Verticalização e ambiente térmico urbano: análise de parâmetros urbanísticos integrados à abordagem bioclimática em Arapiraca, Alagoas

Abstract

The study of urban parameters in the face of horizontal and vertical urban expansion becomes essential, due to the potential to optimize the use of natural resources appropriate to the local climate, the principle of bioclimatic urbanism. The absence of prior urban planning causes a loss of quality of life in the urban environment, followed by several environmental impacts, such as: heat islands, floods, smog effect, among others. In view of this scenario, this research aimed to analyze the influence of urban density through verticalization in the urban thermal environment, based on a traditional urban parameter (progressive retreat), from the lot as a minimum planning unit, taking as a study of the case of Arapiraca, located in the semi-arid region of Alagoas, in the hot / dry period. This was made possible through computer simulations of hypothetical urban scenarios (predictive research), using the ENVI-met 4.0 software. In view of the bioclimatic strategies appropriate to the local climate, 18 models were developed, with north equal to 0 ° and 45 °, under the concept of porosity and roughness, climatic conditions that have a close connection with the geometry of the urban canyon (H / W ratio) , based on the type of urban fabric that tends to verticalize in the city. The analysis of thermal performance was performed using data on air temperature, radiant temperature, wind speed / direction and the PMV index. The results obtained indicated that the direction of incidence of natural ventilation oblique to the building (N = 45 °) presented milder thermal sensation conditions. Regarding the progressive setback, the scenarios in which only the initial setback was used presented better conditions of urban thermal sensation, due to the greater shadow area generated by the verticalized buildings, which coincides with the main bioclimatic strategy identified for the local climate: the shading. However, in the analysis of the winds, the use of progressive retreat showed superior climatic performance in terms of porosity and roughness of the urban fabric. Therefore, the importance of bioclimatic urbanism as a tool for urban planning became evident.