Urban morphology, outdoor thermal comfort and walkability in hot, dry cities

摘要

Urban morphology should carefully consider climatic and behavioural aspects for hot arid climates. To put these insights into practice, this study aims to investigate different urban environments in the hot, dry city of Sidi Okba, Algeria (Biskra) during the summer season and defines the upper and lower limits of the thermal comfort range for the PET index. A second aim is to quantify the walkable environment and highlight the relationship between urban morphology and walking behaviour. The study was based on physical measurements combined with a questionnaire survey and a walking audit instrument. The findings from this research show that urban morphology, defined by building density, height/width (H/W) ratio and tree density, is significantly associated with the outdoor thermal conditions and potential pedestrians over short distances. The study also shows that in order to provide a comfortable climate and to increase pedestrian choice in the urban environment, the public space should include high building density, combined with deep streets with a high connection between them, and a large amount of vegetation along the lower parts of streets. This type of design has a positive effect on the walkability score of public spaces.