《AJAE》| Shiqi Guo: 秸秆焚烧如何影响中国城市空气质量?
摘要:
在过去的十年里,秸秆燃烧一直被认为是发展中国家严重空气污染的原因之一。然而,其对空气质量影响的程度和模式尚未得到精确估计。本研究利用不同卫星源的秸秆火灾遥感数据,分析了秸秆火灾对中国城市空气质量的总体影响。利用290个城市和620天的差异策略,通过研究秸秆燃烧活动和空气污染的日变化,我发现了一个清楚的秸秆燃烧效应的时间模式。在燃烧后的第一天,城市空气污染指数上升了6.5,相当于平均值的9.4%。这种影响随着时间的推移而减少,并在至少8天内保持显著。相对于城市地区,位于逆风方向的火灾影响更大,风速较低时影响有限。就距离而言,污染主要是由距离城市中心100公里以内的秸秆火灾造成的,但也可能受到远达600公里以外的火灾影响。在不同的污染物中,秸秆燃烧增加的颗粒物最多。这种影响在10月和11月最为显著和持久——这两个季节是北方收获后普遍燃烧秸秆的季节,但在其他季节也是不可忽视的。
关键词:农业火灾;空气污染;中国;秸秆焚烧
Abstract:
Over the past decade, straw burning has been debated as one of the causes of severe air pollution in developing countries. However, the magnitude and pattern of its impact on air quality have not been precisely estimated. This study employs remote sensing data on straw fires from different satellite sources and examines its overall impact on urban air quality in China. Exploiting daily variations in straw burning activities and air pollution with a difference-in-differences strategy across 290 cities and 620 days, I find a clear temporal pattern for the straw burning effect. On the first day after burning, the index of air pollution increases by 6.5 in urban areas, equivalent to 9.4% of the mean. This impact decreases over time and remains significant for at least eight days. The effect is larger for fires located in the upwind direction relative to urban areas and is limited with lower wind speed. In terms of distance, pollution is mostly driven by straw fires within 100 km from urban centers but could also be influenced by fires as far as 600 km away. Among different pollutants, particulate matters are increased most by straw fires. The effect is largest and most persistent in October and November, when straw burning prevails in the north after harvest, but is also non-negligible in other seasons.
Keywords: Agriculture fire; Air pollution; China; Staw burning
《AJAE》全称为《American Journal of Agricultural Economics》,最新影响因子为4.082,刊载方向为管理科学-农业经济与政策。
原文链接:
https://doi.org/10.1111/ajae.12132