Parbati glacier shrinks
owing to rising temperatures due to global warming, the Parbati glacier in Himachal Pradesh is melting fast. A study of satellite images shows the glacier has retreated by 578 metres between 1990 and 2001, a decline of almost 52 metres per year. This is bad news, as the glacier is the largest in the Parbati river basin, and is an important water source for the river Beas. The glacier is economically significant too because an 800 megawatt (mw) power project is under construction and another 520 mw power project is being planned in the area. The glacier's retreat would not only affect the river flow, but also these power projects.
The study was conducted by Anil V Kulkarni and B P Rathore from the Ahmedabad-based Space Applications Centre, Suresh Mahajan from Nepal's Tribhuvan University and P Mathur from the Snow and Avalanche Study Establishment, Chandigarh. The researchers used satellite data to study the retreat. The boundary of the glacier was delineated from topographic maps. Thereafter, the boundary was super imposed on images for the years 1990, 1998, 2000 and 2001. Images were selected for the August-September season when the snow cover is minimum and the glaciers are fully exposed. Field investigations were also carried out to verify the satellite observations.
The researchers found the total loss in glacial extent is 8.3 square kilometres (sq km) from 1962 (when the glacial extent was 48.44 sq km) to 1990. In addition, 1.93 sq km and 1.32 sq km loss in extent was observed over the periods 1990-1998 and 1998-2001 respectively. The loss in glacial length was estimated at 5,991 metres from 1962 to 1990 and 578 metres from 1990 to 2001.
According to the researchers, the retreat of the Parbati glacier is much higher than seen in other glaciers in the Himalaya. This is because the glacier is located at a low altitude