Question

Name the flat, longitudinal valleys in the Shiwaliks.

Answer 1

Hint:
i) It is a local word for valley, in the Siwaliks or between the Siwaliks and higher Himalayan foothills, particularly an open valley.
ii) In Nepal and India, such valleys are called the Inner Terai.
iii) The Valley is located between the Outer Himalayas (a.k.a. the Shivalik Hills) and the Lesser Himalayas, known locally as the Mussoorie Range, two intermittent ranges in the Himalayas.

Complete answer:
Shiwaliks -
The Shivaliks, also known as the lower Himalaya, are a mountain chain in India. With the Himalayas in the north and east, and the smaller Shivalik (or Shiwalik) range in the south, most of the state is mountainous.

Three Shivalik Range Features-
(i)The Outer Himalayas or Shivaliks are considered the outermost range of the Himalayas.
(ii) They stretch over 10-15 km in range.
(iii) These heights range from 900 metres to 1100 metres.

Flat, Longitudinal valleys in the Shiwaliks -
The Doon Valley, in the Lesser Himalayas, in the Indian states of Uttarakhand, Himachal Pradesh and Haryana, is an exceptionally large, long valley within the Shivalik Hills. The city of Dehradun, the capital of Uttarakhand state, lies within the valley.

Among the lesser himalayas and shiwaliks, longitudinal valleys are known as 'duns' in the west and 'duars' in the east. The main examples are Dehra Dun, Kothari Dun and Patli Dun.

Formation of dun(duns)-
-The accumulation of conglomerates formed the Shivalik Hills (sand, stone, silt, gravel, debris etc.).
-These conglomerates obstructed the courses of the rivers draining from the higher reaches of the Himalayas in the initial stages of deposition and created temporary lakes.
-When time passed, more and more conglomerates accumulated in these temporary reservoirs. At the bottom of the reservoirs, the conglomerates were well settled.
-The lakes were washed out, leaving behind planes called 'duns' or 'duns' in the west and 'duars' in the east, as the rivers were able to carve their course through the lakes filled with conglomerate deposits.
-The best example [75 km long and 15-20 km broad] is DehraDun in Uttarakhand.
-Other important dunes include Kotah, Patli Kothri, Chumbi, Kyarda, Chaukhamba, Udhampur and Kotli.

Note: The outermost range of the Himalayas is Shiwalik. They stretch over 10-50 km in width and have a height ranging from 900 to 1100 meters. It is composed of unconsolidated sediments carried down from the major Himalayan ranges by rivers. With thick gravel and alluvium, these valleys are filled.