JOSÉ RICARDO RODRIGUES ROCHA
Abstract:
Man has been causing changes in the environment through the transformations, occupation and modeling of space, which generates the urban climate. Thus, urban studies are necessary, because the sums of these transformations lead to hydrothermal discomfort and heat differentiation in the urban fabric, as already evidenced in many studies. Thus, the aim of the study was to verify the variation of temperature and relative humidity (maximum and minimum) in two small cities of the Brazilian Cerrado, Jataí and Caçu (GO). Thus we sought to identify the relationships between the physical aspects of the environment (hypsometry, slope exposure and land use) with the variation of climatic aspects at fixed collection points in cities. Both cities are located in the Sul Goiano mesoregion, Jataí in the southwestern Goiás microregion and Caçu in the Quirinópolis microregion. The methodological basis was the urban climate theory proposed by Monteiro (1976) and Monteiro and Sezarino (1990), addressing the thermodynamic subsystem. To collect temperature and relative humidity data, thermohygrometers (model HT-4000 and HT-500) were used, distributed in 5 points in Caçu and 09 in Jataí, where they were collected every 30 minutes. For the making of maps such as: hipsometry, slope exposure, land use were used GIS Arcgis 10.1. It was found that the absolute maximum temperature value (44.6 ° C) was recorded at P3 in Caçu at 2:39 pm, and Jataí showed 43.1 ° C at P1 at 1:25 pm, where land use influenced the values between the collection points, and the altitude for the difference between cities (amplitude of 1.5 ° C). The lowest values of minimum temperatures also occurred in August, on the 28th and 29th, when a stationary front operated, where Jataí had 4.9 ° C in P6, with very low construction rate (1.1%) and high vegetation rate (81.5%), besides being located in valley bottom. In Caçu was recorded 6.4 ° C, in P3, it has low construction rate, average pasture rate (11.5%) and vacant land with soil exposure (34.6%). The maximum relative humidity occurred in November 2013, ranging from 100 to 81% between cities, on days 5, 8 and 26 under the action of ZCAS and ZCOU. The minimum relative humidity values occurred in August, on days 02, 03, 04, 05 09, 18, 28 and 29 and in September on days 02, 09, 11 and 13, where the values ranged from 6 to 52 %, between 1:00m and 5:00mm. From the analysis, we considered that there was influence of urban structure and physical aspects on hygrothermal behavior between cities. This was due to the fact that densely built and vegetation-free sites had higher temperatures and lower relative humidity, while sites with higher arborization rates and lower building rates had lower temperatures and higher relative humidity.
