Spatio-Temporal Assessment of Air Quality in Rajsamand District,Rajasthan Using Cloud-Based Google Earth Engine Approach

This study examines the spatial and temporal variations of key air pollutants in Rajsamand District, Rajasthan, from January 2015 to December 2019, using Sentinel-5P TROPOMI data. The pollutants analysed include carbon monoxide (CO), nitrogen dioxide (NO₂), formaldehyde (HCHO), sulphur dioxide (SO₂), methane (CH₄), and aerosols. The findings reveal significant impacts of marble mining activities on local air quality. CO levels increased notably near mining sites, with mean annual values rising from 0.022 mol/m² in 2015 to 0.026 mol/m² in 2019. NO₂ concentrations peaked near urban and industrial areas, increasing from 0.00013 μg/m³ in 2015 to 0.00016 μg/m³ in 2019. Elevated HCHO levels were observed near mining clusters, with concentrations rising from 0.00018 μg/m³ in 2015 to 0.00021 μg/m³ in 2019, posing significant respiratory health risks. SO₂ emissions, primarily from diesel machinery and blasting activities, increased from 0.00028 ppm in 2015 to 0.00031 ppm in 2019. CH₄ concentrations, influenced by underground releases during mining, increased from 1795 ppm in 2015 to 1810 ppm in 2019. Aerosol levels, elevated due to dust emissions from mining, increased from 0.48 μg/m³ in 2015 to 0.51 μg/m³ in 2019. These results underscore the need for stringent air quality regulations and sustainable mining practices to mitigate environmental and health impacts in Rajsamand District.