基于城市大气环境荷载指数的大气污染排放变率估算

基于地面气象观测资料计算大气自净能力指数ASI，和环境监测站的实测PM_2.5浓度数据，利用城市大气环境荷载指数研究分析了2个时段单位人口的污染物排放率的变化，以及2013年9月~2019年2月京津冀及周边主要城市气象条件和减排措施对空气污染物浓度变化的作用.结果显示：秋冬季节污染物的削减力度明显大于春夏季.2014年秋冬季有74.5%城市实现减排，区域平均减排12.6%，减排初见成效；2017年和2018年秋冬季，京津冀及周边地区持续大幅减排，其中京津冀区域相对基准年分别减排54.0%和47.7%.长治市在2014~2017年秋冬季排放率均高于基准年，直至2018年冬季始实现减排27.6%；石家庄市排放率变化幅度波动较大，2016年冬季相比2014年冬季增加68.2%，今后区域污染物防控需要重点关注以上2个城市.城市大气环境荷载指数能够客观定量反映出典型减排时段的排放率变化方向和幅度，是一种评估气象条件和排放控制措施二者对污染物浓度变化各自作用的简单有效方法.

Quantitative estimation of air pollutant emission rate based on urban atmospheric load index

Based on observed PM_2.5 concerntration data and atmospheric self-cleaning ability index (ASI) calculated by meteorological observation data, the change of pollutant emission rate per capita during two periods by applying urban atmospheric load index was analyzed. Meanwhile, the effects of meteorological condition and emission reduction on the change of air pollutant concentration during Sep. 2013 to Feb. 2019 were investigated. The emission reduction in autumn and winter was more obvious than that in spring and summer. The effect initially appeared in autumn and winter of 2014 due to emission reductions occurred in 74.5% cities, and on average emission reduction was 12.6% in this area. Emission reduced substantially in the autumn and winter of 2017 and 2018 in major cities of Beijing-Tianjin-Hebei and its surrounding areas, with emission reduction rate being 54.0% and 47.7% respectively relative to the baseline. Emission of autumn-winter in Changzhi during 2014~2017 was more than that in baseline, and started to decline in 2018. The change of emission rate in Shijiazhuang presented large fluctuation, and it in winter of 2016 was 68.2% more than that in 2014. Hence, special attention should be paid to these two cities. Urban atmospheric load index can objectively and quantitatively reflect the direction and magnitude of the change of emission rate in typical emission reduction periods, so it is an effective method to evaluate the effects of meteorological conditions and emission control measures on pollutant concentration change.