Geography of Assam and North-East India
This domain tests regional physiography, climate hazards and resource use in Assam and the north-eastern states.
Physiography
Assam has three divisions: the Brahmaputra valley, an alluvial plain with braided channels and shifting sandbars; the Barak valley in the south, drained by the Barak which becomes the Surma in Bangladesh; and the surrounding hills and plateaus, including the Karbi Anglong plateau, the Meghalaya plateau and the Nagaland–Manipur hills. Majuli, in the Brahmaputra, is the world's largest river island and is shrinking through bank erosion. The region lies in seismic zone V; the earthquakes of 1897 and 1950 reshaped river courses.
Climate
The climate is tropical monsoon. The south-west monsoon from June to September brings very heavy rain, with Mawsynram and Cherrapunji among the wettest places on earth. Floods, bank erosion and landslides are annual hazards; winters are dry and cool.
Resources and conservation
Tea, petroleum, coal, limestone and forests underpin the economy. Protected areas include Kaziranga (one-horned rhinoceros), Manas, Pobitora and Nameri. Key problems are flooding, erosion, deforestation and oil pollution.
Worked example
Explaining Majuli's shrinkage: braided channels shift, so the river attacks the island's banks during high floods; upstream deforestation raises silt load and bed aggradation; the result is loss of land and displacement of villagers.
Traps
- Saying the Barak flows into the Brahmaputra; it flows to Bangladesh.
- Counting the north-east as seven states - there are eight with Sikkim (seven sisters plus one brother).
- Locating Kaziranga on the south bank; it lies mainly on the north bank of the Brahmaputra.