Quantifying the Protective Role of the Sundarbans Mangroves Against Cyclones Using Landsat-Derived NDVI and EVI (2007–2024)

The Sundarbans, the largest mangrove forest in the world, acts as a major natural defense against cyclones along the coast of Bangladesh. This paper examines the relationship between vegetation health (measured by the Normalized Difference Vegetation Index, NDVI, and the Enhanced Vegetation Index, EVI) and cyclone-induced deaths and housing losses from 2007 to 2024. Remote sensing data from Landsat, cyclone impact data from the Bangladesh Bureau of Statistics (BBS) and EM-DAT, and spatial GIS were integrated to measure vegetation change and cyclone impact in Sundarban-protected and unprotected coastal districts. Findings indicate a minor shrinkage in thick vegetation (86 percent in 2007 to 85 percent in 2024) and growth in water bodies, which are evidence of erosion and storm activities. Regression analysis showed that EVI exhibited strong negative relationships with the death rate ( β = -0.888, p = 0.018) and the house damage rate ( β = -0.962, p = 0.002) in protected areas, supporting the argument that healthier vegetation reduces cyclone losses. Similar, but weaker relations were found in NDVI.The results point to the vitality of the Sundarbans in protecting the coastal area and the necessity of continuous vegetation control and mangrove restoration to enhance long-term cyclone resistance in Bangladesh.