矿区生态风险评价研究述评

作为世界上矿产资源最丰富的国家之一,我国的矿山开采活动在给经济发展注入强大拉动力的同时,也给矿区生态环境带来了巨大的生态风险。总结前人相关研究,在对比分析了矿区生态风险及其评价与区域生态风险评价异同的基础上,初步明晰矿区生态风险具有风险源的多样性、空间影响边界的模糊性、随空间距离的衰减性及时间累积的延续性等特性。目前矿区生态风险评价的矿区类型过多集中于金属矿区的重金属污染等单项风险,对综合生态风险评价的重视不充分,多基于景观格局、生态环境问题视角,结果多对斑块或生态系统风险评价进行拼接,欠缺基于空间异质性的整体综合;风险度量模型、指标体系法和空间分析法则是较为常用的矿区生态风险评价方法,但在模型模拟方面略显不足。基于现有研究进展,预期矿区独特性的体现、空间格局的关注、"3S"技术的综合应用、生态安全阈值的设定、不确定性表征、基于评价结果的风险规避等将有望成为未来研究的重点。

Research progress in ecological risk assessment of mining area

The rich mineral resources along with the active mining industry in China have contributed a lot to the economic boom for the past years. However, it has also posed tremendous ecological risk to the regional socio-economic system and ecosystem. Therefore, researchers have started to evaluate ecological risk for mining areas since the end of 1990s. From ecological risk assessment to regional ecological risk assessment,and then to ecological risk assessment for mining areas, the research paradigm has a significant shift. Traditional ecological risk assessment usually focuses on a simplex stress factor in the single risk source on a special situation, while regional ecological risk assessment, as a branch of ecological risk assessment, emphasizes several stress factors caused by different risk sources. Based on these related conceptions and references of ecological risk assessment, the study first discussed the features of ecological risk assessment for mining areas, such as accumulation effects with increase of spatial distance and temporal evolution, diversity of risk sources, and fuzziness of affected edges, which make the ecological risk assessment for mining areas different from other regional ecological risk assessments. Ecological risk assessment for mining areas should emphasize to express the accumulation and faintness effects with variation in spatial and temporal scale by different risk sources with proper models on the background of the mining areas so as to characterize the possibility of the disadvantageous effects caused by mining industry to ecological and socio-economic systems. After that, the basic methodologies and theories concerning mining and risk types, research perspectives and methods were discussed. The previous researches focused on metal mining and the risk of heavy metal pollution because the Hakanson method was almost mature, and tended to diversify in terms of the types of mining areas, the indexes, the types of risk types. But previous studies ignored to deal with a common comprehensive risk,especially in the coal mining area. Most researchers made ecological risk assessment from the perspective of landscape ecology or ecological problems or both of them, while comprehensiveness of results based on spatial heterogeneity should be considered. As for the methods, risk measurement models, index system methods and spatial analysis have been frequently used. Risk measurement models consider the possibility of ecological risk and the damages caused by ecological risk, such as landscape ecological pattern indexes. But the index systems are mostly large, confusing and subjective, which are also the disadvantages of index system methods. For index system methods, another problem to be dealt with is a kind of appropriate method to determine the weight of each index. The spatial analysis method just uses the spatial analysis functions of RS and GIS to describe the spatial distribution characters of ecological risk and needs to be further researched. So in general there are some flaws in the model simulation of existing researches. After all, the paper concluded the prospects for further study. Considering the deficiencies of former researches and prospective technological developments, researchers should pay more attention to the employment of 3S techniques, the application of methods and theories of landscape ecology, the determination of ecological security threshold, and application of research results in risk management in further studies.