Mathematical Modeling of Motor Vehicle Exhaust Gas Dispersion in The Conditions of Andijan City

Abstract

In this study, changes in atmospheric air quality in the city of Andijan under conditions of global urbanization and the rapid development of motor transport complexes were investigated using sophisticated mathematical models. The specific climatic characteristics of Andijan — situated in the central geoecological section of the Fergana Valley — were analyzed, including its low aerodynamic potential, very low mean annual wind speed (1.8–2.2 m/s), and the frequent recurrence of thermal inversion layers. To quantify harmful components (CO, NOₓ, PM10 particulate matter) emitted from road corridors, an integrated combination of the international COPERT methodology and Gaussian linear diffusion models was applied. Traffic loads on Babur Avenue, the New Market district, and Navoi Avenue — the highest-traffic routes in the city — were studied and modeled concentrations were compared against Maximum Permissible Concentration (MPC) standards. The “street canyon” effect arising from the vertical density of the built environment was identified and its negative impact on air purification (stagnation of up to 40%) was assessed. The article concludes with scientific recommendations for the innovative architectural-phytocenotic “Green Shield” project and the “Smart Air Andijan” digital monitoring platform, both aimed at improving the urban ecological environment.