Differentiate the causes of landslides in the Himalayan region and Western Ghats.

The Himalaya and the Western Ghats together account for most Indian landslides, but the causal mix differs sharply between the young fold mountains of the north and the old, stable escarpment of the west.

Causes in the Himalayan region

• Tectonic youth: ongoing India–Eurasia convergence keeps rocks folded, faulted, jointed and inherently unstable; frequent earthquakes trigger slides.
• Fragile lithology — crushed shales, phyllites and schists — combined with very steep slopes and deep river gorges.
• Intense triggers: cloudbursts, glacial-lake outbursts and snow-melt saturation (Kedarnath 2013, Chamoli 2021).
• Anthropogenic aggravation: road widening (Char Dham), hydropower blasting, deforestation and unplanned towns — Joshimath’s subsidence (2023) is symptomatic.

Causes in the Western Ghats

• A tectonically stable block, so earthquakes are minor; instability comes from deep chemical weathering — thick lateritic regolith over hard basalt or gneiss forms a slip-prone interface.
• Concentrated south-west monsoon bursts saturate slopes within days, causing shallow debris slips and flows (Kerala 2018–19; Wayanad 2024).
• Steep west-facing escarpment slopes and high drainage density accelerate failure.
• Human causes dominate proportionally: quarrying, monocrop plantations replacing forests, terracing for settlements and tourism-driven construction — concerns flagged by the Gadgil Committee (2011).

In short, Himalayan landslides are structurally and seismically driven, deeper-seated and often earthquake- or cloudburst-triggered, while Western Ghats slides are rainfall-triggered, shallow, weathering- and land-use-driven. Mitigation must differ accordingly — slope-sensitive infrastructure norms in the Himalaya, and land-use regulation of ecologically sensitive zones in the Ghats.