区域农田土壤重金属污染源解析方法研究现状及展望

Research Status and Prospects of Apportionment Methods for Heavy Metal Pollution Sources of Farmland Soil at Regional Scale

重金属污染来源精细解析是区域农田土壤开展污染消减与阻控措施的首要措施。农田土壤重金属来源复杂多样,且污染物的迁移与累积过程受到地形、气象、植被等多种因素的影响,导致污染源对区域不同位置农田产生差别化污染贡献。为精细解析该差别化污染贡献,需使用多个类别型和连续型代理变量表征各污染源空间输出强度及影响因素,并建模代理变量与农田土壤重金属含量之间的关系。而在区域尺度这一关系往往存在空间异质性,现有方法能否有效解决该问题。对此,本文在分析农田土壤重金属污染来源及其空间异质性污染贡献的基础上,梳理了区域农田土壤重金属污染源解析方法的研究现状及其发展趋势,并展望了新的源解析方法,为我国各级政府和相关组织制定既经济又环保的农田土壤重金属污染风险防控措施提供技术支撑。

Fine apportionment of the heavy metal pollution sources is the prerequisite for pollution reduction and prevention for farmland soil. The sources of heavy metals in farmland soil are complex and diverse, and the migration and accumulation process of pollutants are affected by multiple factors such as topography, meteorology, vegetation, etc., resulting in different pollution contributions from pollution sources to farmland soil in different places in the region. In order to analyze the different pollution contribution accurately, it is necessary to use multiple categorical and continuous proxy variables to characterize the emission intensity of each pollution source and corresponding influencing factors, and to model the relationship between proxy variables and heavy metal content in farmland soil. The relationships between the heavy metal contents and proxy variables are spatially heterogeneous, thus whether existing methods can solve this problem deserves investigation. To answer this question, we first analyze the sources of heavy metal pollution in farmland soil and their spatially heterogeneous pollution contribution, and then summarize the research status and prospects of apportionment methods of heavy metal pollution sources of farmland soil at a regional scale. This study aims to provide technical support for the government and related organizations to take measures to prevent and control heavy metal pollution risks in farmland soil that are both economical and environmentally friendly.