Physiography of Assam

The present physiography of Assam is geologically of recent origin. It is characterized by diverse features such as floodplains, marshes and beels, scattered hillocks, folded hill ranges and old plateaus. The erosion and depositional process intensified by heavy rainfall and frequent seismic movements play a dominant role in shaping the physiography of Assam. However, Assam can be divided into three major physical divisions:

1. The Brahmaputra valley in the North
2. The hills of Karbi Anglong and North Cachar and
3. The Barak valley or Surama Valley in the South

1. The Brahmaputra valley in the North

The almond shaped Brabmaputra Valley is the result of depositional works of the river Brahmaputra and its tributaries. It is a flat plain with a length and breadth of 725 km and 80-100 km respectively. The Brahmaputra Valley covers a substantial part of the State and most of the important towns and cities of Assam are situated in this valley.

2. The hills of Karbi Anglong and North Cachar

These hills divides the two valleys of Assam. These hills rise abruptly from the surrounding plains and merge with the Barail range of hills, which is the highest in Assam. The height of this region varies from 1000 m to 1200 m above mean sea level. Dense forests and rare wildlife are the common features of this region.

3. The Barak valley or Surama Valley in the South

The Barak Valley is named after the river Barak. Like Brahmaputra, the river Barak has also created a fertile valley which is bordered by North Cachar Hills, Manipur and Mizoram. The Barak Valley is a amazing plain interspersed with low hills and lakes.