Global warming effect: Faster snow melting in Himachal despite rise in cover

CHANDIGARH:  A bigger snow cover in Himachal Pradesh melted at a faster pace this year due to a sudden rise in temperatures in March-April this year.

This is the finding of a study conducted by the State Centre on Climate Change under the aegis of the Himachal Pradesh Council for Science Technology and Environment (HIMCOSTE) in collaboration with Space Applications Centre (ISRO), Ahmedabad.

Early this year, Himachal saw a rich spread of snow that was 19.47% per cent more in the area under snowfall during winters last year. The happy news, however, lasted hardly a month as a sudden rise in temperatures melted the snow cover at a faster pace, reducing it by 19 to 25% per cent compared to 4-10% last year.

The study predicts reduced snow cover in the coming months in various river basins of the state, affecting the hydropower generation in the downstream areas and water shortage.

The study says about one-third of the total geographical area of the hill state remains under a thick snow cover during the winter season.

Most major rivers such as the Chenab, Beas, Parvati, Baspa, Spiti, Ravi, Satluj and its perennial tributaries originating from the Himalayas depend upon the seasonal snow cover, besides the glacier input for their discharge dependability.

Besides, the snow cover also helps in controlling the accumulation and ablation patterns of the glaciated regions in the state. Talking to this newspaper, SS Randhawa, Principal Scientific Officer of HIMCOSTE said due to early winters last year and snowfall in October, more areas came under snow. The maximum variation was noticed in the Ravi catchment, where the snow cover increased from 127 km (2020-21) to 2,167 km (2021-22) — about 1,594% per cent increase.

But due to early summers this year, the snow cover melted quickly as the temperature in April rose to almost eight degree higher than normal this year.

“The analysis of April, which is considered the beginning of the ablation period, shows a decreasing trend in the snow cover area in all four basins. In other words, we can say the snow cover area has been vacated by virtue of melting during April ranging between 19 and 27% in comparison to 2020-21,’’ said Randhawa.

When compared to the corresponding months in 2021, the maximum temperature increased by 3.00C in May this year in the Chenab basin, while in Ravi basin the temperature rise was 2.30C in March, 6.10C in April  and 3.50C in May. At Chamba and Dalhousie, the rise was  2.10C, 7.60C and 5.00C in March, April and May, respectively. Likewise, the temperature increase in Satluj basin was 2.80C in March, 8.20C in April and 2.90C in May.  

“Due to this abrupt rise in temperature in all the basins, the melting rate was accelerated in all the basins, thereby leading to reduction of snow cover area in each basin,’’ the study stated.

According to Randhawa, if the trend continues in the coming winter season as well, then this depletion will have serious repercussions on the hydro sector in the state, leading to water shortage in the downstream areas.

Lalit Jain, Member Secretary HIMCOSTE, said snow melting and snowfall patterns have become quite unpredictable due to climate change.

CHANDIGARH:  A bigger snow cover in Himachal Pradesh melted at a faster pace this year due to a sudden rise in temperatures in March-April this year. This is the finding of a study conducted by the State Centre on Climate Change under the aegis of the Himachal Pradesh Council for Science Technology and Environment (HIMCOSTE) in collaboration with Space Applications Centre (ISRO), Ahmedabad. Early this year, Himachal saw a rich spread of snow that was 19.47% per cent more in the area under snowfall during winters last year. The happy news, however, lasted hardly a month as a sudden rise in temperatures melted the snow cover at a faster pace, reducing it by 19 to 25% per cent compared to 4-10% last year. The study predicts reduced snow cover in the coming months in various river basins of the state, affecting the hydropower generation in the downstream areas and water shortage. The study says about one-third of the total geographical area of the hill state remains under a thick snow cover during the winter season. Most major rivers such as the Chenab, Beas, Parvati, Baspa, Spiti, Ravi, Satluj and its perennial tributaries originating from the Himalayas depend upon the seasonal snow cover, besides the glacier input for their discharge dependability. Besides, the snow cover also helps in controlling the accumulation and ablation patterns of the glaciated regions in the state. Talking to this newspaper, SS Randhawa, Principal Scientific Officer of HIMCOSTE said due to early winters last year and snowfall in October, more areas came under snow. The maximum variation was noticed in the Ravi catchment, where the snow cover increased from 127 km (2020-21) to 2,167 km (2021-22) — about 1,594% per cent increase. But due to early summers this year, the snow cover melted quickly as the temperature in April rose to almost eight degree higher than normal this year. “The analysis of April, which is considered the beginning of the ablation period, shows a decreasing trend in the snow cover area in all four basins. In other words, we can say the snow cover area has been vacated by virtue of melting during April ranging between 19 and 27% in comparison to 2020-21,’’ said Randhawa. When compared to the corresponding months in 2021, the maximum temperature increased by 3.00C in May this year in the Chenab basin, while in Ravi basin the temperature rise was 2.30C in March, 6.10C in April  and 3.50C in May. At Chamba and Dalhousie, the rise was  2.10C, 7.60C and 5.00C in March, April and May, respectively. Likewise, the temperature increase in Satluj basin was 2.80C in March, 8.20C in April and 2.90C in May.   “Due to this abrupt rise in temperature in all the basins, the melting rate was accelerated in all the basins, thereby leading to reduction of snow cover area in each basin,’’ the study stated. According to Randhawa, if the trend continues in the coming winter season as well, then this depletion will have serious repercussions on the hydro sector in the state, leading to water shortage in the downstream areas. Lalit Jain, Member Secretary HIMCOSTE, said snow melting and snowfall patterns have become quite unpredictable due to climate change.