RAS question
The Shiwalik Hills are also known as:
Correct answer: (D) Outer Himalayas.
The Shiwalik Hills are the outermost Himalayan range and are therefore known as the Outer Himalayas.
Explanation
The Shiwaliks are called the Outer Himalayas because NCERT identifies them as the outermost of the three parallel Himalayan ranges. The Great or Inner Himalayas are the Himadri; immediately to their south lies Himachal, or the Lesser Himalaya; and the Shiwaliks form the outer edge. The Shiwaliks are the youngest and southernmost Himalayan range. NCERT gives their altitude as 900-1100 metres and their width as 10-50 kilometres. The long valleys between the Lesser Himalaya and the Shiwaliks are called Duns; standard examples are Dehra Dun, Kotli Dun and Patli Dun.
Why the other options are wrong
- (A) Trans-Himalayas refers 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 north-to-south arrangement of the three parallel Himalayan ranges: Himadri, Himachal and the Shiwaliks. The topic recurs in RAS because Indian physical geography questions often require candidates to identify these ranges by their alternate names and by associated valleys such as Duns.