Clima urbano: análise do campo termo-higrométrico em episódios de inverno e primavera em Ituiutaba-MG

Abstract

From the second half of the 20th century, Brazil experienced a quick transition of the rural population migrating to urban spaces, which contributed to a fast population growth and urban restructuration, with consequent environmental impact. According to Monteiro (1976, p.95) urban climate is “a system that includes the climate of a given terrestrial space and its urbanization”, wherein the elements that are the most influenced and also have the most influence over the citizen's daily life are temperature and air humidity. This work sought to investigate the thermal and hydrometrical variation of Ituiutaba City – MG, in spring and winter episodes of 2018, and their relationship with different elements of the urban landscape, supported by the Theory of Urban Climate System (U.C.S.), by Monteiro (1976), which refers to your thermal field (Channel 1: thermal comfort, thermodynamic subsystem), under the perspective of the systemic analysis. The study used the methodological approach Monteiro (1976) and Mendonça (2004), which was divided in four steps. First, a bibliographic review about the subject was conducted, followed by a geographic and cartographic survey (on their geoecological and geo-urban aspects) of the urban study area; next, an investigation of the thermo-hygrometric data was conductes for a period of twenty-four hours in July, August and October with the distribution of five fixed points in different geographic characteristics sectors among the city. The data was summarized in a table for the discussion of the results. The results showed that even a medium-sized city like Ituiutaba presents thermo-hygrometric variations due to its urban and geological settings. Data colected on October 29, station 1 at 9:00 a.m. showed the lowest temperature and highest relative humidity at that specific time. At stations 3 and 4, the temperatures were higher at 9:00 p.m. and they had lower relative humidity. On the 29th of August at 09h00min the stations did not have significant temperature changes, which varied only 2°C. Station 1 had the highest temperature at 3:00 p.m.; station 3 had the highest temperature at 9:00 p.m. and the lowest relative humidity. In the spring, with data collected on October 27th, low daily temperature ranges were found between seasons. High relative humidity levels were observed (between 54% and 90%) due to the presence of several days of precipitation. The temperature ranged between 23.7°C and 30.1°C between stations. It could be inferred that the thermo-hygrometric variation was due to differences of rural ecology and some geo-urban aspects.