Water channel investigation of flow and dispersion in street canyons

This paper describes experiments conducted in the water channel for studying the turbulent dispersion of a passive pollutant emitted by a line source located at the bottom of a street canyon. Velocity and pollutant concentration fields have been measured simultaneously in correspondence of an arrangement of two-dimensional obstacles that simulate a street canyon with aspect ratio unity. From the instantaneous values of the pollutant concentration, high-spatial resolution maps of mean, standard deviation and skewness factor of the concentration field have been determined both within and outside the canyon.