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.