Northern Plain of India :

This great plain extends in between the Himalayas and the Peninsular plateau extending from Punjab Plains to Assam Valley. It is 2400 km. long and 240 to 320 km wide. Its average height is 150 metres. It covers an area of 7.5 lakh sq. km.

It is an alluvium filled trough. It has been formed by the deposition of sediments brought from the Himalayas by the Ganga, Sutlej and by the. rivers of the peninsular plateau. Therefore it is called an alluvial plain. It is a dead flat lowland. The maximum height is 283 metres near Ambala. It has fertile alluvial soils of Khadar and Bangar. It is agriculturally a very productive part of India.

Division of Northern Plain :

1. Bhabar and Terai. It is a long, narrow zone along the foothills. It is a pebble studded zone. Swampy areas occur in Terai.
2. Punjab Plain. This plain has a slope in the South-West direction. It has been formed by the deposition of sediments by Ravi, Beas and Sutlej rivers. Chos (Seasonal streams) cause soil erosion in the foothills of Shivalik.
3. Ganga Plain. This plain has been formed by the deposition of sediments brought by the Ganga and its tributaries. It can be divided into three regions :
   (1) upper Ganga plain,
   (2) middle Ganga plain and
   (3) the lower Ganga plain. It occupies an area of about 3.5 lakh sq. km. Sunderban Delta is formed in the lower Ganga plain. This fertile delta is the largest delta of the world.
4. Brahmaputra Plain. This plain is situated in the eastern part and is often known as Assam valley. The Brahmaputra river forms a large delta in Bangladesh. The river forms a narrow, deep gorge called ‘Dihang gorge’ which is 12,000 metres deep.