Abstract
Coastal watersheds are experiencing rapid transformation driven by increasing anthropogenic pressures and climate change, with profound consequences for ecosystem dynamics and long-term sustainability. Although land use and land cover (LULC) transitions strongly influence ecological resources, these dynamics remain underexplored in the subtropical coastal regions of Bangladesh. To address this gap, this study examined LULC evolution within the Chowfaldandi watershed of the Matamuhuri River in southeastern Bangladesh from 1993 to 2023, utilizing a maximum likelihood supervised classification of Landsat Thematic Mapper (TM) and Sentinel-2 Multispectral Instrument (MSI) imagery. The classifications for 1993, 2008, and 2023 achieved high overall accuracies of 83.75%, 84.50%, and 86.50%, respectively, ensuring reliable change detection. Results reveal substantial expansion of built-up and agricultural areas over three-decade, accompanied by marked declines in forest/vegetation, water bodies, and barren land. Most notably, rapid urbanization contributed to the loss of 46.99 km2 of vegetation, with additional conversions to water and barren land; reciprocal transitions occurred for built-up, barren, and water categories. These insights contribute to formulation of sustainable land resource management strategies amidst escalating coastal development and agricultural intensification.
