Sarkar Mohan, Das Anupam, Mukhopadhyay Sutapa
Department of Geography, Visva-Bharati, Santiniketan, West Bengal 731235 India.
Department of Geography, Panihati Mahavidyalaya, Sodepur, Kolkata, West Bengal 700110 India.
Environ Dev Sustain. 2021;23(6):8613-8642. doi: 10.1007/s10668-020-00985-7. Epub 2020 Sep 22.
The worldwide spread of COVID-19 caused a nationwide lockdown in India from 24 March 2020 and was further extended up to 3 May 2020 to break off the transmission of novel Coronavirus. The study is designed to assess the changes in air quality from the pre-lockdown period to the during lockdown period in Kolkata and Howrah municipal corporation, West Bengal, India. GIS-based techniques include the spatial and temporal distribution of pollutants using interpolation method, and on the other hand, statistical methods like analysis of variance (ANOVA) was applied to determine the mean differences two phases and correlation matrix helps to understand the changing association of the pollutants in pre- and during lockdown phases. Significant correlations have been found among the pollutants, ANOVA (Two-Way) has shown the significant mean difference of NAQI between the two phases, (1,611) = 465.723, < 0.0001; pairwise comparison for Ballygunge has shown the highest mean difference 108.194 at < 0.0001 significant level between lockdown and pre-lockdown phase. Significant positive correlation has been found between PM, PM (0.99*); PM NO (0.81*); PM, NO (0.81*); CO, NO (0.77*) and some negative correlations have also been found between O, NO (- 0.15); O and NH (- 0.36) in the pre-lockdown phase. The reduction amount of mean concentration from the pre-lockdown phase to during lockdown of the main pollutants like PM, PM and NO are ~ 58.71%, ~ 57.92% and ~ 55.23%. Near Rabindra Bharati University constant emission of PM, 10 and NO have been recorded due to the nearby Cossipore thermal power station.
新冠疫情在全球范围内的传播导致印度自2020年3月24日起实施全国封锁，并进一步延长至2020年5月3日，以阻断新型冠状病毒的传播。本研究旨在评估印度西孟加拉邦加尔各答市和豪拉市市政当局在封锁前至封锁期间空气质量的变化。基于地理信息系统（GIS）的技术包括使用插值法分析污染物的时空分布，另一方面，应用方差分析（ANOVA）等统计方法来确定两个阶段的平均差异，相关矩阵有助于了解封锁前和封锁期间污染物之间变化的关联。研究发现污染物之间存在显著相关性，双因素方差分析显示两个阶段的空气质量指数（NAQI）存在显著平均差异，F(1,611) = 465.723，p < 0.0001；对巴利冈杰的成对比较显示，封锁期和封锁前期之间的平均差异最高，为108.194，在p < 0.0001的显著水平。在封锁前期，细颗粒物（PM）与可吸入颗粒物（PM₁₀）之间存在显著正相关（r = 0.99*）；PM₁₀与二氧化氮（NO₂）之间存在显著正相关（r = 0.81*）；PM₂.₅与NO₂之间存在显著正相关（r = 0.81*）；一氧化碳（CO）与NO₂之间存在显著正相关（r = 0.77*），同时也发现臭氧（O₃）与NO₂之间存在一些负相关（r = - 0.15）；O₃与氨（NH₃）之间存在负相关（r = - 0.36）。主要污染物如PM₂.₅、PM₁₀和NO₂从封锁前期到封锁期间的平均浓度降低量分别约为58.71%、57.92%和55.23%。由于附近的戈斯波雷热电厂，在罗宾德拉·巴蒂大学附近记录到PM₁₀和NO₂的持续排放。
