An avalanche hit a Border Roads Organisation (BRO) project site near Mana Pass in Uttarakhand’s Chamoli district.

About Avalanche 

• Avalanche is a rapid descent of snow, ice, and debris down a mountain slope.It is triggered by natural or human-induced factors.
• It can cause widespread destruction, burying people, structures, and transport routes.

Types of Avalanches

• Loose Snow Avalanche: Occurs on steep slopes (>40°) with loosely bonded snow.
• Slab Avalanche: Large, cohesive snow layer fractures and slides. Most deadly, with speeds up to 100 km/h.
• Gliding Avalanche: The entire snowpack slides over smooth surfaces (e.g., rock).

• • Common on slopes >15°.
• Powder Avalanche: High-speed avalanche with suspended snow particles in the air.
• Wet Snow Avalanche: Triggered by melting snow due to temperature rise or rain.

Causes of Avalanches

• Heavy Snowfall and Wind: Rapid accumulation of snow adds weight and stress to the snowpack.
  • Wind can transport snow to leeward slopes, creating unstable snowdrifts that are prone to avalanches.
  • Mana Village Avalanche (Feb, 2025): Heavy snowfall for two days prior to the event increased the load on the snowpack, leading to the avalanche​.
• Steep Slopes (30° to 45° Slope Angle): Avalanches are most likely on slopes with angles between 30° to 45°.
  • Chamoli Avalanche (2021): A massive avalanche, caused by a chunk of glacier falling from a steep slope, led to flash floods, missing or dead over 200 people.
• Temperature Fluctuations and Melting: Rising temperatures or solar radiation cause the snowpack to melt and refreeze, weakening its bond.
  • Rohtang Pass Avalanche (Mar 2019): Melting snow triggered an avalanche that affected road infrastructure and stranded tourists.
• Earthquakes and Vibrations: Seismic activity or vibrations disturb the snowpack, dislodging unstable layers.
  • Sikkim Earthquake (2011): Triggered landslides and avalanches in the North Sikkim region.

• Weak Snow Layers (Slab Formation): Weakly bonded snow layers beneath a cohesive slab of snow can collapse, causing the slab to slide.
  • Slab avalanches are the deadliest, moving at speeds up to 100 km/h.
  • Avalanche in Gulmarg (2010): A slab avalanche killed 17 Indian Army soldiers due to weak underlying snow layers.
• Deforestation and Construction Activities: Human activities, such as deforestation and infrastructure projects, destabilize slopes and increase avalanche risk.
  • Char Dham Project, Uttarakhand: Large-scale construction in the fragile Himalayan zone has increased the frequency of avalanches and landslides.
• Human Activities: Skiing, snowboarding, and military exercises disturb snow layers, increasing instability.
  • Siachen Avalanche (Feb 2016): Military operations in high-altitude areas triggered an avalanche, killing 10 soldiers.

Avalanches Prone Areas in India 

• The Himalayas are well known for the occurrence of snow avalanches, particularly the Western Himalayas i.e. the snowy regions of Jammu and Kashmir, Himachal Pradesh and Western Uttar Pradesh.
  • Jammu and Kashmir – Higher reaches of Kashmir and Gurez valleys, Kargil and Ladakh and some of the major roads
  • Himachal Pradesh – Chamba, Kullu- Spiti and Kinnaur vulnerable areas
  • Uttarakhand  – Parts of Tehri Garhwal and Chamoli districts are vulnerable areas.

Why Himalayan Regions Are Prone to Avalanches?

• Steep Slopes and Fragile Geology: The Himalayas are characterized by steep slopes (30° to 45°), which are ideal for avalanche formation.
  • The region formed by the ongoing collision of the Indian and Eurasian plates, makes the terrain unstable and prone to landslides and avalanches.
• Heavy Snowfall and Snow Accumulation: The Himalayas receive heavy snowfall during winter, especially in higher altitudes where snow accumulates rapidly.
• Temperature Fluctuations and Freeze-Thaw Cycles: The Himalayan region experiences rapid temperature fluctuations, especially between day and night.
• High Seismic Activity and Earthquakes: The Himalayan region lies in Seismic Zones IV and V, making it prone to earthquakes.
• Climate Change and Global Warming: Rising global temperatures are causing glacial retreat and increased melting of snow and ice in the Himalayas.
• Unplanned Construction and Deforestation: Unregulated construction and deforestation in the fragile Himalayan ecosystem weaken slope stability.

Consequences and Impact of Avalanches

• Loss of Life and Injuries: Avalanches cause suffocation, trauma, and hypothermia.
• Destruction of Infrastructure and Property: Avalanches can bury roads, railways, buildings, and bridges, cutting off essential communication and transport links.
• Disruption of Communication and Utilities: Avalanches damage power lines, communication networks, and water supply systems.
• Environmental Hazards: Melting snow from avalanches increases water runoff, leading to landslides and flash floods in downstream areas.
• Economic Impact: Avalanches disrupt tourism, damaging infrastructure and affecting the livelihoods of local communities.

Protection Measures Against Avalanches

• Snow Barriers and Fences: Snow fences and barriers are installed on avalanche-prone slopes to reduce wind speed and control snow accumulation.
  • These barriers stabilize snow layers, preventing their sudden collapse.
  • Types: 
    • Rigid Snow Fences: Reduce wind speed and allow snow to accumulate gradually.
    • Flexible Barriers: Absorb and dissipate avalanche energy, minimizing impact.
• Deflecting Structures (Avalanche Deflectors and Diversion Dams): Deflectors and diversion dams redirect avalanche flow away from populated areas and critical infrastructure.
  • These structures channel snow to safer zones, reducing the impact on vulnerable regions.
  • Types:
    • V-Shaped Deflectors: Split avalanche flow and divert it to both sides.
    • Diversion Dams: Block and guide avalanches toward predetermined routes.
• Controlled Explosions and Artificial Avalanche Triggers: Controlled explosions trigger smaller, manageable avalanches before larger, uncontrollable ones can occur.
  • Snow accumulation is reduced by inducing preemptive avalanches under controlled conditions.
  • Methods:
    • Gas Exploders: Remotely detonated devices that trigger avalanches.
    • Avalanche Mortars: Shells fired into high-risk zones to loosen snowpacks.
• Avalanche Protection Tunnels and Galleries: Avalanche tunnels and galleries provide safe passage for vehicles and pedestrians through avalanche-prone zones.
  • These structures are built with reinforced concrete and designed to withstand the impact of snow and debris.
  • Example: Rohtang Tunnel (Atal Tunnel), Himachal Pradesh: Built to ensure year-round connectivity and protect travelers from avalanches.
• Slope Modification and Stabilization Techniques: Modifying slopes to reduce steepness and increase stability minimizes avalanche risks.
  • Slope modification involves terracing, vegetation planting, and slope reinforcement.
  • Techniques:
    • Terracing: Reduces slope angle and snow accumulation.
    • Snow Rakes: Prevent large snow slabs from forming.
• Zoning and Land Use Planning: Proper zoning and land-use regulations prevent construction in avalanche-prone areas.
  • High-risk zones are classified based on avalanche hazard maps, and construction is restricted accordingly.
  • Zoning Categories:
    • Red Zone: High-risk area; construction prohibited.
    • Blue Zone: Medium-risk area; restricted development with safety measures.
    • Yellow Zone: Low-risk area; occasional avalanches possible.
• Community Training and Preparedness Programs: Educating local communities about avalanche risks and survival techniques improves disaster resilience.
  • Community members are trained to recognize warning signs and follow Standard Operating Procedures (SOPs) during emergencies.

Government Initiatives for Avalanche Management and Mitigation in India

• National Disaster Management Authority (NDMA) Guidelines – 2009
  • NDMA formulated the “Management of Landslides and Snow Avalanches” Guidelines (2009) to strengthen disaster preparedness and response.
  • The guidelines focus on risk assessment, hazard zonation, and capacity building for avalanche-prone regions.
  • Key Provisions:
    • Hazard Zonation Mapping: Identification of high-risk avalanche zones.
    • Early Warning Systems: Establishment of real-time monitoring systems using Doppler radars and remote sensing.
    • Training and Capacity Building: Conducting awareness programs and mock drills for communities and disaster response teams.
• Border Roads Organisation (BRO) – Infrastructure Resilience
  • BRO undertakes construction and maintenance of strategic roads and tunnels in avalanche-prone areas to ensure year-round connectivity.
  • It incorporates avalanche protection structures in high-altitude regions to safeguard transportation networks.
  • Key Projects:
    • Atal Tunnel (Rohtang Tunnel), Himachal Pradesh: Built to ensure all-weather connectivity and protect commuters from avalanches.
    • Zojila Tunnel, Jammu & Kashmir: Designed to withstand heavy snow and avalanche conditions, ensuring connectivity to Ladakh.
• National Remote Sensing Centre (NRSC) – Satellite-Based Monitoring
  • NRSC, under ISRO (Indian Space Research Organisation), monitors avalanche-prone regions using satellite imagery and remote sensing data.
  • It uses Cartosat, Sentinel-2, and Landsat imagery for real-time snow cover analysis and avalanche prediction.
  • Key Activities:
    • Avalanche Hazard Mapping: Identification of snow-covered zones with high avalanche potential.
    • Real-Time Monitoring: Use of satellite data for continuous monitoring and early warning dissemination.
• State Disaster Management Authorities (SDMAs) – State-Level Preparedness
  • SDMAs, established under the Disaster Management Act, 2005, implement state-level disaster management plans to mitigate avalanche risks.
  • They coordinate with IMD, SASE, and NDMA for localized forecasting and community training.
• National Landslide and Avalanche Risk Mitigation Project (NLARMP)
  • Launched under the Ministry of Home Affairs, NLARMP focuses on reducing the risk of landslides and avalanches through scientific research, capacity building, and infrastructure resilience.
  • Key Components:
    • Risk Mapping and Vulnerability Assessment: Identifying high-risk zones in collaboration with NRSC and SASE.
    • Development of Early Warning Systems: Establishment of real-time monitoring systems for avalanche-prone regions.
• Avalanche Early Warning Systems (EWS)
  • India Meteorological Department (IMD) Avalanche Forecasting System: IMD monitors and forecasts avalanches by tracking snowfall, slope stability, temperature fluctuations, and wind patterns.
    • It uses Numerical Weather Prediction (NWP) models and historical data to predict avalanche-prone areas.
  • Snow and Avalanche Study Establishment (SASE) – DRDO Initiative
    • SASE, under DRDO, conducts avalanche research and forecasting using:
      • Automatic Weather Stations (AWS): Monitors temperature, wind speed, and snow depth.
      • Remote Sensing Data: Assists in mapping avalanche-prone areas.
    • Provides avalanche warnings for high-altitude military zones and civilian areas.
  • Remote Sensing and AI-Based Prediction Models: Remote sensing satellites (e.g., Cartosat, Sentinel-2, and Landsat) provide real-time imagery to identify snow accumulation and avalanche risks.
  • Doppler Radar and Infrared Satellite Sensing (DrISS): Doppler radar and infrared satellite imaging detect snowpack density, velocity, and movement in real time.

Way Forward for Avalanche Management in India

• Strengthen Avalanche Early Warning Systems (EWS): Enhance real-time detection and forecasting capabilities by integrating Artificial Intelligence (AI) and Machine Learning (ML) with existing prediction models.
  • Expand the network of Doppler Radars and Automatic Weather Stations (AWS) in avalanche-prone zones for continuous monitoring.
• Develop Climate-Resilient Infrastructure: Design and construct avalanche-resilient infrastructure to withstand harsh weather conditions in high-risk regions.
  • Incorporate deflecting structures, snow barriers, and avalanche protection tunnels in vulnerable zones.
• Community-Based Disaster Preparedness and Awareness: Empower local communities in avalanche-prone areas through capacity-building programs, mock drills, and awareness campaigns.
  • Educate residents, tourists, and workers on recognizing avalanche warning signs and following safety protocols.
• Integrate Remote Sensing and AI-Based Monitoring: Utilize satellite-based remote sensing technology and AI algorithms for real-time snowpack monitoring and hazard mapping.
  • Establish an Avalanche Risk Mitigation Hub to analyze satellite imagery and detect early signs of slope instability.
• Enforce Strict Zoning and Land Use Regulations: Implement stringent land-use policies and hazard zonation to prevent unplanned construction in avalanche-prone regions.
  • Restrict development in high-risk zones while promoting eco-sensitive construction in medium-risk areas.
• Strengthen Inter-Agency Coordination and Response Mechanism: Foster better collaboration between NDMA, IMD, SASE, BRO, SDMAs, and the Indian Army for an integrated approach to avalanche management.
  • Establish a Unified Avalanche Response Mechanism (UARM) to streamline disaster response efforts.

Conclusion

Effective avalanche management in India requires a multi-pronged approach that integrates advanced forecasting, climate-resilient infrastructure, community awareness, and strict zoning regulations. By adopting global best practices and strengthening inter-agency coordination, India can significantly reduce avalanche-related risks and protect vulnerable communities in the Himalayan region.

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