Physiography of India - Part 2

PHYSIOGRAPHY OF INDIA - PART 2

MAJOR PHYSIOGRAPHIC REGIONS
•    Three Major Structural components –
(1)    The Great Mountains of North.
(2)    The Northern Plains Subdivisions:-
        (a)    Great Plains
        (b)    Thar Desert
(3)    The great peninsular plateau – Having Subdivisions.
        (a)    Central Highlands
        (b)    Peninsular Plateaus
        (c)    Coastal Plains
•    Islands of Andaman & Nicobar and Lakshadweep form the fourth division of India.
•    Area wise these subdivisions can be arranged as – Peninsular Plateaus, Northern Mts., Great Plains, Central Highlands, Coastal Plains, Thar Desert and Islands.

GREAT MOUNTAIN WALL OF NORTH
Trans Himalyas
•    From Pamir Knot (The roof of the world) run several mountain ranges. Kunlun run into Tibet, Karakorum enters Kashmir and runs S-E and includes the Plateau of Aksai Chin. It extends further east, known as Kailas Range in Tibet. Pamir is the connecting  link between the Himalayas and the high ranges of Central Asia.
•    Karakoram contains K2 (Godwin Austin), second highest peak in the world. Karakoram pass is situated in Karakoram Range.
•    Baltoro and Siachin are some of the glaciers in this area. Length wise glaciers of Karakoram are – Siachen (in Nubra valley), Hispar, Biafo and Baltoro.
•    To the south of Karakoram lie two parallel ranges – Ladakh and Zaskar.
•    Indus originates beside Kailash. Flows between Ladakh and Zaskar ranges from  south-east to north-west. Indus forms deepest gorge of this region in Gilgit.
•    Nanga Parbat overlooks Indus in the North.

The Himalyas
•    Himalayas emerged out of the Tethys Sea in three different phases. The first phase commenced about 120 million years ago, when the great Himalayas were formed. The formation was completed about 70 million years ago. The second phase took place about 25 to 30 million  years ago  when  the  Middle Himalayas  were formed. The Shiwaliks were formed about 2- 20 million years ago.
•    Himalayas run for a distance of 2500 km (over 22o longitudes) between Indus and Brahmputra. Width of Himalayas varies from 400 km in the west to 150 km in the east.
•    Himalayas are wide in the west and narrow towards the east. The height of the eastern half is greater than the western half.
•    Wider in west because of many parallel and oblique ranges.
•    Himalayas in J&K and H.P. are called us western Himalaya. In Uttarakhand and Nepal are known as central Himalayas and in W.B., Sikkim, Bhutan and Arunachal Pradesh they are known as Eastern Himalayas.
•    Mountains along the eastern boundary of India are called Purvanchal. These are less spectacular them Himalaya. They are of medium height and comprise the Patkai Bum, and Naga Hills in the north and Mizo hills in the south.

The Greater Himalyas
•    Greater Himalayas or Himadri are the northern most and loftiest of all.
•    Mt. Everest or Sagarmatha (8848 m) is the highest peak of the world, located in Nepal. Tibetans call it Chomlungma
•    Kanchanjunga is the second highest peak of Himalaya and lies in Sikkim.
•    Namcha Bharwa (located in China) is an important peak in east overlooking the Brahmputra where this range takes a sudden turn (like a hairpin) towards south to enter India.
•    The area where Himalayas stand today together with the northern plains of India was occupied by a Sea, called ‘Tethys’.
•    Tethys was elongated and shallow sea sandwiched between two giant masses ‘the
Angaraland’ in the north and ‘the Gondwanaland’ in the south.
•    Tethys stretched from the present Indo-Burmese border in the east and covered the vast area including western Asia, North eastern and central parts of Africa before it joined the South Atlantic Ocean in the Gulf of Guinea.
•    As the Himalaya began to gain in height, the rivers and the other agents of denudation became increasingly active in eroding them, and carrying huge amounts of silt deposits in  the shrinking Tethys. Thus Northern plains or Indo-Gangetic Plains formed.
•    Himalayas are not an effective water divide as the rivers like Indus, Satluj and Brahmputra cut gorges through it in order to turn towards south.

Middle/ Lesser Himalyas
•    To the south of Great Himalayas, known as the Himachal. All the important hill stations
such as Dalhousie, Dharamshala, Shimla, Mussoorie, Nainital – Darjelling.
•    Southernmost ranges of Himalayas are called Shivaliks – made up of unconsolidated deposits of rivers are prone to earthquakes and landslides.
•    Shiwalik result of deposition of Indo-Brahm river (hypothetical) sediments at  foothills  of Middle Himalayas.
•    Himalayas have “ridge-and-valley-topography”. The most outstanding valleys are the valley of Kashmir and the Karewas, the Kangra and Kulu valley in Himachal Pradesh; the  Dun valley; the Bhagirathi Valley (near Gangotri) and the Mandakini Valley (near Kedarnath) in Uttarakhand and the Kathmandu Valley in Nepal.
•    Shiwaliks is an almost unbroken succession of low hills except for a gap of 80-90 km which is occupied by the valley of the Tista River. The Churia Ghat Hills of Nepal also form parts of the Shiwalik Range.
•    Ranges of the Middle Himalayas are as follows:-
     o    Kashmir Section    :    Pir Panjal and Dhaola Dhar (Punjab Himalayas)
     o    Himachal Section   :    Mussorie and NagTiba (Punjab Himalayas)
     o    Nepal Section       :    Mahabharat Range (Nepal Himalyas)
     o    Assam Section     :    Assam Himalyas

•    The arrangement of different ranges in Himalayas is classified according to the name of that region:
     a.    Between Indus and Sutlej    :    Kashmir Himalayas
     b.    Between Sutlej and Kali       :    Himachal in west + Kumaon in East
     c.    Between Kali and Tista         :    Nepal Himalayas
     d.    Between Tista and Brahmaputra    :    Assam Himalayas
     e.    Kashmir + Himachal Himalayas make Punjab Himalayas

NORTHERN PLAINS
•    Length is about 3000 km from Indus to Brahmaputra; width varies from 150 km (Assam) to 400 km (Allahabad).
•    It slopes south east, from Punjab towards W. Bengal.
There are primarily 5 divisions of Plains:-
Punjab Plains
•    Indus and its tributaries make these plains, with 5 Doabs (area between two rivers). Punjab derives its name from 5 river waters. These are (from south to north):-
       o    BIST: Between Sutlaj & Beas
       o    BARI: Between Beas & Ravi
       o    RACHNA: Between Ravi & Chenab
       o    CHAJ: Between Chenab & Jhelum
       o    SIND SAGAR: Between Jhelum & Indus

•    Placed from South to North, these rivers are: Sutlej, Beas, Ravi, Chenab, Jhelum and Indus
•    Northern hilly region has enormous gullying, resulting into badlands called Chos
•    Less than one-third of the Indus basin is located in India (J&K, H.P & Punjab)

Haryana Plains
•    Act as a water divide of Indian Plains (Ambala distt.). These separate the Indus system from the Ganga system. Drained by River Yamuna (tributary of Ganga).
•    The outcrops of Aravalli in the southern part have broken the monotony of these plains. This region is called Bhavani Bangar

Ganga Plains
•    Ganga after rising from Gangotri enters Northern plains at Haridwar, Yamuna joins it at Allahabad.
•    Plains are dominated by the confluence of cones of the tributaries of Ganga.
•    These consist of three sub-divisions, namely (from west to east): Rohailkhand Plains, Awadh Plains and Bihar Plains.

West Bengal Delta
•    Delta formed by Ganga, Brahmaputra and Damodar.
•    Largest and fastest growing delta of the world and it is also the most fertile delta.
•    Important for Jute and Rice cultivation. Three crops of rice per year.
•    The marshes here are important for Sundari trees (Sunderbans)

Brahmaputra Plains
•    Lie in Assam, these plains are prone to floods, earthquakes and gullying.