Landslides

Story hook

It is 30 July 2024, 2:00 am. Wayanad, Kerala, Mundakkai village. After 572 mm of rain in 48 hours — a record — saturated slopes give way. A wall of mud, rock and debris descends from Punjirimattam ridge at an estimated 160 km/hr. By the time it stops at the Iruvazhinjipuzha riverbed 3 km below, it has swept 8 villages — Mundakkai, Chooralmala, Punjirimattam, Attamala, parts of Kalpetta. 426 dead, 47 still missing. 220 houses vanish into the muck. Survivors describe "a sound like a thousand thunderclaps."

This is India's deadliest landslide since the 1998 Malpa landslide (255 dead) — and a textbook multi-cascade hazard:

• Extreme rainfall (climate-amplified).
• Saturated weathered soil on Charnockite-Gneiss bedrock.
• Deforestation (Western Ghats Gadgil report 2011 flagged Wayanad as Ecologically Sensitive Zone-1; not implemented).
• Plantation monoculture (tea, coffee).
• Slope-stability ignored in settlement planning.

Wayanad sits on the Western Ghats landslide belt — 15% of India's land area mapped as landslide-prone by the Geological Survey of India (GSI). Joshimath subsidence in January 2023 warned us about Himalayan slopes. Wayanad shows the Western Ghats are equally fragile.

This unit covers landslide types, GSI's Landslide Hazard Zonation map, the LMR (Landslide Mitigation Programme), Joshimath as paleo-landslide case, Wayanad 2024, and the climate-landslide nexus.

Why this matters for UPSC

15% of India's land is landslide-prone. Recent disasters — Wayanad 2024 (426), Joshimath 2023 (subsidence), Kedarnath 2013 (6,000 cascading flash flood + landslide), Malin 2014 (151) — make this annually testable in Prelims (GSI, Hill states, LMR) and Mains. Interview boards push on the Gadgil vs Kasturirangan Western Ghats debate.