Role of Mangrove Forests in Coastal Protection: An Analytical Study of the Sundarbans as a Natural Barrier against Cyclones, Erosion, and Sea-Level Rise

Abstract

The Indian Sundarbans faces threats from tropical cyclones, storm surges, channel migration, 
coastal erosion, rising relative sea levels, and frequent embankment collapses. Mangrove ecosystems may 
mitigate some aspects of this risk; nevertheless, their protective efficacy is contingent upon factors such as forest 
breadth, plant architecture, landform characteristics, water depth, sediment availability, and the severity of 
hazards. Methods: This analytical secondary-data investigation amalgamated official cyclone documentation for 
Amphan, Yaas, and Remal; evaluations from the Forest Survey of India; a remote-sensing dataset spanning 2000
2020 for biosphere-reserve areas and coastal islands; a comprehensive water-level analysis across the delta; and 
scholarly research on the flood-mitigating effects of mangroves. Descriptive statistics, absolute and percentage 
variations, compound rates, Pearson and Spearman correlations, and simple linear regression were used just in 
the presence of similar data. Findings: The chosen cyclones had an average sustained wind speed of 136.7 km/h 
and an average recorded gust of 158.3 km/h. Amphan traversed the West Bengal-Bangladesh coastline via the 
Sundarbans, with sustained winds of 155-165 km/h and gusts reaching 185 km/h; the official post-event report 
documented a tidal wave or surge height of around 4.6 m in the impacted coastal regions. Nine uncovered 
mangrove islands saw a reduction of 48.6 km² from 2000 to 2020, averaging a loss of 5.40 km² and a percentage 
decline of 18.6%. The initial island area exhibited a positive albeit non-significant correlation with absolute loss 
(Pearson r=0.58, p=0.101). Core and buffer mangroves diminished, and plantations in the transition zone 
proliferated. Conclusion: Mangroves need to be seen as a risk-mitigating layer instead of an impenetrable barrier. 
Successful policy necessitates the safeguarding of extensive natural corridors, restoration sensitive to sediment 
and hydrology, provision for landward migration, robust embankments and shelters, settlement planning based 
on hazards, and monitoring that correlates vegetation health with observed waves, water levels, erosion, and 
damage.