These are the plains which lie to the south of Himalaya's and to the north of the peninsula .It is formed by the depositional work of three major river systems viz.the Indus,the Ganga,the Brahmaputra.This is also known an Indo-Gangetic Brahmaputra plain.This is the largest alluvial tract of the world extending for a length of 3,200 km from the mouth of the Indus to the mouth of the Ganga.
Some characteristics of this plain are:
It is a depositional plain.
It is a largest alluvial tract of the world.