A computer model consisting of wind distribution, emission dispersion, modified Gaussian equation, and stochastic prediction models has been developed to identify street canyon and vehicle wake effects on the transport air pollution from urban road microenvironments. In this work, wind flow and their components in the street canyon are simulated and analyzed considering a two-dimensional street canyon flow pattern. Wind parameters obtained from the analysis are then applied to estimate wind speed and vehicle wake turbulence in microenvironments. Turbulent parameters are integrated in Gaussian equations to estimate pollutant concentrations. A stochastic method has also been considered for predicting maximum concentration in road microenvironments. The model takes traffic data, emission rates, meteorological data, vehicle dimensions, and canyon geometry, and outputs pollutant concentration in microenvironments in an uninterrupted traffic flow section in numerical and graphical form. The model has the predictive capability for CO and NOx. (Author/publisher).
Abstract