Climate Change

Why did the Chamoli tragedy happen in winter

Identifying hotspots through vulnerability mapping and strengthening EIA can enhance preparedness and build adaptive capacity in areas most at risk from climate change

By Shazneen Cyrus Gazdar
Published: Tuesday 09 February 2021
Photo: @Kenli22490149 / Twitter

A sudden surge of water in the Rishiganga river in Chamoli district, Uttarakhand on February 7, 2021 led to the Dhauliganga dam being completely obliterated and 28 lives lost, while 170 people are still missing.

Anil Agarwal, the founder of Delhi-based non-profit Centre for Science and Environment and renowned environmentalist wrote in 1973 in the State of the Environment Report:

The deep gorges of Himalayan rivers seem sufficient to transport excess rainwater. Surprisingly, this is not true. Floods have been taking place in the Himalayan mountains since time immemorial

He still remains correct. The Himalayas do flood, though not during winter time. Identifying the cause of where this mass of water has come from, has left both the government and scientists perplexed.

A GLOF or glacial lake outburst flood, is suspected. However, the paradox is that this region of the Himalayas does not have any known glacier lakes. However if it was indeed a GLOF, the question of where the glacier lake is, still holds.

Argha Banerjee, a glaciologist who works at the Indian Institute of Science Education and Research (IISER), Pune, said it was possible that a glacier lake was present in the area but not known to scientists. This is because there are also instances of lakes forming inside glaciers that cannot be detected in satellite images.

The Defence Research and Development Organisation (DRDO) said a portion of the Nanda Devi glacier broke off, creating an avalanche, releasing water trapped behind the ice.

LK Sinha, Director, Defence Geo-Informatics Research Establishment, DRDO, said:

Our team conducted an aerial survey of the glacier where the incident took place in Chamoli. Prima facie it looks that a hanging glacier broke away from the main glacier and came down in the narrow valley. In the valley, it formed a lake that burst later and caused the damage. The data is being analysed by our scientists in detail and if required, they would again go to get more details

A second theory is a proglacial lake, formed when a glacier retreats, was held together by boulder and sediment. It was breached by the said avalanche. The final working theory is that the part of the glacier that broke off, blocked the river, eventually melting and thereby releasing the mass of water.

Why winter?

More importantly, the question arises as to the cause of the breaking off the Nanda Devi glacier during this cold winter month. Glacier and ice sheet mass loss is one of the impacts of climate change.

The 2019 Intergovernmental Panel for Climate Change Special Report on the Ocean and Cryosphere states that based on different studies using global and regional climate model projections for the Hindu Kush-Himalaya region, the mean annual temperature is projected to increase in a range of 1-4°C by mid-21st century and 2-6°C by the late-21st century relative to the late-20th century. Currently, we are just seeing the impacts of a 1°C warming in the form of reduced snowfall and runaway glacier melt water in the Himalayas.

What will a 6°C rise in the Himalayas look like? Cataclysmic is the word.

A study published in 2019, spanning 40 years of satellite observations across India, China, Nepal and Bhutan, states that climate change is the primary driver of ice loss. The study states that a 1°C warming is causing over a vertical foot and half of ice melting per year since 2000 — double the amount of melting that took place from 1975-2000.

The accelerated melting appears so far to be swelling runoff during warm seasons. But scientists project that this will taper off within decades as the glaciers lose mass. This, the researchers said, will eventually lead to water shortages.

The IPCC 1.5°C Report states that “Impacts may also be triggered by combinations of factors, including ‘impact cascades’ through secondary consequences of changed systems. Recent studies also identify compound events (eg, droughts and heat waves), that is, when impacts are induced by the combination of several climate events.”

Therefore to a large extent, global warming, melting of ice, reduced snowfall and pockmarking the ecologically sensitive Himalayan riverine system with disproportionate construction of infrastructure including that of hydropower projects can be the exasperator of this disaster.

What needs to be done?

Development is essential however it needs to be conducted sustainably. For this, before the construction of any development project, the government is mandated to conduct an Environmental (and Social) Impact Assessment or ESIA.

Pre-2020, the ESIA was mandated to conduct a thorough study of the environment, biodiversity and the social dimension of consulting with various stakeholder groups.

This essential step has been removed in the new EIA (2020). Local people are caretakers of their environment. But their inputs to new projects have been severely reduced. This is important as where current climatic data is hard to come by, the direct line of testimonials on the impacts of climate change experienced by locals has been cut off.

The now-destroyed Dhauliganga dam’s EIA was conducted during the time of a more robust EIA. Yet, it has been at the epicentre of both, the 2013 and 2021 Uttarakhand flooding incidents. This clearly indicates that the EIA is in its current (and previous) avatar is not good enough. We cannot risk life and ecological integrity at the cost of short term development.

To develop a more long-ranging view, it is essential to conduct vulnerability mapping and identifying hot zones most at risk of socio-ecological and climatic disasters and come up with a preparedness plan.

It is important that as a G-20 country, India gets ahead of now-projected disasters which are bound to occur more frequently. Overlapping climate vulnerable maps with critically important habitats will also provide a guide to where development can and should be perused and where it will do more damage than good.

It is worth mentioning, before the nay sayers begin, that there are methods available to identify hot zones most at risk through the vulnerability mapping exercise. These do not depend on empirical data but the support of the local community and government agencies.

It has been done and can be recreated. Through the vulnerability mapping of at-risk districts such as Chamoli, enhancing preparedness should be an imperative. We need to shift gear and be proactive rather than just reactive. We can and we must do better for our environment and people.

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