| 地累积指数法评价多金属环境质量的方法优化探索:以农业发达地区为例 |
| 摘要点击 2045 全文点击 537 投稿时间：2021-05-24 修订日期：2021-07-30 |
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| 中文关键词 土壤重金属污染 三角模糊数 地质累积指数评价 随机抽样 地理信息系统(GIS) |
| 英文关键词 soil heavy metal pollution triangular fuzzy number geoaccumulation index evaluation random sampling geographic information system(GIS) |
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| 中文摘要 |
| 准确合理的土壤污染评价方法是进行区域性土壤污染评价的前提.将三角模糊数引入地质累积指数法，结合α-截集技术以及Latin Hypercube抽样（LHS）随机模拟方法对研究区重金属含量差异较大的5种不同土壤类型（潮土、风沙土、黄绵土、褐土和新积土）分别进行土壤重金属（Cd、Hg、As、Pb和Cr）累积性评价，能够避免因传统地质累积指数法在背景值选择、研究区局部与整体重金属含量差异较大所带来评价结果不够准确的问题，可更加全面真实地综合表征区域土壤重金属污染状况，为科学决策提供理论基础.结果表明，对于重金属含量差异较小的情况，也就是当所有点位地质累积指数评价结果均在某一区间等级时，或所有点位地质累积评价结果均小于0的情况，方法上的改进不会影响评价结果.传统的以及基于三角模糊数的地质累积指数法得出的评价结果为一确定的等级，而这一等级由整个研究区重金属含量平均值决定，当研究区土壤采样点位重金属含量差异较大时，会放大重金属含量较小的或缩小重金属含量较大的地区，使评价结果不够准确.而结合LHS抽样法使评价结果变成各个污染等级的可能性，能够大大改进传统评价方法的局限性，使评价结果更加合理准确，再结合地理信息系统（GIS）方法还能对区域性重金属污染累积集中地进行可视化表达. |
| 英文摘要 |
| An accurate and reasonable soil pollution assessment method is the premise of regional soil pollution assessment. Triangular fuzzy numbers were introduced into the geo-accumulation index method, combined with α-cut technology and the Latin hypercube sampling (LHS) stochastic simulation method, to evaluate the accumulation of heavy metals in five different soil types (moisture soil, aeolian sandy soil, cinnamon soil, loessal soil, and alluvial soil), with large differences in heavy metal (Cd, Hg, As, Pb, and Cr) content in the study area. This method can avoid the inaccuracy of the evaluation results caused by the traditional geological accumulation index method in the selection of background values and the great difference between local and whole heavy metal contents in the study area and can comprehensively and truly represent the regional soil heavy metal pollution status, thus providing a theoretical basis for scientific decision-making. The results showed that the improvement in the method will not affect the evaluation results when the heavy metal content difference is small, that is, when the evaluation results of the geological accumulation index at all points are within a certain interval level or when the evaluation results of the geological accumulation index at all points are less than 0. The traditional and geological cumulative index method based on the evaluation with triangular fuzzy numbers provides results for a certain level, which is determined by the heavy metal content in the study area average; conversely, differences in the heavy metal content of soil sampling points throughout the study area can result in a decrease or increase in the recorded heavy metal contents in larger areas, making the evaluation result inaccurate. Combined with the LHS sampling method, the possibility of changing the evaluation results into various pollution levels can greatly improve the limitations of traditional evaluation methods and make the evaluation results more reasonable and accurate. Combined with the geographic information system (GIS) method, the regional heavy metal pollution accumulation concentration can also be visualized. |
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