Analytical study of land surface temperature with NDVI and NDBI using Landsat 8 OLI and TIRS data in Florence and Naples city, Italy

TLDR

The study investigates how land surface temperature relates to vegetation and built‑up indices (NDVI and NDBI) in Florence and Naples using Landsat 8 imagery. Using NDVI/NDBI thresholds, a self‑organizing data analysis technique, and a maximum‑likelihood classifier, the authors mapped land‑use types and applied an urban thermal field variance index to assess thermal and ecological comfort. They identified urban heat islands with mean LST differences of 3.15 °C (Florence) and 3.31 °C (Naples), found strong overall negative LST–NDVI and positive LST–NDBI correlations that weaken within UHIs, and noted that 85.21 % of Naples and 76.62 % of Florence UHIs lie in built‑up or bare land, marking ecological stress.

Abstract

The present study focuses on determining the relationship of estimated land surface temperature (LST) with normalized difference vegetation index (NDVI) and normalized difference built-up index (NDBI) for Florence and Naples cities in Italy using Landsat 8 data. The study also classifies different land use/land cover LU–LC) types using NDVI and NDBI threshold values, iterative self-organizing data analysis technique and maximum likelihood classifier, and analyses the relationship built by LST with the built-up area and bare land. Urban thermal field variance index was applied to determine the thermal and ecological comfort level of the city. Several urban heat islands (UHIs) were extracted as the most heated zones within the city boundaries due to increasing anthropogenic activities. The difference between the mean LST of UHI and non-UHI is 3.15°C and 3.31°C, respectively, for Florence and Naples. LST build a strong correlation with NDVI (negative) and NDBI (positive) for both the cities as a whole, especially for the non-UHIs. But, the strength of correlation becomes much weaker within the UHIs. Moreover, most of the UHIs (85.21% in Naples and 76.62% in Florence) are developed within the built-up area or bare land and are demarcated as an ecologically stressed zone.