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Shrinking deltas

Krishna delta lost 1,783 ha between 1977 and 2000
A study published in Current Science (Vol 87, No 9) noted that the Godavari delta had lost 1,836 hectares (ha) between 1976 and 2000 (at 73.4 ha per year). The researchers said reduced river flow had caused reduction in sediment load in the delta. The study warns that coastal erosion may be a slow process but it will lead to intrusion of saline water affecting agriculture and fishery in the deltas.

A report by the International Water Management Institute says similar trends were observed in the Krishna basin which lost 1,783 ha between 1977 and 2000 (see map). The report also hints at more such reductions after the construction of the Polavaram and Inchampalli dams on the Godavari river is over.

Environmentalists in India have been demanding a certain minimum flow, called environmental flow, to sustain downstream ecology while planning for diversion of river water."This is a fallout of not considering environmental water demand while planning for diversion of water. Rivers have a rich marine life. It is important to factor in the environmental water needs and maintain a certain flow to sustain fresh water and marine life downstream,' says Parikshit Gautam of wwf India. "We cannot treat river and marine ecosystems separately. Estuaries provide the breeding ground for a number of marine and fresh water species,' he adds.

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