GLOFS IN THE INDIAN HIMALAYA – TRANS BOUNDARY CHALLENGES AND RESILIENCE PATHWAYS

THE CONTEXT: A string of Glacial Lake Outburst Flood (GLOF) events has struck the Hindu‑Kush Himalaya since 2023; the South Lhonak breach in Sikkim (October 2023), the Kedarnath‑style Chorabari cascade (2013), and the July 8 2025 Rasuwagadhi flash‑flood that disabled up to ten hydro‑electric projects and 8 % of Nepal’s power supply.

THE BACKGROUND: HIMALAYAN CRYOSPHERE AND HYDRO‑CLIMATOLOGY:

The Indian Himalaya hosts one of Earth’s fastest‑retreating glacier systems, influenced simultaneously by a warming summer monsoon and westerly disturbances. Glacial retreat is generating thousands of new melt‑water ponds perched above densely populated valleys, converting a slow‑onset climate signal into sudden‑onset disasters.

TYPOLOGY OF GLACIAL LAKES AND TRIGGERS:

• • Supraglacial lakes: Depressions atop glacier tongues; ice‑armoured but highly sensitive to warm spells.
  • Moraine‑dammed (pro‑glacial) lakes: Impounded by unconsolidated debris or buried ice cores; dams fail through piping, permafrost thaw or seismic shaking.
    Nearly two‑thirds of Himalayan GLOFs are triggered by ice/rock avalanches or landslides; the remainder by hydrostatic over‑pressurisation and earthquakes.

THEORETICAL FRAMEWORK:

• • The Climate‑Induced Multi‑Hazard Chain (UNDRR) views a GLOF not as an isolated flood but as a cascade: glacier retreat → lake expansion → slope destabilisation → dam breach → hyper‑sediment flood.
  • Coupling this with the Pressure‑and‑Release model reveals that vulnerability (poor land‑use, dam siting, tourism pressure) multiplies the physical hazard.

SCALE OF THE HAZARD (LATEST DATA):

• • 28,043 glacial lakes mapped across the Indian Himalayan River Basins by the National Remote Sensing Centre (NRSC).
  • 195 high‑risk lakes on NDMA’s dynamic watch‑list under the National GLOF Risk Mitigation Programme (NGRMP).
  • 100+ downstream dams flagged by the Central Water Commission (CWC) for urgent retrofits.

DRIVERS AND DYNAMICS:

• • Rapid warming: 2023‑24 were the hottest global years on record, accelerating melt.
  • Permafrost degradation: Thawing ice‑cemented moraines weaken natural dams.
  • Infrastructure push: Hydropower cascades and highways narrow river floodways.
  • Tourism footprint: Unregulated hotel clusters and waste loading destabilise slopes.
  • Seismo‑tectonics: Active thrust faults can trigger lake‑dam failures.

SOCIO‑ECONOMIC AND ECOLOGICAL VULNERABILITY: The 2025 Rasuwagadhi GLOF washed away the Sino‑Nepal “friendship bridge” and disrupted at least four operational hydropower plants, signalling the macro‑economic stakes of trans‑boundary early‑warning gaps.

POLICY AND INSTITUTIONAL ARCHITECTURE:

TECHNICAL APPROACHES AND EARLY WARNING:

• • Interferometric SAR (InSAR): Detects centimetre‑scale slope creep; Sentinel‑1 feeds make weekly updates possible.
  • UAV‑enabled bathymetry for volume estimates at lakes more than 4,500 m.
  • SCADA‑linked sluice gates in downstream dams for real‑time draw‑down during surges.
  • LoRa / satellite backhaul AWWS sending 10‑minute hydromet packets to State DMAs.

HYDRO‑DIPLOMACY AND TRANS‑BOUNDARY EARLY WARNING:

• • The 2025 Lehende‑Khola flood highlighted the absence of a China–Nepal–India Cryosphere Alert Protocol.
  • India’s Indus Treaty experience (with its 3‑day flash‑flood notification clause) offers a template for a tri‑national early‑warning compact with reciprocal data feeds and joint drills.

CASE‑STUDY:

THE ISSUES:

• • Monitoring Blind‑spots: Fewer than 40 functional hydromet stations above 4,500 m across 2,400 km of Himalaya.
  • Funding Uncertainty: NGRMP relies on interim grants; long‑term scaling hinges on 16th Finance Commission allocations (FY 2027–31).
  • Logistics & Altitude Physiology: Thin‑air expeditions allow < 6 weeks of safe fieldwork annually.
  • Fragmented Mandates: Twelve central agencies share cryosphere tasks; coordination bottlenecks persist.
  • Unregulated Development: Hydropower siting and hill‑town sprawl seldom undergo cryo‑risk audits.
  • Trans‑boundary Data Gaps: Upstream nations hold satellite and hydrological data close, stalling early warnings.
  • Community Disconnect: Sacred‑lake beliefs sometimes resist scientific intervention, as seen during Sikkim expeditions.
  • Permafrost Unknowns: India lacks a dedicated permafrost observatory network, hampering dam‑failure prediction models.
  • Sediment Surge Aftermath: Post‑GLOF siltation raises riverbeds (Teesta case), undercutting future flood‑carrying capacity.
  • Insurance Vacuum: No tailor‑made catastrophe‑bond or crop‑insurance product for GLOF impacts.

THE WAY FORWARD:

• • Cryosphere Observatory Grid: Deploy a chain of solar‑powered AWWS and camera traps at every ‘red‑flag’ lake; integrate feeds with ISRO’s RISAT‑constellation for 24×7 lake‑level telemetry; fund via NGRMP and special purpose grants.
  • Predictive InSAR Analytics: Contract Earth‑observation start‑ups to run weekly Sentinel‑1 interferograms, flag centimetre‑scale slope shifts, and push alerts to State DMAs; couple with machine‑learning thresholds validated by field geodesy.
  • Lake‑Top Siphoning & Notch‑Cutting: Lower water levels by 3–5 m in critical moraine‑dammed lakes using HDPE siphons and controlled outlet notches; guidelines to be standardised by the Central Water Commission and NDMA.
  • Risk‑Informed Dam Design: Mandate high‑capacity spillways, rapid‑open sluice gates, and debris‑blocking weirs for all new Himalayan dams; retrofit existing structures under the Dam Safety Act 2021 compliance window.
  • Community Sentinel Corps: Train local youth, ITBP outposts and high‑altitude trekkers as “first observers” equipped with satellite messengers to relay abnormal lake changes instantly to State Emergency Operation Centres.
  • Trans‑boundary Alert Protocol: Negotiate an ICIMOD‑facilitated trilateral MoU (China–India–Nepal) for glacier‑lake telemetry sharing, joint expeditions and annual simulation drills, building on Indus Treaty precedents.
  • Himalayan Climate Resilience Fund: Launch a blended‑finance window (sovereign + multilateral + private) that issues catastrophe‑bonds and parametric insurance covering GLOF‑induced losses to infrastructure and livelihoods.
  • Permafrost Monitoring Network: Establish 30 bore‑hole thermistor arrays across altitude transects to model ice‑core stability in moraines; integrate outputs with Bureau of Indian Standards codes for slope‑cutting.
  • Mountain‑ecosystem Buffer Zoning: Enforce no‑construction buffer of 50 m from active river channels and 1 km from high‑risk lakes; align with Eco‑Sensitive Zone notifications under the Environment (Protection) Act 1986.

THE CONCLUSION:

Envision a “Himalayan Resilience Grid” that hard‑wires InSAR analytics for all 195 high‑risk lakes with community‑run sensor beacons and a China‑India‑Nepal cryosphere‑data pact, turning every glacial lake into a real‑time safety valve rather than a ticking bomb. Powered by a $1 billion blended‑finance Himalayan Climate Resilience Fund, this grid can avert $20 billion in downstream losses, create 50,000 green‑tech jobs in mountain states, and make India the global test‑bed for climate‑proof alpine development.

UPSC PAST YEAR QUESTION:

Q. Explain the mechanism and occurrence of cloudburst in the context of the Indian subcontinent. Discuss two recent examples. 2022

MAINS PRACTICE QUESTION:

Q. Critically evaluate India’s National Glacial Lake Outburst Flood Risk Mitigation Programme (NGRMP).

SOURCE:

https://www.thehindu.com/sci-tech/energy-and-environment/how-is-india-preparing-against-glof-events-explained/article69861536.ece#:~:text=The%20National%20Disaster%20Management%20Authority%20(NDMA)%20has%20markedly%20accelerated%20its,Disaster%20Risk%20Reduction%20(CoDRR).