A new study by researchers from Balasore-based Fakir Mohan University and international collaborators has revealed that landslides are triggered by the combined impact of climate change and rapid development, not just extreme rainfall and unstable terrain. The study highlights that human activities, such as infrastructure expansion and hill cutting, significantly contribute to landslide risks.
Mapping Landslide-Prone Zones
The researchers used advanced machine-learning techniques to map landslide-prone zones across the Western Ghats. They found that nearly 72% of landslides occurred near roads or developed areas, underscoring the impact of infrastructure expansion, hill cutting, and slope modification. The study was published in the journal Earth Surface Processes and Landforms on May 6.
Key Findings
The study found that landslides in the Western Ghats are exacerbated by intense rainfall aggravated by climate change and inadequate environmental and urban planning. The region typically receives 3,000-4,000mm of annual rainfall during the southwest monsoon, but rainfall is no longer evenly distributed. Intense bursts over short periods saturate soil rapidly, weakening slopes and triggering landslides, debris flows, and flash floods. Events such as the 2018 Kerala floods and Kodagu landslides are examples of this growing climate threat.
Using geospatial data and 22 environmental factors, the researchers applied four machine-learning models, including random forest, to identify areas susceptible to landslides. District-level factors such as deforestation, slope modification, and heavy rainfall were significant contributors, according to lead researcher Manoranjan Mishra.
Vulnerable Areas
The analysis classified the Western Ghats into zones ranging from very low to very high susceptibility, with large stretches falling under moderate to high-risk categories. The most vulnerable areas were concentrated in parts of Maharashtra, Karnataka, Kerala, and Tamil Nadu, including districts such as Wayanad, Idukki, Kodagu, and Raigad.
Key Drivers
The study identified key drivers of landslides, including rainfall intensity, elevation, geological structures, proximity to faults, land-use changes, and population pressure. Mishra noted that landslides are emerging as a major threat to infrastructure like highways, railways, tourism centres, and settlements in hilly regions, often cutting off villages, damaging utilities, and disrupting economic activity.
Recommendations
The researchers stressed the need for a multipronged approach, including real-time rainfall monitoring, strict controls on construction in vulnerable areas, improved road engineering, ecological restoration, and community awareness. They said the susceptibility maps can support regional planning, early warning systems, and disaster mitigation strategies.
Urgent Action Needed
The researchers warned that without urgent action, landslide disasters are likely to intensify as climate change increases extreme rainfall events. Protecting mountain ecosystems, they said, is now critical not only for environmental conservation but also for safeguarding lives, infrastructure, and long-term climate resilience.
