Avaliação geo-espacial das Ilhas de calor urbanas baseada em geoprocessamento e imagens de satélite, caso de estudo: cidade de Tete entre os anos de 2017 a 2024

Abstract

This monograph investigated the influence of the spatial distribution of vegetation cover on training and intensification of urban heat islands (ICU) in the city of Tete, from 2017 to 2024. Through the analysis of diverse and nightly terrestrial surface temperature (TST), obtained by images of the sentinel-3 satellite, and the evaluation of vegetation cover using the index vegetation by normalized difference (NDVI) and the index of vegetation adjusted to the soil (SAVI) of Sentinel-2. The results consistently demonstrated surface temperatures higher in the urban center of tete compared to the vegetated area. During the day, they were areas in the urban center with TST exceeding 50 ° C, strongly associated with predominance of impermeable surfaces such as asphalt and concrete, which have high absorption of solar radiation and low evapotranspiration. Night temperatures in the urban center also They remained high, in some cases above 30 ° C, reflecting the slow release of heat stored and the contribution of anthropogenic heat sources. The analysis of vegetation cover confirmed the greater vegetation density in the reference area, with values ​​of NDVI and SAVI significantly higher compared to the urban center. The direct comparison of surface temperatures between the two areas revealed the existence of a Urban Heat Island (ICU) from surface in tete, with variations in its intensity and magnitude over the years and between day and night periods. The magnitude of the daytime icu oscillated between weak and medium intensity, while the nightly had less intensity with a few years registering values ​​close to zero or even negative, possibly influenced by the cloud coverage. The application of the non-parametric Mann-Kendall test to identify trends in the intensity of daytime and night ICU over the analyzed period did not reveal statistically significant trends at 0.05. However, the analysis suggests a slight tendency to decrease in daytime ICU and a slight increase in the intensity of Night Icu, indicating a complex dynamic in the thermal evolution of the city. The limitations of study, such as the spatial resolution of Sentinel-3 data and the influence of cloud cover in some measurements, they were considered in the interpretation of the results(TRADUÇÃO NOSSA)