The general orientation of these ranges is from northwest to the southeast direction in the north-western part of India. Himalayas in the Darjeeling and Sikkim regions lie in an east west direction, while in Arunachal Pradesh they are from southwest to the northwest direction. In Nagaland, Manipur and Mizoram, they are in the north south direction. The approximate length of the Great Himalayan range, also known as the central axial range, is 2,500 km from east to west, and their width varies between 160-400 km from north to south.
There are three main mountain ranges under the Himalayan Mountain range:
- Great Himalayas of Inner Himalayan range
- Lesser Himalayas or the Himachal range
- Outer Himalayas or Shiwalik range
GREAT HIMALAYAS
- They are also known as ‘Himadari’/ Main Himalayas/ Snowy Himalayas
- They extend from Indus gorge in the West to the bend of Brahmaputra river in the East in Arunachal Pradesh
- Highest peak – Mount Everest, also known as Sagarmatha.
- Slope is steeper towards South and gentler towards North.
- The height of snowline is more in the West than in the East implying that snow can be seen on a lower level in the eastern part than in the Western. The reason being that western part is less humid.
- Other important peaks:
- Kanchenjunga
- Makalu
- Dhaulagiri
- Nanga Parbat
- Annapurna
- Nanda Devi
- Badrinath
- Kedarnath
LESSER HIMALAYAS
- Lies in South of the Himalayas.
- It is 80-100 Km wide having average height between 3700 – 4500 m.
There are several small ranges under lesser Himalayas as shown below:
Pir Panjal Range
- Extends from Jhelum in Kashmir to Beas in Himachal Pradesh
- Famous passes: Banihal and Pir Panjal
Dhauladhar Range
- It runs parallel to the southern part of the Pir Panjal range.
- It extends to Jammu Kashmir, Himachal Pradesh and Uttarakhand
- It starts from the place where Alaknanda river crosses Great Himalayas near Badrinath.
Nag Tibba Range
- It starts from the place where River Kali Gandak (in Nepal) passes through Great Himalayas.
Mahabharat Range
- In Nepal
Note: Kashmir valley and Kathmandu valley lies in between the Great Himalayas and the Lesser Himalayas and are created due to sedimentation of the lakes. For ex. Dal lake and Wular lake are present in Kashmir. ‘Marg’ in Kashmir and ‘Bugyal’ in Uttarakhand are the local names of Meadows found here. Famous hills stations like Shimla, Mussoori, Chakrata, Nainital, Ranikhet, Darjeeling are situated.
OUTER HIMALAYAS
- It extends from Potwar basin in the West to Kosi river in the East.
- It gradually becomes narrower in the East.
- ‘Dun’ are the valleys between lesser and outer Himalayas. E.g. – Dehradun in Uttarakhand.
- ‘Duars’ are the terai areas in West Bengal.
Potwar Basin:
Potwar Plateau, tableland in Rāwalpindi, Attock, and Jhelum districts, Punjab Province, Pakistan. Lying between the Indus and Jhelum rivers and bounded on the north by the Hazāra Hills and on the south by the Salt Range, its varied landscape is constantly affected by erosion.
Duars:
The Dooars or Duars are the foothills of the eastern Himalayas in North-East India around Bhutan. Duar means ‘door’ and the region forms the gateway to Bhutan from India. There are 18 passages or gateways through which the Bhutanese people can communicate with the people living in the plains. This region is divided by the Sankosh River into the Eastern and the Western Dooars. The Western Dooars is known as the Bengal Dooars and the Eastern Dooars as the Assam Dooars. Dooars is synonymous with the term Terai used in Nepal and northern India and form the only nitrate rich plain in India.
The Western Duars is an important centre of the tea industry. Physical conditions such as moderate slope, thick soil cover with high organic content, well distributed rainfall throughout the year and mild winters helps tea plantations in this region.
NORTHEASTERN MOUNTAIN RANGE
- They are also called as hills of Purvanchal.
- Part of Himalayan mountain system.
| States | Ranges |
| Assam | Mikir hills |
| Arunachal Pradesh | Dafla, Miri, Abor, Mishmi, Patkai Bum |
| Nagaland | Naga hills |
| Manipur | Manipur hills |
| Mizoram | Mizo hills (Lushai hills)Mizoram which is also knownas the ‘Molassis basin’ – made up of soft unconsolidated deposits. |
| Tripura | Tripura hills |
| Meghalaya | Garo, Khasi, Jaintia |
