Regional Division of the Himalayas

The Himalayas, though a single mountain system, show regional variations in their physiography, drainage, climate, vegetation, and human life. That’s why geographers divide them into three main sectors:

1. Western Himalayas (Indus → Kali River)
2. Central Himalayas (Kali → Tista)
3. Eastern Himalayas (Tista → Brahmaputra/Dihang)

Western Himalayas

In this section we’ll focus on the Western Himalayas, which extend for about 880 km from the Indus in the west to the Kali/Sharda River in the east.

This region covers Jammu & Kashmir, Ladakh, Himachal Pradesh, and Uttarakhand.

Punjab Himalayas

• Located between Indus and Sutlej rivers (~560 km long).
• Spread across J&K and Himachal Pradesh.
• Commonly called the Kashmir and Himachal Himalayas.

Major Ranges:

• Karakoram
• Ladakh
• Pir Panjal
• Zaskar
• Dhauladhar

👉 Here, all rivers of the Indus system (Indus, Jhelum, Chenab, Ravi, Beas, Sutlej) flow westwards.
👉 General elevation decreases westward.

Kashmir Himalayas

This part is most diverse and unique.

Ranges present: Karakoram, Ladakh, Zanskar, Pir Panjal.

Glaciers: Baltoro, Siachen (world’s largest outside poles).

• Northeastern corner → Aksai Chin, a cold desert.

Valleys & Lakes:

• Kashmir Valley between Great Himalayas & Pir Panjal.
• Freshwater lakes: Dal, Wular.
• Saltwater lakes: Pangong Tso, Tso Moriri.

Passes:

• Zoji La → Zanskar Range.
• Banihal → Pir Panjal.
• Photu (Fotu) La → Zaskar.
• Khardung La → Ladakh Range.

Drainage:

• Rivers → Indus, Jhelum, Chenab.
• Srinagar lies on the Jhelum.

Pilgrimage Centres:
Vaishno Devi, Amarnath Cave, Charar-e-Sharif.

Himachal Himalayas

• Lies between Ravi (west) and Kali/Sharda (east).
• Drained by both Indus system (Ravi, Beas, Sutlej) and Ganga system (Yamuna, Ghaghara).

Ranges:

• Pir Panjal & Dhauladhar (Lesser Himalaya).
• Shiwalik (Outer Himalaya).
• Himadri also present.

Physiography:

• Southern slopes → rugged, steep, forested.
• Northern slopes → bare and gentle.
• Northernmost part (Spiti, Lahul subdivisions) = extension of Ladakh cold desert.

Human Settlements:

• Altitude 1000–2000 m → favourite for British colonial hill stations like Shimla, Mussoorie, Dharamshala, Kasauli, Almora, Ranikhet, Lansdowne.

Kumaon Himalayas

• Located in Uttarakhand → between Sutlej and Kali Rivers.

Inhabitants:

• Valleys occupied by Bhotias, a nomadic group.
• Practice transhumance → migrate to Bugyals (alpine pastures) in summer, return to valleys in winter.

Ranges:

• Mussoorie & Nag Tibba ranges (Lesser Himalaya).
• Shiwalik Range → south of Mussoorie, between Ganga & Yamuna rivers.

Special Physiographic Features:

• Presence of Shiwalik and Dun formations (longitudinal valleys between Lesser Himalaya & Shiwaliks).
• Dehra Dun is the most famous dun (35–45 km long, 22–25 km wide).

Central Himalayas

Extent

• Stretch: 800 km between the Kali River (Sharda) in the west and the Teesta River in the east.
• This includes Nepal Himalayas and parts of Sikkim Himalayas.

Key Features

• The Great Himalaya (Himadri) reaches its maximum height here.
• World-famous peaks:
  • Mount Everest (8848 m)
  • Kanchenjunga (8598 m)
  • Makalu, Annapurna, Dhaulagiri, Gosainthan.
• The Lesser Himalaya in this region is called the Mahabharat Lekh.
• Major rivers: Ghaghara, Gandak, Kosi — they cut across the ranges.

Valleys

• Between Himadri and Himachal lie the famous Kathmandu Valley and Pokhara Valley.
• Both were once lake basins, later drained by river erosion.

Shiwalik Range

• The Shiwaliks are present but become narrow and discontinuous beyond the Narayani (Gandak River).

Eastern Himalayas (Assam Himalayas)

Extent

• From Teesta River (west) to Brahmaputra River (east), about 720 km long.

Key Features

• Lower elevation compared to Nepal Himalayas.
• Dominated by fluvial erosion due to heavy rainfall.
• Slopes:
  • South slopes → steep.
  • North slopes → gentler.
• Lesser Himalayas are narrow and lie close to the Greater Himalayas.
• Shiwaliks → almost absent.
• Beyond Dihang Gorge, the Himalayas suddenly bend southwards → giving rise to the Purvanchal Hills.

Sikkim Himalayas

• Known for:
  • High peaks → Kanchenjunga.
  • Fast-flowing rivers → Teesta.
  • Deep valleys → spectacular landscapes.
• Population:
  • Lepchas → in higher altitudes.
  • Darjeeling region → Nepalis, Bengalis, tribals from Central India.
• Shiwaliks absent here → replaced by Duar formations, which have fertile soils → famous for tea plantations (Darjeeling Tea).
• Rich in flora (orchids) and scenic beauty → global tourism hub.

Arunachal Himalayas

• Extent: East of Bhutan Himalayas → Diphu Pass.
• Prominent peaks: Kangto, Namcha Barwa (7756 m).
• Rivers: Kameng, Subansiri, Dihang, Dibang, Lohit.
  • Perennial, steep gradient → highest hydroelectric potential in India.
• Terrain: deeply dissected by rivers, creating gorges.
• Transport: difficult due to ruggedness; movement often through the duar region along Arunachal–Assam border.

Tribal Communities:

• Monpa, Daffla, Abor, Mishmi, Nishi, Nagas.
• Most practice Jhum (slash-and-burn cultivation).
• Rich in biodiversity, preserved by indigenous traditions.

Tea Plantations:

• Introduced by the British due to:
  • Fertile soils with organic matter,
  • Heavy rainfall,
  • Mild winters.
• Assam & Arunachal → globally renowned tea-producing regions.

Eastern vs Western Himalayas

Feature	Eastern Himalayas	Western Himalayas
Relief	Rise abruptly from plains (Bengal, Oudh).	Rise gradually through successive ranges.
Proximity to Plains	Peaks like Everest, Kanchenjunga very close to plains.	Snow peaks 150–200 km away from plains.
Rainfall	High (monsoonal, >200 cm), leads to intense erosion.	Lower (due to continentality).
Vegetation	Evergreen, dense forests, orchids.	Dry, alpine vegetation in higher reaches.
Shiwaliks	Absent or negligible.	Well developed.