针对PM2.5跨界输送的重点区域协同控制机制研究

PM2.5 has become the major pollutant that leads to adverse effects upon air quality in China. The PM2.5 pollution presents typical regional and complex patterns. Both the experience from regional PM2.5 pollution control in the U.S. and Europe, and the practice of air quality secure for important events in China has shown an effective approach to reduce regional PM2.5 pollution by lower transboundary transport of PM2.5. And this approach relies on well designated responsibility for all parties, tailored policy measures and regional coordination based upon understanding of the patterns of transboundary transport of major chemical components of PM2.5. Several major fundamental issues will be investigated in this research to provide scientific support to China’s policies on regional joint control of PM2.5 pollution. The PM2.5 control target for key regions will be studied based on the gap between current pollution status and requirements of ambient air quality standards. The transboundary transport patterns of major chemical components of PM2.5 among administrative areas will be analyzed with particle source apportionment technology via CAMx model. The regional emission control targets of other major pollutants will be identified so as to reduce transboundary PM2.5. Finally, a set of the recommendations on the regional coordination mechanism will be developed to achieve PM2.5 and other pollutants reduction.

PM2.5已经成为影响我国大气环境质量的最主要污染物，并呈现出典型的区域型、复合型污染特征。欧美国家控制区域PM2.5污染的历程和我国保障重大赛会期间空气质量的经验都表明，深入研究PM2.5主要化学组分的跨界输送规律，并在此基础上制定有针对性的措施，明确个体责任，通过区域协同控制减少其跨界输送，是减轻区域PM2.5污染程度的有效途径。本研究将针对我国区域PM2.5协同管理和政策制定过程中的关键科学问题进行研究：根据我国区域PM2.5污染现状和环境空气质量标准的要求研究重点区域的PM2.5控制目标；使用CAMx空气质量模型的颗粒物来源追踪技术分析重点区域内各行政主体之间PM2.5及其化学组分的输送关系；在此基础上研究以减少PM2.5及其化学组分跨界输送为目的的各区域主要污染物排放量控制目标；并提出为达到此目标所需要的区域协作机制和主要政策建议。

本项目通过收集梳理我国已有PM2.5空气质量监测和化学组分采样分析数据，结合环境空气质量标准要求，研究了全国和京津冀区域2020年PM2.5年均质量浓度的控制目标；使用CAMx模型进行PM2.5组分生命过程模型，在此基础上首次建立了全国31个省级行政区划间PM2.5及前体物输送矩阵，分析PM2.5及前体物空间输送关系；着重针对京津冀区域的13个城市以及周边地区，使用CAMx模型的PSAT技术分析PM2.5及其主要化学组分的相互传输特征，在此基础上提出了京津冀PM2.5污染防治的重点。研究发现：（1）要实现全国大多数城市PM2.5浓度达标，则需要使全国PM2.5浓度降低50%～70%；（2）京津冀区域一次PM2.5、SO2、NOX、VOCs和NH3等污染物的排放量需要在“十三五”期间进一步削减约30%；（3）绝大部分省份PM2.5仍以本地源贡献为主，部分重点区域空间输送效应强；（4）河南省对京津冀空气质量影响显著，针对京津冀区域的大气污染防治应该更加重视对南部区域的污染物减排；（5）对于硝酸盐和硫酸盐，要在更大区域内，通过联防联控和总量控制，减少SO2和NOX的排放量，才能有效降低京津冀硫酸盐和硝酸盐浓度。