Glaciers in Himachal Pradesh, especially those along the Chinese border, are receding alarmingly. Since 1962, the total area of glaciers has come down from 2,077 sq km to 1628 sq km. Studies reveal that there has been deglaciation of 21% of the total area since 1962. Glacier retreat was estimated in Chenab, Parbati and Baspa and Spiti basins.
In wake of rapid glacial melting, Space Applications Centre had initiated a programme to map glaciers and permanent snowfields in the Satluj basin.
Using Indian Remote Sensing satellite data, an inventory was completed for the Satluj basin right from its origin in Tibet catchment. The studies were carried jointly by three agencies comprising Space Application Centre, Wadia Institute of Himalayan Geology, Dehradun, and Himachal Pradesh Research Centre, Shimla.
The studies showed that there were 334 glaciers in Satluj basin. The aerial extent of glaciers in the basin has been calculated as 1,515 square km. The study also shows presence of 1,987 permanent snowfields which have a total area of 1182 sq km. Total area under glaciers and permanent snowfields in Satluj basin has been calculated as 2,607 sq km.
Similar investigations were carried out in the Chenab and Ravi basins in Himachal Pradesh. Investigation suggests the presence of total 457 glaciers in the Chenab basin with a total aerial extent of 1,055 sq km. A total of 732 permanent snowfields were also mapped having a total area of 245 sq km. Geological Survey of India estimated retreat in 3 glaciers in Sutlej basin, 6 glaciers in Chenab and 5 glaciers in Beas and 2 glaciers in Ravi basin.
As many as 19 glaciers were selected to estimate glacier retreat in Baspa basin. Investigation reveals that in the last 39 years, almost 19% glaciated area has reduced in Baspa basin. On basis of ground observations and satellite data interpretation, Janapa glacier retreated by 650 metres in last 34 years. While Shuane Garnag glacier receded by nearly one kilometer.
Glacier retreat was noticed more in Spiti basin particularly in area along the China border. To study the impact of global warming, data of 993 glacier layers was extracted from the Himalayan Glacier Information System (HGIS). Comparative studies reveal that about 5% glacial area has been lost between 1962-93; 2% area loss in between 1993-2001 and about 12% loss between 2001 and 2007.
When compared with 2001 glacier layer, it is found that total glacier area for these 188 glaciers have been reduced to 230.84 square km in 2001 from 311.13 sq km in 1962, indicating an overall reduction of 25.80% glacier area from 1962 to 2001.
Studies revealed that glaciers in Spiti showed retreating trend both in spatial as well as in linear retreat. In case of 188 glaciers, when data of 1962 was compared with that of 2001, deglaciation of 25.80% was recorded.
Session on glaciers
Centre for Climate Change, as part of initiative under the National Mission For Sustaining Himalayan Ecosystem, is organising a brainstorming session at Shimla on snow and glaciers and the Himalayan river system on May 29-30.
