A MATHEMATICAL-MODEL OF WIND FLOW, VEHICLE WAKE, AND POLLUTANT CONCENTRATION IN URBAN ROAD MICROENVIRONMENTS - PART II - MODEL RESULTS

Theoretical formulations of the proposed model for prediction of pollu tant dispersion in microenvironments was previously introduced in part I of this paper (Karim and Matsui, 1998). This paper discusses the ne w model findings and presents model evaluation results. This paper fir st explains the current problems that the road environment plays in em ploying field data for wind and temperature collected along a road nor th of Nagoya, Japan. A complete simulation is done on wind components in street-canyon and wind distribution, including vehicle wake effect, and is evaluated with experimental results. Next, the paper provides the atmospheric stability and dispersion parameters and then predicts pollutant buildups estimated using several techniques: a numerical mod el, modified Gaussian dispersion model,and a stochastic model. The sto chastic model is specially developed to predict pollutant buildups in microenvironments. Model sensitivity analysis is done, varying the phy sical parameters; vehicle dimensions to wind speed in microenvironment s, vehicle dimensions to dispersion parameter, and wind speed to pollu tant concentrations. The modeled results are then compared to experime ntal data collected in micro-environmental locations in a road of Nago ya City, Japan. Finally, the implications of the research findings are discussed. (C) 1998 Elsevier Science Ltd. All rights reserved.