Air quality changes during the COVID-19 lockdown over the Yangtze River Delta Region: An insight into the impact of human activity pattern changes on air pollution variation
Air quality changes during the COVID-19 lockdown over the Yangtze River Delta Region: An insight into the impact of human activity pattern changes on air pollution variation
复制标题
长三角地区COVID-19封锁期间空气质量变化：深入探讨人类活动模式变化对空气污染变化的影响
DOI：
10.1016/j.scitotenv.2020.139282
复制
发表时间：
2020-08-25
影响因子：
9.8
通讯作者：
Chan, Andy
中科院分区：
文献类型：
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作者：
Li, Li;Li, Qing;Chan, Andy
新冠肺炎疫情在全球迅速蔓延。为了控制病毒的快速传播，中国实施了全国封锁政策，以保持社会距离。这导致人类活动减少，从而减少了主要空气污染物的排放，从而改善了空气质量。为了研究新冠肺炎疫情封锁期间长三角地区空气质量的变化，我们应用WRF-CAMx建模系统结合监测数据，研究了人类活动模式变化对空气质量的影响。结果表明：人类活动显著降低，工业运行、VKT、在建建筑等活动显著减少，导致SO2、NOx、pm2.5和VOCs排放量在ⅰ级和ⅱ级响应期内分别降低了约16-26%、29-47%、27-46%和37-57%；这些减排对改善空气质量起到了重要作用。PM2.5、no2和so2浓度在一级期间分别下降了31.8%、45.1%和20.4%；二级期间同比增长33.2%、27.2%、7.6%。然而，臭氧并没有减少，反而增加了很多。我们的研究结果还表明，即使在一次减排15%-61%的封锁期间，pm2.5的日平均浓度在15 - 79 μg m−3之间，这表明背景污染和残留污染仍然很高。来源解析结果表明，长三角地区pm2.5残留污染来源主要为工业（32.2 ~ 61.1%）、移动（3.9 ~ 8.1%）、扬尘（2.6 ~ 7.7%）、居民（2.1 ~ 28.5%）和北方远程输运（14.0 ~ 28.6%）。这表明，尽管一次排放大幅减少，但仍不能完全解决当前的空气污染问题。我们需要进一步考虑重整能源及工业策略，以及跨区域联合管制空气污染的长远计划。
The outbreak of COVID-19 has spreaded rapidly across the world. To control the rapid dispersion of the virus, China has imposed national lockdown policies to practise social distancing. This has led to reduced human activities and hence primary air pollutant emissions, which caused improvement of air quality as a side-product. To investigate the air quality changes during the COVID-19 lockdown over the YRD Region, we apply the WRF-CAMx modelling system together with monitoring data to investigate the impact of human activity pattern changes on air quality. Results show that human activities were lowered significantly during the period: industrial operations, VKT, constructions in operation, etc. were significantly reduced, leading to lowered SO2, NOx, PM2.5and VOCs emissions by approximately 16–26%, 29–47%, 27–46% and 37–57% during the Level I and Level II response periods respectively. These emission reduction has played a significant role in the improvement of air quality. Concentrations of PM2.5, NO2and SO2decreased by 31.8%, 45.1% and 20.4% during the Level I period; and 33.2%, 27.2% and 7.6% during the Level II period compared with 2019. However, ozone did not show any reduction and increased greatly. Our results also show that even during the lockdown, with primary emissions reduction of 15%–61%, the daily average PM2.5concentrations range between 15 and 79 μg m−3, which shows that background and residual pollutions are still high. Source apportionment results indicate that the residual pollution of PM2.5comes from industry (32.2–61.1%), mobile (3.9–8.1%), dust (2.6–7.7%), residential sources (2.1–28.5%) in YRD and 14.0–28.6% contribution from long-range transport coming from northern China. This indicates that in spite of the extreme reductions in primary emissions, it cannot fully tackle the current air pollution. Re-organisation of the energy and industrial strategy together with trans-regional joint-control for a full long-term air pollution plan need to be further taken into account.