3.1.5. Eastern Hills and Mountains or Purvanchal

Eastern hills or Purvanchal are part of the Himalayan mountain system. On the southern border of Arunachal Pradesh, the Himalayas take a southerly turn and the ranges are arranged in a north-south direction. They are known by different local names. In the north, they are known as Patkai Bum (Arunachal Pradesh), Naga hills (Nagaland), the Manipur hills (Manipur) and in the south as Mizo or Lushai hills (Mizoram).

Most of these ranges are separated from each other by numerous small rivers. The Barak is an important river in Manipur and Mizoram. The physiography of Manipur is unique by the presence of a large lake known as ‘Loktak’ lake at the centre, surrounded by mountains from all sides. Mizoram which is also known as the ‘Molassis basin’ is made up of soft unconsolidated deposits. Most of the rivers in Nagaland form the tributary of the Brahmaputra. These are low hills, inhabited by numerous tribal groups practicing Jhum cultivation.