Shoreline Change and Vegetation Dynamics of Kuakata Sea Beach, Bangladesh (2008–2023): A DSAS and Remote Sensing-Based Assessment

Kuakata Sea Beach, located along the dynamic coast of southern Bangladesh, has experienced substantial geomorphological and ecological changes over recent decades due to both natural processes and increasing human pressure. This study assesses shoreline change and vegetation dynamics along the Kuakata coast over a 15-year period (2008–2023) using multi-temporal Landsat imagery and GIS-based analysis. Shorelines were extracted from Landsat 5 TM and Landsat 8/9 OLI images and analyzed using the Digital Shoreline Analysis System (DSAS) to quantify erosion and accretion through End Point Rate (EPR) and Linear Regression Rate (LRR) statistics. Vegetation change was evaluated using the Normalized Difference Vegetation Index (NDVI). Results indicate pronounced spatial and temporal variability in shoreline behavior. The western segment of the coast experienced persistent erosion, while localized accretion dominated parts of the eastern and southeastern shoreline. Maximum shoreline advance reached approximately 37.5 m/year based on LRR analysis, whereas maximum retreat exceeded −32 m/year in erosion-prone zones. Area-based analysis shows that erosion has increasingly outweighed accretion since 2013, resulting in net land loss in recent years. NDVI analysis reveals a long-term decline in vegetation cover, closely associated with expanding built-up areas and coastal modification. DSAS-based forecasting suggests continued shoreline retreat over the coming decades, indicating heightened risk to coastal land, ecosystems, and human activities. The findings highlight the highly dynamic nature of the Kuakata coastline and emphasize the need for integrated, evidence-based coastal management strategies that balance development with ecosystem protection.