关键词：
土壤重金属污染;单因子指数;内梅罗指数;复合指数
摘 要：
土壤重金属污染严重阻碍土地资源的有效利用,准确的风险评估是防治土壤重金属污染的重要依据和前提。为探讨不同评估方法的差异,选取更为可靠、有效的评估方法应用于实际工作中,分别使用内梅罗指数法和复合指数法对研究区土壤重金属污染情况开展评估并对评估结果加以比较。结果表明,等级不一致的区域有739.12hm2,占研究区的4.36%,该区域的内梅罗指数均比复合等级指数低1个等级,主要原因是数据分布特征与内梅罗指数计算方法的特点,在单因子指数平均值较小,而最大值稍大于分级临界值时,容易降低计算结果,造成某种元素单因子指数大于某个等级,而内梅罗指数却小于该等级,因此可能会降低污染等级,减少污染面积。而复合指数法可以直观得到几种元素复合污染及污染等级,全面反映区域土壤环境质量,建议在实际工作中应加以推广和利用。
译 名：
Comparative study between Nemerow Index Method and Compound Index Method for the risk assessment of soil heavy metal pollution
作 者：
XUE Zhibin;LI Ling;ZHANG Shaokai;DONG Jing;College of Resources and Environment,Henan Agricultural University;Henan Geological Geophysical Surveying and Mapping Technology Co.,Ltd.;
关键词：
soil heavy metals pollution;;index of single factor;;Nemerow index;;compound index
摘 要：
[Background] The accumulation of heavy metals in soil will influence the physical and chemical properties of soil,leading to soil structure damage and soil and water loss. Furthermore,along with the function of food chain,heavy metal pollutants can migrate to animals and plants,as well as human beings,which is harmful to food safety and human health. The sustainable development of economy and human health are seriously endangered by soil heavy metal pollution. Thus the risk assessment of soil heavy metal pollution is an important basis and premise for solving this problem.[Methods] There are many methods for assessing the risks of soil heavy metal pollution,in order to explore the differences among different assessment methods and the reasons for the differences of the results,as well as to choose a more reasonable and operable method,we calculated Nemerow index and compound index according to single factor index. We used Arc GIS to overlay the spatial variation of Nemerow index and compound index and obtained the areas with different levels. Then we compared and analyzed the results. [Results] According to Nemerow Index Method,1. 73% of the study area wasslight pollution,with an area of 292. 87 hm2,and 0. 15% of the study area was moderate pollution,with an area of 24. 82 hm2. The result based on Compound Index Method indicated that the areas with slight pollution,moderate pollution and heavy pollution were 494. 74 hm2,138. 71 hm2 and 11. 30 hm2,respectively,which were 2. 92%,0. 82% and 0. 07% in percentage. The results of above-mentioned two methods were inconsistent in the region of 739. 12 hm2( i. e. 4. 36% of the study area). The warning area based on Nemerow index and the compound index slight pollution were overlapped in 1. 93% of the study area,whereas Nemerow index slight pollution area and the moderate pollution area according to compound index were overlapped in 0. 74% of the area. The overlap areas for these two cases were327. 05 hm2 and 125. 18 hm2,respectively. At the same time,0. 07% of the study area,with an area of11. 30 hm2,was predicted to be moderate pollution according to Nemerow index,and was estimated as heavy pollution area using compound index. We selected 4 spots for the areas with inconsistent estimations using a random function. The Nemerow index of spot b was 0. 811,indicating a level of warning; while the compound index was 1. 038,indicating slight pollution. [Conclusions] Nemerow Index Method will reduce its index in the calculation process. And when the maximum of single factor is large,but the average index is small,Nemerow Index Method may reduce the level. Compound Index Method can avoid these problems. Therefore,Compound Index Method can reflect the regional soil environmental quality more objectively and reasonably, thus it should be popularized and used in practical work.
