Plains of Northern India, also popular as Indo-Gangetic Plain or the North Indian River Plain, are a flat and enormous plain. These plains extend in the east west direction between the Himalayan in the north and Great Indian Peninsular Plateau in the south. These plains form an unbroken belt of alluvium varying in thickness from east Bihar Plain to Punjab and northern Rajasthan. Sutlej Plain in the west, the Ganga Plain in the middle, the Ganga Delta and the Brahmaputra Valley in the east constitute the northern plains. The desert in the west of the Aravalli Mountain Ranges being largely a plain formed partly by corrosion and partly by deposition is also included in the plains of Northern India. These plains continue to the west beyond Punjab and Rajasthan and merge into the Indus Plains in neighbouring country Pakistan. The Plains of Northern India, also known as the Gangetic Plains, is situated in the southern Himalayan Region. The Northern Plains spreading from Assam to Punjab has a length of around 2400 km and the width ranges between 150 km to 300 km, varying in different regions. It can be found in Bihar, Punjab, Assam, West Bengal, Uttar Pradesh, parts of Delhi and Haryana.

Features of Plains of Northern India
The plains of Northern India are consistently level plains without any interruption except for a few outliers of the Aravalli Mountain Range, such as, in the environs of Delhi. These plains outline isolated low hills or ridges and come out of the adjacent alluvium as islands in the ocean. Basically this region was formerly a deep trench of around 6 to 8 km in depth. The trench was formed as a fore deep, when the Himalayas rose as fold mountains. This east-west depression received drainage from the Himalaya Mountains in the north and the plateau in the south. Owing to continued silting, the depression was filled up with sediments. Stability in the level of these plains is mainly due to two basic facts. Firstly, no earth movement disturbed their flatness later and secondly the deposition took place in water. The watershed that divides the Sutlej Plain from the Ganga Plain is low and is hardly as one enters the Haryana-Punjab Plain from the Uttar Pradesh Plain.

Division of Plains of Northern India
The Plains of Northern India are generally divided into 2 river systems-
* The Indus in the west, and
* The Ganga-Brahmaputra in the east.

Indus Basin
Less than 1/3rd of the Indus basin is situated in India (Jammu and Kashmir, Himachal Pradesh and Punjab). It is approximately 2900 km long and its primary tributaries include the Sutlej River, Beas River, Ravi River, Chenab River and Jhelum River. A glimpse in the map of India will show how these rivers unite together before they finally merge into the Indus River. The northern plain stretches over 1200 km between the Arabian Sea in the south-west and foothills of the Western Himalaya in the north-east. Over this whole distance, the total descend of the plain is hardly 300 m. Interestingly, these rivers have turned the plain of country`s northern region pretty productive and it now has one of the densest systems of irrigation canals.

Sutlej Basin
The Sutlej Basin is located in the west of the Northern plains. Beas, a tributary of Sutlej, adjoins the river at Harike. Both Haryana and Punjab are included in this basin, as well as parts of Chandigarh. In the Sutlej Basin, crops like Wheat, sugarcane, rice, gram, oil seeds and cotton are cultivated. Rice and wheat, 2 of the major crops are supplied from here, to the rest of the country.

Ganga Basin
Ganga River has two primary origins in the Himalaya the Bhagirathi River and the Alaknanda River. Both merge in Dev Prayag and flow as the Ganga afterward. It enters the northern plains at Haridwar. Yamuna River joins it in Allahabad. Chambal River, Sindh River, Betwa River and Ken River in turn join the Yamuna River. They all stream through the Malwa Plateau before entering into the northern plains. The Son River is the only big river that joins Ganga immediately from the southern plateau. Further east, the Damodar River, irrigating the entire region of Chota Nagpur Plateau, joins the Hooghly River, another tributary of the Ganga River.

The big Himalayan Rivers uniting with the Ganga downstream of Allahabad from west to east comprise the Gomti River, Ghaghara River, Gandak and Kosi River. The Ganga river system waters most of Haryana, southeast Rajasthan, and northern Madhya Pradesh, Uttar Pradesh, Bihar and most parts of West Bengal. Ambala is located on the water divide between the river systems of Indus and the Ganga. The plains from Ambala in the northwest to Sundarban in the east expand over almost 1800 km. During its total expansion from Haryana to Bangladesh; there is descend of barely 300 metres in its slope.

Brahmaputra Valley
Brahmaputra initiates in Tibet near the source of the Indus River and Sutlej River. Brahmaputra River is longer compared to the Indus, but most of its course lies in Tibet. It streams parallel to the Himalaya Mountains in Tibet, where it is called Tsangpo. In Arunachal Pradesh it is called Dihang. After the convergence of the Lohit River, Dihang and Dibang River, it is named the Brahmaputra. Leaving a huge volume of water, it also transports a gigantic amount of silt with it.

Ganga-Brahmaputra Delta
The Ganga-Brahmaputra delta is the largest and the fastest developing delta of the world. This is not only well-watered, but is also the most productive of the region. Ganga and Brahmaputra Rivers divide into several distributaries during their lower courses. Due to the mild slope or incline, the 2 rivers become slow, and islands of sediment and mud expand in their channel. To avoid these obstacles, the rivers generally divide into a number of channels. The process is recurred various times to build up a classical delta. The lower part of Ganga Brahmaputra delta goes sloppy, where fresh water and sea water gets merged, because of high and low tides.

Composition of Northern Plains of India
The northern plains of India are composed of the excellent silt known as alluvium. The main rivers of the region bring it down from the Himalayas in the north and the peninsular plateau in the south. Such a plain is also termed as alluvial plain. The rivers being heavily charged with boulders, sand and mud unexpectedly loosen in speed when they debouch on these plains and deposit their load in the form of gravel fans along the foot of the Himalayan ranges. The southern edge of the Ganga Plain is broken by several gorges turning the productive alluvial land into unusable waste lands. In states of Punjab, Haryana and Uttar Pradesh, where rainfall is deficient the main rivers of the region have been tapped for irrigation purposes.

The Plains of Northern India are very essential and significant for the economic development of the country. The land, being even, has stimulated and sustained the growth of improved transportation and communication system. Some of the major industries that have developed, evenly, over the whole region include Iron and Steel, Jute, Cement, Sugar and Textile Industries.