Efeitos do adensamento construtivo sobre microclimas urbanos : estudo em uma cidade de porte médio no sul do Brasil

Abstract

This study aimed to analyze the effects of building density increase in pedestrian thermal comfort on open spaces in Bagé Brazilian city. The building density increase, induced by agents such as the real estate market, changing urban microclimates that, cumulated with climate change scenarios on a global scale, interfere with pedestrian thermal comfort in open spaces. The investigation has been because of the need for predictive studies about the effects of urban morphology in urban microclimates in medium size Brazilian cities. Bagé is a medium size Southern city that increased building density considerably in the last decade (2011-2021), mainly in the Central zone. It has a subtropical humid climate with hot summers (Cfa), wide temperature variations in the year, and low temperatures in the winter. The methodology of this research is quali-quantitative, divided into four stages. In the first stage, the scenario base of this study and a building density prognosis to 2060 was defined based on a historical and urban analysis of Bagé. In the second, the scenarios applying the prognosis on scenario base accumulated with two levels of global climate changes and four urban hypothetical scenarios. The next stage consisted of the modeling and the simulation of the urban microclimate scenarios, which ran to extreme summer and winter days. In the last step, the Mean Radiant Temperature results were analyzed on the sidewalk and interior block for all scenarios. The Physiological Equivalent Temperature (PET) index was applied to base and prognosis scenarios to understand their effects on thermal comfort. The building density increase, by inserting buildings with three storeys, reduced the Mean Radiant Temperature modestly in some schedules. It did not cause adverse impacts on thermal comfort in analyzed situations. In the summer, increased heat thermal stress was observed from scenario base to prognosis with increased air temperature at a high level. Those results alert us to air heating effects caused by predicted climate changes on a global scale.