基于土地破坏的矿区生态风险评价:理论与方法

Theory and method of ecological risk assessment for mining areas based on the land destruction

矿区生态风险评价已成为区域生态风险研究的热点领域。如何合理选择和表征区域生态风险源和风险受体,量化多风险源和多风险受体的交互作用,是目前区域生态风险评价研究的焦点。为此,在总结矿区生态风险评价研究成果的基础上,构建了矿区生态风险源、风险受体及作用对象与过程的因果链模型,结合矿区生态环境问题产生过程的独特性,将土地挖损、占用及塌陷等土地破坏作为矿区的直接生态风险源。基于土地破坏类型提出了适宜矿区的区域生态风险评价流程、指标体系与计算方法;并专门在定量化多风险源与多风险受体交互作用上做出探讨,构建了生态系统单元暴露指数和土地破坏累积作用指数来评价矿区土地破坏与生态系统单元间的暴露与危害作用关系。为矿区生态风险评价的实证研究提出了理论基础与方法框架,未来可结合实证研究对此方法及相关指标参数做出完善与改进,为矿区生态环境管理与生态安全建设提供科学的参考依据。

Ecological risk assessment in mining areas is a hotspot and frontier of regional ecological risk researches.At present,how to rationally select and quantify multiple regional ecological risk sources,receptors and their relationships have been the key issues of regional ecological risk assessment studies.Based on the relative ecological risk assessment researches in mining areas,this paper established the cause-effect chain analysis model from ecological risk incentives,sources,receptors to the ecological effect objects and processes,summarized the specificity of environmental problems,and reasonably took the destructed lands by mining activities as the original ecological risk sources,such as the subsided land caused by underground mining,the excavated land caused by open-pit mining,and various occupied lands caused by the mining dumps and tailings.On the basis of the definition and description of the land destruction,the ecological risk assessment procedure,indicator system and method suitable for the mining areas were proposed.The main contents include defining the boundary of mining areas,identifying and interpreting land destruction types,quantifying the degree and probability of multiple destructed lands,evaluating the integrated ecological losing degree of ecosystem units by the ecological niche and vulnerability index,and quantifying the coupling relationship between the land destruction and ecosystem units.The quantitative method of the coupling relationship was especially discussed in this paper,which included the spatial exposure chance index of ecosystem units and the spatial cumulative effect index of multiple land destructions based on the geographic information system（GIS）.In summary,this paper developed an operational ecological risk assessment framework and calculation model for mining areas.The more ecological risk assessment case studies of mining areas will be carried out,and the proposed ecological risk assessment method will be practiced and improved in the future research,which are helpful for promoting the ecological security and sustainable development in mining areas.