环境影响评价的尺度约束性及技术框架

尺度约束是地表复杂系统的基本规律,环评尺度约束常隐存于主观经验或零存于环评导则中,环评尺度约束较少被明确关注。讨论了环境影响尺度约束、环评尺度约束和环评技术框架尺度约束。研究发现,环境影响的尺度约束性内在原因在于环境影响主体、客体和影响内容存在等级结构;环评受空间、时间和分析三类尺度约束,空间尺度约束体现于空间范围和空间信息分辨率对环评影响,时间尺度约束体现于环评的时长和时频,分析尺度约束表现为环评技术方法和环境影响主观认知水平对评价的影响,三类尺度约束同时贯穿于环评过程,任何环评都可以在三类尺度空间中定位;环评技术框架的关键环节都受空间、时间和分析尺度约束,且以环境影响主体的空间、时间尺度为核心,具有一定弹性,一般空间或时间范围先放大再缩小、分辨率由粗到细。

Scale constraint and technique frame for environmental impact assessment

Scale constraint is a basic rule of the surface complex system on earth. For environmental impact assessment (EIA), scale constraint is hid in the experience of EIA professionals, or scattered among EIA technical guidelines; it is not a large concern for EIA professionals. This paper discusses the scale constraints of environmental impact, EIA, and the EIA technical frame. Results show that scale constraint of environmental impact responds to the hierarchical structures of human activities, environmental elements, and the influence of human activities on the physical environment. EIA is apparently restricted by spatial extent and resolution, temporal duration and frequency, and analysis scale, which includes the EIA technical models and the perception or the level of understanding about the environmental impact. The spatial, temporal, and analysis scales are independent, while being integrated in the process of EIA and restricting the EIA conclusion. Any EIA can be positioned in the three scales. Generally, the spatial data with low resolution may be available for EIA with large spatial extent, while spatial data with high resolution is required for EIA with small extent, so is the relationship between temporal frequency and duration. Furthermore, spatial, temporal and analysis scale restrict the key technical contents of EIA based on the officially published EIA technical guidelines both for project and for planning EIA. It proposes that the spatial and temporal scales of EIA subject should be the core scale, during the process of EIA, spatial and temporal extents may vary flexibly from large to small, while their resolutions may change from coarse to fine.