Gayen Amiya, Haque Sk Mafizul, Mishra Swasti Vardhan
Department of Geography, The University of Calcutta, 35 B. C. Road, Kolkata 700 019, India.
Department of Geography, Amity Institute of Social Sciences, Amity University Kolkata, Rajarhat, Newtown, Kolkata 700135, West Bengal, India.
Urban Clim. 2021 Mar;36:100786. doi: 10.1016/j.uclim.2021.100786. Epub 2021 Jan 29.
The air quality in the cities of developing countries is deteriorating with the proliferation of anthropogenic activities that add pollutant matters in the lower part of the troposphere. Particulate matter with an aerodynamic diameter lower than 10 μm (PM) is considered one of the direct indicators of air quality in an urban area as it brings health morbidities. The article empirically investigates the role COVID-19 related lockdown has played in bringing down pollution level (PM) in the megacity of Kolkata. It does so by taking account of PM level in three stages - pre, presage and complete-lockdown timelines. The extracted results show a significant declining trend (about 77% vis-a-vis the pre-lockdown period) with 95% of the geographical area under 100 μm/m and a strong fit with the station-based records. The feasibility and robustness showed by the remotely sensed data along with other earth observatory information for larger-scale pollution prevalence make its adoption imperative. Simultaneously, it becomes urgent in times of lockdown when the physical mobility of maintenance and research staff to stations is significantly curtailed. The work contributes to study on PM by its ability to replicate in examining cities of both the global north and global south.
随着增加对流层下部污染物的人为活动激增，发展中国家城市的空气质量正在恶化。空气动力学直径低于10微米的颗粒物（PM）被视为城市地区空气质量的直接指标之一，因为它会引发健康问题。本文实证研究了与新冠疫情相关的封锁措施在降低加尔各答这座特大城市的污染水平（PM）方面所起的作用。研究通过考虑三个阶段（封锁前、封锁预兆期和全面封锁期）的PM水平来进行。提取的结果显示出显著的下降趋势（与封锁前时期相比下降约77%），95%的地理区域低于100微米/米，并且与基于监测站的记录高度吻合。遥感数据与其他地球观测信息在大规模污染监测方面所展现出的可行性和稳健性，使其采用成为必要。同时，在封锁期间，维护和研究人员前往监测站的实际行动大幅受限，此时这一点变得尤为迫切。这项研究通过其在研究全球北方和南方城市方面的可复制性，为PM研究做出了贡献。
