Environ Sci Pollut Res Int. 2025 Nov 15. doi: 10.1007/s11356-025-37148-y. Online ahead of print.
ABSTRACT
Understanding how urbanization reshapes local thermal conditions is essential for planning in fast-growing tropical cities. We assessed Landsat-derived LST, NDVI, and BU; land-use dynamics; and the station-based Thom’s Discomfort Index (DI) for João Pessoa, Brazil. The series covers 2013, 2016, 2019, and 2022, using images acquired on December 3, 2013; November 25, 2016; May 26, 2019; and August 6, 2022 (Landsat OLI/TIRS). The selected dates represent months typically within the region’s dry (November-December) and rainy (May-August) seasons; where indicated, DI was also summarized by dry and rainy periods. Using cloud masking and zonal statistics in buffers around meteorological stations, we paired remote-sensing indices with DI for the north and south sectors. Results confirm that the loss of green areas due to urban expansion contributes to higher thermal conditions and the intensification of surface urban heat islands; these areas reached LST up to 37 °C in 2022. Citywide NDVI statistics-computed over valid pixels within the municipal boundary after cloud/water masking-declined from 2013 (max, 0.4427; mean, 0.1983) to (Thom and Thom 2022) (max, 0.3876; mean, 0.1277), reflecting vegetation loss. The BU analysis highlighted the expansion of built-up areas and its correlation with thermal increases, with conditions categorized as “slightly uncomfortable.” DI remained “partially comfortable” (24 °C ≤ DI ≤ 26 °C) in all years, indicating proximity to discomfort thresholds. Overall, João Pessoa requires targeted mitigation and prevention strategies to safeguard public health and quality of life.
PMID:41240279 | DOI:10.1007/s11356-025-37148-y
