Development and validation of a model for predicting air temperature in street canyons

Based on the thermal balance and theories of atmospheric boundary layer, a simple urban canopy model was developed to predict air temperature in street canyon environment. This model considered the shade effect of buildings on solar radiation, the multi-reflection of radiation between building surfaces and the road and the effect of anthropogenic heat on local thermal environment. Furthermore, sensible heat exchange between the canyon space and the overlaying atmosphere was also modeled on the basis of the classical theory of dynamics of atmospheric boundary layer. Simulation results of this model was validated through a field measurement, which was carried out in a street canyon located near the center of Harbin, China. The filed measurement result has shown that the model can well predict heat island intensity when there is no precipitation. However, this model will over evaluate the air temperature in the condition with rainfall, because the heat island effect nearly disappears in such condition.