Comprehensive University Study Notes on Indian Geography

Geographical Location and Extension of India

  • Global Position: India is located entirely in the Northern Hemisphere relative to the Equator and in the Eastern Hemisphere relative to the prime meridian. More specifically, it is situated in the North-Eastern Hemisphere.

  • Continental Context: Within Asia, India is located in the southern part of the continent, often referred to as the center of the Indian Subcontinent.

  • Indian Subcontinent Members: The subcontinent includes India, Pakistan, Nepal, Bhutan, Bangladesh, Sri Lanka, and the Maldives.

  • Area and Rank:

    • Total Area: Approximately 32,87,263 km232,87,263\,km^2.

    • Global Share: India occupies 2.4%2.4\% of the world's total land area.

    • Rank: India is the 7th7^{th} largest country by area. The countries larger than India in order are Russia, Canada, USA, China, Brazil, and Australia.

  • Population:

    • According to the 2011 Census, India housed approximately 17.5%17.5\% of the world's population.

    • As per the United Nations Population Fund (UNFPA) State of World Population Report released in April 2023, India has surpassed China to become the most populous country in the world.

  • Geographical Dimensions:

    • North to South Length: 3214 km3214\,km (from Ladakh to Kanyakumari).

    • East to West Width: 2933 km2933\,km (from Arunachal Pradesh to Gujarat).

  • Latitudinal and Longitudinal Extent:

    • Latitudinal Range (Mainland): From 8∘4′ N8^\circ 4'\,N to 37∘6′ N37^\circ 6'\,N.

    • Longitudinal Range: From 68∘7′ E68^\circ 7'\,E to 97∘25′ E97^\circ 25'\,E.

  • Important Latitudinal Line (Tropic of Cancer): The line at 23.5∘ N23.5^\circ\,N latitude passes almost through the middle of the country across 8 states: Gujarat, Rajasthan, Madhya Pradesh, Chhattisgarh, Jharkhand, West Bengal, Tripura, and Mizoram.

  • Standard Time Meridian (IST): The 82.5∘ E82.5^\circ\,E longitude determines Indian Standard Time. It passes through Mirzapur near Allahabad in Uttar Pradesh. IST is 5.5 hours5.5\,hours ahead of Greenwich Mean Time (GMTGMT). It passes through 5 states: Uttar Pradesh, Madhya Pradesh, Chhattisgarh, Odisha, and Andhra Pradesh.

  • Extreme Points:

    • Northernmost: Indira Col (Ladakh near Siachen Glacier).

    • Southernmost (Mainland): Cape Comorin (Kanyakumari, Tamil Nadu).

    • Southernmost (Overall): Indira Point (Great Nicobar Island), formerly known as Pygmalion Point.

    • Easternmost: Kibithu (Anjaw district, Arunachal Pradesh).

    • Westernmost: Guhar Moti (Kutch, Gujarat).

  • Boundaries and Coastline:

    • Land Boundary: 15,106.7 km15,106.7\,km.

    • Coastline (Updated): According to government data from April 29, 2025, using new satellite technology, the total coastline length (including islands) is 11,998.81 km11,998.81\,km. Gujarat has the longest coastline among states.

  • Maritime Zones (UNCLOS):

    • Territorial Sea: Extends to 12 nautical miles12\,nautical\,miles (NMNM) from the coast; provides full sovereignty.

    • Contiguous Zone: Extends to 24 NM24\,NM; allows rights over customs, sanitation, and immigration.

    • Exclusive Economic Zone (EEZ): Extends to 200 NM200\,NM; provides rights for fishing, mineral/oil extraction, and scientific research.

    • Conversion: 1 nautical mile≈1.852 km1\,nautical\,mile \approx 1.852\,km.

  • Channels and Straits:

    • 8 Degree Channel8\,Degree\,Channel: Separates Minicoy (Lakshadweep) from the Maldives.

    • 9 Degree Channel9\,Degree\,Channel: Separates Minicoy from the rest of the Lakshadweep islands.

    • 10 Degree Channel10\,Degree\,Channel: Separates the Andaman Islands from the Nicobar Islands in the Bay of Bengal.

    • Great ChannelGreat\,Channel: Located between Great Nicobar and Sumatra (Indonesia).

    • Palk StraitPalk\,Strait: Located between Tamil Nadu (India) and Sri Lanka.

  • International Land Borders:

    • Longest: Bangladesh (4096 km4096\,km).

    • Shortest: Afghanistan (106 km106\,km on the Durand Line, currently in POK).

    • Nepal (Capital:KathmanduCapital: Kathmandu): Shares borders with Uttarakhand, Uttar Pradesh, Bihar, West Bengal, and Sikkim.

    • Bhutan (Capital:ThimphuCapital: Thimphu): Shares borders with Sikkim, West Bengal, Assam, and Arunachal Pradesh.

    • Myanmar (Capital:NaypyidawCapital: Naypyidaw): Shares borders with Arunachal Pradesh, Nagaland, Manipur, and Mizoram.

Physical Subdivisions of India

  • Major Regions: India is divided into 6 geomorphic regions:

    1. The Northern Mountains (Himalayas).

    2. The Great Northern Plains.

    3. The Peninsular Plateau.

    4. The Indian Desert.

    5. The Coastal Plains.

    6. The Islands.

  • Area Distribution by Landform:

    • Plains: 43%43\%.

    • Plateaus: 27.7%27.7\%.

    • Hills: 18.6%18.6\%.

    • Mountains: 10.7%10.7\%.

  • The Northern Mountains (Himalayas):

    • Formation: Approximately 200 million years200\,million\,years ago, the supercontinent Pangea split into Angara Land (Laurasia) in the north and Gondwanaland in the south. Between them was the Tethys Sea. The Indian peninsula broke from Gondwanaland and collided with the Eurasian plate (Angara Land). The sediments of the Tethys Sea folded and rose, creating the Himalayas. They are classified as Young Fold Mountains, and their height continues to grow.

    • Dimensions: Length is approximately 2500 km2500\,km. Width varies from 400 km400\,km in the west to 160 km160\,km in the east. Average height is 6000 m6000\,m.

    • Latitudinal Classification (North to South):

      • Trans Himalayas: Comprises the Karakoram, Ladakh, Zanskar, and Kailash ranges. Karakoram is called the "Backbone of Asia." K2 (Godwin Austen) at 8611 m8611\,m is the highest peak in India (located in POK). Major glaciers include Siachen, Hispar, and Baltoro. The Indus River flows between the Ladakh and Zanskar ranges. Mount Rakaposhi in the Ladakh range is the steepest peak in the world.

      • Great Himalayas (Himadri): Permanent snow home. Extends from Nanga Parbat (West) to Namcha Barwa (East). Contains the world's highest peaks: Mount Everest (8848.86 m8848.86\,m, called Sagarmatha in Nepal and Chomolungma in Tibet), Kanchenjunga (highest peak fully within Indian territory, located in Sikkim), Makalu, and Dhaulagiri.

      • Lesser/Middle Himalayas: Known for hill stations (Shimla, Manali, Musuri). Regional names: Pir Panjal (J&K), Dhauladhar (HP), Nag Tibba (UK), Mahabharata (Nepal). Features beautiful valleys like Kashmir and Kullu between Great and Lesser ranges.

      • Shiwalik (Outer Himalayas): Youngest and lowest range. Characterized by grasslands called 'Duns' (e.g., Dehradun) in the west and 'Duars' (e.g., Haridwar) in the east.

    • Regional Classification (West to East by Rivers):

      • Punjab/Kashmir Himalayas: Between Indus and Satluj (560 km560\,km). Known for Saffron (Zaffran) cultivation.

      • Kumaon Himalayas: Between Satluj and Kali (320 km320\,km). Peaks: Nanda Devi, Kedarnath.

      • Nepal Himalayas: Between Kali and Teesta (800 km800\,km). Tallest and longest section; home to Mount Everest.

      • Assam Himalayas: Between Teesta and Brahmaputra/Dihang (720 km720\,km).

Major Mountains and Hills

  • Definitions: A landform under 2000 feet2000\,feet (600 m600\,m) is a hill; above that, it is a mountain. A plateau is a tableland (elevated but flat-topped).

  • North-East Hills:

    • Arunachal Pradesh: Dafla, Miri, Abor, and Mishmi (named after local tribes). Patkai Bum forms the natural boundary with Myanmar.

    • Nagaland: Mount Saramati (3826 m3826\,m) is the highest peak.

    • Manipur: Lemakol and Manipur Hills surround the Imphal Valley.

    • Mizoram: Lushai Hills (Mizo Hills); highest peak is Phawngpui (Blue Mountain).

    • Meghalaya: Garo, Khasi, and Jaintia hills. Nokrek is the highest point of Garo. Mawsynram and Cherrapunji (wettest places) are in the Khasi Hills.

    • Assam: Mikir (Karbi Anglong), Rengma, and Barail ranges.

  • Central and South India:

    • Aravali Range: Oldest fold mountain world-wide, now a residual mountain. Extends 670 km670\,km from Gujarat to Delhi. Highest Peak: Guru Shikhar (1722 m1722\,m) in Mount Abu. Raisina Hill (President's House) is part of this range.

    • Vindhya Range: Block mountains dividing North and South India. Highest peak: Sadbhavna Shikhar (Goodwill Peak). Extends to Kaimur (Bihar) and Parasnath (JH).

    • Satpura Range: Block mountains between Narmada and Tapti rivers. Highest peak: Dhupgarh (1352 m1352\,m) in Mahadeo Hills. Maikal range's highest peak is Badargarh, though Amarkantak is often cited.

    • Western Ghats (Sahyadri): Continuous range, biodiversity hotspot. Highest peak: Anaimudi (2695 m2695\,m) in Annamalai Hills (Kerala). North to South order of peaks: Salher, Kalsubai, Mahabaleshwar (Maharashtra); Kudremukh, Mullayanagiri (Karnataka); Doddabetta (Nilgiris); Anaimudi; Cardamom Hills.

    • Eastern Ghats: Discontinuous, eroded by rivers. Highest peak: Jindagada Peak (1690 m1690\,m) in Andhra Pradesh. Some sources still list Mahendragiri (1501 m1501\,m) in Odisha.

    • Meeting Point: Western and Eastern Ghats meet at the Nilgiri Hills.

    • Islands: Highest peak of Andaman & Nicobar is Saddle Peak (732 m732\,m) in North Andaman. Highest point of Lakshadweep is Mount Narcho on Agatti Island.

The Great Northern Plains

  • Formation: Formed by the deposition of alluvium by the Indus, Ganga, and Brahmaputra river systems over millions of years.

  • Attributes: Covers 7 lakh km27\,lakh\,km^2. Length is 2400 to 3200 km2400\text{ to }3200\,km. Largest alluvial plain in the world.

  • Geomorphic Structure:

    1. Bhabar: 8-10 km wide belt of pebbles/stones at the foothills of Shiwaliks. Highly porous; small rivers disappear underground here. Unsuitable for agriculture.

    2. Terai: Located south of Bhabar (10-20 km wide). Rivers reappear, creating marshy, damp land. Highly fertile; known for Paddy, Sugarcane, and Wheat. Home to dense forests.

    3. Bangar: Older alluvium. Elevated above flood levels, so it doesn't receive fresh soil annually. Less fertile than Khadar; contains calcareous deposits (Kankar).

    4. Kadar: Newer alluvium. Received fresh flood deposits annually. Highly fertile; predominant in Eastern UP, Bihar, and WB.

    5. Delta: Triangular deposition at river mouths. Extension of Khadar. Sundarbans Delta (Ganga-Brahmaputra) is the world's largest.

  • Regional Divisions:

    • Punjab & Haryana Plains: Characterized by 'Doabs' (land between two rivers).

      • Chaj DoabChaj\,Doab: Chenab and Jhelum.

      • Rechna DoabRechna\,Doab: Ravi and Chenab.

      • Bari DoabBari\,Doab: Beas and Ravi.

      • Bist DoabBist\,Doab: Beas and Satluj.

      • Sindh Sagar DoabSindh\,Sagar\,Doab: Jhelum and Indus.

    • Ganga Plains: Divided into Upper (Western UP), Middle (Eastern UP, Bihar – features the Kosi river), and Lower (West Bengal).

    • Rajasthan Plains: West of Aravalis. Divided by the 25 cm rainfall line25\,cm\,rainfall\,line into Thar Desert (world's most densely populated desert) and Rajasthan Bangar (fertile). Key river: Luni.

    • Brahmaputra Plains: Located in Assam; high rainfall region. Home to Majuli, the world's largest river island.

The Peninsular Plateau

  • Origin: Oldest part of India, part of ancient Gondwanaland. Triangular in shape.

  • Malwa Plateau: Western MP and SE Rajasthan. Formed of volcanic lava (basaltic rocks) with black soil. Called Hadoti Plateau in Rajasthan. Rivers: Chambal, Betwa, Shipra.

  • Bundelkhand Plateau: UP and MP border. Granite and Gneiss rocks; rugged terrain. Highest point: Siddhababa Peak.

  • Chota Nagpur Plateau (Ruhr of India): Primarily in Jharkhand. Second largest plateau in India. Highest peak: Parasnath (Jain pilgrimage). Wealthy in minerals:

    • Jaduguda: Uranium.

    • Hazaribagh/Koderma: Mica.

    • Singhbhum: Iron ore/Copper.

    • Damodar Valley: Coal (Jharia, Raniganj, Bokaro).

  • Meghalaya Plateau: Eastern extension of the peninsula, separated by the Rajmahal-Garo Gap. Contains Garo, Khasi, Jaintia hills. Highest peaks: Shillong Peak, Nokrek.

  • Deccan Plateau: South of Narmada. Formed during the Cretaceous period by volcanic eruptions (Deccan Trap). Predominantly black (Regur) soil suitable for cotton.

    • Karnataka Plateau: Highest peak: Mullayanagiri. Bababudan hills famous for coffee. Kudremukh for iron ore.

    • Telangana Plateau: Highest peak: Doli Gutta. Hyderabad is located here on the banks of the Musi River.

    • Rayalaseema Plateau (AP): Rain-shadow region; very low rainfall. Rich in Barites.

    • Maharashtra Plateau: Called the "Cotton Belt of India." Highest peak: Kalsubai.

  • Chronological Order (West to East): Malwa →\rightarrow Bundelkhand →\rightarrow Baghelkhand →\rightarrow Chota Nagpur.

Coastal Plains of India

  • Western Coastal Plains (Submergent): Between Western Ghats and Arabian Sea. Narrow (sometimes only 10 km10\,km). Characterized by deep, indented shores favoring natural harbors (Mumbai, Kandla, Mormugao). Rivers form Estuaries instead of deltas due to high speed.

    • Kathiawar Coast (Gujarat): Kutch to Daman. Features Kandla Port (Deendayal Port) and Alang (world's largest ship-breaking yard).

    • Konkan Coast: Daman to Goa. Rivers: Pinjal, Zuari, Mandovi.

    • Kannada/Canara Coast: Goa to Mangalore. Narrowest part (8 km8\,km). Shravati river forms Jog Falls. Known for cashew, coffee, and pepper.

    • Malabar Coast (Kerala): Mangalore to Kanyakumari. Famous for 'Kayals' (Backwaters/Lagoons) created by sandbars. Vembanad and Ashtamudi are key lakes. Home to the Nehru Trophy Snake Boat Race. Soil contains Monazite sand (Thorium source).

  • Eastern Coastal Plains (Emergent): Between Eastern Ghats and Bay of Bengal. Wide and level due to massive river deltas (Mahanadi, Godavari, Krishna, Kaveri).

    • Utkal Coast (Odisha): Subarnarekha River to Mahanadi Delta. Features Chilika Lake (largest saltwater lagoon in India) and Abdul Kalam Island (Wheeler Island - missile testing site).

    • Northern Circars (AP): Chilika to Pulicat Lake. Includes Kolleru and Pulicat lakes. Visakhapatnam Port is protected by the Dolphin's Nose hill. Sriharikota island houses the Satish Dhawan Space Centre (ISRO).

    • Coromandel Coast (TN): Pulicat to Kanyakumari. Known as the "Rice Bowl of South India" (Kaveri Delta). Unique rainfall pattern: receives rain from North-East (Retreating) Monsoon in Oct-Nov, while the rest of India is dry.

Drainage Systems: River Networks

  • Indus River System:

    • Source: Bokhar Chu Glacier near Mt. Kailash (Tibet).

    • India Entry: Demchok (Ladakh).

    • Tributaries (Right): Shyok, Nubra, Gilgit, Kabul.

    • Tributaries (Left - Panchnad): Jhelum, Chenab (largest), Ravi, Beas (entirely in India), Satluj (enters via Shipkila Pass).

    • Indus Water Treaty (1960): Pakistan uses 80%80\% of Western rivers (Indus, Jhelum, Chenab); India uses 80%80\% of Eastern rivers (Ravi, Beas, Satluj).

  • Brahmaputra River System:

    • Source: Angsi/Chemayungdung Glacier (Tibet).

    • Names: Yarlung Tsangpo (Tibet), Dihang/Siang (Arunachal), Brahmaputra (Assam), Jamuna (Bangladesh).

    • Major Features: Majuli Island (largest river island), Bhupen Hazarika Setu (on Lohit River).

  • Ganga River System:

    • Formation: Meeting of Bhagirathi and Alaknanda at Devprayag.

    • Length: 2525 km2525\,km (Longest in India). Passes through 5 states: UK, UP, Bihar, JH, WB.

    • Attributes: Self-purifying due to Bacteriophage virus. National River (2008). Gangetic Dolphin is the National Aquatic Animal.

    • Panch Prayag:

      1. Vishnuprayag: Alaknanda + Dhauliganga.

      2. Nandprayag: Alaknanda + Nandakini.

      3. Karnaprayag: Alaknanda + Pindar.

      4. Rudraprayag: Alaknanda + Mandakini.

      5. Devprayag: Alaknanda + Bhagirathi.

    • Tributaries: Yamuna (longest, source: Yamunotri), Son (South bank), Kosi (Sorrow of Bihar), Damodar (Sorrow of Bengal).

  • Peninsular Rivers:

    • East Flowing (Delta forming): Mahanadi, Godavari (Dakshin Ganga/Vridha Ganga), Krishna, Kaveri (Evergreen; Dakshin Bharat ki Ganga), Vaigai, Tamraparni.

    • West Flowing (Estuary forming): Luni (disappears in Kutch), Sabarmati, Mahi (crosses Tropic of Cancer twice), Narmada (longest west-flowing; flows through rift valley), Tapti, Mandovi, Periyar.

Dams, Lakes, and Waterfalls

  • Significant Dams:

    • Tehri (UK): Highest (260.5 m260.5\,m) – on Bhagirathi.

    • Hirakud (Odisha): Longest (25.8 km25.8\,km) – on Mahanadi.

    • Bhakra (HP): Highest Gravity Dam (226 m226\,m) – on Satluj.

    • Sardar Sarovar (GJ): On Narmada.

    • Idukki (Kerala): Largest Arch Dam.

  • Significant Lakes:

    • Wular (J&K): Largest freshwater lake.

    • Chilika (Odisha): Largest saltwater lagoon/coastal lake.

    • Sambhar (RJ): Largest inland salt lake.

    • Chalamu (Sikkim): Highest lake.

    • Vembanad (Kerala): Longest lake.

    • Lonar (MH): Crater lake from a meteorite.

    • Loktak (Manipur): Floating National Park (Keibul Lamjao).

    • Roopkund (UK): Skeleton lake.

  • Significant Waterfalls:

    • Kunchikal (Karnataka): Highest (455 m455\,m) – on Varahi river.

    • Jog/Gersoppa (Karnataka): On Shravati river.

    • Chitrakoot (Chhattisgarh): "Niagara of India" – on Indravati river.

    • Dhuandhar (MP): On Narmada river.

Soils and Agriculture

  • Soil Types (ICAR): Classified into 8 types. Top 4 by area: Alluvial →\rightarrow Red →\rightarrow Black →\rightarrow Laterite.

    • Alluvial Soil: Most fertile (43%43\%). Divided into Bangar (Old) and Khadar (New).

    • Black Soil (Regur): Volcanic origin. Best for Cotton (Cotton soil). High water retention.

    • Red Soil: Red due to Ferric Oxide. Good for Millets.

    • Laterite Soil: Formed by leaching in high rainfall (>200 cm>200\,cm) areas. Used for making bricks, tea, coffee, and cashew.

  • Agricultural Seasons:

    • Rabi: Sown Oct-Nov, Harvested Mar-Apr (Wheat, Barley, Gram, Mustard).

    • Kharif: Sown Jun-Jul, Harvested Nov-Dec (Rice, Maize, Cotton, Bajra).

    • Zaid: Mar-Jun (Watermelon, Cucumber).

  • Agricultural Revolutions: Green (Food grains - MS Swaminathan), White (Milk - Verghese Kurien), Blue (Fish), Yellow (Oilseeds), Pink (Shrimp/Onion), Black (Petroleum).

Climate and Meteorology

  • Classification: Tropical Monsoon Climate. Determined by Altitude, Mountains, Latitude, and Distance from Sea.

  • South-West Monsoon (Jun-Sept): Enters via Kerala. Branches into Arabian Sea and Bay of Bengal branches.

    • Mawsynram (Meghalaya) receives highest rainfall due to funnel-shaped hills.

    • Punjab is the only state receiving rain from both branches.

  • Retreating Monsoon (Oct-Nov): Blows from land to sea. Causes heavy rain on the Coromandel Coast (Tamil Nadu).

  • Western Disturbances: Moisture from Mediterranean Sea brought by Jet Streams. Causes winter rain in NW India (Punjab/Haryana - called Maavat) and snow in Himalayas. Acts as a 'Tonic' for Rabi crops.

National Parks, Tiger Reserves, and Wetlands

  • National Parks (NP): 106 NPs exist as of 2025.

    • First: Jim Corbett (Helly NP), Uttarakhand (19361936).

    • Largest: Hemis NP (Ladakh) – Snow Leopards.

    • Smallest: South Button Island (Andaman).

    • Floating: Keibul Lamjao (Manipur) – Sangai Deer.

  • Tiger Reserves (TR): 58 TRs as of 2025.

    • First: Jim Corbett (19731973).

    • Largest: Nagarjunsagar-Srisailam (AP/Telangana).

    • Smallest: Bor (Maharashtra).

    • 58th: Madhav TR (MP).

  • Ramsar Sites (Wetlands): 96 sites as of December 2025.

    • Largest: Sundarbans (WB).

    • Smallest: Renuka (HP).

    • Highest: Tso Moriri (Ladakh).

    • 96th: Silsehd Lake (Rajasthan).

    • Wetland Cities (20252025): Indore and Udaipur.

Census 2011 and Infrastructure

  • Census 2011: Total population was 121.08 crore121.08\,crore.

    • Density: 382 persons/km2382\,persons/km^2.

    • Literacy: 74.04%74.04\% (male: 82.14%82.14\%, female: 65.40%65.40\%).

    • Sex Ratio: 943943 females per 10001000 males.

    • Most Populous State: Uttar Pradesh. Least: Sikkim.

    • Highest Density: Bihar (11061106). Lowest: Arunachal Pradesh (1717).

  • Major Ports: 13 major ports.

    • Kandla (Deendayal): Tidal port, free trade zone.

    • Mumbai: Largest natural port.

    • Visakhapatnam: Deepest and land-locked.

    • Chennai: Oldest artificial port.

    • Kolkata (Shyama Prasad Mukherjee): Only major riverine port.

  • Minerals:

    • Iron Ore: Bailadila (Chhattisgarh), Kudremukh (Karnataka).

    • Copper: Khetri (Rajasthan).

    • Gold: Kolar (Karnataka).

    • Diamonds: Panna (MP), Golconda (AP).

    • Mica: Koderma (JH) – "Mica Capital."