The Indo-Gangetic Plain, also called the North Indian, is a vast north-central part of the Indian Peninsula, stretching to the west, including the combined delta of the Brahmaputra River Valley and the Ganges River to the Indus Valley.
The region has the richest and most densely populated areas of the subcontinent. Most of the plain consists of alluvial soils deposited by the three main rivers and their tributaries. In the eastern part of the plain, light rains occur in winter and droughts occur, but in summer the rainfall is so great that vast areas turn into swamps or small lakes. The territory of the plain gradually becomes drier to the west, where the Thar desert is located.
Where is
The Indo-Gangetic Plain is a large land area located in countries such as India, Pakistan and Bangladesh. From the north, its border is the Himalayas, from the south - the Deccan Plateau.
The main here are three large rivers: Indus, Ganges and Brahmaputra. This part of the land runs parallel to the Himalayas, from Jammu and Kashmir in the west to Assam in the east, and captures most of northern and eastern India. It extends almost 3,000 kilometers from west to east with a width of 250 to 350 km and covers an area of 700,000 km².
How the Indo-Gangetic lowland was formed, what plains it includes
It is a foothill (marginal) deflection, the base of which is the Hindustan platform, which is covered by significant loose deposits. The valley was formed in the process of sediments of ancient and modern alluvium (sediments of constant water flows).
It accumulated continuously, with different intensities. Such a cyclical nature of sediments led to different thicknesses of pebble and sand-clay layers. It includes the plains of the upper, middle and lower Ganges.
Soil features
The composition of the ancient alluvium includes sands and dense clay, which make up wide flat terraces. Later sediments are located along the Indus and Ganges. Its finest fractions are silts, the sediments of which remain in the lower reaches and deltas. Clays and sands remain in the middle part of the rivers. In the foothills, pebbles make up the bulk. Replenishment of modern alluvium deposits occurs mainly during the flood of rivers in the summer.
Characteristic
The main rivers in this region are the Ganges, Indus and Brahmaputra, as well as their main tributaries - the Yamuna, Chambal, Gomti, Gaghara, Kosi, Sutledge, Ravi, Beas, Chenab and Tiesta, as well as the rivers of the Ganges delta, such as Megna. The Great Plain, as it is also called, is home to almost 1/7 of the world's population. It is connected in the north with the Himalayas, which feed its numerous rivers and are a source of fertile alluvium, accumulated in the region by two river systems. The southern edge of the plain is marked by the ridge of Vindhya and Satpur, as well as the Chota Nagpur plateau. In the west rises the Iranian plateau.
The exact depth of alluvium on the Indo-Gangetic plain has not yet been fully determined. According to recent estimates, its average depth in the southern part of the plain (north of Bundelhand) varies from 1300 to 1400 meters, while in the direction of Shivalik (the lowest and youngest mountain range in the south of the Himalayas), the depth increases.
Absolute heights - from 270 to 30 meters above sea level. The largest refers to the watershed of the Ganges and Indus rivers. The average height of the Indo-Gangetic plain is 100 m.
Great Plain Regions
Indo-Gank lowland can be divided into several parts.
The Bhabar region adjoins the foothills of the Himalayas and consists of boulders and pebbles that were demolished by river flows. Since the porosity of this territory is very high, so many flows here disappear or flow underground. For the same reason, this area is not suitable for sowing, and only large trees survive here.
The Terai region is located next to the Bhabar region and consists of a newer alluvium. Underground streams reappear here. The area is excessively wet, swampy and densely planted with trees. Terai is located south of Bhabar. This region is wider in the eastern part, especially in the Brahmaputra valley. High humidity and a large number of forests determine the biodiversity of this area. Over a period of time, forests in the states of Uttarakhand, Uttar Pradesh, Haryana, Punjab and Jammu were cut down for growing crops.
The Bhangar region (Bangar) is the largest part of the Indo-Gangetic plain, consisting of an old alluvium and forming an alluvial terrace of floodplains. The soil in this region consists of calcareous deposits called Kankar. Bhangar formations were postponed during the middle Pleistocene period. The old alluvial soil is dark in color, rich in humus and fertile. The land lies above the boundaries of river floods.
The Khadar region of the Indo-Gangetic Plain is located in the lowlands after Bhangar. It consists of a fresh new alluvium, which is deposited by rivers flowing down the plain. Its territory is annually replenished with fresh sediment in the rainy season. The land here consists of sand, silt, clay and mud.
Division
Depending on the geographical features within this plain, three parts can be distinguished: the plain of the upper Ganges, the middle and lower.
The first part is limited by a 300-meter contour near Shivalik in the north, the border of the peninsula in the south, and the course of the Yamuna River in the west. Its eastern border is undefined and has become a controversial topic among geographers.
This plain has a length of about 550 km in the east-west direction and a width of about 380 km in the north-south direction. The height of the Indo-Gangetic plain in this part ranges from 100 to 300 m above mean sea level. The average land slope is about 25 cm per km.
The plain of the middle course of the Ganges occupies the eastern part of Uttar Pradesh and Bihar. Its length is about 600 km from east to west and almost 330 km in the north-south direction. Its northern and southern borders are clearly defined by the foothills of the Himalayas and the edge of the peninsula, respectively. Its western and eastern borders are rather poorly defined, the plain quietly begins in the west of the valley of the upper Ganges and quietly passes into the lower in the east.
As such, it is a transitional region. However, several attempts have been made to distinguish between the western and eastern borders of this transition zone. It is quite low, not a single part of it rises above 150 m above sea level.
The plain of the lower Ganges includes the Kishanganj province of Purnea district in Bihar, all of West Bengal (excluding Purulia district and the mountainous regions of Darjeeling county) and most of Bangladesh. Its length is about 580 km from the foot of the Himalayas in the north to the Bay of Bengal in the south and almost 200 km from the Chotanagpur Highlands in the west to the border with Bangladesh in the east. Its width varies greatly and narrows to 16 km between the Rajmahal hills and the border of Bangladesh.
The formation of the delta is about two-thirds of this plain. It is the largest delta in the world. The slope here is only 2 cm per km. Two thirds of the area is below 30 m above sea level.