Morphology of Sagar Island, A Part of Ganga Delta

The deltaic morphology of Sagar island is controlled by the river Hugli to the north and the Bay of Bengal to the south. The seasonal (summer and winter) and diurnal (two high tides and two low tides) fluctuations of sea level and the Hugli discharge with a large amount of silt contribute to the formation of the largest island in Ganga delta. Deposition of sand, silt, clay and mud from south to north is also characteristic of this deltaic island. The 12 km shoreline and its sand ridges are deformed by wind and waves. Mangroves in the swamp, some halophytic plants on the sand dunes and different marine organisms on the sea beaches and mud flats are responsible for the development of some micro-morphological features in this westernmost island of Sundarban. At present the nature of human settlement, reclamation of low land, indiscriminate resource utilisation and finally the mangrove destruction cause deterioration of the deltaic environment. Land erosion is severe in south, east and west of the island. The deposition in old creeks such as Phuldubi, Ganga Sagar etc. and the predominance of new creeks in the southwest of the island are the result of tidal scouring and deposition.