(a) Bring out the causes for more frequent occurrence of landslides in the Himalayas than in the Western Ghats. (b) There is no formation of deltas by rivers of the Western Ghats. Why?

(a) Why landslides are more frequent in the Himalayas

• Tectonic youth: the Himalayas are rising fold mountains at an active convergent boundary; frequent earthquakes (seismic zones IV-V) repeatedly shatter and destabilize slopes.
• Weak lithology: folded, faulted and jointed sedimentary and metamorphic rocks are far more failure-prone than the massive basalts and gneisses of the Western Ghats.
• Steeper, higher slopes with glacial and snow-melt action, cloudbursts and intense orographic rain lubricate slip planes.
• Anthropogenic stress: road cutting, hydropower blasting, deforestation and unplanned towns (Joshimath subsidence, Kedarnath 2013) magnify hazard.
• The Western Ghats, being an old, stable, fault-scarp edge of the Deccan block, see landslides mainly as monsoon-season slips in lateritic soils aggravated by quarrying and plantations (Wayanad 2024), but with lower frequency and magnitude.

(b) Why Western Ghats rivers form no deltas

• They are short, swift streams descending a steep western slope; the high gradient till near the mouth prevents sediment dumping.
• Flowing over hard crystalline rock, they carry limited alluvial load, and much of it is trapped in structural basins or reservoirs.
• The western coast is a submergent, faulted coast with a narrow continental shelf and deep water close inshore — no shallow platform for delta building.
• Strong waves and tidal scour of the Arabian Sea disperse whatever sediment arrives, so rivers like the Mandovi, Zuari, Sharavathi and Periyar end in estuaries, rias and lagoons instead of deltas.

Contrasting age, structure and coastal setting thus explain both phenomena.