Estimation of air pollution removal capacity by urban vegetation from very high-resolution satellite images in Lithuania

In cities, particulate matter (PM10), carbon dioxide (CO2), nitrogen dioxide (NO2), and ground-level ozone (O3) are some of the most significant air pollutants that have negative effects on human health, vegetation, and biodiversity. The city of Kaunas (Lithuania) represents the geographical region of north-eastern Europe and the Humid continental climate zone. By using a satellite-based approach with Worldview-3 (WV-3) satellite imagery at the very-high spatial and spectral resolution, we have detected and classified the most common tree species (a total of 284,305 trees) in Kaunas with an overall accuracy of about 88% e.g., Acer spp. (10%), Aesculus hippocastanum (11%), Pinus spp. (9%), Quercus spp. (24%), and Tilia spp. (5%) in both private (e.g., residential gardens) and public areas over a large study area (56 km2). The green cover of Kaunas city represents 64% of the total study area. In 2022, the 284,305 trees detected in Kaunas city center and surrounding areas have removed approximately 2084 tons of NO2, 217 tons of PM10, and 22,938 tons of CO2 while dominant trees formed more O3 than they absorbed (1204 tons released) mainly due to the high ozone formation potential of Quercus spp.