Urban Expansion and Vegetation Decline: A Remote Sensing Analysis of LULC Changes in Habiganj Sadar and Madhabpur in Sylhet (1989-2024)

Urban expansion and population pressure have accelerated and Land Use and Land Cover (LULC) changes, leading to degradation of vegetation and aquatic ecosystems. This research aims to analyze the spatiotemporal dynamics of Normalized Difference Vegetation Index (NDVI) and LULC pattern changes and how they affect urban area transformation and offensive land use for various endeavors in the contexts of Habiganj Sadar and Madhabpur in Sylhet, Bangladesh, from 1989 to 2024. Using multitemporal Landsat satellite imagery, LULC was classified into groups such as vegetation, urbanized regions, aquatic environments, and barren terrain. NDVI values, which ranged from −0.23 to 0.81, were used as indices to assess vegetative health. Overall classification accuracy varied between 86% and 92.5%, with Kappa coefficients ranging from 0.80 to 0.93. Destruction of the environment is the result of a substantial reduction in vegetation in the Madhabpur area (31.91% to 7.43%), as well as Habigonj Sadar (18.99% to 8.71%). The fast urbanisation is prompted by the overcrowding in the Habigonj Sadar (1.82% to 21.08%) and Madhabpur (1.80% to 16.33%) settlement regions. Madhabpur's water body experienced terrible environmental circumstances between 1989 and 2024, falling from 30.41 sq. km to 5.60 sq. km. The data show a significant loss in vegetation health, as demonstrated by a drop in NDVI values from 0.78 in 1989 to 0.43 in 2024, coinciding with an increase in settlement areas from 1.82% to 21.08% in Habiganj Sadar and 1.80% to 16.33% in Madhabpur. This paper demonstrated the pattern of urban expansion coincides with a dramatic decline in both vegetation and aquatic bodies.