Facts about the Northern Plains
- Aggradational Plains formed by the deposition of silt brought down by the three main rivers of Indus, Ganga, Brahmaputra and their tributaries.
- These are lies at south of the Himalayas and extends for about 2500 kms from east to west.
- The plains are 280 km wide near Allahabad and 160 km wide near Rajmahal Hills. These are narrowest in Assam varying between 90-100 km.
- The Great Nothern Plain of India are sub-divided into four main regions:
- Rajasthan Plains or Great Indian Desert
- Punjab-Haryana Plains
- Ganga Plains
- Brahmaputra Plains
Geomorphology of the Plains
- It is a narrow belt about 8-16 km wide running in east-west direction along the foot of the Shiwaliks.
- It is an alluvial fan comprising of unasserted sediments brought down by rivers as they descend the mountains.
- Lies south of Bhabhar and is about 15-30 kim wide.
- It is marked by the re-emergence of the underground streams of the Bhabhar belt.
- It is a marshy and ill-drained tract covered with thick forests.
- It is old alluvium of the middle Pleistocene age and forms the alluvial terrace above the floodplains.
- It is new alluvium and forms the floodplains of the river banks.
Divisions of the Northern Plains
- Rajasthan Plains or Great Indian Desert
- An extensive sandy desert lying in north-west India and in eastern Pakistan.
- Locally called Marusthali, it is bound by the Sutlej river in the north-west, the Aravalli range in the east, the Rann of Kutch in the south and the Indus Plains in the west.
- About 800 km long and 490 km wide, it consists of rolling sand hills with rock outcroppings and scattered growth of shrubs.
- Receives scanty rainfall less than 25 cm annually.
- Eastern part is rocky, while the western part is covered by shifting sand dunes, locally known as dhrian.
- Eastern part of the desert upto Aravali Range is a semi-arid plain known as the Rajasthan Bagar. This part is drained by a number of short seasonal streams, which supports agriculture in patches of fertile tract called Rohi.
- Luni is an important seasonal stream. The tract north of Luni is known as sandy plain or thali.
- North of Luni is an area of inland drainage and consists of several saline lakes, like Sambhar, Didwana, Degana, Kuchaman, Sargol and Khatu, Sambhar is the largest.
- Punjab Haryana Plains
- Lies to north-east and east of the Rajasthan Plains in Punjab and Haryana.
- Extends in a north-west to south east direction for a length of 640 km and a width of 300 km.
- Eastern boundary formed by River Yamuna.
- Average height of the plain is about 240 m above mean sea level.
- Formed by the alluvial deposits of five rivers Sutlej, Ravi, Beas, Jhelum and Chenab. Hence known as the Punjab Plains, i.e. Land of Five Rivers.
- The Khaddar Belt is known as dhaya and is agriculturally valuable.
- Consists of doabs (land between rivers), namely, Bist Doab, Upper Bari Doab, Lower Bari Doab, Rachna Doab, Chaj Doab, Sindh Sagar Doab and Malwa Doab.
- The northern part has been intensively eroded by numerous streams called chos.
- The area between rivers Ghaggar and Yamuna is called Haryana Tract. It acts as a water divide between the Yamuna and Sutlej rivers.
- Ganga Plains
- Stretches from Delhi to Kolkata and covers the states of Uttar Pradesh, Bihar and West Bengal (an area of 3.75 sq km).
- Formed by the silt deposited by rivers Ganga and its tributaries, namely, Ghaghara, Gandak, Gomti, Yamuna Kosi etc.
- Slope of the plain is from east to south-east.
- Sub-divided into three parts :
- Upper Ganga Plain
- Middle Ganga Plain
- Lower Ganga Plain
(a) Upper Ganga Plain
- It is delimited by the Shiwaliks in the north, Peninsula in the south and Yamuna river in the west.
- Drained by Ganga and its tributaries Yamuna, Ram Ganga, Sharda, Gomati and Ghagara.
- Rivers flow sluggishly as the gradient decreases greatly.
- Ganga-Yamuna doab lies in the western part of the plain
(b) Middle Ganga Plain
- Occupying the eastern part of Uttar Pradesh and northern Bihar this plain lies to the east of the Upper Ganga Plain.
- Length is about 600 km and width is 330 km, total area is 198,000 sq. km.
- To the north lies the Himalayan foothills and to the south lies Peninsula Plateau.
- Drained by Ghagara, Gandak and Kosi with their tributaries.
- Important features such as levees, bluffs, ox-bow lakes, marshes, tals, ravines etc.
- Almost all the rivers are prone to changing their courses and so the region frequently floods. In fact the Kosi River is known as the Sorrow of Bihar.
(c) Lower Ganga Plain
- Includes the Kishanganj tehsil of Purnea district of Bihar, the whole of West Bengal and most parts of Bangladesh.
- Area is approximately 81 sq km. The width varies greatly. It is narrowest near Rajmahal Hills and Bangladesh border (where it is a mere 16 km).
- Northern part of the plain is drained by the rivers Tista, Jaldhaka and Torsa.
- The Ganga divides into several channels, known as distributaries, and forms a delta that covers about two thirds of the plain. It is the largest in the world.
- The seaward face of the delta consists of mudflats, estuaries, mangrove swamps, sandbanks, islands and forelands.
- Large part of the delta is covered by thick tidal forest called Sundarbans because of the predominance of the Sundari trees.
(d) Brahmaputra Plains
- These are also called Assam Plains as most of Brahmaputra valley is situated in Assam.
- Bordered by Eastern Himalayas in the north, Patkai and Naga hills in the east, Garo-Khasi-Jaintia and Mikir hills in the south, Indo-Bangladesh border in the west.
- It is an aggradational plain built by the depositions of the Brahmaputra and its tributaries, covering an area of 56000 sq km.
- Northern margin marked by steep slopes but the southern part gently falls from the hill ranges.
- Numerous tributaries of the Brahmaputra fall suddenly and form a number of alluvial fans.
- There are large marshy tracts in this area.
- The alluvial fans formed by the coarse alluvial debris have lead to the formation of tarai and semi tarai conditions.
Characteristics of the Northern Plains
- The fertile alluvial soils, flat surface and favourable climate favour agriculture.
- Support one of the densest populations of the world, which depends on an agro based economy.
- Perennial rivers have made irrigation possible, which in turn has made Punjab, Haryana and western Uttar Pradesh the Granary of India.
- Well connected by a close network of roads and railways, which has lead to large scale industrialization and urbanization.
- Trade and commerce is also well developed.
- Many religious places are located along the banks of the sacred rivers of Ganga and Yamuna.