Monday, March 24, 2008

'No immediate threat to Gangotri that feeds river Ganga'

Contrary to what prophets of doom contend, that Gangotri will disappear in the next 30 to 40 years, some of India's leading scientists believe there's no immediate or even medium-term threat to the glacier that feeds one of India's greatest rivers, Ganga.

India has 9,575 glaciers, of which around 50 are being monitored by the Geological Survey of India (GSI) on a regular basis. None of these show a particularly high rate of retreat. Gangotri's drawdown - 20 metres per annum in the '70s - is now mere six metres a year.

Bhagirath Khadak in the Himalayas was retreating at 12 m annually but last year it didn't recede at all. Machoi in Jammu & Kashmir has showed no change since 1957. Same is true of Siachen and Kagriz in Ladakh, according to GSI.

This was revealed by V K Raina, chairman, Monitoring Committee on Himalayan Glaciology, government of India, at a conference in Lucknow University recently. He told TOI that while efforts to preserve the environment must go on, there was no reason to press the panic button based on Western analysis of melting Arctic glaciers.

"Western estimates are true for regions around the North Pole - but these glaciers open into the sea. In India, glaciers are situated over 3,500 m above the sea level. The Himalayas, in fact, are conducive for the preservation of glaciers," he said, and added, "Even if Gangotri retreats at 20 m per annum, it will last for 1,500 years."

Raina, also a former deputy director general of GSI, said doomsayers have based their claims of a much shorter life of Gangotri on the basis of reduction in discharge of water from the glacier into the Ganga.

But, he said, the glacier contributes only 25% to river discharge - the remaining 75%depends on snowfall and rainwater.

"The discharge in Ganga had increased in 2001 when there was heavy snowfall. This year, too, the snowfall's been heavy, hence the discharge will increase," he said.

Dhruv Sen Singh, who teaches geology at Lucknow University and who was part of India's first scientific expedition to the Arctic in '07, said, "Not only the rate of retreat of Gangotri has decreased, in Leh, 123 years of temperature data shows a cooling of .04 degree per decade."

He adds that the 20% rate of retreat of Gangotri in the '70s wasn't because of warming but because of the cracking of the linear structure of the glacier at the snout.

Then, some of its tributaries had become inactive and were contributing water instead of ice. These factors keep changing in the natural course leading to fluctuation in the rate of retreat of high mountain glaciers.

Source: http://economictimes.indiatimes.com/News/PoliticsNation/No_immediate_threat_to_Gangotri_that_feeds_river_Ganga/articleshow/2893038.cms


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