A dataset for the validation of flow and dispersion models at an urban intersection

Abstract

Dispersion modelling concerning air pollution caused by road traffic is 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 to be considered. For the validation of models claimed to be applicable to intersections, measurements of meteorological parameters and pollutant concentrations were performed at an urban intersection. Though those field observations are important to get information about the actual immission situation, they cannot render data to the extent necessary 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 structure at an intersection, concentration distributions with a high confidence level can be gained only by a combination of field observations with wind tunnel studies and/or model runs.