Synergizing google earth engine and earth observations for potential impact of land use/ land cover on air quality

Abstract

Changes in land use and land cover are imperative drivers of climate change in urbanization. The conversion of land use modifies the physical and thermal characteristics of the land surface and also has an impact on the air quality. This study aims to assess the potential impact of Land Use Land Cover (LULC) on the air quality in Gujarat state, India for 6 years, 2018, 2020, and 2023. Six land-use types, water bodies, forest, agricultural land, built-up, barren land, and scrubland obtained from the Landsat 8 land cover product processed in GEE, where LULC of each category was estimated. The analysis findings indicated that variations in pollution response to LULC change exhibit distinct differences across different regions, influenced by natural factors or human activities like deforestation and urbanization. Over the years 2018–2023, agricultural land seems to consistently decrease in area, but urban areas saw exponential growth. The combined percentage of agricultural land and forest area slightly decreased from 61.08% to 60.7%, while the water spread area increased from 4.07% to 5.13%. The category of bare land decreased from 29.59% to 27.56%, mainly due to urbanization converting bare soil into built-up areas. The Sentinel-5P satellite data was used to estimate atmospheric pollution i.e., carbon mono-oxide (CO), Nitrogen dioxide (NO2), Methane (CH4), Sulfur Dioxide (SO2), and formaldehyde (HCHO). Over the past decade, a significant portion of land use land cover has transitioned from forest to vegetation areas in the western region, while urbanization has rapidly expanded in the eastern and central-western parts.