New Delhi:

The expanding glacial lakes in the Himalayas are a matter of serious concern and the National Disaster Management Authority or NDMA has finalised a list of 189 “potentially dangerous” lakes.

NDTV has learnt that of the nearly 7,500 glacial lakes in the Indian part of Himalayas, NDMA has finalised a list of 189 lakes where the risk factor needs to be lowered.

Rising global temperatures lead to faster melting of ice in these lakes and pose a risk of flooding – a situation known as Glacial Lake Outburst Flood or GLOF.

This is the kind of flood that had devastated the Kedarnath valley in 2013 and parts of Chamoli in 2021, sources said. 

In October last year, the South Lhonak Lake in North Sikkim breached, causing a Glacial Lake Outburst Flood.

The Teesta III dam, the biggest hydropower project in Sikkim was decimated by a GLOF, which also unleashed devastation on downstream areas and communities. 

Now, “all central and state agencies are working closely and have already completed expeditions to 15 of these high-risk lakes — six in Sikkim, six in Ladakh, one in Himachal Pradesh and two in Jammu and Kashmir,” a senior official told NDTV.

Another seven expeditions are underway, he said.

“Given the inhospitable terrain and weather conditions at heights of 4,500 m and above, there is only a June to September window to approach these formidable lakes. Several visits will be needed to implement lake-lowering measures, some of which could require civil engineering,” he said. 

One such expedition is going on in Arunachal Pradesh, where teams are assessing threats from six high-risk glacial lakes.

Considering the risk of these glacial lakes, the NDMA has suggested that there is an immediate need to take up measures to mitigate the effects of Glacial Lake Outburst Flood. The measures being considered include early warning systems, automatic weather stations, and others, the sources said.

“These composite expeditions are assessing structural stability and potential breach points of glacial lakes, gathering relevant hydrological and geological samples and data, measuring water quality and flow rates, identifying risk zones and making downstream communities aware,” said another official, explaining the work being done by NDMA.

The National Glacial Outbhrst Flood Risk Mitigation Programme (NGRMP ) was approved by the government on July 25.

The Home ministry has allocated Rs150 crore to support the efforts of state governments of Himachal Pradesh, Uttarakhand, Sikkim and Arunachal Pradesh in this matter.

There is a separate programme envisaged on the same lines for Jammu and Kashmir and Ladakh.

The programme aims at detailed technical hazard assessments, and installing automated weather and water level monitoring stations (AWWS) and early warning systems (EWS) at the lakes and in downstream areas.

The NDMA has indicated that the Uttarakhand government is also evaluating the risk of Glacial Lake Outburst Floods. Thirteen of the most vulnerable lakes in India are in Uttarakhand.

New Delhi:

The Hindu Kush Himalaya is experiencing significantly lower snow persistence this year, raising serious concern over water security for downstream communities, according to a new report.

Leading experts from the International Centre for Integrated Mountain Development (ICIMOD), a Nepal-based intergovernmental organisation, have urged water management officials to initiate drought management strategies and preemptive emergency water supply measures.

The Hindu Kush Himalaya (HKH) region heavily depends on the cryosphere — frozen water on the Earth’s surface, including snow, permafrost, and ice from glaciers, lakes and rivers. This frozen water is a critical source of freshwater for around 240 million (24 crore) people living in the HKH region and has far-reaching benefits for around 1.65 billion (165 crore) people downstream.

Snowmelt accounts for around 23 per cent of the total water flow of 12 major river basins originating in the HKH. However, its contribution varies from river to river, representing 74 per cent of the Amu Darya’s flow, 77 per cent of the Helmand’s flow, and 40 per cent of the Indus’ flow.

Monitoring shows snow levels are almost a fifth below normal across the region this year, with the most dramatic declines in the west, where its contribution to water supply is the highest.

Snow persistence dropped 17 per cent below normal in the Ganga basin and 14.6 per cent below normal in the Brahmaputra basin, said the Snow Update Report – 2024, released on Monday.

The Helmand river basin shows the most significant drop in snow persistence at 31.8 per cent below normal. Its previous lowest level was in 2018, with a 42 per cent reduction.

The Indus basin has fallen to 23.3 per cent below normal, the lowest level in 22 years. The previous lowest year for this basin was 2018, with a 9.4 per cent shortfall. The Mekong basin had the smallest variation from normal, with snow persistence around 1 per cent below normal.

“We have seen a pattern of decreasing amounts and persistence of snow across the Hindu Kush Himalaya, with 13 of the past 22 years registering lower-than-normal seasonal snow persistence,” said ICIMOD cryosphere specialist Sher Muhammad, who is also author of the report.

“This is a wake-up call for researchers, policymakers and downstream communities. Lower snow accumulation and fluctuating snow levels pose a serious increased risk of water shortages, particularly this year,” he said.

Miriam Jackson, ICIMOD’s senior cryosphere specialist, said agencies must take proactive steps to address possible drought situations, especially in early summer. “Plans must be updated to accommodate water stress, and communities need to be notified of the risks.” “Beyond that, it’s clear that governments and people in this region need urgent support to adapt to changes in snow patterns that carbon emissions have already locked in. G20 countries need to cut emissions faster than ever before to prevent even more changes that could prove disastrous to major population centres and industries reliant on snowmelt in the mountains,” she said.

The experts said promoting rainwater harvesting and establishing local water committees may help mitigate the immediate impacts of below-normal snowfall on the water supply in the HKH region.

However, to ensure long-term resilience to climate change, countries sharing trans-boundary rivers must collaborate to update their water management laws. Such actions are crucial to addressing water shortages in south Asia, which relies on snowmelt, they said.

(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)

Rare stable auroral red arc event in Ladakh due to solar storms, creating spectacular northern lights in high latitudes

In Ladakh, astronomers at the Hanle Dark Sky Reserve saw a red glow on the northwest horizon in the sky from about 1 am on May 11 that continued till early dawn.

“We were fortunate to witness Aurora activities on our all-sky camera during regular telescope observations,” Stanzin Norla, an engineer at the Hanle Dark Sky Reserve, told PTI.

He said a faint red glow was visible to the naked eye along the horizon and the event was captured in much detail by a DSLR camera installed at the Hanle Dark Sky Reserve.

“It streaked through the sky from about 1 am till 3:30 am,” Stanzin said, adding that the skies turned red along the horizon and to a pinkish hue later.

Dorje Angchuk, an engineer at the Indian Astronomical Observatory in Hanle, described the event as a stable auroral red arc, which was a rare occurrence over the skies at Ladakh.

“Auroras seen near the north or south poles are dynamic events. They keep changing. But the one witnessed at Ladakh was more stable. It is called the stable auroral red arc. The steady glow remained in the sky for a couple of hours”, Angchuk said.

Such events are rare at Hanle because it is located far south, Dibyendu Nandi, Head, CESSI at the Indian Institute of Science Education and Research Kolkata, told PTI.

He said the chances of such events being witnessed at places such as Hanle become higher during intense disturbances triggered by solar storms.

“These auroral red arcs are likely caused by heating of the atmosphere by electric currents that are circulating between Earth and outer space,” Mr. Nandi said.

“These ring currents get enhanced during geomagnetic disturbances induced by solar storms and thus the likelihood of observing the red auroral arcs is higher at times when we are in the midst of a severe geomagnetic storm”, he said.

The CESSI said the sun produced strong solar flares beginning on May 8, resulting in five outbursts of plasma capable of disrupting satellites in orbit and power grids here on Earth.

“We are witnessing severe Space Weather at levels we have not seen in the last two decades. It might get worse as more solar storms are expected to impact Earth or maybe just more spectacular auroras for all,” Mr. Nandi said.

The U.S.’ National Oceanic and Atmospheric Administration (NOAA) is calling this an unusual event, pointing out that the flares seem to be associated with a sunspot that’s 16 times the diameter of Earth. An extreme geomagnetic storm in 2003 took out power in Sweden and damaged power transformers in South Africa.