浙江省水稻产地环境镉污染分布及其风险评价  

Pollution Distribution and Risk Assessment of Soil Cd in Rice-production Areas in Zhejiang Province

作　　者：赵科理[1] 刘杏梅[1] 徐建明[1] 

机构地区：[1]浙江大学土水资源与环境研究所,浙江杭州310029

出　　处：《土壤通报》2009年第2期394-399,共6页Chinese Journal of Soil Science

基　　金：国家自然科学基金(40601051);国家973项目课题(2005CB121104);浙江省科技项目(2005E10004)资助

摘　　要：利用GIS和地统计学分析方法,分别采集了231、167和309个土壤样品,对浙江省水稻产地1:5万比例尺的南浔区、嵊州市和温岭市土壤Cd进行了空间变异性分析,结果表明:南浔区土壤Cd符合平方根正态分布,嵊州市和温岭市符合对数正态分布,南浔区和温岭市土壤Cd的空间变异较好的符合球状模型,而嵊州市符合指数模型,研究区Cd的块基比均小于25%,具有强烈的空间相关性。在此基础上根据污染评价分级标准,采用单因子污染指数法,通过kriging插值,得到了研究区土壤Cd的空间分布图和污染评价分级图。分级评价表明,嵊州市有52.4%的土壤受轻污染,南浔区97.8%已受到轻污染,温岭市则是90.7%轻污染之外,还有5.4%土壤严重污染。研究区土壤受人为活动影响增加了Cd含量水平,但未超过土壤环境质量二级指标,总体来说,研究区环境质量还是符合水稻安全生产要求的。231,167 and 309 samples were collected from three rice-production areas including Nanxun, Shengzhou and Wenling in Zhejiang Province, respectively, and the spatial variability of Cd in soils was studied using Geographical Information System （GIS） and Geostatistics techniques. The results showed that theoretical semivariogram models of soil Cd in Nanxun by square root transformation and Wenling by logarithm transformation were best fitted with a spherical model. However, in Shengzhou by logarithm transformation was fitted with an exponential model. The spatial correlation of soil Cd in the study areas were all strongly dependent in spatial, with their Nugget/ Sill values were less than 25 %. Based on the pollution threshold of soil Cd in China, the risk assessment of Cd was carried out by means of the single-factor pollution index method. Spatial distribution and pollution evaluation maps of soil Cd were delineated using kriging method. It was found that 52.4% of the soil in Shengzhou and 97.8% of Nanxun were lightly polluted, 90.5% of Wenling was lightly polluted and 5.4% highly polluted. It was suggested that the soils in the study areas were polluted by Cd to a degree, but not exceeding the environmental quality standard. Therefore, generally speaking, environmental quality of Cd in the study areas was suitable for rice production.

关 键 词：镉 地统计学 单因子污染指数 评价标准 水稻产地 

分 类 号：X53[环境科学与工程—环境工程]