Salinity Intrusion due to Fresh Water Scarcity in the Ganges Catchment : A Challenge for Urban Driking Water and Mangrove Wetland Ecosystem in the Sundarbans Region, Bangladesh (original) (raw)

The Sundarbans is situated in the Ganges transboundary catchment which is known as the single largest mangrove ecosystems in the world and covers 10,000 km² between Bangladesh and India. Since the diversion of Ganges water at Farakka Barrage in India from early 1975, salinity level has increased drastically in the south western part of Bangladesh. Due to reduction of fresh water flow urban drinking water supply, industrial production, agriculture, fisheries, navigation, hydromorphology and mangrove wetlands ecosystems have been affected. Urban area both surface and groundwater have become unfit for human consumption. In the consequences about 0.170 million hectares (20.4%) of new land, and almost 27 small towns have been affected by various degrees of salinity during the last three decades. The saline front defined by 6 dS/m iso-haline has penetrated up to 173 km north from the coast. The salinity has exceeded the recommended level 1 dS/m for potable water. It is a new threat to supply quality drinking water to the small towns in the south western region in Bangladesh. The dominant mangrove Heritiera fomes and Ceriops decendra species are affected by top dying disease which is recognised as key management concern. The Fourier Polynomial water salinity models on Sundarbans rivers are showing the cycling increasing behaviour. The findings of this study a potential contribution for making comprehensive management plan are for urban water supply, and protection of the mangrove wetlands ecosystems in the Sundarbans region.