2020年新冠肺炎疫情管控期江苏省大气污染物浓度变化特征北大核心

利用江苏省大气环境监测站点的大气污染物监测数据,分析了2020年初新冠肺炎疫情管控期间(2—3月)主要大气污染物浓度的变化特征。结果显示,相比于2019、2020年疫情管控期间PM_(2.5)、PM_(10)、NO_(2)、SO_(2)、CO浓度的全省平均降幅分别为37.5%、36.9%、31.9%、28.2%和21.2%。严格管控期的2月和生产恢复期的3月,江苏省十三市PM_(2.5)、PM_(10)浓度同比降幅大致相当,呈现出较好的时间连续性和空间均匀性。但各市臭氧浓度同比变化呈现出较大的时空差异。空间上,沿江以南城市南京、无锡、常州、苏州和镇江五市臭氧浓度明显上升,而其他城市臭氧浓度以下降为主;时间上,2月南京等九市臭氧浓度上升,3月徐州等八市臭氧浓度持平或者下降。假设未发生新冠肺炎疫情以及未采取为阻断疫情蔓延而实施的种种举措,在仅考虑近年来大气污染防治政策持续实施的情况下,与预期降幅相比,疫情管控对NO_(2)实况浓度降幅的影响最大,其次是PM_(2.5)和PM_(10)。

Characteristics of air pollution concentration changes during COVID-19 restriction periods in Jiangsu Province

The characteristics of air pollution concentration changes during COVID-19 restriction periods in 2020(February-March) were investigated based on air monitoring data at surface monitoring stations in Jiangsu Province. Compared with the same period in 2019, the concentrations of PM_2.5, PM₁₀, NO₂, SO₂, CO were reduced by 37.5%, 36.9%, 31.9%, 28.2%, and 21.2%, respectively. In February (the period of lockdown) and March (the period of recovering), PM_2.5, PM₁₀ concentrations in all 13 cities of Jiangsu Province present approximate decreasing, performing well temporal continuity and spatial uniformity, respectively. However, the changes of ozone concentration in different cities performing large spatial and temporal differences. In terms of spatial distribution, Nanjing, Wuxi, Changzhou, Suzhou and Zhenjiang show an obvious increasing of ozone concentration, while the other eight cities mainly present a decreasing trend. In terms of temporal distribution, ozone concentration increase in nine cities in February, but remain flating or decreasing in eight cities in March. Under the assumption that COVID-19 epidemic and restriction do not happen, and only considering the consistent implementation of enforcement regulations on prevention of air pollution, compared with the expected concentration, epidemic control has the greatest impact on the decline of NO₂ concentration, followed by PM_2.5 and PM₁₀.