Investigating Urban Environmental Shifts in Hyderabad and Bangalore Cities in India During The COVID-19 Lockdown

Abstract This study investigates the complex dynamics of air quality and the Urban Heat Island (UHI) effect in urban region and rural region of Hyderabad and Bangalore pre-lockdown, lockdown, and post-lockdown during the COVID-19 pandemic. Employing advanced spatial and temporal analyses, including spatio-temporal maps, box plots, independent samples t-test, ANOVA, and post-hoc analysis, the study meticulously examines the distribution and temporal changes in key pollutants. In Bangalore, carbon monoxide (CO) levels exhibited a significant urban-rural disparity, with urban areas experiencing higher concentrations during the pre-lockdown period. However, an intriguing shift occurred during the lockdown, with CO levels decreasing in urban areas while increasing in rural areas. Formaldehyde (HCHO) and Aerosol Optical Depth (AOD) levels displayed a consistent urban-rural gradient, significantly higher in urban areas. Notably, both HCHO and AOD levels decreased in regions both rural and urban during the lockdown, indicating a notable impact of reduced anthropogenic activities. Nitrogen dioxide (NO 2 ) levels, a critical indicator of vehicular emissions, showed a substantial reduction during the lockdown in both urban and rural environments. Ozone (O 3 ) levels, on the other hand, increased post-lockdown, revealing a complex interplay of factors influencing air quality. Sulfur dioxide (SO 2 ) levels, typically associated with industrial emissions, exhibited lower concentrations in urban areas during the lockdown. The UHI effect, manifested through elevated Land Surface Temperature (LST) in urban regions, demonstrated a significant reduction during the lockdown, aligning with decreased anthropogenic heat sources. In Hyderabad, CO levels were consistently higher in urban areas, reaching a peak during the lockdown, indicative of localized emissions. HCHO and AOD levels followed a similar pattern to Bangalore, with a significant urban-rural gradient. NO 2 levels experienced a substantial reduction during the lockdown, consistent with a decrease in vehicular activities. O 3 levels showed an interesting urban-rural dichotomy, with increases in urban areas post-lockdown and higher concentrations in rural areas during the lockdown. SO 2 levels did not exhibit a consistent urban-rural gradient, indicating diverse emission sources. LST in urban areas demonstrated a significant reduction during the lockdown, suggesting a moderation of the UHI effect. This research provides a meticulous examination of the complex interplay between lockdown measures, pollutant concentrations, and the UHI effect in two distinct urban environments. These findings provide important insights that may be used for urban planning strategies and environmental management in the context of global pandemics and emphasize the need for sustainable approaches to mitigate air quality challenges in urban regions.