ANALYSIS OF THE INFLUENCE OF GEOMETRIC PARAMETERS OF URBAN CANYONS IN A TROPICAL SAVANNAH CLIMATE

Abstract

The growing population growth in urban centers has driven a gradual process of modification from the natural to the built environment. These transformations condition a typically urban climate, often characterized by increased air temperature, a phenomenon known as urban heat islands (ICU). In the search for sustainable and resilient cities, the literature points to the compact city model, and verticalization emerges as an alternative to enable the increase in population density. The study of urban canyons, can contribute to the creation of microclimatic conditions favorable to thermal comfort for pedestrians. The objective of this investigation was to analyze the effects of the geometry of the urban canyon, based on the H/W ratio and the orientation of roads on the urban microclimate, taking as object of study the city of Arapiraca, Alagoas, with a tropical savannah climate. For that, computer simulation was used in the ENVI-met software in predictive analysis from 18 hypothetical scenarios. The scenarios have variations regarding the application of minimum setback and progressive setback to the number of floors, with the predominant incidence of ventilation perpendicular (N=0°) and oblique (N=45°) to the buildings, for the hot and dry period. The canyon performance was evaluated by comparing mean radiant temperature and wind direction/speed, at 15h, as it is the hottest period of the day. The results revealed that in deep canyons using the initial setback, the extent of the shaded area was greater, which decreased the mean radiant temperature. However, the scenarios using progressive retreat showed better performance in terms of wind direction/speed. In this case, the oblique orientation of the pathways enhanced this result.