A DATASET FOR THE VALIDATION OF FLOW AND DISPERSION MODELS AT AN URBAN INTERSECTION

Dispersion modelling concerning air pollution caused by road traffic i s reduced to a two-dimensional problem within street canyons. However, significant pollution loads are also to be expected at intersections. In this case, three-dimensional flow and dispersion structures have t o be considered. For the validation of models claimed to be applicable to intersections, measurements of meteorological parameters and pollu tant concentrations were performed at an urban intersection. Though th ose field observations are important to get information about the actu al immission situation, they cannot render data to the extent necessar y for model validation. Therefore, the same intersection was subjected to wind tunnel studies, whereby wind and pollution data were measured . Evaluation of results showed that, owing to the complex flow structu re at an intersection, concentration distributions with a high confide nce level can be gained only by a combination of field observations wi th wind tunnel studies and/or model runs.