Subject: Indian Geography

The occurrence of landslides in India's major mountain ranges presents a fascinating study of geological and climatic interactions, with the Himalayas experiencing significantly more frequent landslides than the Western Ghats.

Geological Factors

• The Himalayas' complex lithology comprising mudstones, sandstones, shales, and various metamorphic rocks makes them more susceptible to mass movements.
• The Western Ghats' stable structure of horizontal lava sheets and granitoid gneiss provides better resistance to slope failures.
• The ongoing tectonic activity in the Himalayas creates zones of weakness and fractures, increasing landslide vulnerability.

Climatic and Rainfall Patterns

• The Western Ghats receive structured monsoon rainfall with some areas recording over 6000mm annually, allowing better drainage development.
• The Himalayas experience erratic precipitation patterns, including cloudbursts and intense rainfall events, triggering sudden mass movements.
• The freeze-thaw cycles in the Himalayas further weaken rock structures, unlike the Western Ghats' relatively stable temperature regime.

Statistical Evidence

• The North-western Himalayas account for 66.5% of landslides while the Western Ghats contribute only 14.7% of total landslides.
• Mizoram (12,385) and Uttarakhand (11,219) have reported the highest number of landslides between 1998-2022.

Anthropogenic Factors

• Rapid infrastructure development in the Himalayas, including roads and hydroelectric projects, destabilizes slopes.
• The primary forest loss increased by 14% between 2023-24, further compromising slope stability.
• The Western Ghats have better-regulated development and more established vegetation cover.

The disparity in landslide frequency between these two major ranges highlights the need for region-specific disaster management strategies and sustainable development approaches, particularly in the vulnerable Himalayan states like Uttarakhand and Mizoram. Implementation of advanced early warning systems and stricter construction regulations in the Himalayas can help mitigate these geological hazards.