Marginal decrease in snow cover in four river basins

Marginal decrease in snow cover in four river basins

The total average area recorded under snow has reduced to 20,064.00 sq km in 2019-20 from 20,210.23 sq km during 2018.

Tribune News Service

Shimla, July 12

There has been a marginal decrease of 0.72 per cent in the area under snow in the four river basins as compared to the last year. The Sutlej basin received the maximum snow, which could augur well for hydro power generation.

Snow mapping in the major river basins of Sutlej, Chenab, Ravi and Beas was undertaken between October 2019 and May 2020 by the State Centre for Climate Change, the HP Council for Science, Technology and Environment and Space Application Centre, ISRO, Ahmadabad. The assessment was done by SS Randhawa, Nishtha Gautam,

IM Bahuguna and BP Rathore from ISRO.

With the Sutlej basin receiving heavy snowfall, the hydro power sector is expected to make gains. This basin has some of the biggest hydro power projects such as Nathpa Jhakri, Karcham Wangtoo and Baspa.

The total average area recorded under snow during 2018-19 (20,210.23 sq km) has reduced to 20,064.00 sq km in 2019-20, indicating a marginal decrease of 0.72 per cent.

“The snow mapping in the main river basins in Himachal during the winter season from October to May is an important input in order to understand the contribution of snow in different catchments to sustain the hydrology of the river basins,” said DC Rana, Director, Science and Technology.

The maximum snow is received by all major river basins in the months of December and January, resulting in substantial increase in snow cover. In December, as per basin-wise increase in the surface area, there was an increase by 13 per cent in the Chenab, 28 per cent in the Beas, 45 per cent in the Ravi and 41 per cent in the Sutlej as compared to 2018-19.

In January, the Chenab basin showed an increase of about seven per cent, 72 per cent in the Beas basin, 95 per cent in the Ravi basin and 30 per cent in the Sutlej basin.

Likewise, in the months of February and March, the snow cover started receding and the area under snow reduced. During February 2020, all basins showed a decrease in their area under snow cover with 3 per cent in the Chenab, 4 per cent in the Beas, 38 per cent in the Ravi and four per cent in the Sutlej basin as compared to 2018-19.

In March too, the Beas (28 per cent) and the Ravi (45 per cent) basins show greater decrease in the surface area under snow. In Chenab and the Sutlej, the decrease is less at seven and eight per cent, respectively, as compared to the last season.

During winter months (November to January), there was more snow in 2019-20 winter in the southeastern part of the Pir Panjal range in Himachal covering mainly the Sutlej basin. The Chenab basin does not show much change in 2019-20 over the previous year.


Sutlej basin gets heavy snowfall

  • Snow mapping in the major river basins of Sutlej, Chenab, Ravi and Beas was undertaken between October 2019 and May 2020
  • With the Sutlej basin receiving heavy snowfall, the hydro power sector is expected to make gains
  • During winter months (November to January), there was more snow in 2019-20 winter in the southeastern part of the Pir Panjal range in Himachal covering mainly the Sutlej basin