Spatio-temporal trend analysis of air pollutants during COVID-19 over Korba district, Chhattisgarh (India) using Google Earth Engine

Abstract

Air pollution is a significant public health concern and impacts a country’s well-being. The COVID-19 pandemic and subsequent lockdowns have provided researchers with a unique opportunity to examine the impact of human activities and industries on air pollution. The annual mean PM2.5 grids were validated by comparing them with collocated surface in situ PM2.5 measurements and were then used for trend analyses. Using ground in-situ data validated in 2020–21 showed a good correlation (R2 = 0.90, 0.81 & 0.99) with Satellite-derived for summer, monsoon, and winter seasons, respectively. Among these pollutants, human and industrial activities are a significant source of Sulfur dioxide (SO2), Nitrogen dioxide (NO2), Formaldehyde (HCHO), and Ozone (O3). This study examined how these pollutants changed between February 2019 to January 2022 in Korba District, Chhattisgarh (India). The Google Earth Engine (GEE) is based on the cloud platform time series from the Sentinel-5P TROPOMI satellite data sets. The findings show that the annual average concentration of (SO2: R2 = 0.90, 0.97, and 0.97), (NO2: R2 = 0.97, 0.94, and 0.94), (HCHO: R2 = 0.99, 0.99, and 0.99), and (O3: R2 = 0.99, 0.94, and 0.94) and also increased monsoon, summer, and winter in ascending order for 2019–20, 2020–21, and 2021–22 respectively, due to topology, meteorology, and anthropogenic activities. These results are essential guidelines for future industrial, transportation, and traffic management as sustainable development legislation and programs. Additionally, by applying the COVID-19 scenario, it is now feasible to research how industrial activities, transportation, and biomass burning are, compounded by the region’s topography, affecting air quality using free satellite-derived data sets. These findings also benefit future policy choices on dealing with viral proliferation and reducing its negative societal and economic repercussions.