May 26, 2001
Melting glaciers a flood threat
S. P. Sharma
Tribune News Service
Shimla, May 25
The melting glaciers of Himachal Pradesh and Uttaranchal have rung alarm bells among environmentalists. They fear this might result in unprecedented floods and thereafter acute water scarcity in the plains.
The Bara Shigri glacier in Himachal Pradesh and the Pindari glacier in Uttaranchal are shrinking at an alarming rate of about 36 metres and 135 metres per year, studies have revealed.
The deep cracks in the Chhota Shigri glacier of Himachal indicate that it was receding. Studies indicate that it was shrinking by 6.7 metres per year and the Trilokinath glacier was receding by 15.4 metres.
The 26-km-long Gangotri glacier in Uttaranchal was shrinking by about 18 metres a year. Regular visitors to the area point out that it was receding at an alarming rate. Similar was the fate of the Milam glacier which was shedding about 13 metres of snow every year.
The size of the Bara Shigri glacier reduced by 650 metres between 1997-1995, while the Trilokinath glacier got reduced by 400 metres between 1969 to 1995.
Despite a severe winter in 1997, the 5-km-long Dokriani Bamak glacier in Himachal Pradesh shrunk by 20 metres, while its average melting rate had been 16.5 metres a year. The glacier might soon vanish in case it continued to melt.
Studies have indicated that almost all 335 glaciers in the Sutlej, Beas and Spiti basins were receding. These have created artificial lakes which might cause floods in the lowlying areas. The volume of water in the lake created due to melting of the Gepang Gath glacier increased to 8.46 cubic metres in 1998 against 7.56 cubic metres in 1990. The size of the lake has also increased to 0.47 sq. km in 1998 from 0.27 sq. km in 1976.
The Tribune
February 18, 2001
Melting glaciers threaten floods
S.P. Sharma
Tribune News Service
SHIMLA, February 17
Unprecedented melting of glaciers and formation of artificial lakes in the higher reaches of Himachal Pradesh has created a threat of flashfloods in the low lying areas.
According to an official study through remote sensing, almost all 335 glaciers in the Sutlej, Beas and Spiti basins are receding probably because of global warming.
The threat from these artificial lakes is not immediate, but could cause much damage incase these burst anytime.
In all, 164 deglaciated valleys covering an area of 133 sq. km have been mapped in the Sutlej basin where the total area under glaciers and permanent snow fields is estimated to be 2696 sq. km.
The Barashigri glacier in Lahaul-Spiti is receding at an alarming rate of 10 metres a year. This is the second largest glacier in the world.
Three artificial lakes have been created on the hills on top of the strategic Pangi valley road which are threatening it in case these burst and their waters came down swirling. Such lakes are considered unsafe as these contain a sufficient quantity of water for causing floods downstream. Rupturing of moraine dammed lakes can cause floods in the valleys.
The volume of the lake in the Gepang Gath glacier in the Chandra basin was estimated to be 4.86 million cubic metres in 1976 and it increased to 7.56 million cubic metres in 1990 and 8.46 million cubic metres in 1998.
Environmentalists have warned that the low lying areas might be devastated by flashfloods in case the process of melting of glaciers continued in the present manner.
The study indicates that the aerial size of the lake created by the Gepang Gath glacier was 0.27 sq. km in 1976 which increased to 0.47 sq. km in 1998.
Through remote sensing, 38 moraine dammed lakes have been mapped in the Beas and Sutlej basins, of which 14 are in the state.
Bursting of any of these lakes could cause significant damage to life, property and roads.
Scientists have suggested that in order to assess the hazards from these lakes, it is very important to study all these lakes in detail.
This will help in making the assessment of possible hazards and to suggest measures to avoid floods due to bursting of moraine dammed lakes.
The size of the lake near another glacier was 0.30 sq. km in 1972 and has now grown to 1.22 sq. km.
Another glacial lake on the Sissu Nullah was 0.27 sq. km in 1976 and it increased to 0.47 sq.km in 1998.
The recent flashflood in the Sutlej,which claimed about 170 lives,is feared to have been caused either due to a cloud burst or breach of lake in the upper reaches.
The Manali and Kulu areas suffered widespread damage due to a flashflood in the Beas and its tributaries a few years ago when the headquarters of the Snow and Avalanche Study Establishment (SASE), which predicts such disasters, was itself devastated.
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