大气环境容量理论的再思考和总量控制

大气环境容量理论在我国的空气污染控制政策研究和管理实践中一直作为重要的基础理论之一，但长期以来其概念定义和理论模型一直存在模糊之处，也未能建立公认的数学规划模型和算法.基于大气环境容量理论发展和应用回顾，对大气环境容量的定义和内涵进行了探讨，并对其理论和计算方法的实用性与局限性进行了分析.该研究基于不同的大气环境容量定义，提出了绝对大气容量、广义大气容量和狭义大气容量3种概念的区分，提出大气环境容量规划的主要理论困难是大气规划空间的开放性以及由此带来的空间边界定义和规划区外约束缺失问题，指出除一次空气污染物在局地尺度夜间边界层或山谷特殊地形等条件下可获得广义大气容量解以外，其他大部分情形往往并不能获得确定的广义大气环境容量解；指出因臭氧、二次细粒子复合污染存在二次污染物与前体物排放的非一一对应及非线性关系，传统的单物种大气环境容量理论和单目标线性优化规划方法不再适用.空气质量问题，特别是区域尺度空气污染问题并不一定是排放量超出大气容量所致，大气环境容量理论并不是一个普适理论.针对区域性复合空气污染控制问题，建议在全国或大区域尺度，基于排放状况与经济、技术可行性，采用空气质量模式情景分析与影响评估的规划方法，优化确定区域排放总量；长远可探讨建立包含技术、经济、社会变量的多物种和多目标规划方法. 

Revisiting Atmospheric Environmental Capacity Theory and Emission Cap

Atmospheric capacity theory has been one of the important fundamental theory for air pollution control policy and management in China for a long time, but it is ambiguous in terms of concept definition and theoretical model and is not able to establish commonly recognized mathematical models and algorithms. Based on the review of the development and application of atmospheric capacity theory, this paper discussed the concept definition, connotation and the difficulties and limitations of the theoretical model and algorithms. The difference between the absolute, generalized and narrowly defined concepts of atmospheric capacity is proposed. The main theoretical difficulties of atmospheric capacity planning are identified, i.e., the openness of the atmospheric planning space and the resulting spatial border definition difficulty and the absence of constraints outside the planning domain. Except for a quasi-confined space such as nocturnal boundary layer or valley complex terrain where generalized atmospheric capacity can be defined for a primary air pollutant, it is unable to obtain a definite optimal capacity solution for most of other cases. Due to the non-one-to-one correspondence and non-linear relationship between secondary air pollutants and their precursors, the traditional capacity theory for single air pollutant specie and single objective linear optimization methods are no longer applicable for ozone and secondary fine particulate air pollutants problems. The atmospheric capacity theory is not a valid and universal theory, especially for regional problems, because air quality problems may no longer be capacity-exceeding problems. For the regional combined air pollution problem, it is recommended to adopt a scenario analysis or impact assessment planning approach using air quality models at the national or regional scale based on the status quo and future emission scenario as well as economic and technical feasibility to obtain the optimized regional emission cap. In the long run, a multi-species and multi-objective planning approach that takes into account technical, economic and social variables could be considered.