RAS question
The Shiwalik Hills are also known as:
Correct answer: (D) Outer Himalayas.
The Shiwalik Hills are the Outer Himalayas, the outermost range of the Himalayas.
Explanation
The Shiwaliks are called the Outer Himalayas because NCERT places them as the outermost of the three parallel Himalayan ranges. The Great or Inner Himalayas are the Himadri, the range to their south is Himachal or the Lesser Himalaya, and the Shiwaliks form the outer edge. The Shiwaliks are the youngest and southernmost Himalayan range, with altitudes around 900-1500 metres. NCERT also explains why Duns are linked with this range: the longitudinal valleys between the Lesser Himalaya and the Shiwaliks are known as Duns, with Dehra Dun, Kotli Dun and Patli Dun as standard examples.
Why the other options are wrong
- (A) Trans-Himalayas points to the region beyond the main Himalayan system, whereas the Shiwaliks are the outermost Himalayan range.
- (B) Greater Himalayas refers to the Great or Inner Himalayas, also called Himadri, not to the Shiwaliks.
- (C) Purvanchal means the Eastern hills and mountains where the Himalayas bend south along India's eastern boundary, not the outer Himalayan foothill range.
Concept
This tests the longitudinal division of the Himalayas into Himadri, Himachal and Shiwaliks. It recurs in RAS because Indian physical geography often asks candidates to match Himalayan ranges with their alternate names and associated valleys such as Duns.