Uso de imagens do Landsat 8 para determinação da correlação entre a temperatura de superfície e o índice de vegetação em Municípios da Grande Vitória

Abstract

This paper presents the findings of the study for evaluating the correlation between the Land Surface Temperature (LST) and the presence of vegetation cover, identified by the Normalized Difference Vegetation Index (NDVI). Therefore, the researchers used images from LANDSAT 8 (L8) satelite, specifically, the spectral bands 4, 5 and 10 were used, whose capture dates the September 27th of 2016. These bands represent, respectively, the red band (0,64 – 0,67 μm), the near infrared band (0,85 – 0,88 μm) and the thermal infrared band (10,60 – 11,19 μm). The studied area encompasses the following counties of the main metropolitan area of the state of Espírito Santo: Vitória, Vila Velha and Serra, with a 10 km buffer surrounding it’s political limits, including, thus, part of the neighboring counties and also a sea track. Regarding the importance of population ́s quality life, both terrestrial surface temperature and vegetation presence should be considered together, since the knowledge about the possible correlation between these two variables becomes preponderant for decision towards the well-being of the population. The analysis of the scatter plot between the TST and NDVI values showed that the behavior of the trendline was best represented by a degree 3 polynomial, whose R-Squared was 0.73, indicating a high correlation between the values of TST and NDVI. In relation to the values associated with the presence of dense vegetation (NDVI greater than 0.5), characterized by areas of preserved native vegetation, such as riparian forests, parks and natural reserves, it was verified that the TST decreases according as the NDVI increases and that represents a temperature reduction of approximately 4°C