Geography
Comprehensive notes for BPSC Combined Competitive Examination — covering Physical Geography, Bihar Geography, Economic Geography, World Geography, and Environment & Ecology. All facts sourced from standard references (NCERT, Census 2011, Survey of India).
1. Physical Geography of India
India is located in South Asia, occupying the greater part of the Indian subcontinent. It is surrounded by the Indian Ocean on the south, the Arabian Sea on the southwest, and the Bay of Bengal on the southeast. The Himalayas form the northern boundary, while the Western Ghats and Eastern Ghats border the Deccan plateau.
BPSC Key Facts — India's Position
- Latitude: 8°4'N to 37°6'N (mainland; Andaman Islands extend to about 6°N)
- Longitude: 68°7'E to 97°25'E
- Total area: 3.28 million sq km (7th largest country in the world)
- Land boundary: approximately 15,200 km
- Coastline (mainland): approximately 6,100 km; total with islands: 7,516 km
- Standard Meridian: 82°30'E (passes through Mirzapur, UP)
- Tropic of Cancer (23°30'N) passes through 8 states: Gujarat, Rajasthan, MP, Chhattisgarh, Jharkhand, West Bengal, Tripura, Mizoram
- Southernmost point (mainland): Kanyakumari; India's southernmost point including islands: Indira Point (Great Nicobar)
1.1 The Himalayas
The Himalayas (Sanskrit: "abode of snow") form the world's highest mountain system and stretch along India's northern frontier for approximately 2,400 km. They were formed through the collision of the Indian tectonic plate with the Eurasian plate — a process that began about 50 million years ago and continues today, making the Himalayas among the youngest fold mountains on Earth. They run in a northwest-to-southeast arc, covering the countries of Pakistan, India, Nepal, Bhutan, and China.
The Himalayas are conventionally divided into three parallel ranges:
Greater Himalayas (Himadri)
The innermost and highest range. Average elevation exceeds 6,000 m. Contains all the world's highest peaks including Mt. Everest (8,849 m, Nepal-China border), K2 (8,611 m, in Pakistan-administered territory), Kanchenjunga (8,586 m, India-Nepal border — highest peak within India's boundaries), Nanda Devi (7,816 m — highest entirely within India), and Kamet (7,756 m). The range is permanently covered with snow and contains many glaciers, including Gangotri and Siachen (longest glacier in the Himalayas and second longest in the world outside the polar regions at about 72 km). Passes in this range include Zoji La, Bara Lacha La, and Shipki La.
Middle Himalayas (Himachal or Lesser Himalayas)
Located south of the Greater Himalayas, with an average elevation between 3,700 m and 4,500 m. Contains the famous valley systems of Kashmir, Kangra, and Kullu. Hill stations such as Shimla, Mussoorie, Nainital, Darjeeling, and Ooty (Nilgiris) are situated here. The Pir Panjal and Dhauladhar ranges are part of this zone. Patkai Hills, Naga Hills, and Mizo Hills are extensions in the northeast.
Outer Himalayas (Siwalik Hills)
The southernmost and lowest range, with average elevation of 900–1,200 m. Width varies from 10 to 50 km. Composed of unconsolidated sediments (conglomerate, sandstone, silt). Contains the longitudinal valleys called "Duns" (e.g., Dehradun, Patli Dun, Kotli Dun). The Siwaliks are highly prone to erosion and landslides.
The Himalayas act as a major climatic barrier, preventing cold Central Asian winds from entering the Indian subcontinent and forcing monsoon winds to rise and precipitate on the windward side. They are also the source of India's major river systems — the Indus, Ganga, and Brahmaputra systems.
1.2 Northern Plains (Indo-Gangetic Plains)
The Northern Plains form one of the world's largest and most fertile alluvial plains, stretching about 2,400 km from Punjab in the west to Assam in the east. They were formed by the deposits of three river systems — the Indus, the Ganga, and the Brahmaputra — over millions of years. The plains vary in width from about 150 km in the east to about 300 km in the west.
Sub-divisions of the Northern Plains
- Punjab Plains: Formed by the Indus and its five tributaries (Jhelum, Chenab, Ravi, Beas, Sutlej). The "doabs" (land between two rivers) are agriculturally significant.
- Ganga Plains: The largest sub-division, extending from Delhi to the Bengal delta. Includes the states of UP, Bihar, and West Bengal. Characterized by a level topography, fertile alluvial soil, and dense population.
- Brahmaputra Plains: Located in Assam, known for annual floods that deposit fresh nutrients. Forms a narrow strip in the northeast.
- Bhangar: Old alluvium, found at higher elevations in the plains; slightly coarser texture; contains calcareous nodules called "kankars."
- Khadar: New alluvium deposited annually by flood waters in the floodplains; more fertile than bhangar; renewed every year.
- Terai: Narrow belt of marshy/swampy land south of the Siwaliks; receives heavy rainfall; formerly forested, now largely converted to agriculture.
- Bhabhar: Pebble-strewn narrow belt (8–16 km wide) south of the Siwaliks where rivers lose themselves in the pebble deposits before re-emerging in the Terai.
1.3 The Peninsular Plateau
The Peninsular Plateau is the oldest and most stable landmass of India, forming part of the ancient Gondwanaland. It is composed of ancient crystalline, igneous, and metamorphic rocks. The average elevation is 600–900 m above sea level. It is bounded by the Western Ghats on the west and the Eastern Ghats on the east.
- Deccan Plateau: The main plateau region south of the Narmada and Tapti rivers. The lava-covered basaltic region in the northwest is called the Deccan Trap — formed by massive volcanic eruptions about 65 million years ago and covering an area of about 500,000 sq km (Maharashtra, parts of MP, Gujarat, Karnataka).
- Central Highlands: North of the Narmada, includes Malwa Plateau, Chota Nagpur Plateau, and Bundelkhand.
- Western Ghats (Sahyadri): Continuous range running from the Tapi River to Kanyakumari, about 1,600 km long. Average elevation: 1,000–1,500 m. Highest peak: Anamudi (2,695 m, Kerala) — highest peak in India south of the Himalayas. The Western Ghats are a UNESCO World Heritage Site and one of the world's eight "hottest" biodiversity hotspots.
- Eastern Ghats: Discontinuous range along the eastern coast, cut by rivers flowing into the Bay of Bengal. Average elevation: 600 m. Highest peak: Jindhagada Peak (1,690 m, AP). Less prominent than the Western Ghats.
- Nilgiri Hills: Junction of Western and Eastern Ghats; contains Ooty (Udhagamandalam).
- Chota Nagpur Plateau: Located in Jharkhand and adjoining areas; rich in minerals (coal, iron ore, copper, mica, bauxite).
BPSC Exam Point — Coastal Plains
- Western Coastal Plain: Narrow strip (50–80 km wide) between Western Ghats and Arabian Sea. Sub-divided into: Konkan Coast (Maharashtra-Goa), Kanara Coast (Karnataka), Malabar Coast (Kerala). Known for backwaters (kayals) in Kerala.
- Eastern Coastal Plain: Wider (100–130 km) between Eastern Ghats and Bay of Bengal. Sub-divided into: Coromandel Coast (Tamil Nadu) and Northern Circar (Andhra Pradesh-Odisha). Contains major river deltas (Mahanadi, Godavari, Krishna, Kaveri).
1.4 Soils of India
The Indian Council of Agricultural Research (ICAR) has classified Indian soils into 8 major types. Understanding soil types is essential for both agriculture and BPSC examinations.
| Soil Type | Also Known As | Main States | Key Crop | Characteristic |
|---|---|---|---|---|
| Alluvial Soil | Khadar / Bhangar | UP, Bihar, Punjab, Haryana, WB, Assam | Rice, wheat, sugarcane, jute | Most fertile; lacks nitrogen, humus; richest in India |
| Black Soil | Regur / Cotton Soil | Maharashtra, MP, Gujarat, AP, Karnataka | Cotton, wheat, jowar, linseed | Self-ploughing; high water retention; rich in Ca, K, Mg; poor in N, P |
| Red and Yellow Soil | — | Odisha, Tamil Nadu, parts of AP, Jharkhand | Groundnut, millets, tobacco | Red colour due to iron diffusion; yellow when hydrated; poor in N, P, humus |
| Laterite Soil | — | Kerala, Karnataka, Maharashtra (ghats), Odisha, Assam hills | Tea, coffee, cashew, rubber | Formed under tropical conditions with heavy rain and high temp; leached; poor in lime, N, P |
| Arid / Desert Soil | — | Rajasthan, SW Punjab, S Haryana | Bajra, jowar (with irrigation) | Sandy; low humus; saline; high evaporation; kankar layer impedes water infiltration |
| Forest / Mountain Soil | — | Himalayan slopes, NE states, Western Ghats | Tea (lower slopes), wheat, maize, barley | Loamy, silty in valleys; coarse in upper slopes; rich in humus; acidic |
| Saline / Alkaline Soil | Usar / Reh / Kallar | UP, Punjab, Haryana, Bihar, Rajasthan | Poor for most crops | Formed in dry climate; contains NaCl, MgSO4; unproductive without reclamation |
| Peaty / Marshy Soil | — | Kerala, Tamil Nadu coast, Bihar, Odisha | Rice | Heavy; highly organic; black colour; saline; low humus content outside Kerala |
1.5 Natural Vegetation of India
India's diverse climate and topography support an extraordinary variety of vegetation types. India has about 47,000 plant species and is one of the 17 mega-biodiverse countries in the world.
Tropical Evergreen Forests
Found in regions receiving more than 200 cm of annual rainfall — the Western Ghats (above 1,500 m), northeastern hills, Andaman & Nicobar Islands. Trees do not shed leaves simultaneously; hence they appear ever-green. Multiple canopy layers. Species include: ebony, mahogany, rosewood, rubber, cinchona. Dense undergrowth. Not commercially very important due to inaccessibility and species diversity.
Tropical Deciduous Forests (Monsoon Forests)
The most widespread forests in India; cover about 64% of total forest area. Shed leaves in the dry season to reduce water loss. Two types: (a) Moist Deciduous — 100–200 cm rainfall; teak, sal, shisham, sandalwood, bamboo, arjun; found in Jharkhand, WB, UP, AP, Maharashtra. (b) Dry Deciduous — 70–100 cm rainfall; more open; found in central India and parts of peninsular India.
Thorn / Scrub Forests
Found in areas with less than 70 cm annual rainfall — Rajasthan, SW UP, Haryana, Punjab, Gujarat. Plants have thorns, waxy leaves, long roots. Species: acacia, euphorbias, cacti (some introduced). Leaves small or absent to reduce transpiration.
Montane Forests
Found on the slopes of the Himalayas and other mountain ranges. Altitude determines vegetation: 1,000–2,000 m: deciduous (oak, chestnut); 1,500–3,000 m: temperate coniferous (pine, deodar, cedar, silver fir, spruce); above 3,600 m: alpine meadows (junipers, rhododendrons, mosses, lichens); above 4,500 m: permanent snow (no vegetation).
Mangrove Forests (Littoral / Tidal Forests)
Found in the tidal, swampy deltas of the Ganga, Mahanadi, Godavari, Krishna, Kaveri — and on the Andaman Islands. Sundarbans (WB and Bangladesh) is the world's largest mangrove forest and a UNESCO World Heritage Site. Species: Sundri (gives Sundarbans its name), agar, rhizophora. Trees have aerial roots (pneumatophores) for gas exchange in waterlogged soil. Provide coastal protection against storms.
1.6 Climate of India
India has a tropical monsoon type of climate with three main seasons: Summer (March–May), Southwest Monsoon (June–September), and Winter (October–February). The climate is influenced by several factors:
Factors Controlling India's Climate
- Latitude: The Tropic of Cancer divides India into tropical (south) and sub-tropical (north) zones. Southern India has a hotter climate throughout the year.
- Altitude: Higher elevations experience cooler temperatures. The Himalayas experience alpine climates while coastal areas remain warm.
- Distance from the Sea: Coastal areas have moderate temperatures (maritime influence); interior regions experience extreme temperatures (continental influence).
- Western Ghats: Act as an orographic barrier; windward side (west) receives heavy monsoon rainfall; leeward side (east — rain shadow) receives less.
- Monsoon Winds: The SW monsoon (June–September) brings 75–90% of India's total annual rainfall. The NE monsoon affects the Coromandel coast in winter (October–December).
- Jet Streams: The Sub-tropical Westerly Jet Stream controls winter weather in northern India. The Somali Jet (low-level) helps drive the SW monsoon.
- Western Disturbances: Extra-tropical cyclones originating over the Mediterranean Sea that bring winter rainfall to north India (beneficial for rabi crops).
BPSC: Rainfall Distribution
- Highest rainfall in India: Mawsynram (Meghalaya) — about 11,871 mm per year (world record holder); nearby Cherrapunji (Sohra) also records among world's highest.
- Lowest rainfall: Jaisalmer (Rajasthan) — about 8–9 cm annually; Leh also very low.
- Bihar receives about 1,200 mm annually, mainly from the SW monsoon (June–September).
- "Loo" — hot, dry, dusty wind blowing in May–June over the plains of Punjab, Haryana, UP, and Bihar.
- "Nor'westers" (Kalbaisakhi / Bordoisila) — violent pre-monsoon storms affecting WB and Assam; beneficial for tea, jute.
- "Mango Showers" — pre-monsoon rainfall in Kerala and Karnataka; helps mango ripening.
2. Indian Rivers
India's river system is one of the most extensive in the world. Rivers are classified into two broad groups based on their origin and character: (a) Himalayan Rivers and (b) Peninsular (Deccan) Rivers. The Himalayan rivers are perennial, fed by both glacial meltwater and monsoon rainfall. The Peninsular rivers are largely rain-fed and tend to be seasonal.
2.1 Himalayan River Systems
The Indus System: The Indus River originates near Mansarovar Lake in Tibet (China) at an elevation of about 5,180 m. It flows northwest through Ladakh (India), then enters Pakistan through the Hindukush ranges. Total length is about 3,180 km (one of the longest in Asia). Its main tributaries on the left bank include Zaskar, Shyok, Nubra; on the right bank: Jhelum, Chenab, Ravi, Beas, Sutlej (the famous five rivers of Punjab — "Panj Ab" means "five waters"). Under the Indus Waters Treaty (1960), India controls the eastern rivers (Ravi, Beas, Sutlej) and Pakistan controls the western rivers (Indus, Jhelum, Chenab).
The Ganga System: The Ganga is India's most important river in cultural, economic, and ecological terms. It originates at Gangotri Glacier in Uttarakhand (the stream emerging from the snout of the glacier is called Bhagirathi). The Ganga proper begins at Devprayag where Bhagirathi meets Alaknanda. Total length: about 2,525 km. Falls into the Bay of Bengal via the Sundarbans delta, the world's largest delta.
Major Tributaries of the Ganga
- Yamuna: Longest tributary; originates at Yamunotri; joins Ganga at Prayagraj (Triveni Sangam). Major sub-tributaries: Chambal (Rajasthan), Betwa (MP), Ken, Sind, Tons.
- Ghaghra (Karnali): Originates in Tibet; major tributary of Ganga joining near Chhapra (Bihar).
- Gandak (Narayani): Originates in Nepal; joins Ganga at Sonpur (near Hajipur, Bihar).
- Kosi: Originates in Nepal; famous for frequent course changes; called "Sorrow of Bihar." Joins Ganga near Kursela (Bihar).
- Son: Major right-bank tributary; originates near Amarkantak (MP); joins Ganga near Patna (at Arrah/Dinapur area).
- Chambal: Tributary of Yamuna; originates near Mhow (MP); famous for ravine topography and Chambal Sanctuary (gharial).
- Mahananda: Right-bank tributary in Bihar/WB; joins Ganga near Farakka.
- Ramganga: Left-bank tributary joining near Kannauj (UP).
The Brahmaputra System: The Brahmaputra originates in Tibet (China) near Mansarovar Lake as "Tsangpo" and is one of the world's longest rivers at about 2,900 km. It enters India through Arunachal Pradesh (as the Dihang/Siang), then flows through Assam as the Brahmaputra. It creates the largest river island in the world — Majuli (Assam). Joins the Ganga in Bangladesh (becomes Jamuna) and flows to the Bay of Bengal as the Meghna. Major tributaries in India: Subansiri, Jia Bharali, Manas, Sankosh (left bank); Dibang, Lohit, Barak (right bank).
2.2 Peninsular River Systems
Eastward-flowing rivers (into Bay of Bengal): These rivers have well-developed deltas and are generally shorter than the Himalayan rivers.
| River | Length (km) | Origin | States | Outfall | Special Feature |
|---|---|---|---|---|---|
| Mahanadi | 858 | Sihawa plateau, Chhattisgarh | CG, Odisha | Bay of Bengal (delta near Cuttack) | Hirakud Dam (longest earthen dam); "Vena of Odisha" |
| Godavari | 1,465 | Trimbakeshwar (near Nashik), Maharashtra | MH, TS, AP | Bay of Bengal | Longest peninsular river; "Dakshin Ganga" (Ganga of the South) |
| Krishna | 1,400 | Mahabaleshwar, Maharashtra | MH, KA, AP | Bay of Bengal | Nagarjuna Sagar Dam (largest masonry dam) |
| Kaveri (Cauvery) | 800 | Talakaveri (Coorg/Kodagu), Karnataka | KA, TN | Bay of Bengal | "Ganga of the South"; water dispute between KA & TN |
| Pennar | 597 | Nandi Hills, Karnataka | KA, AP | Bay of Bengal | Flows through Nellore |
Westward-flowing rivers (into Arabian Sea): Notable because they flow through rifts/fault valleys (tectonic depressions), not through deltas. They flow fast and are harnessed for hydropower.
| River | Length (km) | Origin | States | Outfall |
|---|---|---|---|---|
| Narmada | 1,312 | Amarkantak (MP) | MP, Maharashtra, Gujarat | Arabian Sea (Gulf of Khambhat) |
| Tapi (Tapti) | 724 | Multai, Betul (MP) | MP, Maharashtra, Gujarat | Arabian Sea (Gulf of Khambhat) |
| Mahi | 583 | Vindhya range (MP) | MP, Rajasthan, Gujarat | Gulf of Khambhat |
| Luni | 495 | Pushkar Lake (Rajasthan) | Rajasthan, Gujarat | Rann of Kutch (disappears in salt flats) |
| Sabarmati | 371 | Aravallis (Rajasthan) | Rajasthan, Gujarat | Gulf of Khambhat (near Ahmedabad) |
2.3 Major Dams and Reservoirs of India
| Dam | River | State | Type / Significance |
|---|---|---|---|
| Bhakra-Nangal | Sutlej | Himachal Pradesh (dam); benefits Punjab, Haryana, Rajasthan | India's tallest gravity dam (226 m); Gobind Sagar reservoir |
| Hirakud | Mahanadi | Odisha | World's longest earthen dam (25.8 km); first large multipurpose dam post-independence |
| Nagarjuna Sagar | Krishna | Telangana / Andhra Pradesh | World's largest masonry dam; Nagarjuna Sagar reservoir |
| Tehri Dam | Bhagirathi (Ganga) | Uttarakhand | India's tallest dam (260 m) and one of the world's tallest; generates about 1,000 MW (later expanded) |
| Sardar Sarovar | Narmada | Gujarat (dam); benefits Gujarat, MP, Rajasthan, Maharashtra | Controversial dam; associated with Narmada Bachao Andolan |
| Mettur Dam | Kaveri | Tamil Nadu | One of the largest dams in India; irrigates TN delta |
| Gandhi Sagar | Chambal | Madhya Pradesh | One of the four Chambal Valley Development projects |
| Tungabhadra Dam | Tungabhadra | Karnataka / Andhra Pradesh border | Joint project; irrigates both states |
3. Bihar — Physical Geography
BPSC Critical: Bihar Basic Facts
- Location: 24°20'38"N to 27°31'15"N latitude; 83°19'50"E to 88°17'40"E longitude
- Area: 94,163 sq km (13th largest state in India)
- Borders: Nepal (North), West Bengal (East), Jharkhand (South), Uttar Pradesh (West)
- Capital: Patna (on the south bank of Ganga; historically "Pataliputra")
- Number of Districts: 38
- Number of Divisions: 9 (Patna, Magadh, Nalanda, Tirhut, Saran, Darbhanga, Kosi, Purnia, Bhagalpur)
- Official Language: Hindi; secondary: Urdu
- State Animal: Gaur (Indian Bison); State Bird: House Sparrow; State Tree: Peepal; State Flower: Marigold (Genda)
- Highest point: Someshwar Hill (Champaran area), approximately 881 m
3.1 Physical Features of Bihar
Bihar is almost entirely a plain state. It can be broadly divided into two physical regions:
North Bihar Plains (Trans-Ganga Plains)
The area north of the Ganga river. This region is part of the Gangetic alluvial plain and is characterized by a flat, low-lying topography. It is extensively drained by the rivers Gandak, Burhi Gandak, Bagmati, Kamla-Balan, Kosi, and Mahananda — all flowing from Nepal (from the Himalayas) in a generally south-to-southeastward direction. The region is highly fertile but extremely flood-prone, especially in the Kosi and Gandak basins. The major ecological feature here is the Terai zone adjoining Nepal in Champaran district, which is home to the Valmiki Tiger Reserve.
South Bihar Plains (Cis-Ganga Plains)
The area south of the Ganga river. This region drains into the Ganga from rivers like Son, Punpun, Falgu, and Phalgu. It is generally more elevated than north Bihar and less affected by floods. The Gaya-Nawada-Aurangabad area forms a transition zone toward the Chota Nagpur Plateau (which is in Jharkhand). The extreme south of Bihar has a fringe of rocky uplands (part of the Kaimur Plateau extending from MP and Jharkhand), with some areas reaching 300–400 m elevation. Patna, the capital, lies on the southern bank of the Ganga.
3.2 Rivers of Bihar
Bihar is a river-dominated state. The Ganga is the master river, and almost all rivers of Bihar are its tributaries or sub-tributaries. Rivers from the north drain from Nepal/Himalayas; rivers from the south drain from the Chota Nagpur and Vindhyan highlands.
BPSC Key: Rivers of Bihar
- Ganga: Enters Bihar at Buxar and exits near Rajmahal (Jharkhand border). The total length of Ganga in Bihar is about 445 km. It is the lifeline of Bihar — navigation, irrigation, and cultural significance. Major cities on the Ganga: Buxar, Patna, Barh, Munger, Bhagalpur.
- Gandak (Narayani): Originates in Nepal (as Kali Gandaki). Enters Bihar at Valmikinagar (West Champaran). Joins Ganga at Sonpur (Saran district), opposite Hajipur. The Gandak Barrage at Valmikinagar is a major irrigation project. About 260 km within Bihar.
- Burhi Gandak: "Old Gandak." Originates in the Someshwar Hills of West Champaran. Passes through Muzaffarpur and Samastipur before joining Ganga near Khagaria. About 320 km long within Bihar.
- Bagmati: Originates in Nepal (near Kathmandu). Enters Bihar at Sitamarhi. Joins Burhi Gandak near Badlaghat (Khagaria). Important in Madhubani and Sitamarhi districts; frequently floods.
- Kamla-Balan: Originates in Nepal. Enters Bihar in Madhubani. Joins Kosi at Nirmali. Causes severe flooding in Madhubani district.
- Kosi (Koshi): Known as the "Sorrow of Bihar" due to its devastating floods. Originates in Tibet, passes through Nepal (where it forms the Kosi Barrage at Hanuman Nagar). Joins Ganga near Kursela (Katihar district). Notorious for its highly mobile meandering — it has shifted its course westward by about 120 km over the past 200 years. The 2008 Kosi flood (breach at Kusaha, Nepal) was catastrophic, affecting millions in Supaul, Madhepura, Saharsa, Araria districts.
- Mahananda: Originates in Darjeeling Hills. Flows through Purnia and Katihar districts of Bihar. Joins Ganga near Manikchak (WB). The Mahananda is the easternmost major river of Bihar.
- Son: Major right-bank (southern) tributary of Ganga. Originates near Amarkantak (MP). Joins Ganga near Arrah/Dinapur (Patna district). Length in Bihar: about 200 km. The Son Barrage at Dehri-on-Son (Rohtas district) is a major irrigation source for south Bihar. Rich in limestone and sand deposits.
- Punpun: Smaller river rising in Palamu Plateau (Jharkhand). Joins Ganga just south of Patna. Historically important (Patna's ancient settlement grew near its confluence).
- Falgu (Phalgu): Formed by the confluence of Lilajan and Mohana rivers near Gaya. Joins Ganga at Fatwa (near Patna). The Falgu is religiously significant — Gaya (a major Hindu pilgrimage center) is located on its banks.
- Sone Canal System: Bihar's most important canal irrigation network, drawing water from the Son River at the Indrapuri Barrage (Rohtas) and Sone Barrage (Dehri). Irrigates parts of Patna, Rohtas, Bhojpur, Nalanda, Gaya districts.
Floods in Bihar — A Recurring Disaster
Approximately 76% of North Bihar's population lives under the threat of flood annually. The main flood-prone rivers are Kosi, Gandak, Bagmati, Kamla-Balan, Burhi Gandak, and Mahananda. North Bihar (Darbhanga, Madhubani, Sitamarhi, Muzaffarpur, Supaul, Madhepura, Saharsa, Khagaria, West & East Champaran) is most severely affected. The Bihar flood of 2008, triggered by the Kosi breach, displaced millions and caused massive economic loss.
3.3 Soils and Climate of Bihar
Soils of Bihar: Bihar's soils are predominantly alluvial, given its position in the Gangetic plain. There is some variation across the state:
- Gangetic Alluvial Soil: The dominant soil type, covering most of the state. Highly fertile, suitable for rice, wheat, maize, and vegetables. Contains adequate amounts of potash and lime but is deficient in nitrogen and phosphorus.
- Terai Soil: Found in the northern strip adjoining Nepal (Champaran). Rich in organic matter; waterlogged in monsoon; good for sugarcane, paddy.
- Bhangar (Old Alluvium): Elevated portions of the plains; coarser texture; contains calcareous nodules (kankar). Found in southern Bihar districts.
- Khadar (New Alluvium): Fresh floodplain deposits; replenished every monsoon; very fertile; found along river banks in north Bihar.
- Sandy Soil: Found in Ganga's southern doabs and river islands (diara land). Low water retention; used for melons, cucumbers, vegetables.
- Calcareous Soil: Found in the southern plateau fringe (Kaimur, Rohtas, Gaya, Nawada); suitable for gram and arhar.
Climate of Bihar: Bihar has a sub-tropical monsoon climate with hot summers, humid monsoons, and mild winters.
| Season | Months | Characteristics |
|---|---|---|
| Summer (Hot Weather) | March–May | Temperatures rise to 40–45°C; "Loo" (hot dry winds) blow from W/NW; dust storms; very low humidity |
| Southwest Monsoon | June–September | 90–100 cm average rainfall; south Bihar gets slightly less than north; humidity very high; major flood season |
| Post-Monsoon / Autumn | October–November | Retreating monsoon; temperatures moderate (25–30°C); lingering humidity |
| Winter (Cold Weather) | December–February | Temperatures fall to 5–10°C (sometimes below 5°C in North Bihar near Nepal border); dense fog; occasional rainfall from western disturbances; beneficial for rabi crops |
Muzaffarpur Earthquake (1934)
The Bihar-Nepal Earthquake of January 15, 1934 was one of the deadliest earthquakes in Indian history. Magnitude: 8.0 (Richter scale). Epicenter: near Munger, Bihar. Caused massive destruction in Muzaffarpur, Munger, Motihari, Darbhanga. Led to formation of temporary lakes. Resulted in significant land level changes. Bihar lies in seismic zone IV (high damage risk) in the northeast and zone III in central and south Bihar.
4. Agricultural Geography
4.1 India's Agricultural Zones
India is primarily an agricultural country — about 60–65% of the population depends on agriculture for livelihood. Agriculture contributes approximately 18–20% of GDP. India is one of the world's largest producers of many agricultural commodities.
| Crop | Type | Leading States | Climate / Soil Requirement |
|---|---|---|---|
| Rice (Paddy) | Kharif | WB, UP, Punjab, Andhra Pradesh, Bihar | High rainfall (150 cm+); high temp; clayey soil; loamy alluvial |
| Wheat | Rabi | UP, Punjab, Haryana, MP, Rajasthan | Cool winters, warm dry spring; loamy/alluvial soil |
| Cotton | Kharif | Gujarat, Maharashtra, Telangana, AP, Punjab | High temp (21–30°C), 50–100 cm rainfall; black regur soil ideal |
| Jute | Kharif | West Bengal (leading), Bihar, Assam, Odisha | Humid climate, 150–200 cm rain, alluvial soil; flooded land |
| Tea | Plantation | Assam, West Bengal (Darjeeling), Tamil Nadu, Kerala | High rainfall (150–200 cm), high humidity, well-drained acidic soil |
| Coffee | Plantation | Karnataka (Coorg/Kodagu), Kerala, Tamil Nadu | Tropical highlands, 150–250 cm rainfall, shade; humid |
| Sugarcane | Kharif / Perennial | UP (leading), Maharashtra, Karnataka, Bihar | Tropical/sub-tropical; 75–150 cm rain; deep fertile loamy soil |
| Groundnut | Kharif | Gujarat (leading), AP, Tamil Nadu, Karnataka | Sandy loam; 50–75 cm rain; warm temp (25–30°C) |
| Mustard (Rapeseed) | Rabi | Rajasthan, UP, Haryana, MP, Bihar | Cool climate; light loamy soil; 25–40 cm rain |
| Maize | Kharif (also Rabi in Bihar) | MP, Karnataka, Bihar, Rajasthan, UP | Warm temp; 60–90 cm well-distributed rainfall; well-drained sandy loam |
Green Revolution (1960s–70s)
Initiated under the guidance of M.S. Swaminathan and Norman Borlaug (Nobel Peace Prize 1970). Introduced High Yielding Varieties (HYVs) of wheat and rice, modern irrigation, chemical fertilizers, and pesticides. Punjab and Haryana benefited most (wheat). Led to food self-sufficiency but raised concerns about groundwater depletion, soil degradation, and regional inequality. Subsequent revolutions: White Revolution (milk, Operation Flood — Dr. Verghese Kurien), Blue Revolution (fisheries), Yellow Revolution (oilseeds).
4.2 Agriculture in Bihar
About 81% of Bihar's population lives in rural areas and a majority depends on agriculture. Bihar is one of India's major agricultural states. The state is divided into agro-climatic zones — north Bihar (humid, prone to floods), south Bihar (drier, dependent on groundwater and canal irrigation).
BPSC: Bihar Crop Calendar
- Kharif crops (sown June–July, harvested Oct–Nov): Paddy (main Kharif crop), Maize (Bihar is one of the top producers; Kosi, Bhagalpur region), Arhar (pigeon pea), Urd, Moong, Jute (northern Bihar), Sugarcane.
- Rabi crops (sown Oct–Nov, harvested March–April): Wheat (main Rabi crop in Bihar), Maize (in some districts — dual season), Mustard (Bhojpur, Rohtas, Kaimur), Gram/Chana, Peas, Masoor, Barley.
- Zaid crops (summer; Feb–May): Vegetables, watermelon, muskmelon (especially on diara/river island land), moong.
- Lichi: Bihar produces about 40% of India's litchi. Muzaffarpur "Shahi Litchi" has a GI (Geographical Indication) tag. Also grown in Vaishali, East Champaran.
- Makhana (Fox Nut/Lotus Seeds): Bihar produces about 85–90% of India's makhana. Darbhanga, Madhubani, Supaul, Sitamarhi are leading producers. Makhana has a GI tag.
- Sugarcane: Important in West Champaran, East Champaran, Muzaffarpur. Bihar has several sugar mills (mostly in north Bihar).
Irrigation in Bihar: Bihar's irrigation network includes:
- Canal Irrigation: The Son Canal System (oldest and most important), Gandak Canal System, Eastern Kosi Canal, Western Kosi Canal, Sone High Level Canal.
- Tube Wells: The most widely used form of irrigation, especially in North Bihar and Patna, Nalanda, Bhojpur districts.
- Ponds and Tanks: Traditional sources, especially in south Bihar plateau fringe (Gaya, Nawada, Aurangabad).
5. Economic Geography
5.1 Industrial Distribution in India
| Industry | Major Centers | Raw Material / Reason |
|---|---|---|
| Iron and Steel | Jamshedpur (Jharkhand), Bhilai (CG), Durgapur (WB), Rourkela (Odisha), Bokaro (Jharkhand), Vijayanagaram (AP) | Proximity to iron ore, coal, water, and transport networks (Chota Nagpur region) |
| Cotton Textiles | Mumbai (leading), Ahmedabad, Surat, Coimbatore, Kanpur | Cotton growing areas (Gujarat, Maharashtra); Mumbai's humid climate; port access |
| Jute Textiles | Kolkata and along the Hooghly River (Hugli belt) | West Bengal produces jute; Kolkata port for export; Hooghly water for retting |
| Silk Textiles | Varanasi (Banarasi silk), Mysuru/Bengaluru (Karnataka), Bhagalpur (Tussar silk), Srinagar (Pashmina) | Traditional craft centers; mulberry cultivation |
| Software / IT | Bengaluru (Silicon Valley of India), Hyderabad (Cyberabad), Chennai, Pune, Gurgaon, Noida | English-speaking workforce, educational institutions, infrastructure |
| Petrochemicals | Mumbai (Trombay), Jamnagar, Vadodara, Chennai, Mathura | Port access; refineries (Jamnagar — world's largest single refinery complex) |
| Cement | Rajasthan (leading), AP, MP, Gujarat, Karnataka | Limestone deposits |
| Automobile | Chennai (Detroit of India), Pune, Gurgaon, Kolkata | Industrial infrastructure; labor; market access |
5.2 Mineral Resources of India
Key Minerals and Their Distribution
- Coal: India has the 4th largest coal reserves in the world. Leading states: Jharkhand (Dhanbad — "Coal Capital of India"), Chhattisgarh, Odisha, West Bengal (Raniganj coalfield — first major coalfield), MP. Major coalfields: Jharia, Bokaro, Raniganj, Talcher, Korba, Singrauli.
- Iron Ore: India has large iron ore reserves. Leading states: Odisha (leading), Chhattisgarh, Jharkhand, Karnataka (Kudremukh). Major mines: Dalli-Rajhara (CG), Bailadila (CG), Singhbhum (JH), Barsua (Odisha).
- Bauxite (Aluminium ore): Odisha (leading), Gujarat, Jharkhand, Maharashtra, MP.
- Mica: Jharkhand (leading — produces most of world's mica at one time), Rajasthan, Andhra Pradesh. Used in electrical and electronic industries.
- Copper: Rajasthan (Khetri — largest copper mine), Jharkhand (Singhbhum), MP.
- Gold: Karnataka (Kolar Gold Fields — historically; now largely exhausted), Andhra Pradesh.
- Petroleum: Assam (Digboi — first oil well in Asia, 1889), Mumbai High (offshore — largest producer), Rajasthan (Barmer), Gujarat (Ankleswar, Khambhat).
- Natural Gas: KG Basin (Krishna-Godavari, AP-Odisha), Mumbai High, Rajasthan.
- Manganese: Odisha (leading), Karnataka, Madhya Pradesh, Maharashtra.
- Limestone: Rajasthan, Madhya Pradesh, Chhattisgarh, Andhra Pradesh; essential for cement industry.
- Diamonds: MP (Panna — India's only diamond mining area of significance).
5.3 Industries in Bihar
Bihar is primarily an agricultural state; large-scale industry is limited. However, several important industries exist:
BPSC: Bihar's Key Industries
- Sugar Industry: Bihar is the 3rd largest sugar producer in India. Major sugar mills in West Champaran, East Champaran, Muzaffarpur, Sitamarhi, Darbhanga, Gopalganj, Siwan, Saran. Bihar had over 25 operating sugar mills (numbers fluctuate with production).
- Silk (Tussar Silk): Bhagalpur is known worldwide as the "Silk City of Bihar." Bihar is India's largest producer of Tassar/Kosa silk. Bhagalpur silk has a GI tag.
- Leather / Footwear: Patna, Hajipur, and Muzaffarpur; significant cottage and small-scale industry.
- Food Processing: Dals, maize processing, makhana processing, lichi processing units in Muzaffarpur and Darbhanga.
- Cement: Dalmianagar (Rohtas district) — one of the earliest and largest cement plants in eastern India (Dalmia Bharat).
- Glass Industry: Sheikhpura district, and Bhagalpur area.
- Tobacco / Bidi: Important cottage industry in Darbhanga and Muzaffarpur regions.
- Handicrafts: Madhubani Painting (GI tag, Mithila art from Madhubani and Darbhanga), Sikki grass products, Tikuli art (Patna), Sujini embroidery (Muzaffarpur).
- Hajipur (EPIP): Export Promotion Industrial Park at Hajipur (Vaishali) is an important industrial zone. Also known for banana processing.
- BIAADA: Bihar Industrial Area Development Authority manages industrial zones at Hajipur, Gaya, Muzaffarpur, Darbhanga, Purnia, Biharsharif, Bhagalpur.
5.4 Transport in Bihar and India
Railways in Bihar:
- Hajipur (Vaishali) is the headquarters of East Central Railway (ECR) — one of India's 18 railway zones.
- Patna Junction is the major railway station of Bihar.
- Mahendrughat and Patna Sahib are important stations near Patna.
- Rajendra Setu (bridge) at Mokama (1959) — first rail-cum-road bridge over the Ganga in Bihar.
- Mahatma Gandhi Setu (1982) at Patna — one of the world's longest river bridges (5.575 km); road bridge over Ganga.
- Digha-Sonpur Bridge — combined rail-and-road bridge, opened 2016.
Roads in Bihar: Bihar has a network of National Highways. NH-19 (formerly NH-2, the Grand Trunk Road) passes through Bihar. NH-28, NH-57, NH-31 are important highways. The Bihar State Highway network connects district headquarters. Roads in rural Bihar are largely unpaved (Pradhan Mantri Gram Sadak Yojana has improved rural connectivity).
Air Transport:
- Patna (Jay Prakash Narayan International Airport) — the main airport; connects to Delhi, Mumbai, Kolkata, etc.; has international connections.
- Gaya International Airport — receives Buddhist pilgrimage flights (India, Thailand, Sri Lanka, Japan, Myanmar); connects to Bodh Gaya.
- Darbhanga Airport — became operational for commercial flights (2020) under UDAN scheme; connects to Delhi, Mumbai.
- Proposed airports: Purnia, Bhagalpur, Muzaffarpur.
Major Indian Ports (for national context):
| Port | Location / State | Notable Features |
|---|---|---|
| Mumbai Port + JNPT (Jawaharlal Nehru Port) | Maharashtra | Largest natural port; JNPT is India's busiest container port |
| Kolkata Port (includes Haldia) | West Bengal | Oldest major port; only major river port (on Hooghly); Haldia is deeper outport |
| Chennai Port | Tamil Nadu | 2nd busiest container port; first artificial harbor in India |
| Visakhapatnam Port | Andhra Pradesh | Deepest landlocked port; major steel and petroleum exports |
| Paradip Port | Odisha | Major iron ore, coal export port |
| Kandla Port (Deendayal Port) | Gujarat | Largest port by tonnage; important after Partition (to replace Karachi) |
| Kochi Port | Kerala | Natural harbor; largest port in the Arabian Sea on India's west coast (after Mumbai); backwater navigation |
| Mangaluru Port | Karnataka | Coffee, cashew, fertilizer |
6. Population Geography
India — Census 2011 Key Data (BPSC Exam Essential)
- Total Population: 121.09 crore (1.21 billion) — 2nd most populous country in the world at the time of Census 2011
- Population Density: 382 persons per sq km
- Annual Growth Rate (2001–2011): 1.64%
- Sex Ratio (2011): 943 females per 1,000 males (improved from 933 in 2001)
- Literacy Rate (2011): 74.04% (Male: 82.14%, Female: 65.46%)
- Most Populous State: Uttar Pradesh (about 19.98 crore)
- Least Populous State: Sikkim
- Highest Population Density: Bihar (1,106 per sq km — highest among large states)
- Lowest Population Density: Arunachal Pradesh (17 per sq km)
- Best Sex Ratio: Kerala (1,084 females per 1,000 males)
- Worst Sex Ratio (large states): Haryana (879), UP
- Highest Literacy: Kerala (94.0%); Lowest: Bihar (63.82%)
Bihar — Census 2011 Key Data
- Total Population: 10.41 crore (104.1 million) — 3rd most populous state
- Population Density: 1,106 per sq km — 3rd highest in India (after West Bengal and Kerala among states; Bihar was actually the highest density state among states without city-states); Note: various sources differ slightly
- Sex Ratio: 918 females per 1,000 males (below national average of 943)
- Child Sex Ratio (0–6 years): 935 girls per 1,000 boys
- Literacy Rate: 63.82% (Male: 73.39%, Female: 53.33%) — one of the lowest in India
- Urban Population: About 11.3% (very low urbanization — most of India's states have higher urban %)
- Decadal Growth Rate (2001–2011): 25.42% (one of the highest in India)
- Population of SC: About 15.9% of total; ST: About 1.3% (very low)
Major Cities of Bihar:
| City | District | Significance |
|---|---|---|
| Patna | Patna | State capital; historical Pataliputra (Mauryan capital); population ~1.7 million (city); on Ganga |
| Gaya | Gaya | Major pilgrimage center (Hindu & Buddhist); Bodh Gaya nearby; Falgu River |
| Bhagalpur | Bhagalpur | "Silk City"; on Ganga; 3rd largest city; ancient Vikramshila university nearby |
| Muzaffarpur | Muzaffarpur | Litchi production center; major commercial hub of north Bihar |
| Hajipur | Vaishali | HQ of East Central Railway; banana production; connected to Patna via Gandhi Setu |
| Darbhanga | Darbhanga | Cultural capital of Mithila; Madhubani painting hub; now has airport |
| Purnia | Purnia | Commercial hub of northeast Bihar; jute processing |
| Arrah | Bhojpur | Historical significance (1857 revolt); agricultural market |
7. World Geography
7.1 Continents and Oceans
| Continent | Area (approx.) | Largest Country | Notable Feature |
|---|---|---|---|
| Asia | 44.6 million sq km (largest) | Russia (partly) | Highest point: Everest; lowest: Dead Sea; most populous |
| Africa | 30.4 million sq km (2nd largest) | Algeria (by area) | Equator passes; Sahara Desert; Nile River; Rift Valley |
| North America | 24.7 million sq km | Canada (by area) | Rocky Mountains; Mississippi River; Great Lakes |
| South America | 17.8 million sq km | Brazil | Amazon River; Andes Mountains; Angel Falls |
| Antarctica | 14.0 million sq km | — | No permanent population; highest average elevation; ice sheet |
| Europe | 10.5 million sq km | Russia (European part) | Alps; Rhine, Danube; lowest population density (excl. Antarctica) |
| Australia/Oceania | 7.7 million sq km (smallest continent) | Australia | Great Barrier Reef; Outback; driest inhabited continent |
World's Major Mountain Ranges
- Himalayas (Asia): Highest range; highest peak Mt. Everest (8,849 m, Nepal-China); fold mountains; geologically young.
- Andes (South America): World's longest mountain range (~7,000 km, along western coast of South America); highest peak: Aconcagua (6,961 m, Argentina) — highest outside Asia.
- Rockies (North America): Extend from New Mexico to Alaska (~4,800 km); form the Continental Divide.
- Alps (Europe): Highest peak: Mont Blanc (4,808 m, France-Italy border); important for winter tourism and hydropower.
- Ural Mountains (Russia): Form the traditional boundary between Europe and Asia; not very high (max ~1,895 m).
- Atlas Mountains (Africa): Northwest Africa (Morocco, Algeria, Tunisia).
- Drakensberg (Africa): South Africa; highest point Thabana Ntlenyana.
7.2 Major Rivers and Deserts of the World
| River | Length (km) | Continent | Outfall | Special Note |
|---|---|---|---|---|
| Nile | 6,650 (approximately) | Africa | Mediterranean Sea | Traditionally called world's longest river; Egypt, Sudan, Ethiopia |
| Amazon | 6,400 (approximately) | South America | Atlantic Ocean | World's largest river by discharge volume; largest rainforest basin |
| Yangtze (Chang Jiang) | 6,300 | Asia | East China Sea | Longest river in Asia; Three Gorges Dam |
| Mississippi-Missouri | 6,275 | North America | Gulf of Mexico | Largest drainage basin in North America |
| Yenisei-Angara | 5,539 | Asia | Arctic Ocean | Russia; drains into Kara Sea |
| Congo (Zaire) | 4,700 | Africa | Atlantic Ocean | World's deepest river; 2nd largest discharge |
| Desert | Location | Area (approx.) | Type |
|---|---|---|---|
| Sahara | North Africa (11 countries) | 9.2 million sq km | Hot desert; world's largest hot desert |
| Arabian Desert | Arabian Peninsula | 2.3 million sq km | Hot desert; includes Rub' al Khali (Empty Quarter) |
| Gobi | China and Mongolia | 1.3 million sq km | Cold desert; stony; source of dinosaur fossils |
| Patagonian | Argentina (South America) | 670,000 sq km | Cold desert; rain shadow of Andes |
| Thar (Great Indian Desert) | Rajasthan (India) & Pakistan | 200,000 sq km | Hot desert; world's most populous desert; Indira Gandhi Canal Project |
| Atacama | Chile (South America) | 105,000 sq km | Driest non-polar desert on Earth |
BPSC: Important Straits, Gulfs, Bays Relevant to India
- Palk Strait: Separates India (Tamil Nadu) from Sri Lanka; shallow water; Rameswaram Island in between; proposed Sethusamudram Ship Canal project.
- Lakshadweep Sea: Part of the Arabian Sea between India and Lakshadweep Islands.
- Gulf of Mannar: Between South India and Sri Lanka; rich in coral reefs; Gulf of Mannar Marine Biosphere Reserve.
- Gulf of Khambhat (Cambay): Northeastern Arabian Sea (Gujarat coast); where Narmada, Tapi, Mahi, Sabarmati rivers empty.
- Gulf of Kutch: Between Kutch peninsula (Gujarat) and Kathiawar; Kandla Port; oil refinery at Vadinar.
- Strait of Hormuz: Between Iran and Oman; most important oil chokepoint in world; crucial for India's oil imports.
- Strait of Malacca: Between Malay Peninsula and Sumatra (Indonesia); crucial for India's trade with East and Southeast Asia.
- Duncan Passage: Between South Andaman and Little Andaman islands.
- Ten Degree Channel: Separates Andaman Islands from Nicobar Islands.
- Eight Degree Channel: Separates Minicoy from Maldives; separates Lakshadweep from Maldives.
- Nine Degree Channel: Within Lakshadweep, separating groups of islands.
8. Environment and Ecology
8.1 Biomes and Ecosystems
Biome
A large naturally occurring community of flora and fauna occupying a major habitat (e.g., tropical rainforest, grassland, tundra, desert). A biome is defined by its climate (temperature and precipitation), not by its location. India has representatives of most major biomes: tropical rainforest, tropical deciduous forest, desert, grassland, alpine/tundra (in high Himalayas), and mangrove.
Ecosystem
A community of living organisms (plants, animals, and microbes) interacting with their physical environment (soil, water, air, climate) as a system. Ecosystems can be terrestrial (forest, grassland, desert) or aquatic (freshwater — pond, lake, river; marine — coral reef, ocean, estuary).
8.2 National Parks and Wildlife Sanctuaries in India
India has an extensive network of protected areas comprising National Parks, Wildlife Sanctuaries, Biosphere Reserves, and Tiger Reserves. As of recent years, there are over 100 national parks and more than 550 wildlife sanctuaries.
Important National Parks — BPSC Context
- Jim Corbett National Park (Uttarakhand): India's oldest national park (established 1936); first Tiger Reserve under Project Tiger (1973); Ramganga River flows through it.
- Kaziranga National Park (Assam): UNESCO World Heritage Site; home to world's largest population of one-horned Indian Rhinoceros; also home to tigers, elephants, wild water buffaloes.
- Sundarbans National Park (West Bengal): Part of the world's largest mangrove forest; UNESCO World Heritage Site; Bengal Tiger, Irrawaddy Dolphin.
- Gir National Park (Gujarat): Only wild habitat of the Asiatic Lion; both National Park and Sanctuary.
- Kanha National Park (MP): Model for wildlife conservation; Tiger Reserve; inspired Kipling's "The Jungle Book."
- Periyar National Park (Kerala): Tiger and Elephant Reserve; Periyar Lake (reservoir) is a focal point.
- Ranthambore (Rajasthan): Famous Tiger Reserve; tiger sightings; Ranthambore Fort within park.
- Bandhavgarh (MP): Highest tiger density; historical white tigers here (no longer wild).
- Manas (Assam): UNESCO World Heritage Site; Project Tiger; Project Elephant; Golden Langur habitat.
- Valley of Flowers (Uttarakhand): UNESCO World Heritage Site; sub-alpine meadows; numerous Himalayan wildflowers.
8.3 Bihar's Protected Areas
BPSC Essential: Protected Areas of Bihar
- Valmiki Tiger Reserve / Valmiki National Park (West Champaran): Bihar's only Tiger Reserve and National Park. Located in the Terai zone near the Nepal border. Area of the Tiger Reserve is about 898 sq km (core + buffer). Named after the sage Valmiki who is said to have composed the Ramayana in this region. Home to Bengal Tiger, Indian one-horned rhino (reintroduced), Asian elephant, leopard, wild boar. The Gandak River flows through the park. Adjacent to Chitwan National Park (Nepal), forming an important transboundary conservation area.
- Vikramshila Gangetic Dolphin Sanctuary (Bhagalpur): A river sanctuary in the Ganga, stretching from Sultanganj to Kahalgaon (about 60 km of river). Established to protect the Gangetic river dolphin (Platanista gangetica), India's national aquatic animal. One of the most important freshwater dolphin sanctuaries in India. The blind Gangetic dolphin is also called "Susu" (from its breathing sound).
- Rajgir Wildlife Sanctuary (Nalanda): Located in the Rajgir hills. Home to leopard, sloth bear, sambhar, spotted deer. Historical and religious significance (Rajgir was the capital of Magadha; Buddha and Mahavira both spent time here).
- Bhimbandh Wildlife Sanctuary (Munger): Located in the Kharagpur hills (Munger district). Known for its hot springs (hence "Bhim"-bandh, associated with the Pandava Bhima). Diverse wildlife including leopard, sloth bear, sambar, nilgai.
- Udayapur Wildlife Sanctuary (West Champaran): Near Nepal border; smaller sanctuary.
- Gautam Buddha Wildlife Sanctuary (Gaya): In the Gaya-Nawada hills area.
- Kaimur Wildlife Sanctuary (Rohtas, Kaimur): Largest wildlife sanctuary in Bihar; extends into UP; leopard, wolf, chinkara, nilgai; historical Rohtasgarh fort within the sanctuary area.
8.4 Environmental Issues
Key Environmental Issues in Bihar
- Floods: Annual floods affect millions; structural causes include deforestation in Nepal, embankment failures, lack of silt management. The Kosi and Gandak have changed course multiple times.
- Deforestation: Bihar has one of the lowest forest cover percentages among Indian states (about 7–9% of its area as per Forest Survey of India reports). Dense forest cover is only in the Champaran Terai, Rajgir hills, and Rohtas-Kaimur plateau.
- Water Pollution: Ganga river pollution (sewage from Patna, Bhagalpur; industrial effluents; burning ghats). The Ganga in Bihar is among the most polluted stretches.
- Air Pollution: Patna frequently features among India's most polluted cities (high PM2.5 and PM10 during winters, partly due to crop stubble burning in Punjab-UP and local sources).
- Drought: South Bihar (Gaya, Aurangabad, Nawada, Jehanabad, Arwal, Sheikhpura, Lakhisarai) is drought-prone; uneven rainfall distribution.
- Arsenic contamination: Groundwater in several north Bihar districts (Bhojpur, Buxar, Patna, Vaishali, Saran, Samaptipur, Begusarai, Khagaria, and others) has dangerously high arsenic levels; major public health concern.
8.5 Wetlands of Bihar
Bihar has several important wetlands (locally called "tal" or "chaur") that provide habitat for migratory and resident birds, especially waterfowl. Important wetlands include:
- Kanwar Lake (Begusarai): Asia's largest freshwater ox-bow lake; an important bird area; a Ramsar Site (wetland of international importance). Home to hundreds of species of migratory birds in winter.
- Nagi and Nakti Dam Bird Sanctuary (Jamui): Declared Important Bird Area; migratory birds.
- Sanjay Gandhi Jaivik Udyan (Patna): City zoo and botanical garden; on the bank of Ganga.
- Chaurs and Tals: Numerous seasonal wetlands in north Bihar (especially Darbhanga, Samastipur, Khagaria, Begusarai districts) that fill during monsoon floods and dry up in summer; critical habitat for fish, birds, and local livelihoods (fishing, lotus cultivation, water chestnut — singhara).
Ramsar Sites in India
Ramsar Convention (1971) is an international treaty for wetland conservation. India is a contracting party. As of recent years, India has over 75 Ramsar sites — the highest number in Asia and among the largest globally by count. In Bihar, Kanwar Lake (Kabar Taal) at Begusarai was designated a Ramsar site. Other famous Ramsar sites: Chilika Lake (Odisha, largest coastal lagoon in India), Bharatpur (Keoladeo, Rajasthan), Wular Lake (J&K), Loktak Lake (Manipur).
9. Maps and Locations — BPSC Focus
9.1 Districts of Bihar — Key Facts
Bihar has 38 districts organized into 9 divisions. The districts bordering Nepal (international boundary) and those bordering other Indian states are frequently asked in BPSC examinations.
Bihar's Border Districts
- Bordering Nepal (North): West Champaran, East Champaran, Sitamarhi, Madhubani, Supaul, Araria, Kishanganj (7 districts)
- Bordering West Bengal (East): Kishanganj, Purnia, Katihar (3 districts)
- Bordering Jharkhand (South): Kaimur, Rohtas, Aurangabad, Gaya, Nawada, Jamui, Banka, Bhagalpur (8 districts)
- Bordering Uttar Pradesh (West): Kaimur, Rohtas, Buxar, Bhojpur, Saran, Siwan, Gopalganj, West Champaran (8 districts)
| Division | Districts | Notable Features |
|---|---|---|
| Patna Division | Patna, Nalanda, Bhojpur, Buxar, Rohtas, Kaimur | State capital; ancient history (Nalanda University, Rajgir, Pawapuri); Son Canal System |
| Magadh Division | Gaya, Nawada, Aurangabad, Arwal, Jehanabad | Bodh Gaya (UNESCO WHS); Buddhist pilgrimage; Maoist-affected areas |
| Tirhut Division | Muzaffarpur, Vaishali, Sitamarhi, Sheohar, East Champaran, West Champaran | Litchi belt; Valmiki Tiger Reserve; Lord Buddha's birthplace area (Lumbini nearby in Nepal) |
| Saran Division | Saran, Siwan, Gopalganj | Gandak basin; Jayaprakash Narayan's birthplace (Siwan); sugarcane |
| Darbhanga Division | Darbhanga, Madhubani, Samastipur | Mithila culture; Madhubani painting; makhana production; Kameshwar Singh Darbhanga Raj |
| Kosi Division | Saharsa, Supaul, Madhepura | Kosi flood zone; 2008 Kosi disaster; Kosi project |
| Purnia Division | Purnia, Katihar, Araria, Kishanganj | Northeast Bihar; jute; tea (Kishanganj); border with WB and Nepal |
| Bhagalpur Division | Bhagalpur, Banka | Silk city; Vikramshila; Gangetic dolphin sanctuary; Mandar Hills |
| Munger Division | Munger, Lakhisarai, Sheikhpura, Jamui, Begusarai, Khagaria | Munger earthquake 1934; Kanwar Lake; Hajipur (ECR); Begusarai refinery (BPCL) |
9.2 Important Mountain Passes of India
| Pass | State / Region | Connects | Significance |
|---|---|---|---|
| Zoji La | Jammu & Kashmir (Ladakh) | Srinagar to Leh | NH-1 (Srinagar–Leh); altitude ~3,528 m; opens in summer only; strategic |
| Rohtang Pass | Himachal Pradesh | Kullu to Lahaul-Spiti | Alt. 3,978 m; Atal Tunnel (Rohtang) bypasses it for all-weather connectivity |
| Bara Lacha La | Himachal Pradesh | Lahaul to Ladakh | On Manali–Leh Highway; alt. 4,890 m |
| Shipki La | Himachal Pradesh | Kinnaur (HP) to Tibet (China) | Sutlej River enters India here; trade point |
| Nathu La | Sikkim | Sikkim to Tibet (China) | Part of old Silk Road; opened for trade (2006); alt. 4,310 m |
| Bom Di La | Arunachal Pradesh | Arunachal to Tawang (NEFA region) | Strategic military importance; 1962 war |
| Banihal Pass (Jawahar Tunnel) | Jammu & Kashmir | Jammu to Srinagar (through tunnel) | Jawahar Tunnel (2.5 km) provides all-weather road link; Banihal alt. 2,832 m |
| Diphu Pass | Arunachal Pradesh | India–Myanmar–China tri-junction area | Tri-junction of India-China-Myanmar; strategic |
9.3 Major Lakes of India
| Lake | State | Type | Significance |
|---|---|---|---|
| Wular Lake | J&K (Jammu & Kashmir) | Freshwater (largest freshwater lake in India) | Jhelum flows through it; Ramsar site |
| Dal Lake | J&K (Srinagar) | Freshwater | Famous for houseboats and tourism; Srinagar's identity |
| Chilika Lake | Odisha | Brackish (coastal lagoon — largest in India, 2nd largest in world) | Ramsar site; migratory birds; Irrawaddy dolphins |
| Sambhar Lake | Rajasthan | Salt lake (largest inland salt lake in India) | Flamingoes; salt production; Ramsar site |
| Loktak Lake | Manipur | Freshwater (largest in NE India) | Famous for "phumdis" (floating islands); Keibul Lamjao National Park (floating park) |
| Vembanad Lake | Kerala | Brackish (longest lake in India) | Kuttanad — "rice bowl of Kerala" is below sea level here; Nehru Trophy Boat Race |
| Pangong Tso | Ladakh (shared with Tibet, China) | Saltwater/brackish; high altitude (4,350 m) | Indo-China border dispute; about 60% in China; 3 Idiots film; Line of Actual Control |
| Kanwar Lake | Begusarai, Bihar | Freshwater (ox-bow lake) | Asia's largest freshwater ox-bow lake; Ramsar site; migratory birds |
9.4 Quick Reference: BPSC Geography MCQ Points
Frequently Asked in BPSC — Quick Facts
- Bihar's longest river: Ganga (about 445 km within Bihar)
- "Sorrow of Bihar": Kosi River (due to devastating floods and frequent course changes)
- Bihar's only national park: Valmiki National Park (West Champaran)
- Bihar's only Tiger Reserve: Valmiki Tiger Reserve (West Champaran)
- HQ of East Central Railway: Hajipur (Vaishali district)
- India's national aquatic animal: Gangetic River Dolphin (Platanista gangetica) — protected in Vikramshila Gangetic Dolphin Sanctuary, Bhagalpur
- Asia's largest freshwater ox-bow lake: Kanwar Lake, Begusarai (Bihar)
- Silk City of Bihar: Bhagalpur (Tussar silk with GI tag)
- Litchi capital: Muzaffarpur (Shahi Litchi with GI tag)
- Bihar produces about 85–90% of India's makhana (fox nut)
- Highest point in Bihar: Someshwar Hill (West Champaran), about 881 m
- Largest district of Bihar by area: Pashchim (West) Champaran (~5,228 sq km)
- Smallest district of Bihar by area: Sheohar (~443 sq km)
- Most populous district (2011): Patna
- India's Standard Meridian (82°30'E) — IST (Indian Standard Time = UTC +5:30 hours) is calculated from this meridian
- Tropic of Cancer in Bihar: does NOT pass through Bihar; Bihar lies entirely north of Tropic of Cancer (23.5°N), whereas Bihar's southern boundary is around 24°20'N
- Bihar's 2011 sex ratio: 918 (below national average of 943)
- Bihar's 2011 literacy rate: 63.82% (one of lowest)
- Godavari: Largest/longest river of peninsular India ("Dakshin Ganga")
- Narmada and Tapi flow westward through rift valleys (fault-bounded troughs)
- Bhakra-Nangal Dam is on Sutlej River (HP); tallest gravity dam in India (226 m)
- Tehri Dam (Uttarakhand) on Bhagirathi River: India's tallest dam (260 m)
- India's coastline: approximately 7,516 km (mainland + islands)
Summary: Key Numbers for BPSC Geography
- India: 28 states + 8 Union Territories (after August 2019 reorganization of J&K)
- India: 7th largest country in the world by area (3.28 million sq km)
- India: 2nd most populous country at time of 2011 census; surpassed China by recent estimates (as of 2023)
- Bihar: 38 districts, 9 divisions, 94,163 sq km, 13th largest state
- Southernmost point of India (mainland): Kanyakumari (Cape Comorin), Tamil Nadu
- Northernmost point of India (undisputed territory): Indira Col, Ladakh (approximately 37°N)
- Easternmost point: Kibithu (Arunachal Pradesh)
- Westernmost point: Guhar Moti (Gujarat, near the Indus estuary)