Pariksha SaathiLesson 5 of 10 · Bihar General Knowledge
Geography of Bihar: Location, Borders and Physical Divisions
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Location and extent
Bihar lies in eastern India in the middle Ganga plain, between latitudes 24°20'10" N and 27°31'15" N and longitudes 83°19'50" E and 88°17'40" E. Its area of 94,163 sq km is about 2.86 per cent of India's area. It is landlocked, roughly rectangular in shape and wider from west to east than from north to south. The Tropic of Cancer does not pass through Bihar; it runs to the south, through Jharkhand.
Neighbours
Bihar shares an international border with Nepal to the north and state borders with West Bengal to the east, Jharkhand to the south and Uttar Pradesh to the west. The Nepal border runs from West Champaran in the west to Kishanganj in the east and is open: under the India-Nepal Treaty of Peace and Friendship of 1950, people cross without passports. The main crossings are Raxaul, facing Birgunj, and Jogbani, facing Biratnagar. Bangladesh does not touch Bihar, though Kishanganj lies close to the narrow Siliguri corridor of West Bengal.
Three physical regions
Geographers divide Bihar into three broad regions: the Shivalik or sub-Himalayan strip in the far north-west, the vast Ganga plain in the middle, and the southern plateau fringe. The Ganga, flowing from west to east, splits the plain into the North Bihar plain and the South Bihar plain, which differ in soil, rivers and flood behaviour.
Shivalik foothills
A narrow hilly belt along the Nepal border in the north of West Champaran forms the only Himalayan part of the state. It includes the Ramnagar Dun and the Someshwar range, which holds the highest point of Bihar. These hills are covered by the forests of Valmiki and receive heavy rain. South of them lies the terai, a damp belt of tall grass and marsh where many streams emerge from under the gravel.
North Bihar plain
Built up by Himalayan rivers such as the Gandak, Burhi Gandak, Bagmati, Kamla, Kosi and Mahananda, this plain is flat, fertile and very flood-prone. It has new alluvium (khadar) near the rivers and older alluvium (bhangar) farther away. It is dotted with chaurs, saucer-shaped depressions that hold water after the rains, and mauns, abandoned river loops or oxbow lakes, of which Kanwar Lake in Begusarai is the best known. The Kosi has built a vast alluvial fan and has shifted westward over the last two centuries. The diara lands are the islands and sandy banks along the big rivers.
South Bihar plain and the plateau fringe
Narrower than the northern plain, the South Bihar plain slopes north towards the Ganga and is crossed by the Son, Punpun, Falgu and Kiul. Along the Ganga between Mokama and Barh lies the tal area, a low basin that floods in the monsoon and grows lentil and gram in winter. The southern edge rises into hills that are outliers of the Vindhyan ranges and the Chota Nagpur plateau: the Kaimur plateau in the south-west, a Vindhyan extension with the Rohtasgarh fort; the Rajgir hills; the Barabar hills; the Kharagpur hills of Munger; and the hills of Jamui, Nawada and Banka. Hot springs at Rajgir (Brahmakund) and at Sita Kund and Bhimbandh in Munger point to deep faults in the rocks.
Earthquakes and people
North Bihar lies close to the zone where the Indian plate pushes under the Himalaya, and areas along the Nepal border are among the most earthquake-prone in India. The Bihar-Nepal earthquake of 15 January 1934 devastated Munger, Darbhanga and Motihari, and another struck north Bihar on 21 August 1988. Census 2011 counted 10,40,99,452 people in Bihar, the third largest after Uttar Pradesh and Maharashtra, with a density of 1,106 per sq km, the highest among states, a sex ratio of 918 and a literacy rate of 61.8 per cent, the lowest among states.
Key facts
- Latitude 24°20'10" N to 27°31'15" N; longitude 83°19'50" E to 88°17'40" E.
- Area 94,163 sq km, about 2.86 per cent of India; landlocked, and wider from west to east than from north to south.
- Neighbours: Nepal (north), West Bengal (east), Jharkhand (south), Uttar Pradesh (west); the Tropic of Cancer does not pass through Bihar.
- Border crossings with Nepal: Raxaul faces Birgunj and Jogbani faces Biratnagar; the border is open under the 1950 India-Nepal treaty.
- Three physical regions: Shivalik foothills (north of West Champaran), the Ganga plain (north and south of the river) and the southern plateau fringe (Kaimur, Rajgir, Kharagpur hills).
- Highest point: the Someshwar range in West Champaran on the Nepal border; the Ramnagar Dun lies in the same Shivalik strip.
- Chaur: saucer-shaped depression; maun: oxbow lake; diara: riverine islands and sandy banks; tal: low basin between Mokama and Barh flooded in the monsoon.
- Kaimur plateau: a Vindhyan extension in the south-west of Bihar, crowned by the Rohtasgarh fort.
- Hot springs: Brahmakund at Rajgir; Sita Kund and Bhimbandh in Munger.
- Census 2011: population 10,40,99,452 (3rd), density 1,106 per sq km (highest among states), sex ratio 918, literacy 61.8 per cent (lowest among states).
Quick revision
24°20'10" N-27°31'15" N, 83°19'50" E-88°17'40" E; area 94,163 sq km (2.86 per cent); Nepal north, West Bengal east, Jharkhand south, UP west; no Tropic of Cancer; Raxaul-Birgunj, Jogbani-Biratnagar; Shivalik strip with Someshwar (highest point) and Ramnagar Dun; North Bihar plain: chaurs, mauns, Kosi fan, diara; South plain: Mokama-Barh tal; Kaimur plateau; hot springs Rajgir, Sita Kund; earthquake 15 Jan 1934; Census 2011 density 1,106, literacy 61.8.