镉超标耕地的安全利用评价与优化配置方案

THE SAFETY UTILIZATION EVALUATION AND OPTIMIZATION SCHEME OF HEAVY METAL Cd OVER STANDARD CULTIVATED LAND

关键词:  土地管理 镉 耕地 重金属 安全利用 优化方案

Key words:  land management  Cd  cultivated land  heavy metal  safety utilization  optimization scheme

摘要:

［目的］提出分不同pH、不同地类对重金属超标耕地安全利用评价思路，并以A镇为例探讨了以地类转换、作物调整、园艺措施或其他适当的修复措施以及农用地转为非农用地等措施为途径的优化配置方案。［方法］文章选用单因子污染指数评价法，分不同pH值、水田、旱地、菜地对重金属镉超标耕地进行安全利用评价，采用反距离加权插值法得到整个研究区镉含量空间分布图。基于安全利用评价结果及其空间分布特征，分不同pH值探讨了以地类转换、作物调整、园艺措施或其他适当的修复措施以及农用地转为非农用地等措施为途径的优化配置方案。［结果］通过进一步分析评价结果空间分布特征发现A镇土壤大部分无污染，其中镉严重污染的水田土壤面积大于旱地土壤面积，空间分布主要受当地人为活动影响。［结论］优化配置方案有效降低了镉超标耕地的相对污染程度和重金属对农产品安全的影响程度。

Abstract:

Evaluating and optimizing heavy metal over standard cultivated land are the basic requirements to protect cultivated land in new development period of China. This paper used single factor pollution index evaluation method to evaluate the heavy metal over standard cultivated land of paddy, dryland and vegetable field on the basis of different pH. Then it analyzed the space distribution characters with inverse distance weighted interpolation method. The evaluation results indicated that most of soilswere clean and the severe contaminated areas inpaddy soils were larger than that in dryland. The contaminated areas were affected by local human activities. Finally, it put forward some countermeasures to reduce the relative contaminated degree of Cd over standard in cultivated land and the heavy metal contaminated degree to the safety of agricultural products, such as changing land use types andcrops, transforming agricultural land into non-agricultural land.