Expanding Glacial Lakes in the Indian Himalayas

The Indian Himalayas are witnessing a profound transformation as glacial lakes, once modest in size, are expanding at an alarming rate. This phenomenon, attributed largely to climate change, poses a significant threat to the delicate ecological balance of the region and the millions of people who rely on its resources. As temperatures rise and glaciers retreat, these lakes are growing in volume and pose an increasing risk of glacial lake outburst floods (GLOFs), endangering communities downstream. Understanding the drivers and implications of this expansion is paramount for effective mitigation and adaptation strategies in the face of rapidly changing environmental conditions.

Tags: GS – 3 – Enviro & Biodiversity- Conservation, Environmental Pollution & Degradation, Eia

Prelims: Ghepang/Ghepan Ghat and other Glacial Lake, GLOF Glacial Landforms etc.

Mains : Conservation, Environmental Pollution & Degradation, Eia, Glacial Lake importance

Table of Contents

Context:

Satellite images from ISRO reveal an expansion in the size of Gepang Gath Lake, raising alarm over the impacts of climate change. Monitoring data indicates a 27% increase in the size of glacial lakes in the Himalayas.
Situated in the Western Indian Himalaya, Gepang Gath Lake, located at the terminus of the Gepan Gath glacier, is among the largest glacial lakes in the Chandra basin.

ISRO’s Findings of recent study on Glacial Lakes in Himalayas:

ISRO’s findings on glacial lakes in the Himalayas reveal a significant expansion trend. Among the 2,431 lakes identified during 2016-17, 676 were classified as glacial lakes.
Notably, these glacial lakes have shown considerable growth since 1984, with 89% of them more than doubling in size.
The regional distribution of these expanding glacial lakes indicates their presence in various river basins. Out of the identified lakes, 130 are located within India.
Among these, 65 are situated in the Indus River basin, seven in the Ganga River basin, and 58 in the Brahmaputra River basin.
These findings are crucial for assessing environmental impacts and formulating strategies for managing the risks associated with Glacial Lake Outburst Floods (GLOF) and adapting to climate change in glacial environments.

What are Glacial Lakes?

Glacial lakes are formed in depressions on glaciers or in moraines left by retreating glaciers. They take shape as glaciers carve out the landscape through erosion and then melt, filling the depressions formed by their movement.
Categorization: Glacial lakes are classified into four main types based on their formation process: Moraine-dammed, Ice-dammed, Erosion, and Other glacial lakes.
Expansion Distribution: Among the expanding lakes, Moraine-dammed lakes are the most prevalent (307), followed by Erosion (265), Other (96), and Ice-dammed (8) glacial lakes.
Formation Process: Glacial lakes originate from the accumulation of meltwater resulting from glacier ice melting. As glaciers move, they carve depressions in the landscape, which may fill with water over time.
Moraine Formation: When glaciers retreat, they leave behind moraines, acting as natural dams that trap meltwater and create lakes.
Characteristics:
Size and Location: Glacial lakes vary in size, influenced by glacier size and activity, and are typically found in mountainous and polar regions with glaciers.
Water Sources: Melting glacial ice, precipitation, and runoff are the primary water sources for glacial lakes.
Significance:
Water Regulation: Glacial lakes regulate water flow in glacier-fed rivers, crucial for maintaining water availability, especially during dry periods.
Biodiversity: Glacial lakes support unique aquatic species adapted to cold, high-altitude environments.
Landscape Formation: They contribute to landscape evolution and the creation of landforms like cirques and tarns.
Ecological Challenges:
Glacial Outburst Floods: Sudden water releases from glacial lakes, known as glacial lake outburst floods (GLOFs), pose significant risks to downstream communities and infrastructure, as seen in incidents like the Chamoli Disaster.
Rapid Expansion: Increased glacier melting can lead to the rapid expansion of glacial lakes, raising the risk of flooding and landslides in surrounding areas

Case Study: Ghepang Ghat Glacial Lake (Indus Basin)

ISRO highlighted the significant expansion of the Ghepang Ghat glacial lake in Himachal Pradesh, showing a 178% increase in size between 1989 and 2022.
This case study exemplifies the rate of growth of glacial lakes in the region, with the lake expanding at approximately 1.96 hectares per year.

Important Glacial Lakes in India:

Deosai National Park (Jammu and Kashmir): Known for its numerous glacial lakes.
Gangbal Lake (Jammu and Kashmir): At the base of Mount Haramukh.
Zanskar Valley Lakes (Jammu and Kashmir): Includes Tsomoriri Lake, Tsokar Lake, and many others.
Roopkund Lake (Uttarakhand): Known for the human skeletons found at its bottom.
Sarson Patal Lake (Uttarakhand): Within the Nanda Devi Biosphere Reserve.
Deoria Tal (Uttarakhand): Offering stunning views of the surrounding peaks.
Hemkund Lake (Uttarakhand): Near the Hemkund Sahib Gurudwara.
Kedar Tal (Uttarakhand): At the foot of the Thalay Sagar peak.
Nanda Devi East Base Lake (Uttarakhand): Offering views of the Nanda Devi peaks.
Vasuki Tal (Uttarakhand): Near the Chaturangi Glacier.
Chandratal Lake (Himachal Pradesh): Known for its crescent shape.
Suraj Tal (Himachal Pradesh): Close to the Baralacha La pass.
Rupin Lake (Himachal Pradesh): Near the Rupin Pass.
Gurudongmar Lake (Sikkim): One of the highest lakes in the world.

Importance of recent study:

The recent study holds significant importance due to its utilisation of satellite remote sensing technology, which offers extensive coverage and revisiting capabilities, making it an effective tool for inventorying and monitoring.
Understanding the long-term changes in glacial lakes is vital for gauging glacier retreat rates, evaluating risks associated with Glacial Lake Outburst Floods (GLOFs), and gaining insights into the impacts of climate change.
Moreover, the study provides valuable insights into the dynamics of glacial lakes, which are crucial for assessing environmental impacts and formulating strategies for managing GLOF risks and adapting to climate change in glacial environments.

Conclusion:

Thus, the ISRO study sheds light on the evolving dynamics of Himalayan glacial lakes, emphasising the interplay of climate change, glacier retreat, and the expansion of these lakes. It underscores the necessity of adopting a comprehensive approach encompassing scientific research, policy measures, and community engagement to safeguard the environmental stability of the region and mitigate risks to downstream human populations.

UPSC Civil Examinations PYQ

Q:1 Siachen Glacier is situated to the

(a) East of Aksai Chin

(b) East of Leh

(d) North of Nubra Valley [2020]

Ans: D

Source: (TH) (IE)

FAQs

Q: What causes glacial lakes to expand in the Indian Himalayas?

Glacial lakes in the Indian Himalayas are primarily expanding due to the accelerated melting of glaciers caused by climate change. Rising temperatures lead to increased melting of glaciers, which in turn fills these lakes. Additionally, the weakening of glacial moraines (accumulations of rock and debris) can result in the sudden breach of these lakes, leading to dangerous glacial lake outburst floods (GLOFs).

Q: What are the potential risks associated with expanding glacial lakes?

The expansion of glacial lakes poses various risks, including the heightened threat of GLOFs. These floods can cause widespread destruction to infrastructure, communities, and ecosystems downstream. Additionally, the influx of large volumes of water into rivers can disrupt water availability, agriculture, and livelihoods of communities dependent on these water sources.

Q: How do scientists monitor the expansion of glacial lakes in the Indian Himalayas?

Scientists use a combination of remote sensing techniques such as satellite imagery, aerial surveys, and ground-based observations to monitor the changes in glacial lakes. Advanced technologies help in tracking changes in lake size, volume, and surrounding glacial dynamics over time. This monitoring is crucial for understanding the rate of glacial retreat and assessing the associated risks.

Q: What measures are being taken to mitigate the risks associated with expanding glacial lakes?

Mitigation efforts include the development of early warning systems to alert communities downstream about potential GLOFs. Infrastructure projects such as building dams or reservoirs to regulate water flow from glacial lakes can also help mitigate flood risks. Furthermore, initiatives aimed at reducing greenhouse gas emissions and addressing climate change are essential for long-term risk reduction.

Q: How can local communities adapt to the challenges posed by expanding glacial lakes?

Local communities can adopt various adaptation strategies, including land-use planning to avoid settlement in high-risk areas prone to GLOFs. Enhancing community-based disaster preparedness and resilience through education, training, and infrastructure improvements can also help mitigate the impacts of glacial lake expansion. Additionally, diversifying livelihoods away from sectors vulnerable to climate change can enhance the adaptive capacity of communities in the region.

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Expanding Glacial Lakes in the Indian Himalayas – UPSC