A Spatiotemporal and Seasonal Analysis of LST-NDVI Relationship in a Hot Desert City of North Africa

Abstract The relationship between land surface temperature (LST) and the normalized difference vegetation index (NDVI) is crucial for environmental studies. This research investigates LST in Gafsa City, Tunisia, North Africa, and its seasonal links to NDVI. Located in west-central Tunisia, Gafsa experiences a hot desert climate with four distinct seasons: spring, summer, autumn, and winter. Using cloud-free Landsat images from 2013 to 2023, the study reveals a gradual increase in LST over time. The southern part of the city features lower LST and higher NDVI due to abundant vegetation, while the northern regions, dominated by barren land and urban development, exhibit higher LST values. Mean LST and NDVI were highest in summer, followed by spring, autumn, and winter. The analysis showed an almost neutral correlation in spring and autumn, a weak to moderate negative correlation in summer, and a weak to moderate positive correlation in winter. In 2023, the relationship within the city was weak or neutral, but a moderate to strong negative correlation was found in the 2 km buffer zones surrounding it, diminishing with distance from the city. In summary, this study highlights the significant impact of surface characteristics and seasonal changes on LST, providing valuable insights for land use and environmental planning in hot desert cities.