Decadal-Scale Shore Morphological Changes of Hatiya Island (Meghna Estuary, Bangladesh).

Zishan, N.I.; Anwar, M.S., and Rahman, K., 2026. Decadal-scale shore morphological changes of Hatiya Island (Meghna Estuary, Bangladesh). Journal of Coastal Research, 42(1), 106–121. Charlotte (North Carolina), ISSN 0749-0208. Hatiya Island, located at the mouth of the Meghna estuary in Bangladesh's central coast, has been facing continuous erosion–accretion through a strong river current and tidal actions from the Bay of Bengal. The erosion–accretion process caused morphological changes in and around Hatiya Island during the past few decades. This study calculated the shoreline change rates around Hatiya Island from 1989 to 2021, analyzing the tide and water level, and thus explaining the interaction between these factors on spatial and temporal scale. Broadly, a total of 33 Landsat satellite images were selected to detect automatic shoreline positions of the island. Overall, a dominance of erosion (86.0 km2) over accretion (32.6 km2) around the boundary of Hatiya Island was observed during 1989 to 2021. To describe the decadal-scale behavior of erosion–accretion and the associated parameters, the entire study period was further segmented into three distinct subperiods: 1989–2000, 2000–11, and 2011–21. The estimated annual shoreline changes are 25.3 m erosion, 24.7 m erosion, and 4.4 m accretion for the periods 1989 to 2000, 2000 to 2011, and 2011 to 2021, respectively, demonstrating a gradual shifting of erosion–accretion trend. The most erosion around the northern part of Hatiya Island (108.9 m/y) occurred from 2000 to 2011, whereas the SE portion attained land (21.8 m/y) during the same period. The onshore mangrove fringes in the southern portion along with adjacent islands (i.e. Nijhum Dwip and Domar Char) have been protecting Hatiya Island from direct tidal impact as well as contributing toward the land-gaining process. The results of this study provide a valuable reference for decision-makers aiming to understand decadal-scale morphological trends and implementing coastal policies and adaptation strategies to safeguard the densely populated Hatiya Island from ongoing erosion and accretion. [ABSTRACT FROM AUTHOR]