The correct option is 1 and 3 only.
Explanation
Landslides are mass movements of rock, debris, or earth down a slope, driven by gravity. Their occurrence varies based on geological stability, rock composition, and triggering factors such as rainfall or tectonic activity.
Statement 1 is Correct:
The Himalayas are Young Fold Mountains formed by the collision of the Indian and Eurasian plates. They are tectonically active (unstable) and largely composed of sedimentary and metamorphic rocks, which are often unconsolidated or fragile. These factors, combined with steep slopes, make the region highly prone to frequent landslides.
Statement 2 is Incorrect:
The Western Ghats are part of the stable Peninsular Block (Deccan Plateau). They are tectonically stable and mostly composed of hard rocks (such as Basalt and Granite), not soft sedimentary rocks. Unlike the Himalayas, they are not a zone of active plate collision.
Statement 3 is Correct:
Although the Western Ghats are geologically stable and made of hard rock, landslides still occur frequently. This is primarily due to steep slopes (escarpments), heavy rainfall during the monsoon, and anthropogenic activities such as mining, quarrying, and deforestation which destabilize the slopes.
Key Takeaway:
Landslides in the Himalayas are primarily driven by tectonic instability and fragile sedimentary rocks, whereas landslides in the Western Ghats are driven by steep slopes and heavy rainfall despite geological stability.