Decoding outdoor thermal comfort: The role of location in urban canyon microclimate

Abstract

The Urban Heat Island (UHI) effect is a problem aggravated by climate change affecting many urban settings worldwide, with implications for thermal comfort, energy consumption and human health. The study of mitigation strategies is a field of interest for the research community. This study examines the impact of urban geometry and vegetation on creating microclimates in urban areas to improve thermal comfort and mitigate the UHI effect. The novelty is the cross-comparison of urban canyons in two cities with different latitudes and morphologies, Seville in Csa climate and 37°23′00″N latitude and Manta in BWh climate and 0°57′00″S latitude, to determine the most effective strategies for each location. The study uses ENVI-met to simulate 32 variations of typical urban canyon typologies. Results suggest that while air temperature shows minor fluctuations within the same city, thermal comfort differs significantly based on the geometry, orientation, and presence of vegetation. This difference is due to the variations in parameters that affect thermal comfort, such as relative humidity, solar radiation and wind speed. Vegetation improves thermal comfort in Seville while in Manta, where relative humidity is much higher, the addition of vegetation has a negative impact. Therefore, the recommended urban strategies for each city are different and should consider local climatological context and geographic location. The study highlights the need for tailored and context-specific urban design strategies to mitigate the impact of UHI in urban areas while addressing some general recommendations that can be considered in similar climates and urban contexts.