The novel coronavirus (COVID-19) has induced unprecedented improvements of air quality due to drastic shrinking of human activities during the pandemic lockdown in 2020. While declines of most air pollutants have been globally evidenced in most cities worldwide, there is few detailed spatial knowledge at local scale. Therefore, we present here a high resolution mapping of the 2018–2020 evolution of human activities and air pollutants in Wuhan. Human activities were assessed by nighttime light radiance. We measured the air quality index (AQI) as the maximum value among air quality sub-indices of SO₂, NO₂, CO, O₃ and particulate matter. We also compared mean monthly pollutant concentration during January–April in 2018, 2019 and 2020. Mapping results show that variations of nighttime light radiance were heterogenous at local scale, showing both rises and declines in the same district. The radiance decreased in eight districts located mostly in the city center, as a result of lower human activity, but the radiance increased in the five surrounding districts, as a consequence of people staying at home. AQI was low during lockdown, averaging at 57, but showed strong daily variations with a slight pollution around February 5 with AQI rising to 126. During this pollution event, particulate matter, SO₂, NO₂ and CO levels were positively correlated, suggesting common sources, but were not correlated with ozone; and particulate matter, SO₂, NO₂ and CO decreased with relative humidity, suggesting removal by precipitation. Comparison of 2020 data with previous years shows that particulate matter and NO₂ were highly reduced, CO was less reduced due to ongoing power industries, SO₂ first declined then increased to exceed 2018–19 values due to coal combustion, and ozone levels was more abundant due both to less NO_x pollution and the weekend effect.

由于在 2020 年大流行封锁期间人类活动急剧萎缩，新型冠状病毒 (COVID-19) 导致空气质量出现了前所未有的改善。虽然全球大多数城市的大多数空气污染物都在下降，但很少有详细的空间知识在局部范围内。因此，我们在这里展示了武汉 2018-2020 年人类活动和空气污染物演变的高分辨率地图。通过夜间光辐射评估人类活动。_{我们将空气质量指数（AQI）测量为 SO 2}、NO ₂、CO、O ₃的空气质量子指数中的最大值和颗粒物。我们还比较了 2018 年、2019 年和 2020 年 1 月至 4 月的月平均污染物浓度。测绘结果表明，夜间光辐射在局部尺度上的变化是异质的，在同一地区呈现出上升和下降的趋势。由于人类活动减少，主要位于市中心的 8 个区的亮度有所下降，但由于人们呆在家里，周边 5 个区的亮度有所增加。封城期间 AQI 较低，平均为 57，但在 2 月 5 日左右出现轻微污染，AQI 上升至 126，显示出强烈的每日变化。在这次污染事件中，颗粒物 SO ₂、NO ₂和 CO 水平呈正相关，表明存在共同来源，但与臭氧无关；颗粒物、SO ₂、NO ₂和CO随着相对湿度的增加而降低，表明通过降水去除。2020 年与往年的数据比较表明，颗粒物和 NO ₂大幅减少，CO 减少由于持续的电力工业而减少，SO ₂由于煤炭燃烧先下降然后上升超过 2018-19 年的值，臭氧水平更高由于较少的 NO _x污染和周末效应，因此非常丰富。