arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2007.00755physics.soc-phphysics.ao-ph
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COVID-19大流行第一波和第二波期间封锁对特大城市空气质量的影响

Lockdown effects on air quality in megacities during the first and second waves of COVID-19 pandemic

Aswin Giri, Benjamin Schäfer, Rulan Verma, Hankun He, S. M. Shiva Nagendra, Mukesh Khare, Christian Beck

摘要:

空气污染是全世界死亡率最高的因素之一,特别是在城市地区。于二零二零年春季,多个国家实施社交距离措施,以减缓持续的COVID-19疫情。一项特别严厉的措施“封城”敦促人们留在家中,从而防止在第一波(2020年)和第二波(2021年)大流行期间出现新的COVID-19感染。反过来,它也减少了交通和工业活动。但是,这些封锁措施在多大程度上改善了大城市的空气质量,空气质量受到的影响是否存在差异?在这里,我们分析了两个大城市的数据:伦敦作为欧洲的例子,德里作为亚洲的例子。我们考虑了第一波和第二波封锁期间的数据,并将其与2019年的值进行比较。总的来说,我们发现几乎所有的空气污染物都有所减少,但到2021年,除德里外,这两个城市之间存在有趣的差异。在伦敦,尽管平均浓度较低,但我们仍然观察到高污染状态和2020年极端事件的趋势增加(封锁期间概率密度的峰度较高)以及2021年的低污染水平。对于德里,我们观察到污染浓度的大幅下降,包括2020年的高污染状态和2021年的更高污染水平。这些结果可以帮助设计改善特大城市长期空气质量的政策。

英文摘要:

Air pollution is among the highest contributors to mortality worldwide, especially in urban areas. During spring 2020, many countries enacted social distancing measures in order to slow down the ongoing COVID-19 pandemic. A particularly drastic measure, the 'lockdown', urged people to stay at home and thereby prevent new COVID-19 infections during the first (2020) and second wave (2021) of the pandemic. In turn, it also reduced traffic and industrial activities. But how much did these lockdown measures improve air quality in large cities, and are there differences in how air quality was affected? Here, we analyse data from two megacities: London as an example for Europe and Delhi as an example for Asia. We consider data during first and second wave lockdowns and compare them to 2019 values. Overall, we find a reduction in almost all air pollutants with intriguing differences between the two cities except Delhi in 2021. In London, despite smaller average concentrations, we still observe high-pollutant states and an increased tendency towards extreme events (a higher kurtosis of the probability density during lockdown) during 2020 and low pollution levels during 2021. For Delhi, we observe a much stronger decrease of pollution concentrations, including high pollution states during 2020 and higher pollution levels in 2021. These results could help to design policies to improve long-term air quality in megacities.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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