Great Plain of India

The central and eastern part of the plain have been formed by the tributaries of the Ganga and the Bramaputra rivers. The western parts, the Punjab plains were formed by the tributaries of Indus 

The Great plains are of recent origin, less than two million year sold.

They are composed wholly of sediments which were deposited by the rivers

The depth of the sediments varies from place to place. The maximum thickness of the sediments is believed to be about 3000m, in the central part of the plain.

Half of the great plain lies in Uttar Pradesh and half in the states of Bihar, West Bengal, Assam, Punjab and Hariyana

This is the largest alluvial tract of the world

Physical Features

The Bhabar:

• A narrow belt running east - west direction along the foot hills of Shiwalik from Indus to Tista
• Consisting of gravel and assorted sediments
• The porosity of the pebble studded rock beds is so high that most of the streams sink and flow under ground. Therefore, the area is marked by dry river courses except in the rainy season
• This area is not suitable for agriculture and only big trees with large roots thrive in this belt

The Tarai:

• Wide marshy tact in the south of Bhabar running parallel to it
• It is marked by reemergence of the ground water streams of the Bhabar region
• These are ill drained marshy lands of excessive dampness covered with thick forest giving shelter to variety of wild life

The Bhangar:

• Composed of old alluvium and forms the alluvial terrace above the level of flood plains
• It is often impregnated with calcareous concentrations known as the 'Kankar'
• It also contains fossils of animals

The Khadar:

• Composed of newer alluvium and forms the flood plains along the river banks
• Deposited by the river flood almost every year

Reh or Kallar:

• Comprises barren saline efflorescence of drier areas in Uttar Pradesh and Hariyana
• Reh areas have spread in recent areas with increase in irrigation 

Bhur:

• Denotes an elevated piece of land situated along the banks of the Ganga river especially in the upper Ganga - Yamuna Doab

Regional Division of Great Plain Of India

The Rajasthan Plain:

• The western extremity of the great plain of India consisting of the Thar desert or the Great Indian desert
• About two third of the Indian desert lies in Rajasthan, west of the Aravalli range and the remaining one third is in the neighboring states of Haryana, Punjab and Gujarat
• The eastern part of the Thar desert, upto the Aravali range is a semi arid plain which is known as the Rajasthan Bagar
• It is drained by number of short seasonal streams originating from the Aravali and supports agriculture in some patches of fertile lands called rohi. Eg.Luni river.
• North of the Luni basin, there is a large area of inland drainage on the eastern edge of the Thar desert having several saline lakes. They are a great source of common salt and many other salts

       Important Lakes

•  The Sambhar Lake (Largest)
• Degana Lake
• Kuchaman Lake
• Sargol Lake
• Khatu Lake

The Punjab - Haryana Plain:

• Part of the Great plain formed as the result of alluvial deposits by five rivers, viz., the Sutluj, the Beas, the Ravi, the Chenab and the Jhelum
• It is primarily made up of 'doab' - the land between two rivers
• from east to west these doabs are as

1. Bist- Jalandhar Doab  - between the Beas and the Sutluj
2. Bari Doab                   -  between Beas and Ravi
3. Rechana Doab            -  between Ravi and Chenab
4. Chaj Doab                  -  between Chenab and Jhelum
5. Sind Sagar Doab        -  between Jhelum, Chenab and the Indus

• The northern part of this plain adjoining the Shiwalik hills has been intensively eroded by numerous streams called Chos
• The area between the Ghaggar and the Yamuna rivers lies in Haryana is often termed as 'Haryana Tract'. It act as a water divide between Yamuna and Sutluj rivers

The Ganga Plain:

• This is the largest unit of the great plain of India stretching from Delhi to  Kolkata in the states of Uttar Pradesh, Bihar and West Bengal
• Ganga along with its large number of tributaries have brought large quantities of alluvium from the mountains and deposited it to build extensive plain
• At the lower Ganga plain Ganga created largest delta in the world
• Large part of the delta is covered by thick impenetrable tidal forests. These are called Sunderbans because of the predominance of Sundari trees 

The Brahmaputhra Plain:

• Also known as the Brahmaputra valley or Assam valley as most of the Brahmaputra valley is situated in Assom
• Built up by the depositional work of  Brahmaputra and its tributaries

Significance of the Plain:

• It is the home of half of the Indian Population althrough it accounts for less than one forth of the total area of the country
• The extensive use of irrigation has made some part of this plain, especially Punjab, Haryana and western parts of Uttar Pradesh the granary of India
• The entire plain except the Thar desert, has a close network of road and railways which had led to large scale industrialization and urbanization