Receding glaciers in Nanda Devi region affecting lifestyle, agriculture
The study of changes in glaciers in the region covered a 30 year span between 1980 till 2017.Updated: Aug 23, 2020 16:28 IST
The changes in glaciers in the Nanda Devi region of Central Himalayas in Uttarakhand in the last three decades have majorly affected the lifestyle, culture and agricultural practices of people living in nearby villages, says a study carried out by experts from major institutes including IIT Kanpur, Wadia Institute of Himalayan Geology (WIHG), Uttarakhand Space Application Centre (USAC) and HNB Garhwal Central University in Uttarakhand.
The research conducted on the ‘changes in glaciers and associated drivers for the last three decades, Nanda Devi region, Central Himalayas’ was done by studying the state of glaciers from 1980 till 2017 through extensive ground surveys and satellite imagery.
During the study, which started in 2002 and was completed in 2018 before getting published in a science journal last month, it was found that about 26 sq km of the glaciated area of the Nanda Devi region was lost in 37 years which affected the people living in nearby areas.
MPS Bisht, director of USAC, who was among the researchers involved in the study said, “The changes in the glaciated areas had a major effect on various aspects of the life of people living in about 47 villages in the buffer zone of the Nanda Devi Biosphere Reserve hosting the Nada Devi glaciers.”
“It was found that the people in those villages who used to wear heavy winter clothing due to low temperatures, had stopped wearing them due to climatic changes in the last few decades which have caused the receding of glaciers there,” said Bisht.
Agricultural practices and housing changed
The locals in the region were now growing a wide variety of vegetation which points to a change in the agricultural practices as well.
“Their agricultural practices have also changed as earlier they used to grow only buckwheat, potato and kidney beans. But now they have started growing green vegetables also due to the change in temperature and climate over the last three decades,” Bisht added.
During the ground surveys for the study Bisht and other researchers also found that food habits and housing designs have also changed.
“First they used to build houses with logs and grass on the roofs to bear the snowfall. But now, due to the climatic changes, the snowfall has stopped but rains have started due to which they are now using tiles on the roofs which used to be unthinkable a few decades ago,” he said.
On the food habits, he said the locals used to have ghee-mixed tea to keep warm earlier but now that has been replaced by normal tea.
Major effect on the cultivation of apples
Bisht informed that one of the major effects has been on the cultivation of apples in the area and livelihood of the people in the villages.
“Earlier the chilled variety of apples like Golden delicious was cultivated in those areas but it has now stopped because of rise in temperatures due to which those apples could not grow. Similarly, the locals in those villages used to collect medicinal herbs from the jungles and sell for their livelihood. That has been also affected as those herbs are now growing less due to climatic changes,” said Bisht.
The areas vacated by the glaciers are now occupied by vegetation which used to grow in lower regions.
During the study, the team of researchers examined eight glaciers in the Upper Rishi Ganga catchment in Nanda Devi region.
“In 1980, the Upper Rishi Ganga catchment which covers an area of 690 sq km had a glaciated area of about 243 sq km, about 35% of the total area. In 2017, it reduced to 217 sq km, a loss of 26 sq km. Now the total glaciated area is only 26% of the total area,” Bisht said on the receding snowline.
Srikrishna Nautiyal, another researcher involved in the study, said, “The study also suggested that the glaciers in the region have responded to deprived precipitation conditions since 1980, overlapping our understanding of glacier retreat due to temperature increase in the context of global warming scenario.”
He informed that it was found that the largest glacier of the region, UND glacier covered an area of 71.42 sq km in 1980 which was reduced to 63.72 sq km in 2017.
“Similarly, the smallest one, Changbang which occupied 7.85 sq km in 1989, had shrunk to 5.95 sq km in 2017. It was also found that the north-facing glaciers such as Trishul, DRB and Raunthi lost the minimum percentage area compared to south-facing ones like Changbang and Ramni,” said Nautiyal.
“This shows that the slope and aspect play a very important role in glacier change variability,” Nautiyal added.
Non-climatic factors also play a role in variable loss of glaciers
Nautiyal also informed that the study also suggested that “The dynamic response of glaciers to climate is strongly dependent on glacier size and geometry.”
“It can be suggested that besides global warming, the local climatic and non-climatic factors like aspect and slope, play an important role in variable loss and dynamics of glacier snouts even in the same valley,” he said.