Physiographic & Regional Division of Himalayas

The North and North Eastern Mountains

It consist of –

• • Himalayas
  • North eastern hills i.e. Purvanchal

The Himalayan Range

• Himalaya means the Adobe of snow in Sanskrit
• It is also known as Himadri, Himawan and Himanchal.
• Consist of youngest and the loftiest mountain chains in the world.
• Series of several parallel or converging ranges.
• The ranges are separated by Deep valleys creating a highly dissected topology.
• The southern slopes have steep gradients and northern slopes have comparatively gentle slope.
• Most of the Himalayan range fall in India, Nepal and Bhutan.
• Northern slopes are partly situated in Tibet while western Himalayas lies in Pakistan Afghanistan and Central Asia.
• Indian Himalayas runs from eastern boundary of Pakistan to the border of Myanmar in the East India for about 2500 km with varying width about 500 km in the west and 200 km in East.
• It includes parts of Jammu and Kashmir, Himachal Pradesh, Uttarakhand, Nepal, Sikkim, Bhutan and Arunachal Pradesh.
• Their offshoot runs in north south direction along the Indian Myanmar border through Nagaland Manipur and Mizoram.

Division of Himalayas

Geographers has divided northern and north-eastern mountains on following basis –

• • • Physiological division – from north to south
    • Regional division – from east to west

A. Physiographic Division of Himalayas

• • Geographically the entire Himalayas can be divided into following –

1. 1. 1. 1. The Himalayan range
            1. 1. The Shiwalik range
               2. The middle or lesser Himalaya
               3. The greater Himalayas
         2. Trans Himalayan range
         3. The Eastern Himalayas or Purvanchal

1. The Himalayan range

a. The Shiwalik range

• • • Also known as outer Himalayas.
    • Located between great plain and lesser Himalayas.
    • Altitude 600- 1500 m
    • Width varies from 50 km in Himachal Pradesh to less than 15 km in Arunachal Pradesh.
    • Runs almost parallel to lesser Himalayas for a distance of 2400 km from Potwar plateau to Brahmaputra valley.
    • Southern slopes are steep vs. Northern slopes are gentle.
    • Valleys are part of syncline and hills are part of anticlines.
    • They are almost unbroken chain of low hills accept for a gap of 80 to 90 km which is occupied by Valley of Tista River and Raidaik River.
    • Shiwalik range from North East India to Nepal are covered with thick forests but the forest cover decreases towards west from Nepal. (due to the fact that the rainfall decreases from east to west in Shiwalik and Ganga plains)
    • The southern slope of Shiwalik range in Punjab and Himachal Pradesh are almost devoid of forest cover the slopes are highly dissected by seasonal streams called
    • Shiwaliks are formed of unconsolidated sediments brought by rivers from Northern Himalayan range.
    • Shiwalik are formed of great thickness of Mio-Pleistocene sands, gravels and conglomerates which have been brought by The Rivers flowing from the higher ranges of the Himalayas.

Different names of Shiwalik

• • • • Jammu Region – Jammu Hills
      • Arunachal Pradesh – Dafla, Miri, Abor and Mishmi Hills
      • Uttarakhand – The Dhang Range, Dundwa Range
      • Nepal – Churia Ghat

Formation of duns or duras

• • • • Shiwalik range are formed of accumulation of conglomerates
      • These conglomerates in the initial stage of deposition obstruct the courses of the river draining from higher ground of Himalaya and forms temporary lakes.
      • With passage of time this temporary lakes accumulated more and more conglomerates which settled down at the bottom of lake.
      • When the river were able to cut their courses through the league filled with conglomerates deposits the liquid trained away leaving behind plains called duns or doons in east and duras in the west.
      • Dehradun in Uttarakhand.

b. The Middle or Lesser Himalayas

• • • Also known as lower Himalaya, middle Himalaya or Himanchal.
    • In between Shiwalik and the greater Himalayas in the north lies the lesser Himalayas.
    • Runs almost parallel to both the ranges.
    • Elevation 3500 to 4500 m above sea level
    • Width 60 to 80 km wide and 2400 km in length
    • Characterized by steep and bare Southern slopes (steepness prevent formation of soil) and more gentle forest covered Northern slope.
    • Highly dissected and uneven.
    • Consists of mainly unfossiliferous sediments and metamorphosed rocks.
    • Mountain peaks are covered with snow throughout the year.
    • This range is more friendly to human contact.
    • Pir panjal range in Kashmir is the longest and most important range.
    • In Uttarakhand the middle Himalayas are marked by Mussoorie and Nag Tibba range.
    • The Mahabharata lekh in Southern Nepal is discontinuation of Mussoorie range.
    • Majority of Himalayan hills resort like Shimla, Mussoorie, Ranikhet, Nainital, Almora and Darjeeling etc. Are located in this range.
    • Important ranges include Pir panjal the Dhauladhar the Mussoorie range the Nag Tibba and the Mahabharata lekh.
    • Majority of Himalayan hills resort like Shimla, Mussoorie, Ranikhet, Nainital, Almora and Darjeeling etc. Are located in this range.

c. The Greater Himalayas

• • • Also known as inner Himalaya, central Himalaya or Himadri.
    • Average elevation- 6100 km above sea level.
    • Width – 25km.
    • Northernmost and highest range of Himalaya.
    • Most continuous Mountain chain in the world.
    • Core is composed of granite in this mountain chain. Mainly composed of crystalline (granites and gneisses), Igneous rocks overlaid by metamorphosed sediments (limestone).
    • The folds in this range are asymmetrical with steep and gentle North Slope.
    • These mountains are convex to south similar to other Himalayan ranges.
    • Terminates abruptly at syntaxial bends. One on the Naga Parvat in not and other at Namcha Barwa in north east.
    • Peaks are perennially covered with snow.
    • Being lofty, less forest cover is seen.
    • Less erosion as compared to lesser Himalaya or outer Himalaya.
    • All the prominent Himalayan peaks and the tallest peaks of the world lies in this range. Eg. – Mt. Everest, Mt. Kanchenjunga, Nanga Parvat, Namcha Barwa etc.

2. Trans Himalayan Range

• • Also called Tibetan range because most of it lies in Tibet.
  • Himalayan range immediately North to greater Himalayas or Himadri.
  • Main ranges – Jaskar, Ladakh, Kailash and Karakoram.
  • Average elevation- 3000 m.
  • Width – about 40 km wide at extremities and 225 km wide at Central part.
  • Stretch in East West direction- 1000 km
  • Naga Parvat is important range in Jaskar range.
  • North to the Jaskar range is Ladakh range running parallel to it. Only few peaks of this range attain height of 6000 m.
  • The Kailash range in western Tibet is an offshoot of Ladakh range. The highest peak is Mount Kailas (6714m). River Indus originates from the north slope of the Kailash range.
  • The northernmost range of Trans Himalayan range is great Karakoram Range also known as Krishnagiri range.
  • Karakoram Range extends eastward from the Pamir for about 800 km. It is a range with lofty peaks (elevation 5500 m and above).
  • Trans Himalaya are the home of some of the greatest glaciers of the world outside the polar region.
  • Some of the peaks are more than 8000 m above sea level. K2 is second largest peak of the world and highest of India.
  • The Ladakh plateau lies to the north east of the Karakorum Range. It has been dissected into a number of plains and mountains.
  • The glaciers of the range forms India’s frontier with Afghanistan and China and acts as watershed between India and Turkmenistan. It is also called Backbone of high Asia.
  • The Ladakh plateau lies to the north east of the Karakoram Range which are the highest plateau of India.
  • Some of them are classified as Soda plains, Aksai Chin, Lingzi Tang, Depsang plains etc.

3. The Eastern Hills or the Purvanchal

• • Also known as eastern Himalaya.
  • These hills differ in scale and relief but stem from the Himalayan orogeny.
  • Southward extension of Himalaya running along the north south direction in the north eastern edge of India.
  • At the Dihang gorge, the Himalaya takes a sudden southward bend and form a series of comparatively low hills which are collectively known as Purvanchal.
  • Purvanchal hills are convex to west.
  • They extends from Arunachal Pradesh in north to Mizoram in south.
  • These hills are composed of:
    • • Patkai Bum – Border between Arunachal Pradesh and Myanmar
      • Naga Hills
      • Manipuri Hills – Border between Manipur and Myanmar
      • Mizo Hills.
  • In north, Patkai bum hills are made up of strong sandstone, elevation varying from 2000-3000 m merges into Naga Hills where Saramati (3826 m) is highest peak.
  • Patkai bum and Naga Hills form the watershed between India and Myanmar.
  • South of the Naga Hills are Manipuri hills which are generally less than 2500 m in height.
  • Further south, the Brail range swings west into Jaintia, Khasi and Garo hills which are eastward continuation of an Indian Peninsular region which is separated by main block by Ganga and Brahmaputra River.
  • South of the Manipuri hills are Mizo hills (Previously known as Lushai Hills) which have an elevation of less than 1500 m. Highest point is Blue Mountain (2157 m) in south.
  • These hill ranges are forbidding due to their rough terrain, dense forests, and swift streams.
  • Extension of Purvanchal continues in Myanmar as Arakan Yoma –then Andaman and Nicobar Islands.

B. Regional Division of Himalayas

• Beside the physiography division, the Himalaya have been divided on the basis of region from east to west.
• These divisions have been demarcated by River valleys.

1. Western Himalaya

• • Between the Indus in the west and Kali river in the east. (880km)
  • Spreads across three state of Jammu and Kashmir, Himachal Pradesh and Uttarakhand.
  • It encompasses three physiographic provinces namely Kashmir valley Himalayas, Himachal valley Himalayas and Kumaon Himalayas.
  • The Ladakh plateau and the Kashmir valley are two important areas of Himalayan region.
  • In Himachal Himalayas, the greater Himalayas are represented by Zaskar range, lesser Himalayas by Pir panjal and Dhauladhar Range and outer Himalayas by Shiwalik.
  • The southern slopes are rugged, steep and forested while Northern slope are bare, gentle and show plains with lake.
  • Kumaon Himalaya lies in Uttarakhand and extends from Satluj to Kali River.
  • In Kumaon Himalayas, lesser Himalayas is represented by Mussoorie and Nag Tibba range and Shiwalik in this region runs smooth to south of Mussoorie range between Ganga and Yamuna River.
  • The flat valley between lesser Himalaya and Shiwalik Range are called Doons.

a. The Kashmir Himalaya

• • • Area 350000 sq. km in a state of Jammu and Kashmir.
    • Length 700 km width 500 km
    • Ladakh region of Kashmir Himalaya is characterized by cold desert condition.
    • Special features – Karewa (lacustrine) deposits consisting of silt sand and clay.
    • These Karewa devoted to the cultivation of saffron and have all orchid of Apple peach almond walnut and apricot.
    • Characterized by a snow covered peak, deep valleys, interlocked Spurs and high mountain passes.
    • Pir panjal, Banihal, Zoji- la, Pensi-la, Jura-la, Chang-la etc. are important passes of Kashmir Himalaya.

b. The Himachal Himalaya

• • • Stretch over Himachal Pradesh
    • Area 45000 sq. km
    • All the three range are well represented.
    • Northern slope are there and shows plains and lakes while Southern slopes are rugged and forest covered.
    • Rohtang, Baralacha, shipki-la important passes.
    • Beautiful value of Kangra, Manali, Lahul and Spiti lie in Himachal.
    • Shimla, Dalhousie, Chamba, Kullu-Manali are important are important hill station.

c. The Kumaon Himalayas

• • • Lies between Sutlej and Kali River.
    • Length 320 km
    • Area 38000 sq. km.
    • Highest peak – Nanda Devi (7817m), Dunagiri (7066m), Shivaling (6638m), Gangotri (6615m), Kedarnath (6940m), Badrinath (7138m) Banderpunch (6320m) etc. are all important peaks.
    • Gangotri Milam and Pindar are important and main glaciers of Uttarakhand.
    • Important hill station – Mussoorie, Ranikhet, Almora, Bageshwar etc.
    • Important passes- Muling la (5669m), Mana pass, Niti pass, Lipulekh, Marhi-la, Lampiya, Shalsal pass etc.

East- West Division of Himalaya with important peaks

2. The Central Himalayas

• • 800 km between river Kali in West and river Tista in East.
  • The great Himalayan range attain maximum height here.
  • Some of the world famous peaks – Mount Everest, Kanchenjunga, Makalu, Annapurna, Gosainath and Dhaula Giri are located here.
  • Lesser Himalaya are known as Mahabharat lekh in this region.
  • Rivers – gandak, Ghaggra, kosi etc.
  • In between great and lesser Himalayas there are Kathmandu and Pokhara lacustrine deposits.
  • Towards east, Shiwalik Range come closer to lesser Himalaya and almost non-existent beyond Narayani (Gandak).

a. Nepal Himalayas

• • • Tallest section of Himalaya.

b. Sikkim Himalayas

• • • Tista river originates near Kanchenjunga
    • Jelepa la pass is tri junction of India, Bhutan and China borders.

3. The Eastern Himalayan

• • This part of Himalaya lies between river Tista in west and Brahmaputra River in East.
  • Stretches a distance of about 720 km.
  • Also known as Assam Hills.
  • Eastern Himalayas occupy mainly the area of Arunachal Pradesh and Bhutan.
  • The Assam Himalaya shows a marked dominance of fluvial erosion due to heavy rainfall.
  • The Himalaya takes sudden South ward return after the Dihang gorge and the hill range running in north south direction alone India Myanmar border.
  • These are also known by various local names such as Patkai bum, Naga Hills, Kohima Hills, Manipuri Hills, Mizo Hills, Tripura Hills and baral Hills.
  • Extension of Purvanchal Himalayas continues toward south Up to Andaman and Nicobar Island through the Myanmar range (arakan Yoma) and even up to Indonesian archipelago.
  • In the Eastern section of Himalayas rise abruptly from plains of Bengal and suddenly attains great elevation within a short distance from the foot of mountains.
  • In contrast, the Western Himalayas rise gradually from the Plains through a series of ranges, their peaks are covered with snow and are 150 to 250 km away from the plains.

 

Key Difference between Eastern and Western Himalaya

 

So, this is all about Physiographic and Regional Division of Himalayas or Northern mountains of India.

In the Next Post (Click Here), we will discuss about the Great Plains of India.