Dispersion of Traffic Exhausts in Urban Street Canyons with Tree Plantings- Experimental and Numerical Investigations-

Abstract- Wind tunnel experiments and nu-merical computations have been performed in order to investigate the influence of avenue-like tree plantings on the dispersion of traffic exhaust in an urban street canyon. Reduced natural ventilation and enhanced pollutant concentrations have been found in the pres-ence of trees. A comparison of experimental and numerical results shows qualitative good, but quantitative rather poor agreement. In the numerical computations, flow velocities are underestimated and pollutant concentrations are overestimated. Key words- trees, pollutant dispersion, urban street canyon, urban air quality, traffic exhausts