A simplified three-dimensional approach to street canyon modelling using SEP-SCAM

The spatial distribution of pollutant concentrations in street canyons can be described with the newly developed Semi-Empirical Parameterized Street Canyon Model (SEP-SCAM). The model calculates the two-dimensional horizontal pollutant concentration distribution at any height above street level. It makes use of a combination of a plume and a box model as well as of diagnostic equations based on empirically derived techniques previously used in the OSPM, CPB and STREET models. The novel elements in SEP-SCAM are the introduction of new empirical algorithms that refine the aforementioned models, as well as the use of a parameterized approach for the extraction of the horizontal distribution of concentrations. These modifications and approaches were deduced from extensive analysis of experimental data and tests with the three-dimensional microscale model MIMO. The SEP-SCAM is applied to specific street canyons in three European cities, London, Stockholm and Berlin using data from monitoring stations located in the considered domains. The results from these simulations show a good agreement with measured concentrations.