北京市PM2.5的时空分布特征及影响因素

Temporal and Spatial Distribution Characteristics and Influencing Factors of PM2.5 in Beijing

发展中国家快速的城镇化和工业化给生态环境带来极大的负面影响, 尤其是造成严重的空气污染, 成为增加环境健康风险的重要因素。北京是极具代表性的特大城市, 雾霾问题受到广泛的关注, 对雾霾的精准监测和分析至关重要。但是, 雾霾污染兼具长期性和复杂性的特点, 目前北京空气污染程度的时空分布差异及对其影响因素的解释并不充分。因此, 我们选取13个位于北京的空气质量监测站点的PM2. 5浓度, 揭示其不同时间尺度下的空间异质性; 进而使用聚类分析和多元回归分析, 通过多种自然条件和社会经济条件数据拟合PM2. 5的浓度以帮助解释其影响因素。研究结果表明, 北京市PM2. 5浓度存在明显的季节差异, 具体表现为: 冬季>秋季>春季>夏季。PM2. 5浓度分布在不同季节的空间分布特征基本稳定, 大体上是西南部PM2. 5浓度高, 东北部PM2. 5浓度低。拟合的PM2. 5日均浓度和监测站点的数据高度吻合, 说明气象、人口、道路、建筑和NDVI均对PM2. 5的浓度变化具有解释力。

The rapid urbanization and industrialization in developing countries has had a significant negative impact on the ecological environment, especially causing serious air pollution, which has become an important factor in increasing environmental health risks. Beijing is a highly representative megacity where the smog problem has received widespread attention, so it is very important to accurately monitor and analyze the smog. However, smog pollution has characteristics of long-term and complexity, and the current differences in the temporal and spatial distribution of air pollution levels in Beijing and the explanation of influencing factors are not sufficient. Therefore, we select the PM2. 5 concentrations from 13 stations located in Beijing for air quality monitoring to reveal their spatial heterogeneity at different time scales. Then, cluster analysis and multiple regression analysis are used to fit the concentrations of PM2. 5 through a variety of natural and socio-economic conditions to help explain their influencing factors. The results show that there are obvious seasonal differences in the concentrations of PM2. 5, specifically: winter > autumn > spring > summer. The spatial distribution of PM2. 5 concentration is generally stable across seasons, with high PM2. 5 concentration in the southwest and low PM2. 5 concentration in the northeast. The fitted daily average concentration of PM2. 5 is highly consistent with the data from monitoring stations, indicating that meteorology, population, roads, buildings and NDVI all have explanatory power on the variation of PM2. 5 concentration.