Geography of West Bengal
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The Geography of West Bengal, a state in eastern India, spans the Eastern Himalayas in the north, the Terai-Dooars piedmont, the lateritic Rarh uplands of the southwest, the Gangetic deltaic plain and the mangrove Sundarbans at the head of the Bay of Bengal. The state covers 88,752 km² between 21°25′ N and 27°13′ N, with a north-south extent of approximately 600 km.[citation needed]
Physiographic divisions
The conventional physiographic division of the state separates the Himalayan north, the Terai-Dooars piedmont and the Gangetic deltaic plain.[1] Bandyopadhyay et al. (2015) subdivide the state into nine geomorphological zones: the Darjeeling Himalaya, sub-Himalayan alluvial fans, the Barind uplands, the degenerated Chhotanagpur plateau fringe, the lateritic Rarh, the upper Ganga delta, the reclaimed lower delta, the non-reclaimed mangrove Sundarbans and the Medinipur coastal plain.[1] Elevations range from sea level in the Sundarbans to 3,636 m at Sandakphu on the Singalila Ridge.[2]
Darjeeling Himalaya
The Darjeeling Himalaya occupies about one per cent of the state's area but contains its highest relief.[citation needed] Phyllites and schists predominate around Kalimpong. Gneiss dominates around Darjeeling. The rocks have been intensely sheared by the underthrusting of the Indian plate, producing slope instability and landslide hazard across the hill districts.[2] The Singalila Ridge on the India-Nepal boundary carries Sandakphu (3,636 m), the highest point in West Bengal and Phalut (3,600 m).[citation needed] The Teesta gorge separates the Singalila and Darjeeling ranges to the west from the lower hills around Kalimpong to the east.[citation needed]
Terai, Bhabar and the Dooars
South of the Himalayan front a belt of Bhabar (gravel and boulder fans) and Terai (clay and sand alluvium with a high water table) grades into the Dooars piedmont.[citation needed] The Dooars proper lies between 90 m and 1,750 m elevation across Jalpaiguri, Alipurduar and the northern margin of Cooch Behar.[3]
Rarh, deltaic plain and Sundarbans
The Rarh region of the southwest (Purulia, Bankura, Birbhum, parts of Paschim Bardhaman and Paschim Medinipur) is an undulating laterite-capped erosional surface continuous with the Chota Nagpur plateau.[citation needed] The Bhagirathi separates Rarh to the west from Bagri to the east in Murshidabad.[citation needed] The Sundarbans form a tidally active distal delta of the Ganga-Brahmaputra-Meghna system, simultaneously prograding and eroding. Surface elevations range from 0.5 m to 3 m, with about seventy per cent of the area below 1 m.[citation needed]
Climate
West Bengal's climate varies with relief from tropical wet-and-dry in the deltaic south to subtropical highland in the Darjeeling Himalaya. The India Meteorological Department treats the state under two meteorological subdivisions: Gangetic West Bengal and Sub-Himalayan West Bengal and Sikkim.[4] Four seasons are recognised: winter (December to February), pre-monsoon (March to May, with Kalbaishakhi or Nor'wester thunderstorms in the south), the southwest monsoon (June to September) and the retreating or post-monsoon (October to November).[citation needed] Seventy-five to eighty per cent of annual rainfall falls during the southwest monsoon.[4] Tropical cyclones forming in the Bay of Bengal periodically affect the deltaic and coastal districts.[citation needed]
Rivers and hydrology
Three drainage systems converge in West Bengal. Himalayan rivers including the Teesta, Jaldhaka, Torsa, Raidak and Sankosh drain North Bengal into the Brahmaputra system, while the Mahananda joins the Ganga.[citation needed] The Ganga-Padma-Bhagirathi/Hooghly system dominates central and southern Bengal. At the Farakka Barrage the river splits into the Padma (which crosses into Bangladesh) and the Bhagirathi-Hooghly (which carries the southward flow to the Bay of Bengal through Kolkata and Haldia). Peninsular rivers originating in the Chota Nagpur plateau (the Damodar, Ajay, Mayurakshi, Rupnarayan and Kangsabati) drain the Rarh.[citation needed]
| River | Source | Length total (km) | Length in WB (km) | Catchment total (km²) | Catchment in WB (km²) | Course within West Bengal |
|---|---|---|---|---|---|---|
| Ganga-Padma | Gangotri Glacier, Uttarakhand | 2,575 | 570 | 74,732 | Malda, Murshidabad; splits at Farakka | |
| Bhagirathi-Hooghly | Farakka | 520 | 520 | Murshidabad, Nadia, Hooghly, Howrah, Kolkata, South 24 Parganas | ||
| Teesta | Pahunri and Tso Lhamo, Sikkim | 414 | 142 | 12,159 | Darjeeling, Jalpaiguri, Cooch Behar | |
| Jaldhaka | Bitang Lake, Sikkim | 233 | 4,092 | Kalimpong, Jalpaiguri, Cooch Behar | ||
| Torsa | Chumbi Valley, Tibet | 358 | 99 | 7,486 | Alipurduar, Cooch Behar | |
| Raidak | Bhutan | 50 | 4,852 | Alipurduar, Cooch Behar | ||
| Mahananda | Paglajhora Falls, Darjeeling | 360 | 324 | 20,600 | 11,530 | Darjeeling, Uttar Dinajpur, Malda |
| Damodar | Palamau hills, Jharkhand | 592 | 25,820 | 2,220 | Purulia, Bankura, Paschim Bardhaman, Purba Bardhaman, Hooghly |
The combined catchment of the five major North Bengal rivers (Teesta, Torsa, Jaldhaka, Raidak and Sankosh) within West Bengal is 37,545 km².[5] The Sundarbans tidal network (the Hooghly, Matla, Bidyadhari, Raimangal, Ichhamati and Saptamukhi distributaries with their creeks) covers about 4,260 km² in India, of which 1,700 km² is open water.[6]
The Padma-Ganga and lower Bhagirathi floodplains, with their light well-drained silt-renewed alluvial loams, supplied the agronomic foundation of the historical Bengal ganja economy across both banks of what is now the international border.[original research?] The Indian portion of this belt lies in Murshidabad, Malda, Nadia and the northern fringe of North 24 Parganas (see Cannabis in West Bengal).
Soils
The state's soil cover, classified by the Indian Council of Agricultural Research's National Bureau of Soil Survey and Land Use Planning, comprises six broad families.[7]
- Gangetic (new) alluvium. Neutral to mildly alkaline (pH 7.0–8.2), deep, fertile and high in water-holding capacity. Underlies Murshidabad, Nadia, Hooghly, the Bardhaman districts, North 24 Parganas and much of South 24 Parganas. About 3.5 million hectares of alluvial soils statewide.[citation needed]
- Vindhya (old) alluvium. Derived from Rajmahal and Chotanagpur drainage; mildly acidic (pH 6.0–6.6). Parts of Murshidabad, Birbhum and Purba Bardhaman.
- Lateritic and red soils. Coarse, well-drained, ferruginous and acidic (pH 5.5–6.9), low in organic matter. Purulia, Bankura, Birbhum, parts of Paschim Bardhaman and Paschim Medinipur. The Rarh soil regime.
- Terai and Bhabar soils. Darjeeling foothills, Jalpaiguri, Alipurduar and Cooch Behar. Acidic (pH 6.0–6.6), nutrient-poor on the higher fans. Support tea on the better-drained slopes.[3]
- Coastal saline and alkaline soils. South 24 Parganas (Sundarbans), parts of Howrah and Purba Medinipur. Calcium- and magnesium-rich with decomposed organic matter. Salinity from tidal inundation.
- Mountain (skeletal and colluvial) soils. Darjeeling and Kalimpong. Thin and well-drained, supporting tea on the lower flanks and temperate-forest soils above.
Ecology and forests
West Bengal lies at the junction of three biogeographic provinces: the Eastern Himalaya (a global biodiversity hotspot), the Indo-Gangetic plain and the Deccan Peninsular (via the Chota Nagpur plateau).[citation needed] Four principal forest types are mapped under the Champion and Seth classification:[8][9]
- Tropical moist and dry deciduous Sal forests of the Dooars and Terai. Shorea robusta with Tectona grandis, Bombax ceiba and Lagerstroemia. The Mahananda, Gorumara, Jaldapara, Buxa and Chapramari protected areas lie within this belt.[citation needed]
- Tropical dry deciduous and sal coppice of the plateau fringe. Medinipur, Bankura, Purulia, the Bardhaman districts and Birbhum. Dominated by sal with Butea monosperma, Madhuca longifolia and Diospyros melanoxylon. The Jhargram, Garhbeta and Ayodhya Hill ecosystems fall here.[citation needed]
- Tidal mangrove forests of the Sundarbans. Heritiera fomes (sundari), Excoecaria agallocha (gewa), Avicennia spp., Ceriops decandra (goran) and Phoenix paludosa (hantal). The Sundarban Biosphere Reserve covers 9,630 km² in India and contains the Sundarban Tiger Reserve, Sajnekhali, Lothian and Halliday Island sanctuaries.[citation needed]
- Subtropical broadleaf and temperate forests of the Darjeeling-Kalimpong hills. Quercus, Castanopsis, Michelia, Rhododendron, Magnolia and Tsuga dumosa. The Singalila and Neora Valley National Parks protect the highest reaches.[citation needed]
Recorded forest cover totals 16,901.51 km², or 19.04 per cent of the state's geographic area.[6] The Sundarbans hold about 2,114 km² of dense mangrove forest, the largest single block in India and (combined with the Bangladeshi portion of the same delta) the largest contiguous mangrove forest in the world.[10] Two tiger reserves operate in the state: the Sundarban Tiger Reserve (3,629.57 km², the second-largest tiger reserve in India following the August 2025 area expansion approved by the National Board for Wildlife)[11] and the Buxa Tiger Reserve in the Dooars. Three communities are notified as Particularly Vulnerable Tribal Groups (PVTGs): the Toto, the Birhor and the Lodha.[citation needed]
Agriculture
Agriculture is the principal economic activity in rural West Bengal, employing about half of the state's workforce.[citation needed] The state is the largest producer of rice and jute in India and the second-largest producer of potato and tea.[12][citation needed] Six agro-climatic zones are recognised, corresponding to the hill, Terai-Teesta alluvial, old alluvial, new alluvial, red-and-laterite and coastal-saline divisions of the state.[12]
Administrative geography
West Bengal is administered through five divisions (Presidency, Burdwan, Medinipur, Malda and Jalpaiguri) comprising twenty-three districts as of 1 November 2023.[citation needed] Each division corresponds approximately to a coherent physiographic region: Presidency to the lower deltaic plain; Burdwan to the Rarh and Damodar valley; Medinipur to the southwestern plateau-fringe and coastal plain; Malda to the middle Gangetic plain and Barind uplands; and Jalpaiguri to the sub-Himalayan plains, the Dooars and the Darjeeling Himalaya. On 1 August 2022 the state cabinet approved in principle the creation of seven additional districts (Ichhamati, Basirhat, Sundarban, Bishnupur, Jangipur, Berhampore and Ranaghat), which would raise the total to thirty.[13] These had not been formally constituted as of May 2026.
| District | Division | Area (km²) | Population | Predominant zone |
|---|---|---|---|---|
| Darjeeling | Jalpaiguri | 3,149 | 1,846,823 | Himalayan / Hill |
| Kalimpong | Jalpaiguri | 1,044 | 251,642 | Himalayan / Hill |
| Jalpaiguri | Jalpaiguri | 3,386 | 3,872,846 | Dooars / Terai |
| Alipurduar | Jalpaiguri | 3,383 | 1,491,250 | Dooars / Terai |
| Cooch Behar | Jalpaiguri | 3,387 | 2,819,086 | Terai / north plain |
| Uttar Dinajpur | Malda | 3,140 | 3,007,134 | North alluvial plain |
| Dakshin Dinajpur | Malda | 2,219 | 1,676,276 | Barind / north plain |
| Malda | Malda | 3,733 | 3,988,845 | Gangetic plain / Barind |
| Murshidabad | Presidency | 5,324 | 7,103,807 | Gangetic plain (Bagri / Rarh) |
| Nadia | Presidency | 3,927 | 5,167,600 | New alluvium |
| North 24 Parganas | Presidency | 4,094 | 10,009,781 | Lower delta |
| South 24 Parganas | Presidency | 9,960 | 8,161,961 | Lower delta / Sundarbans |
| Howrah | Presidency | 1,467 | 4,850,029 | Lower delta |
| Kolkata | Presidency | 185 | 4,496,694 | Urban / lower delta |
| Hooghly | Burdwan | 3,149 | 5,519,145 | New alluvium |
| Purba Bardhaman | Burdwan | 5,432 | split 2017 | Rarh / Damodar |
| Paschim Bardhaman | Burdwan | 1,603 | split 2017 | Lateritic / industrial |
| Birbhum | Burdwan | 4,545 | 3,502,404 | Rarh |
| Bankura | Medinipur | 6,882 | 3,596,674 | Plateau fringe |
| Purulia | Medinipur | 6,259 | 2,930,115 | Chhotanagpur plateau |
| Purba Medinipur | Medinipur | 4,736 | 5,095,875 | Coastal plain |
| Paschim Medinipur | Medinipur | 6,308 | Jhargram split 2017 | Plateau fringe |
| Jhargram | Medinipur | 3,037 | split 2017 | Sal forest / lateritic |
References
- ↑ 1.0 1.1 Bandyopadhyay, S., Kar, N.S., Das, S. & Sen, J., "River Systems and Water Resources of West Bengal: A Review," Geological Society of India Special Publication 3, 2015, pp. 63–84.
- ↑ 2.0 2.1 Geological Survey of India, Geology and Mineral Resources of West Bengal, Miscellaneous Publication No. 30, Pt. IV, Vol. 1(i), Kolkata: GSI, 2012.
- ↑ 3.0 3.1 Mukhopadhyay, M., Bantawa, P., Das, A., Sarkar, B., Bera, B., Ghosh, P. & Mondal, T.K., "Sick or Rich: Assessing the Selected Soil Properties and Fertility Status across the Tea-Growing Region of Dooars, West Bengal, India," Frontiers in Plant Science 13, 2022, 950993, PMCID PMC9808038.
- ↑ 4.0 4.1 India Meteorological Department, Climatological Tables of Observatories in India 1981–2010, New Delhi: IMD, 2015.
- ↑ 5.0 5.1 Government of West Bengal, Irrigation & Waterways Directorate, Annual Flood Report 2016, Kolkata: WBIWD, 2017.
- ↑ 6.0 6.1 Forest Survey of India, India State of Forest Report 2019, Volume II: State Reports — West Bengal, Dehradun: FSI, 2019, pp. 294–308.
- ↑ Mondal, S. & Mukhopadhyay, P., "A Geographical Study on District Level Soil Status of West Bengal," Journal of Emerging Technologies and Innovative Research 5(8), 2018, pp. 627–636.
- ↑ Champion, H.G. & Seth, S.K., A Revised Survey of the Forest Types of India, New Delhi: Government of India Press / Manager of Publications, 1968.
- ↑ Forest Survey of India, Atlas: Forest Type of India, Dehradun: FSI, 2012.
- ↑ Forest Survey of India, India State of Forest Report 2023, Dehradun: FSI, 2024.
- ↑ "Sundarbans Tiger Reserve now India's second largest, after National Board for Wildlife approves Bengal's proposal to increase area," Down to Earth, 21 August 2025.
- ↑ 12.0 12.1 Department of Agriculture, Government of West Bengal, Agricultural Statistics at a Glance, West Bengal, Kolkata: Government of West Bengal, 2023.
- ↑ "CM Mamata to carve out seven new districts in Bengal, total number rises to 30," The Print, 1 August 2022.
- ↑ Office of the Registrar General & Census Commissioner, India, Census of India 2011: West Bengal — District Census Handbooks, New Delhi: Government of India, 2014.