TheIndo-Gangetic Plain, also known as theNorthern Plain orNorth Indian River Plain, is a fertileplain spanning 700,000 km2 (270,000 sq mi) across the northern and north-eastern part of theIndian subcontinent. It encompassesnorthern andeastern India, easternPakistan, southernNepal, and almost all ofBangladesh. It is named after the two major river systems that drain the region–Indus andGanges.
Its stretches from theHimalayas in the north to the northern edge of theDeccan plateau in the south, and extends fromNorth East India in the east to the Iranian border in the west. The region is home to many major cities and nearly one-seventh of the world's population. As the region was formed by the deposits of the three major rivers–Indus, Ganges andBrahmaputra, the plains consists of the world's largest expanse of uninterruptedalluvium. Due to its rich water resources, it is one of the world's most densely populated and intensely farmed areas.
The region was home to theIndus Valley civilisation in 3000 BCE, which was one of the earliest human settlements in the Indian subcontinent.[1] During theVedic period (c. 1500 – 600 BCE), the region was referred to as "Aryavarta" (Land of theAryans). According toManusmṛti (2.22), 'Aryavarta' is "the tract between theHimalaya and theVindhya ranges, from the Eastern Sea (Bay of Bengal) to the Western Sea (Arabian Sea)".[2][3] The region was part of what was historically referred to asHindustan, a term used to refer to the whole of theIndian subcontinent.[4] The term "Hindustani" is also commonly used to refer to the people,music, and culture of the region.[5][6]
The fertile terrain facilitated the rise and expansion of various empires such as theMauryas,Kushan,Guptas, all of whom had theirdemographic and political centers in the Indo-Gangetic plain. The Maurya Empire existed from 4th to 2nd century BCE and unified most of the Indian subcontinent into one state, and was thelargest empire ever to exist on the Indian subcontinent.[7] The Kushan Empire expanded out of what is nowAfghanistan into the northwest of the Indian subcontinent in the middle of the 1st century CE.[8]Maritime trade along theSilk Road flourished during the period.[9] The Gupta period existed from the 4th to 7th century CE and is noted for its arts, architecture and science.[10]
Physical map of India, showing the different regions.
The plains were named after the two major river systems that drain the region–Indus andGanges. The region was formed as a result of continuous deposition ofsilt by the major river systems of Indus, Ganges andBrahmaputra in the depression that existed between theHimalayas in the north andDeccan plateau in the south. There are different theories about how the depression was formed.Darashaw Wadia, said the depression was a furrow that existed since the formation of the plateau in the south and the mountains in the north.Edward Suess suggested that the depression was a largesyncline that was formed when the southward advance of the Himalayas was blocked by the Indian landmass.[23]
Sydney Burrard opined that the region was a deeprift that existed in theearth's crust, which was subsequently filled with alluvium. He also pointed out the existence of other rift valleys in the Himalayan and Deccan plateau region. However, geologists such asFerdinand Hayden andRichard Oldham have rejected this stating that there is no evidence of existence of a rift valley and that the existence of such a large rift valley is not possible. According to the recent research, sediment deposited at the bed of the per-historicTethys Sea folded towards the northern end due to the northward drift of theIndian plate and a trough was formed later due to the emergence of the Himalayas in the north. Beneath the silt deposition, the region rests on hard crystalline rocks which connect the Himalayan region with the peninsula. As the region was formed by the deposits of major rivers, the plains consists of the world's largest expanse of uninterruptedalluvium.[23]
The Indo-Gangetic Plain is divided into twodrainage basins by theDelhi Ridge, which is a northern extension of theAravalli Hills. The western part is drained by the Indus, and the eastern part consists of the Ganga–Brahmaputra river systems.[26][27] The plains encompassed four distinct geographical regions:[23]
Bhabar: It is a narrow region about 7–15 km (4.3–9.3 mi) wide, located immediately below the foothills of the Himalayas. The stretch is highly porous and is largely made up of stones and rocks carried by the rivers. Most streams disappear underground in the region.[23]
Terai: It is the second strip that lies next to the Bhabar region. The region is largely made up of newsilt deposited by the streams and rivers which reappear. It receives heavy rains for most of the year and consists of thick wet evergreen vegetation.[23][28]
Bangar: The third strip consists of older alluvium deposited by the rivers and forms the major fertile region of the flood plains. It also consists oflaterite deposits.[23]
Khadir: The last region encompasses low-lying areas south of the Bangar belt. It is largely composed of new silt carried by the rivers while flowing through the upper part of the plains.[23]
The region is drained by three major river systems and has a highground water table. Due to its rich water resources and fertile alluvial soil, it is one of the world's most densely populated and intensely farmed areas.[23][29][30] The eastern part of the plain receives heavy rainfall during themonsoon after the summer, which commonly results in floods and inundations. The rainfall decreases from the east towards the west with the western region encompassing drier areas such as theThar desert.[24][31]
TheSindh Plains forms the western part of the plains and encompasses the Sindh region of Pakistan to the west of theThar desert with thePunjab Plains in the north and theIndus River Delta in the south.[32] The region receives about 13 in (330 mm) of rain annually, mostly from June to September.[33] The economy is largely based on agriculture.[34][35]
TheIndus River Delta encompasses the region where theIndus River flows into theArabian Sea. Most of the delta lies in the southernSindh province of Pakistan with a small portion in theKutch region of India. The delta covers an area of about 41,440 km2 (16,000 sq mi), and is approximately 210 km (130 mi) across where it meets the sea.[36][37] The climate isarid, the region receives only 25 and 50 cm (9.8 and 19.7 in) of rainfall.[38] Since the 1940s, the delta has received less water as a result of large-scale irrigation works capturing large amounts of the Indus water before it reaches the delta.[39] The region is home to the largest aridmangrove forests in the world.[40] The population of the active part of the delta was estimated at 900,000 in 2003 with fishing being the major industry.[41]
The Rajasthan Plains form the western extreme of the plains in India and is mostly composed ofThar desert,[a] which occupies an area of 200,000 km2 (77,000 sq mi) stretching across 650 km (400 mi). About three-fourth of the plains lie in India and rest in Pakistan. In India, two-thirds of the region is part of westernRajasthan, extending to the west ofAravalli Hills and rest form parts ofHaryana,Punjab andGujarat. The region has an average elevation of 325 m (1,066 ft) which reduces from east to west, reaching about 150 m (490 ft) towards theIndus delta and theRann of Kutch. The western part of the region is covered by shiftingsand dunes (dharian) and the eastern part of the region (Rajasthan Bagar) is rocky. The region is largely arid with seasonal streams uch asLuni supporting limited agriculture.[23]
ThePunjab-Haryana Plain lies to the east and north east of the Rajasthan Plain. It extends for a length of 640 km (400 mi) in a north west to south east orientation till theAravalli Hills and is about 300 km (190 mi) wide stretching fromHaryana in India into Pakistan'sPunjab Province. The elevation varies from 275 m (902 ft) in the north to 176 m (577 ft) in the south west. The left quarter of the region is drained mainly by the tributaries ofIndus–Ravi,Beas, andSutlej and theYamuna waters a small portion on the eastern border. The in-between land which encompasses the city of Delhi, largely consists of no major streams except the seasonalGhaggar River. The region has a humid sub tropical climate with dry winters and receives the major part of rainfall during thesouth west monsoon between July and September.[23]
Ganga Plains encompassing the eastern part of the Indo-Gangetic Plain over northern and eastern India.
The Ganga Plain forms the largest sub-unit of the plains and encompasses an area of 375,000 km2 (145,000 sq mi) across the states ofUttar Pradesh, Bihar, andWest Bengal. TheGanges along with its tributaries such as theYamuna,Gomti,Ghagara,Gandak,Chambal,Kosi, andSone drain the region. The various rivers and streams originating from both theHimalayas and theDeccan Plateau contribute to fertile soil in the region. The region gently slopes towards the south east and consists of three regions: Upper, Middle and Lower Ganga Plains. The Upper Ganga Plain stretches 149,000 km2 (58,000 sq mi) from theShivalik range in the north and the Deccan Plateau in the south with the Yamuna River forming the rough western boundary. The region extends 550 km (340 mi) in the north–south direction and is about 380 km (240 mi) wide with an average elevation of 100–300 m (330–980 ft).[23]
The Middle Ganga Plain stretches to the east of the Upper Ganga plain and forms part of eastern Uttar Pradesh and Bihar. It covers an area of 1.44 km2 (0.56 sq mi), stretching 330 km (210 mi) in north–south direction and 600 km (370 mi) in the east–west direction. The elevation varies from 100 m (330 ft) in the western boundary to 30 m (98 ft) towards the south east. This plain is largely drained by Ghaghara, Gandak and Kosi rivers. The Lower Ganga Plain includes parts of Bihar, West Bengal and most ofBangladesh. It stretches for 81,000 km2 (31,000 sq mi) along a 580 km (360 mi) stretch from the foothills of theHimalayas in the north to theBay of Bengal in the south, and extends between theChota Nagpur Plateau in the west and Bangladesh's eastern boundary with India. The average elevation is 50 m (160 ft) along the western boundary.[23]
TheBrahmaputra Valley largely covers the Indian state ofAssam and is an eastern extension of the plains. It stretches from theEastern Himalayas in Arunachal Pradesh in the north, to theGaro-Khasi-Jaintia andMikir Hills in the south. Its has thePatkai andNaga Hills to the east and the boundary of the Lower Ganga Plain to the west. The region covers an estimated 56,000 km2 (22,000 sq mi) and is watered byBrahmaputra and its tributaries. The elevation varies from 130 m (430 ft) in the east to 30 m (98 ft) in the west.[23]
TheGanges-Brahmaputra Delta is theriver delta formed by theGanges andBrahmaputra rivers when they enter theBay of Bengal. Spread over theBengal region, consisting of Bangladesh and the Indian state ofWest Bengal, it is the world's largest river delta and is one of the most fertile regions of the plains.[42][43] The delta stretches from about 260 km (160 mi) from theHooghly River east to theMeghna River in the west.[44] It encompasses an area of more than 100,000 km2 (39,000 sq mi) with two-thirds of it in Bangladesh. It is also one of the most densely populated regions in the world with more than 130 million inhabitants.[45] The area is prone to heavytropical cyclones.[46] Agriculture and fishing form important part of the economy in the region.[47]
^TheThar desert is sometimes classified as a separate geographical entity from the Indo-Gangetic plains due to its distinct topography compared to rest of the plains.
^Gopal, Madan (1990). K.S. Gautam (ed.).India through the ages. Publication Division, Ministry of Information and Broadcasting, Government of India. p. 70.
^Michael Cook (2014),Ancient Religions, Modern Politics: The Islamic Case in Comparative Perspective, Princeton University Press, p. 68: "Aryavarta ... is defined by Manu as extending from the Himalayas in the north to the Vindhyas of Central India in the south and from the sea in the west to the sea in the east."
^Kapur, Anu (2019).Mapping Place Names of India. Taylor & Francis.ISBN978-0-429-61421-7.
^"India". CIA – The World Factbook.Archived from the original on 18 March 2021. Retrieved14 December 2007.
^Singh, Gulcharan (July 1981). "Maharaja Ranjit Singh and the Principles of War".USI Journal.111 (465):184–192.
^Grewal, J.S. (1990).The Sikhs of the Punjab. The New Cambridge History of India. Vol. II.3. Cambridge University Press. pp. 101,103–104.ISBN978-0-521-26884-4.
^Markhand, Ghulam Sarwar; Saud, Adila A."Dates in Sindh".Proceedings of the International Dates Seminar. SALU Press.Archived from the original on 1 March 2022. Retrieved29 May 2015.
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