UPSC MainsGENERAL-STUDIES-PAPER-I202010 Marks150 Words
Q6.

How will the melting of Himalayan glaciers have a far-reaching impact on the water resources of India? (Answer in 150 words)

How to Approach

This question requires a multi-faceted answer focusing on the hydrological cycle, the role of Himalayan glaciers as water towers, and the downstream impacts of their melting. The answer should cover impacts on river flows, agriculture, hydropower, and potential for disasters. Structure the answer by first explaining the Himalayan glaciers’ role, then detailing the short-term and long-term impacts, and finally, mentioning the regional variations. Focus on the Indian context, citing relevant reports and data where possible.

Model Answer

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Introduction

The Himalayan mountain range, often referred to as the ‘Water Tower of Asia’, is the source of several of India’s major rivers – Indus, Ganga, and Brahmaputra – providing freshwater to a large proportion of the country’s population. These rivers are fed by glacial meltwater, snowmelt, and monsoon rainfall. However, climate change is accelerating the melting of Himalayan glaciers at an alarming rate, posing a significant threat to India’s water security. The Indian Space Research Organisation (ISRO) has reported a decline in the area covered by Himalayan glaciers. This melting has far-reaching implications for water resources, impacting various sectors and potentially leading to socio-economic disruptions.

The Himalayan Glaciers: India’s Water Resources

Himalayan glaciers store approximately 1200 cubic kilometers of ice. They contribute significantly to the dry season flow of major rivers, sustaining agriculture, industry, and domestic water needs. The glaciers act as natural reservoirs, releasing water gradually during warmer months when rainfall is scarce. This regulated flow is crucial for maintaining ecological balance and supporting livelihoods.

Short-Term Impacts: Increased River Flows & Disasters

Initially, glacial melt leads to increased river flows. This can result in:

  • Increased frequency and intensity of floods: The sudden release of large volumes of water can overwhelm riverbanks and infrastructure, causing widespread damage. The 2013 Uttarakhand floods are a stark example.
  • Glacial Lake Outburst Floods (GLOFs): As glaciers retreat, they form moraine-dammed lakes. These lakes are prone to breaching, causing catastrophic downstream flooding.
  • Landslides and erosion: Melting permafrost and increased water saturation contribute to slope instability, leading to landslides and erosion.

Long-Term Impacts: Water Scarcity & Ecosystem Changes

As glaciers continue to shrink, the long-term consequences will be more severe:

  • Reduced dry season flows: The gradual depletion of glacial ice will lead to a decline in river flows during the dry season, impacting irrigation, drinking water supply, and hydropower generation.
  • Impact on Agriculture: Agriculture, which is heavily reliant on river water, will be severely affected, potentially leading to food insecurity. The Indo-Gangetic Plain, a major agricultural region, is particularly vulnerable.
  • Hydropower Generation: Reduced river flows will diminish the capacity of hydropower plants, affecting energy security.
  • Ecosystem Degradation: Changes in river flows will disrupt aquatic ecosystems, impacting fish populations and biodiversity.

Regional Variations

The impact of glacial melt will vary across different river basins:

River Basin Impact
Ganga Initially increased flows, followed by significant reduction in dry season flows, impacting agriculture in the Indo-Gangetic Plain.
Brahmaputra Higher risk of GLOFs due to numerous glacial lakes in Arunachal Pradesh and Assam. Increased flood frequency.
Indus Water stress in the Indus basin, impacting agriculture in Punjab and Haryana. Potential for transboundary water disputes.

Furthermore, the Western Himalayas are experiencing faster glacial melt compared to the Eastern Himalayas, leading to differing timelines for water resource impacts.

Conclusion

The melting of Himalayan glaciers presents a complex and multifaceted challenge to India’s water security. While initial increases in river flows may offer temporary benefits, the long-term consequences of reduced glacial ice are dire. A comprehensive and integrated approach is needed, including investments in water storage infrastructure, efficient irrigation techniques, climate-resilient agriculture, and robust disaster management strategies. International cooperation with neighboring countries sharing these river basins is also crucial for sustainable water resource management and mitigating the adverse impacts of climate change.

Answer Length

This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.

Additional Resources

Key Definitions

Glacial Lake Outburst Flood (GLOF)
A GLOF is a type of outburst flood that occurs when the dam containing a glacial lake fails. These lakes are often formed by the melting of glaciers and are dammed by moraines, ice, or other natural features.
Permafrost
Permafrost is ground that remains frozen for at least two consecutive years. Thawing permafrost releases greenhouse gases and destabilizes slopes, increasing the risk of landslides.

Key Statistics

Himalayan glaciers have lost approximately 8.6 gigatonnes of ice per year between 2000 and 2018.

Source: IPCC Sixth Assessment Report (AR6), 2021 (Knowledge Cutoff: 2023)

The rate of glacial retreat in the Himalayas has more than doubled in the last two decades (2000-2020).

Source: Glacier Monitoring Cell, Department of Space, Government of India (Knowledge Cutoff: 2023)

Examples

Chandra Tal Lake, Himachal Pradesh

Chandra Tal Lake is a high-altitude lake in Himachal Pradesh that is expanding due to glacial melt, increasing the risk of a GLOF impacting downstream villages.

Frequently Asked Questions

Will glacial melt eventually lead to the complete disappearance of Himalayan rivers?

While complete disappearance is unlikely in the foreseeable future, glacial melt will significantly reduce dry season flows, potentially transforming these rivers into seasonal streams, severely impacting water availability.

Topics Covered

GeographyEnvironmentGlaciologyWater ManagementClimate Change