The north Indian state of Himachal Pradesh and of the most popular tourist hotspots in the country is bearing the brunt of climate change and global warming. The state has witnessed about an 18.5 per cent decrease in snow cover during 2020-21, a study conducted jointly by State Centre on Climate Change (SCCC), state government organ and Space Applications Centre (ISRO), Ahmedabad (Gujarat) has revealed.
There is an overall decrease in the area under snow in 2020-21 winter but the Satluj basin which includes the Spiti basin —primarily the high altitude region of tribal belt and Ravi basin— the Southwestern side of Pir Panjal ranges, has seen a maximum loss of the snow cover up to 23 per cent against 2019-20.
This is further followed by the Beas basin showing a decrease of 19 per cent and the Chenab basin recording a nine per cent decrease.
The study was done by a team led by S S Randhawa and Nishtha Gautam, key scientists at the SCCC, Shimla and I M Bahauguna and B P Rathore, both working at the ISRO centre at Ahmedabad. Conducted using Advanced Wide Field Sensor (AWiFS) satellite data map, the scientific data uncovered by the study could be an eye-opener for the government, which has increasingly been undertaking projects that exploit the state's hydropower potential for building tunnels, dams and carrying out massive road construction works.
The areas have seen fast receding snow cover, glaciers and the formation of artificial lakes. These areas are also the most vulnerable to disasters, landslides, glacier lake bursts and flash floods.
Expressing his concern, Dr Randhawa said, "Himachal Pradesh receives winter precipitation in the form of snow at higher altitudes. About 1/3rd of the total geographical area remains under thick snow cover during the winter season. Major rivers like Chenab, Beas, Parvati, Baspa, Spiti, Ravi, Satluj and their perennial tributaries depend upon the seasonal snow cover for their discharge dependability. The snow cover also helps in controlling the accumulation and ablation patterns of the glaciated regions in the State. Any further decrease in the snow cover is bound to alter the entire ecosystem and biodiversity of the region.”
The dominant reduction in terms of the total monthly average area during October-May was also observed by the study separately to make a detailed analysis about the loss of the snow during peak winter months and subsequently the melting period in higher altitude areas, mainly the ecologically fragile tribal belt
The study observed that during the peak winter months i.e December to February, the Chenab basin showed a negative trend in the total area under snow by about two per cent and seven per cent decrease in 2020-21 respectively in comparison to 2019-20.
Likewise, the Beas basin shows a decrease of about nine per cent, 28 per cent and 26 per cent and Ravi basin by 18 per cent, 16 per cent and 25 per cent reduction in 2020-21. The Satluj basin showed a decrease in the area by about 24 per cent, 24 per cent and 29 per cent during the same period in 2020-21.
At the end of the winter season i.e in March, the Chenab basin showed a reduction in the area by about three per cent, Beas (six per cent), Ravi (0.09 per cent) and Satluj (20 per cent) in 2020-21 in comparison to 2019-20 winters.
In November alone, the decrease in area under snow cover was about 31 per cent in Chenab, six per cent in Beas, about 52 per cent in Ravi and about 21 per cent in Satluj basin in 2020-21 in comparison to 2019-20.
All basins have shown a reduction in the surface area under snow by about two per cent (Chenab), nine per cent (Beas), 18 per cent (Ravi) and 24 per cent (Satluj) basins respectively during December 2020.
In January, the Chenab basin showed a decrease of about two per cent, the Beas basin by 27 per cent, Ravi basin by 16 per cent and the Satluj basin up to 24 per cent in 2020-21 in comparison to 2019-20.