Regional Geography (India and West Bengal)
Regional Geography covers India's physiographic divisions, climate and drainage, plus West Bengal region by region: the Darjeeling Himalaya, the Terai and Duars, the Rarh fringe of the Chhotanagpur plateau, the Ganga–Bhagirathi delta and the Sundarban coast.
India-scale rules
- Four physiographic divisions: Himalaya, Northern Plains, Peninsular Plateau, and Coastal Plains with islands.
- Tropical monsoon climate: south-west monsoon June–September; retreating monsoon October–November; winter rain in north-west India from western disturbances.
- Peninsular rivers are old, graded and seasonal; Himalayan rivers are antecedent, perennial and cut deep gorges.
West Bengal specifics
- Darjeeling Himalaya: very heavy rainfall (often above 300 cm), tea on well-drained slopes, landslides where forest is cleared.
- Terai (moist, tall grass, south) and Duars (tea gardens, north) lie at the Himalayan foot.
- Rarh: older, lateritic, undulating plateau fringe; the Damodar, once the "Sorrow of Bengal", drains it.
- Delta: the Bhagirathi–Hooghly distributary; rice and jute; the Sundarban is tidal halophytic mangrove, home of the Royal Bengal tiger.
Worked example
Why does Chennai get rain in October–November while Kolkata gets it in June–September? Under the south-west monsoon the Coromandel coast lies leeward of the Western Ghats and stays dry. In October the monsoon withdraws, the ITCZ moves south, and the north-east monsoon gathers moisture over the Bay of Bengal and strikes the Coromandel coast first. Kolkata, on the windward delta, receives the south-west monsoon burst from June.
Traps
Do not swap Terai and Duars, and do not place Rarh inside the delta. The Damodar, not the Teesta, is the old "Sorrow of Bengal". Barind is old alluvium in North Bengal, not a plateau.