A influência da cobertura vegetal no conforto térmico urbano em uma região do semiárido Norte Mineiro

Abstract

Urban vegetation cover performs important ecosystem services such as: increasing biodiversity, improving air quality, providing greater thermal comfort, reducing artificial climatization, providing positive consequences for human health and improving life quality in urban areas. In the semiarid region in the North of Minas Gerais State, a region with high incidence of sunlight, high temperatures and low thermal amplitudes, there is a need to understand the beneficial effects of vegetation on thermal comfort, since the vegetation is responsible for easing higher temperatures, among other benefits, being an important regulating component of urban temperature. Thus, this study was aimed at characterizing the differences between the temperatures of heat islands and areas with vegetation cover in urban environments. Specifically, to analyze the microclimatic variables in these environments through thermal comfort indexes; and to determine which of these provide greater influence on the microclimate, and also to quantify the level of thermal comfort provided by the forest cover using the Heat Index (HI) and the Temperature and Humidity Index (THI). The variables sampled were sensitive to the seasons of the year, as well as to the presence of vegetation cover or not, allowing us to affirm that the presence of vegetation contributes to a decrease in temperature and to an increase in the air relative humidity. Consequently, it generates a reduction in HI and THI values, generating an improvement in thermal comfort. The results indicated that there is a strong positive correlation between the variables THI and HI, toward the temperature and the air relative humidity, indicating that increases in room temperature are responsible for significant increases in the values of the indexes. As to the air relative humidity, on the other hand, it showed a strong negative correlation toward the HI, indicating that the decrease in its values, associated with the increase in air temperature values, significantly contributes to the worsening of the HI. It was then concluded that, in addition to the green areas being significantly cooler, the fact that the species in the region are deciduous does not reduce the effectiveness of the improvement in the thermal comfort provided by them. The presence of trees makes a significant and positive difference to urban thermal comfort, proving that there are positive reasons for urban afforestation in the city of Montes Claros, MG, aiming at alleviating the semiarid climate and providing greater social well-being, life quality and sustainability.