHANG Xue-Lei1 and CHEN Jing-Zhong4 |
1 State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China). E-mail: mzhtan@issas.ac.cn;
2 Graduate school of the Chinese Academy of Sciences, Beijing 100039 (China);
3 Chengdu University of Technology, Chengdu 610059 (China);
4 Nanjing Station of Soil and Fertilizer, Nanjing 210036 (China) |
| ABSTRACT |
| Fuzzy classification combined with spatial prediction was used to assess the state of soil pollution in the peri-urban Beijing area. Total concentrations of As, Cr, Cd, Hg, and Pb were determined in 220 topsoil samples (0-20 cm) collected using a grid design in a study area of 2600 km2. Heavy metal concentrations were grouped into three classes according to the optimum number of classes and fuzziness exponent using the fuzzy c-mean (FCM) algorithm. Membership values were interpolated using ordinary kriging. The polluted soils of the study area induced by the measured heavy metals were concentrated in the northwest corner and eastern part, especially the southeastern part close to the urban zone, whereas the soils free of pollution were mainly distributed in the southwestern part. The soils with potential risk of heavy metal pollution were located in isolated spots mainly in the northern part and southeastern corner of the study region. The FCM algorithm combined with geostatistical techniques, as compared to conventional single geostatistical kriging methods, could produce a prediction with a quantitative uncertainty evaluation and higher reliability. Successful prediction of soil pollution achieved with FCM algorithm in this study indicated that fuzzy set theory had great potential for use in other areas of soil science. |
| Key Words: continuous classification, fuzzy c-means, heavy metal, soil pollution, spatial prediction |
| Citation: Tan, M. Z., Xu, F. M., Chen, J., Zhang, X. L. and Chen, J. Z. 2006. Spatial prediction of heavy metal pollution for soils in peri-urban Beijing, China based on fuzzy set theory. Pedosphere. 16(5): 545-554. |
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