Farakka Dam: Cause of Degradation
The hydrology of the Sundarban is dominated by the freshwater flows from the Rivers Ganges, Meghna and Brahmaputra and the tides that range in height from 2 to 5.94 m.The freshwater flows from the rivers and the tidal ingress result in a gradient of salinity that varies both spatially and temporally; salinity is higher nearer the coast whereas the water is nearly fresh on the inland limit of the Sundarban.The water maintains the environment and the ecology of the region and constitutes the main potential for development. Furthermore, the main mangrove species in the Sundarban--the Sundari, Keora and Gewa--require both fresh and saline water for their regeneration and growth.
In 1975, India constructed the Farakka Dam on the River Ganges, 17 km upstream from the Bangladesh border; it was built to revive India's Kolkata port by diverting the Ganges discharge and thus, making the Bhagirathi-Hooghly River navigable. As a result, the downstream discharge was greatly reduced.
The Ganges fresh water withdrawal in the upstream area in India resulted in negative impacts in the downstream catchment. The scarcity of freshwater from the Ganges during the dry season (February-June) and excessive water during the wet season has upset the natural equilibrium within Bangladesh's Sundarban mangrove ecosystem. Water reduction as well as high water and soil salinity has affected the ecosystem and wrought changes in species' composition.Furthermore, lack of freshwater has depleted soil moisture, accelerated top-dying disease among Sundari trees, slowed forest growth and reduced productivity of forest sites.
In 1975, India constructed the Farakka Dam on the River Ganges, 17 km upstream from the Bangladesh border; it was built to revive India's Kolkata port by diverting the Ganges discharge and thus, making the Bhagirathi-Hooghly River navigable. As a result, the downstream discharge was greatly reduced.
The Ganges fresh water withdrawal in the upstream area in India resulted in negative impacts in the downstream catchment. The scarcity of freshwater from the Ganges during the dry season (February-June) and excessive water during the wet season has upset the natural equilibrium within Bangladesh's Sundarban mangrove ecosystem. Water reduction as well as high water and soil salinity has affected the ecosystem and wrought changes in species' composition.Furthermore, lack of freshwater has depleted soil moisture, accelerated top-dying disease among Sundari trees, slowed forest growth and reduced productivity of forest sites.
The diversion of the Ganges discharge has not only affected the Sundarban forest but all those who live within the forest region and/or are dependent on it for their livelihood.