The Himalayas, often called Asia's "Water Towers," are as perilous as picturesque. The tragedy that struck Chatten in North Sikkim on June 1, 2025, is a most recent reminder. Three army personnel were killed, and a critical section of National Highway 310 was destroyed following a massive landslide. The day before, the Mangan region recorded 88.4 mm of rainfall, its highest for that week. This sudden spike in precipitation likely saturated already weakened slopes, increasing pore pressure, reducing shear strength, and possibly reactivating old landslide scars.
Beneath the tranquil Himalayan peaks, the ground shifts silently, and slopes surrender to gravity, unleashing landslides, powerful and often deadly movements of earth, rock, and debris. These landslides may be triggered by natural factors like monsoons, earthquakes, rock-ice avalanches, GLOFs (glacial lake outburst floods) and snowmelt or intensified by anthropocentrism of unregulated construction and deforestation. Every year, they put lives, livelihoods, and lifelines at risk, carving destruction into the very heart of India's most fragile ecosystems.
Landslides are often misunderstood as isolated incidents when they are complex, cascading disasters. They can strike as primary hazards, where unstable terrain, weak geological strata, and gravity cause sudden slope failure, or as secondary effects of larger events like cloudbursts, earthquakes, or floods. This is most evident in the Himalayas, one of Earth's youngest and most tectonically active mountain ranges. Here, soft rocks such as phyllites, schists, and gneisses easily fracture under pressure, and the heavy rains of the monsoon season seep into these cracks, raising pore water pressure and triggering slope creep. What begins as a slow, almost invisible subsidence can end in catastrophic collapse.
The Geological Survey of India (GSI) has recorded more than 87,000 historical landslides, with over 31,000 active sites, 80% triggered during the monsoon. The risks are magnified by rampant, unplanned development that disturbs natural drainage and alters slope stability. Climate change further complicates the scenario, introducing more intense rainfall and erratic weather patterns. This toxic mix of natural fragility and anthropogenic stress
has played out repeatedly in recent years, from the highlands of Sikkim to the steep terrain of Himachal Pradesh, the densely populated valleys of Mizoram, the rain-soaked slopes of Jammu & Kashmir, and the lush hills of Kerala.
These events reinforce the need to link accurate rainfall forecasts with real-time slope monitoring and local preparedness, ensuring that heavy rain does not translate into heavy loss. In Himachal Pradesh, 2023 was a grim year that laid bare the state's vulnerability. Torrential rains in July and August triggered multiple fatal landslides in Shimla, Kullu, Mandi, and Solan. Among the most devastating was the landslide at the Shiva temple in Summer Hill, Shimla, which claimed numerous lives and swept away homes. The state's steep gradients, fractured lithology, and overloaded hill towns make it one of the most landslide-prone regions in the western Himalayas.
Uttarakhand, another Himalayan state deeply etched in the country's landslide history, continues to battle the aftershocks of past disasters like the 2013 Kedarnath GLOF tragedy, which was cascaded with massive landslides and debris flows. More recently, incidents in Joshimath, Tehri, and Pithoragarh have shown how slow subsidence, unchecked tourism-driven development, and seismic fragility can converge dangerously.
Similar concerns emerged from Pernote village in Ramban district of Jammu & Kashmir, where a slow-moving landslide in April 2024 damaged homes and posed a significant threat to the Chenab River. A joint assessment by NDMA and CSIR-CBRI Roorkee identified clayey soil, underground springs, and slope saturation as primary causes. The findings also warned that, come monsoon, such conditions could lead to landslide dams (aka LLOF - landslide lake outburst flood) - blockages that can burst without warning, unleashing flash floods downstream. Mizoram has witnessed multiple landslides in the first week of June 2025, disrupting Aizawl, Lunglei, Siaha, and Champhai. These events, catalysed by the first spells of monsoon rain, demonstrate the extreme vulnerability of hilly terrain when exposed to sudden weather extremes.
Meanwhile, Kerala experienced one of the country's most devastating landslides on July 30, 2024, when the Meppadi region in Wayanad received a staggering 372.6 mm of rainfall, twice the district's average. The result was a catastrophic runout of nearly 8 kilometres. NDMA's field investigations
found evidence of fractured bedrock, thick overburden, and channel erosion, all of which contributed to debris flows and landslide dams that amplified the damage. What ties these disparate events together is not just geography, but a pattern of risk that demands coordinated, data-driven action.
The 3M + 3R framework approach by NDMA offers precisely that. Mapping is the first step high-resolution drone surveys /LiDAR scans help to create detailed terrain models, helping identify unstable slopes and unseen fault lines. This is followed by real-time monitoring using ground sensors and satellite data, which track rainfall, soil movement, and ground deformation to provide early warnings. Mitigation measures include slope stabilisation, engineered drainage, reforestation, and bioengineering-all aimed at reducing vulnerability at the source.
Risk assessment, a critical strategy component, involves integrating geological, climatic, and human activity data to guide land-use planning and infrastructure development. Once disaster does strike, rapid response mechanisms -equipped with emergency teams, communication systems, and relief protocols come into play. Finally, robust recovery ensures that communities rebuild not just to restore the status quo, but to improve upon it, integrating resilience into every layer of recovery planning.
As climate change accelerates and extreme weather becomes more frequent, the urgency to act cannot be overstated. Policy planning in the Himalayas, and indeed all landslide-prone regions, needs to shift from reactive to proactive. Disasters are painful - they take lives and destroy the fabric of communities, but they also leave behind invaluable lessons. Every slope that fails teaches us something about the earth beneath our feet, and every recovery effort shows us what resilience truly looks like because it becomes a living laboratory of learning.
The 3M + 3R formula is central to NDMA's ₹1,000 crore National Landslide Risk Management Programme (NLRMP), and aims to convert vulnerability into resilience across the Himalayan belt and in all landslide-prone regions of India. By combining scientific rigour with local community wisdom and institutional will, we can co-exist with our mountains, not in fear, but in harmony.
(The author is Dipali Jindal, Senior Consultant (Landslides & Avalanches), NDMA)
Disclaimer: These are the personal opinions of the author
