Effect of Trees on Airflow Structure and Pollution Concentration in Street Canyons

The work studies the influence of tree height on aerodynamics and passive gaseous pollutant transport in a three-dimensional street canyon. The calculations were performed using the Large Eddy Simulation (LES) model of turbulent flow with explicit parameterization of vegetation. The integral characteristics of the pollutant concentration in a street canyon in total and in a breathing zone (up to 2 m from the bottom of a canyon) were calculated and analyzed. The results show that the use of long hedges of varying heights in an urban environment can lead to deterioration of air circulation in the street canyons. These results will help to more accurately solve problems in the case of denser development and greening of urban spaces.