Hint: Northern Plains are considered alluvial soil which is formed by the deposits of sediments brought down by the river. According to relief features of the Northern Plains, it can be divided into four regions. Northern Plain is regarded as the youngest physiographic feature of India.
Complete step by step answer:
The Northern Plains, also called as Indo Gangetic plain is extensive north to the central section of the Indian subcontinent. It is formed by three river systems that are Ganga, Indus, and the Brahmaputra along with their tributaries. As we move westwards of Northern Plains, it becomes relatively drier and where it integrates to Thar (Great Indian) Desert.
The Northern Plains can be divided into four regions on the basis of relief features
Bhabar: After going down from the mountain a narrow belt is formed which is 8-16 km by the deposition of river pebbles. This belt is called Bhabar. It lies parallel to the Shiwalik range. Streams again appear in this region and make it a wet and marshy region.
Terai: Terai region lies towards the south of the Bhabar belt with a width of 10-20 km. In this region, the streams reappear and make wet, swampy, and marshy regions. This region was full of forest and wildlife but it was cleared to accommodate the migrants from Pakistan (present-day Bangladesh) and to create agricultural land.
Bhangar: Bhanger is the largest part of Northern Plains and it is composed of old alluvial soil (deposited before the river changed its course). It lies above the floodplain and resembles a terrace. Locally, the soil of this region is called Kankar.
Khadar: This floodplain is formed by younger alluviums called Khadar. The soil of this region is renewed every year and it is highly fertile. This region is considered ideal for intensive agricultural activities.
Note: Northern Plain on the basis of variations can be divided into four regions Bhabar, Terai, Bhanger, and Khadar. Khadar is considered to be relatively younger alluvium. The largest part of the Northern Plains is Bhagar, considered to be old alluvial soil.