A influência de cânions urbanos no conforto térmico: uma abordagem cronomorfológica

Abstract

With climate change and the trend of intensifying urbanization in nowadays cities, new research on comfort in urban areas has been gaining increasing attention, especially those that use computational tools to assess environmental quality at different scales. Urbanization processes usually lead to the creation of urban heat islands and the urban morphology is one of the factors that most impacts the pedestrian’s thermal perception by limiting or allowing solar incidence and local winds, interfering with the thermal comfort perceived by people. Thus, through parametric approaches, the present work aims to analyze how changes in urban morphology impacted the thermal conditions of an urban canyon in the central area of Juiz de Fora, Minas Gerais, Brazil. The analyses, which compared three different moments in history (1940, 1980 and 2020) and a hypothetical scenario, were performed with Ladybug Suite Tools / Grasshopper software for Rhinoceros software; and were based on the Universal Thermal Climate Index (UTCI). The UTCI maps indicates changes in local thermal comfort during its historical development. The results showed that, as the urban morphology became more denser and more verticalized over time, more shaded spaces were created during hot periods of the day, which recorded a reduction of up to 7°C in the UTCI. At night, the phenomenon reversed itself, as the facades of the building’s fabric release the heat stored during the day, and thus, a difference of up to 1°C was recorded in areas near the buildings in the canyon, when compared to open spaces. Therefore, this demonstrates that the urbanization process that has taken place over the years has strongly affected the thermal conditions of the canyon at the pedestrian level.