As zonas climáticas locais e o conforto térmico: uma análise do clima urbano do município de Belém, Pará

Abstract

This study aims to analyze how urban modifications and structures impact the climate and thermal comfort in the municipality of Belém, the capital of the state of Pará. The analysis is conducted using a set of data and variables/parameters, combined with different methodological approaches to identify the possible factors associated with these impacts. The research methodology begins with the acquisition of satellite images from the LANDSAT system to estimate spectral/environmental indices (NDVI, NDBI), with the goal of analyzing land cover and estimating Land Surface Temperature (LST) in both spatial and temporal dimensions. Next, the classification of Local Climate Zone (LCZ) for the study area is carried out using a consolidated methodology. Subsequently, with the aid of a mobile transect, air temperature measurements are performed to assess the influence of urban structures on the thermal field. In the third phase of the research, the Thom Discomfort Index (TDI) is determined using both historical data and data collected from the mobile transect. This aims to evaluate the impact of the urban climate on public health and to identify which Local Climate Zones present the highest levels of discomfort for individuals. The findings reveal that land surface temperature increases in accordance with the process of urban expansion, especially in densely populated neighborhoods, while lower LST values are observed in areas with vegetation and low-density residential structures. LCZs 2 and 3 are predominantly found in neighborhoods within the districts of Guamá, Belém, and Sacramenta. Conversely, the districts of Outeiro and Mosqueiro mostly feature LCZ types 6 and A, which are associated with lower LST values. Regarding the thermal field, maximum air temperatures are observed in LCZs with high building density (clusters of constructed structures and absence of vegetation), while lower air temperature values are recorded in areas with more open and residential construction types, characterized by wider spacing between buildings and the presence of vegetation. Finally, based on historical data and statistical tests, the study identifies a climatic shift in thermal comfort indices associated with the intensification of urbanization processes. Furthermore, it is evident that Belém exhibits varying stages of urbanization and diverse urban structures, which significantly influence thermal comfort. Specifically, areas within Belém’s urban fabric dominated by LCZ- 3 experience higher discomfort levels, while areas dominated by LCZ-6 show partial comfort. Consequently, the analysis concludes that districts such as Outeiro and Mosqueiro, which are predominantly classified as LCZ-A, offer greater thermal comfort.