Street Canyon Geometry Effects on Microclimate and Comfort; A Case Study in Thessaloniki

Abstract

A case study in Thessaloniki provided microclimate data at street canyons with varying orientation and aspect ratio. Seventeen canyons characterized by diverse geometries including four different canyon axis orientations and a range of aspect ratios from 0.6 to 3.3 as well as variations of vegetation and pavement material, were monitored during summer and winter. Measurements are used to calibrate microclimate simulation models, examine results accuracy and produce further data for larger areas or different climatic periods. This paper presents the simulation studies run with ENVI-met software for models of the study area at different scale used to evaluate results accuracy depending on model resolution, influence of the surrounding built environment and of material and geometric details. The large area - low resolution models take into account the urban environment surrounding the study areas which influences thermal and airflow conditions and provide urban microclimate maps. The small area - high resolution models take into account fine geometric elements, individual building heights, tree species, canopies, and pavement materials and provide detailed microclimate data and pedestrian comfort indices which can inform urban space design.