Zonas climáticas locais e índices espectrais em Várzea Grande/MT : uma abordagem ao planejamento urbano

Abstract

Understanding urban morphology and how it is altered becomes relevant in order to also comprehend landscape changes. These changes, when evaluated in a space-time distribution, facilitate a deeper understanding of the effects of urbanization. The city of Várzea Grande forms a conurbation with the capital Cuiabá and has undergone intense population growth and morphological changes in recent decades. Additionally, it is common for temperatures near 40°C and relative humidity below the WHO recommended level (60%) to be recorded in this region. In this research, the objective was to understand the transformation of local climatic zones and spectral indices in the years 2005 and 2020, a period in which the city experienced a population increase of approximately 26.64%, making it the second most populous city in the state. Initially, the classification of urban morphology from a climate perspective was carried out for the two study years, through local climatic zones, where it was possible to identify that LCZ A – dense tree vegetation, despite its increase in total area for the municipality, in some locations, such as near the Urban Macrozone, showed a decrease, while the classes of LCZ 3 – compact low-rise and LCZ 6 – low open building typology, for this same region, increased. With the aid of satellite images from Landsat 5 and Landsat 8, it was possible to calculate the NDVI and TST indices, visualizing that the average TST increased by 2.74°C over a period of 15 years, a result with 95% statistical confidence. Additionally, it was observed that in the LCZ classes related to building typology where an increase in temperature was recorded, a decrease in the NDVI index was also identified, a result at the 95% statistical confidence level, through which it is possible to infer that areas without vegetative cover or with smaller cover tend to record higher temperatures. The LCZ 2 class was identified only in the LCZ classification for the year 2020, suggesting that this is likely a possible path for the urban growth of the municipality, if measures are not developed to consider the need to mitigate the adverse effects of urbanization. Thus, it is necessary for measures for urban growth suitable to climatic conditions to be taken, with the aim of making cities and communities sustainable and resilient.