Complete Geography for UPSC, SSC, Railways, Law Entrance and other competitive Exams

PART 1: PHYSICAL GEOGRAPHY

1. Earth and Universe

• Earth is the third planet from the Sun.

• Earth is the fifth-largest planet in the Solar System.

• Shape: Geoid (slightly flattened at poles).

• Age of Earth: Approximately 4.54 billion years.

• Equatorial diameter: 12,756 km (approx.).

• Polar diameter: 12,714 km (approx.).

• Circumference: 40,075 km (approx.).

• Earth’s axis inclination: 23½°.

• Rotation: West to East; takes approximately 24 hours.

• Revolution: 365 days and 6 hours.

• Speed of rotation is maximum at the Equator.

• Earth’s only natural satellite: Moon.

Important lines and circles

Important facts

• Equator divides Earth into Northern and Southern Hemispheres.

• Prime Meridian (0°) passes through Greenwich, UK.

• International Date Line approximately follows 180° longitude.

• 1° longitude = 4 minutes of time.

• IST = GMT + 5 hours 30 minutes.

• Leap year generally occurs every 4 years (century-year exception: divisible by 400).

2. Motions of Earth

Rotation

• Rotation causes day and night.

• Deflection of winds and ocean currents is due to the Coriolis effect.

• Earth rotates from West to East.

Revolution

• Revolution causes seasons along with Earth’s axial tilt.

• Summer Solstice: 21 June (Northern Hemisphere).

• Winter Solstice: 22 December (Northern Hemisphere).

• Spring Equinox: Around 21 March.

• Autumn Equinox: Around 23 September.

• Equinox: Day and night are approximately equal.

3. Interior of Earth

Earth has three major layers:

• Mohorovicic Discontinuity: Crust–Mantle boundary.

• Gutenberg Discontinuity: Mantle–Outer Core boundary.

• Lehmann Discontinuity: Outer Core–Inner Core boundary.

• Lithosphere: Crust + uppermost mantle.

• Asthenosphere: Weak, plastic part of upper mantle.

4. Rocks

Important facts

• Granite: Intrusive igneous rock.

• Basalt: Extrusive igneous rock.

• Coal: Sedimentary origin.

• Marble: Formed from Limestone.

• Slate: Formed from Shale.

• Gneiss: Commonly formed from Granite.

5. Plate Tectonics

• Earth’s lithosphere is divided into tectonic plates.

• Plates move over the asthenosphere.

Types of plate boundaries

1. Convergent: Plates move towards each other; mountains, trenches and volcanoes may form.

2. Divergent: Plates move apart; mid-ocean ridges form.

3. Transform: Plates slide past each other; earthquakes occur.

Major tectonic plates

• Pacific Plate

• Eurasian Plate

• African Plate

• Indo-Australian Plate

• North American Plate

• South American Plate

• Antarctic Plate

Important: Himalayas formed due to collision of the Indian and Eurasian plates.

6. Earthquakes

• Sudden release of energy inside Earth.

• Focus/Hypocentre: Point of origin inside Earth.

• Epicentre: Point directly above the focus on Earth’s surface.

• Seismograph: Records seismic waves.

• Richter Scale: Commonly used magnitude scale; logarithmic.

• Mercalli Scale: Measures observed intensity and damage.

Types of seismic waves

• P-waves: Fastest; travel through solids, liquids and gases.

• S-waves: Travel through solids only.

• L-waves: Surface waves; generally most destructive.

7. Volcanoes

• Active: Erupting or showing signs of activity.

• Dormant: Inactive for a long period but may erupt.

• Extinct: Not expected to erupt again.

Famous volcanoes

8. Mountains, Plateaus and Plains

Mountains

• Fold Mountains: Himalayas, Alps, Andes.

• Block Mountains: Vosges, Black Forest.

• Volcanic Mountains: Mount Fuji, Kilimanjaro.

• Residual Mountains: Aravalli.

Plateaus

• Tibetan Plateau: Highest and largest extensive plateau.

• Deccan Plateau: India.

• Brazilian Plateau: South America.

• Colorado Plateau: USA.

• African Plateau: Africa.

Plains

• Formed mainly by river deposition, erosion or other geological processes.

• Northern Plains of India are alluvial plains.

9. Weathering and Erosion

• Weathering: Breaking down of rocks in situ.

• Erosion: Removal and transportation of materials.

Agents of erosion

• River

• Wind

• Glacier

• Sea waves

• Groundwater

Important landforms

10. Atmosphere

Composition of atmosphere

• Nitrogen: 78%

• Oxygen: 21%

• Argon: 0.93%

• Carbon dioxide: Approximately 0.04% (varies).

Important facts

• Ozone layer absorbs harmful ultraviolet radiation.

• Ozone layer is mainly in the Stratosphere.

• Weather occurs mainly in the Troposphere.

• Atmospheric pressure decreases with altitude.

11. Temperature and Pressure Belts

Global pressure belts

1. Equatorial Low Pressure Belt.

2. Subtropical High Pressure Belt.

3. Subpolar Low Pressure Belt.

4. Polar High Pressure Belt.

Planetary winds

• Trade Winds: Blow towards the Equatorial Low.

• Westerlies: Blow from subtropical highs towards subpolar lows.

• Polar Easterlies: Blow from polar highs towards subpolar lows.

Important local winds

• Loo: Hot, dry wind in northern India.

• Chinook: Warm, dry wind in North America.

• Foehn: Warm, dry wind in Alps.

• Mistral: Cold wind in southern France.

• Sirocco: Hot wind from Sahara towards Mediterranean.

• Harmattan: Dry, dusty wind in West Africa.

12. Humidity and Rainfall

Types of rainfall

1. Convectional: Due to heating and rising air.

2. Orographic: Due to mountains obstructing moist winds.

3. Cyclonic/Frontal: Due to air-mass convergence and fronts.

Clouds

• Cirrus: High, thin clouds.

• Cumulus: Cotton-like clouds.

• Stratus: Layered clouds.

• Nimbus: Rain-bearing clouds.

• Cumulonimbus: Thunderstorms and heavy rainfall.

13. Cyclones

• Hurricane: Atlantic and eastern North Pacific.

• Typhoon: Western North Pacific.

• Cyclone: Indian Ocean and South Pacific.

• Eye: Calm central region.

• Northern Hemisphere cyclones rotate anticlockwise.

• Southern Hemisphere cyclones rotate clockwise.

14. Oceanography

Four major oceans

1. Pacific Ocean – Largest and deepest.

2. Atlantic Ocean – Second largest.

3. Indian Ocean – Third largest.

4. Southern Ocean.

5. Arctic Ocean – Smallest.

Important ocean features

• Mariana Trench: Deepest known oceanic trench.

• Mid-Atlantic Ridge: Underwater mountain range.

• Continental Shelf: Shallow submerged edge of continent.

• Continental Slope: Steep descent beyond shelf.

• Abyssal Plain: Deep, flat ocean floor.

15. Ocean Currents

Warm currents

• Gulf Stream

• Kuroshio

• Brazil Current

• Agulhas Current

• East Australian Current

Cold currents

• Labrador Current

• Canary Current

• Benguela Current

• Humboldt/Peru Current

• California Current

• Oyashio Current

Important facts

• Warm currents generally raise coastal temperatures.

• Cold currents generally lower coastal temperatures.

• Cold currents meeting warm currents often create rich fishing grounds.

• El Niño: Abnormal warming of central/eastern equatorial Pacific.

• La Niña: Abnormal cooling of central/eastern equatorial Pacific.

16. Tides

• Tides are caused mainly by gravitational forces of Moon and Sun.

• Spring Tide: Highest tidal range; Sun, Moon and Earth approximately aligned.

• Neap Tide: Lowest tidal range; Sun and Moon at right angles relative to Earth.

• High Tide: Rise in sea level.

• Low Tide: Fall in sea level.

17. Important Ocean Phenomena

• Tsunami: Giant sea waves caused mainly by undersea earthquakes.

• Coral Reefs: Formed by coral polyps in warm, shallow seas.

• Atolls: Ring-shaped coral reefs enclosing a lagoon.

• Lagoons: Shallow water bodies separated from sea by barriers.

• Estuary: Tidal mouth of a river where freshwater mixes with seawater.

• Salinity: Amount of dissolved salts in seawater; average approximately 35‰.

• Dead Sea: Famous for extremely high salinity.

PART 2: WORLD GEOGRAPHY

18. Continents

Important superlatives

• Largest continent: Asia.

• Smallest continent: Australia.

• Largest country by area: Russia.

• Smallest country: Vatican City.

• Most populous country: India.

• Highest mountain: Mount Everest.

• Longest continental mountain range: Andes.

• Largest hot desert: Sahara.

• Largest desert overall: Antarctic Desert.

• Largest island: Greenland.

• Largest peninsula: Arabian Peninsula.

• Largest bay: Bay of Bengal.

• Largest gulf: Gulf of Mexico.

• Largest inland water body: Caspian Sea.

19. Important Mountains of the World

Important peaks

• Mount Everest: Nepal–China border.

• K2: Karakoram Range.

• Kanchenjunga: India–Nepal border.

• Aconcagua: Andes, South America.

• Kilimanjaro: Tanzania.

• Denali: Alaska, USA.

• Elbrus: Caucasus, Russia.

20. Important Rivers of the World

Important facts

• Nile: Traditionally regarded as the world’s longest river.

• Amazon: World’s largest river by water discharge.

• Yangtze: Longest river in Asia.

• Volga: Longest river in Europe.

• Congo: Crosses the Equator twice.

• Danube: Flows through several European countries.

21. Important Lakes of the World

22. Important Straits and Canals

23. Important Deserts

Exam facts

• Atacama: One of the driest non-polar deserts.

• Sahara: Largest hot desert.

• Gobi: Cold desert.

• Ladakh: Cold desert of India.

24. Important Grasslands

25. Important Countries and Their Capitals

PART 3: INDIAN GEOGRAPHY

26. India: Location and Extent

• India is located in the Northern and Eastern Hemispheres.

• Area: Approximately 3.287 million sq. km.

• 7th largest country by area.

• Population: Largest in the world.

• Latitudinal extent: 8°4′ N to 37°6′ N.

• Longitudinal extent: 68°7′ E to 97°25′ E.

• Standard Meridian: 82°30′ E.

• IST: UTC + 5:30.

• Tropic of Cancer passes through 8 Indian states.

States through which Tropic of Cancer passes (West to East):

1. Gujarat

2. Rajasthan

3. Madhya Pradesh

4. Chhattisgarh

5. Jharkhand

6. West Bengal

7. Tripura

8. Mizoram

India’s neighbours

• Pakistan

• Afghanistan

• China

• Nepal

• Bhutan

• Bangladesh

• Myanmar

• Sri Lanka (maritime neighbour)

• Maldives (maritime neighbour)

Important facts

• Southernmost point of India: Indira Point.

• Southernmost point of mainland India: Kanyakumari.

• Northernmost region: Ladakh.

• Westernmost region: Gujarat.

• Easternmost region: Arunachal Pradesh.

• Largest state by area: Rajasthan.

• Smallest state by area: Goa.

• Most populous state: Uttar Pradesh.

• Least populous state: Sikkim (2011 Census).

27. Physiographic Divisions of India

India has six major physiographic divisions.

1. Himalayan Mountains

• Young fold mountains.

• Formed by collision of Indian and Eurasian plates.

• Three parallel ranges:

  • Himadri: Greater Himalayas.

  • Himachal: Lesser Himalayas.

  • Shiwalik: Outer Himalayas.

2. Northern Plains

• Formed by Indus, Ganga and Brahmaputra river systems.

• Rich alluvial soil.

• Densely populated.

• Important agricultural region.

3. Peninsular Plateau

• Oldest geological landmass of India.

• Rich in minerals.

• Includes Central Highlands and Deccan Plateau.

• Made largely of ancient crystalline rocks.

4. Indian Desert

• Thar Desert.

• Located mainly in Rajasthan.

• Very low rainfall.

• Luni is an important river.

5. Coastal Plains

• Western Coastal Plain: Narrow.

• Eastern Coastal Plain: Generally wider.

• Eastern coast has large river deltas.

6. Islands

• Andaman and Nicobar Islands: Bay of Bengal.

• Lakshadweep: Arabian Sea.

• Barren Island: India’s only confirmed active volcano.

28. Himalayan Ranges

Important mountain peaks

• Kangchenjunga: Highest peak located in India.

• Nanda Devi: Second-highest peak located entirely within India.

• Kamet: Uttarakhand.

• Anamudi: Highest peak of Western Ghats.

• Guru Shikhar: Highest peak of Aravalli Range.

• Doddabetta: Highest peak of Nilgiri Hills.

29. Major Rivers of India

A. Himalayan Rivers

B. Peninsular Rivers

Important facts

• Ganga is formed at Devprayag by Alaknanda and Bhagirathi.

• Brahmaputra is called Tsangpo in Tibet.

• Godavari is called Dakshin Ganga.

• Narmada flows through a rift valley.

• Tapi also flows through a rift valley.

• Most major Peninsular rivers flow eastwards.

• Narmada and Tapi flow westwards.

• Sundarbans Delta: Ganga–Brahmaputra–Meghna system.

30. Important Dams and Multipurpose Projects

31. Indian Lakes

Important facts

• Chilika: Largest brackish-water lagoon in India.

• Wular: One of India’s largest freshwater lakes.

• Sambhar: Largest inland salt lake in India.

• Loktak: Famous for floating phumdis.

• Lonar: Meteorite-impact crater lake.

32. Climate of India

• India has a tropical monsoon climate.

• Monsoon means seasonal reversal of winds.

• Southwest Monsoon brings most of India’s rainfall.

Four main seasons

1. Winter: December–February.

2. Summer: March–May.

3. Southwest Monsoon: June–September.

4. Retreating Monsoon: October–November.

Important facts

• Mawsynram, Meghalaya: Among the world’s wettest places.

• Rajasthan: Arid and semi-arid climate.

• Western Ghats: Heavy orographic rainfall.

• Tamil Nadu receives significant rainfall from Northeast Monsoon.

• Western disturbances bring winter rainfall to northwestern India.

• El Niño can weaken Indian monsoon conditions, but the relationship is not absolute.

• Jet streams influence Indian monsoon circulation.

33. Indian Soils

Important facts

• Black soil: Regur soil; ideal for cotton.

• Alluvial soil: Important for rice, wheat and sugarcane.

• Laterite soil: Develops under high rainfall and leaching.

• Red soil: Red colour due to iron oxides.

• Khadar: New alluvium.

• Bhangar: Old alluvium.

34. Natural Vegetation of India

Important facts

• Sundarbans: Famous for mangroves and Royal Bengal Tiger.

• Teak: Important deciduous tree.

• Sal: Common in northern and central India.

• Deodar: Himalayan conifer.

• Chandan: Sandalwood tree.

• Evergreen forests remain green throughout the year.

35. Agriculture of India

Cropping seasons

Major crops and leading producing states (commonly important)

Note: Crop rankings vary by agricultural year.

Green Revolution

• Increased food-grain production.

• Focused initially on wheat and rice.

• Associated with high-yielding varieties, irrigation and fertilizers.

• M.S. Swaminathan: Father of India’s Green Revolution.

• Norman Borlaug: Father of the Green Revolution.

Other revolutions

• White Revolution: Milk – Verghese Kurien.

• Blue Revolution: Fisheries.

• Yellow Revolution: Oilseeds.

• Golden Revolution: Horticulture and honey.

• Silver Revolution: Egg production.

• Pink Revolution: Commonly associated with meat and poultry processing.

• Brown Revolution: Commonly associated with leather/cocoa or non-conventional energy in different exam contexts; check the context.

36. Minerals and Energy Resources

Important coalfields

• Jharia: Jharkhand.

• Raniganj: West Bengal.

• Bokaro: Jharkhand.

• Talcher: Odisha.

• Korba: Chhattisgarh.

Types of energy

• Conventional: Coal, petroleum, natural gas, hydropower.

• Non-conventional: Solar, wind, tidal, geothermal, biomass.

37. Industries of India

38. Transport in India

Roadways

• Golden Quadrilateral connects Delhi, Mumbai, Chennai and Kolkata.

• North-South Corridor: Srinagar to Kanyakumari.

• East-West Corridor: Silchar to Porbandar.

Railways

• First passenger train: Mumbai to Thane, 1853.

• Indian Railways is one of the world’s largest rail networks.

• Konkan Railway: Important coastal railway route.

Waterways

• National Waterway 1: Ganga–Bhagirathi–Hooghly system.

• National Waterway 2: Brahmaputra.

• National Waterway 3: West Coast Canal in Kerala.

Major ports

• Deendayal (Kandla): Gujarat.

• Mumbai Port: Maharashtra.

• Jawaharlal Nehru Port: Maharashtra.

• Mormugao: Goa.

• New Mangalore: Karnataka.

• Kochi: Kerala.

• Chennai: Tamil Nadu.

• Visakhapatnam: Andhra Pradesh.

• Paradip: Odisha.

• Syama Prasad Mookerjee Port: Kolkata–Haldia system.

PART 4: HUMAN AND ECONOMIC GEOGRAPHY

39. Population Geography

• Population Density = Total Population ÷ Total Area.

• Birth Rate: Live births per 1,000 people annually.

• Death Rate: Deaths per 1,000 people annually.

• Sex Ratio: Females per 1,000 males in India.

• Literacy Rate: Percentage of literate population as defined by census.

• Migration: Movement of people from one place to another.

Types of migration

• Internal: Within a country.

• International: Between countries.

• Rural to Urban.

• Urban to Rural.

• Seasonal Migration.

• Permanent Migration.

Population theories

• Malthusian Theory: Population grows faster than food supply.

• Demographic Transition Theory: Population changes through stages of birth and death rates.

• Optimum Population Theory: Ideal balance between population and resources.

Demographic Transition Model

1. High birth rate and high death rate.

2. High birth rate and declining death rate.

3. Declining birth rate and low death rate.

4. Low birth rate and low death rate.

5. Very low birth rate; ageing or declining population in some countries.

40. Human Settlements

Types

• Rural Settlement: Primarily agriculture and primary activities.

• Urban Settlement: Industry, trade and services.

Rural settlement patterns

• Compact: Houses close together.

• Dispersed: Houses far apart.

• Linear: Along roads, rivers or coastlines.

• Circular: Around a central feature.

• Rectangular: Along intersecting roads.

Urban settlement patterns

• Conurbation: Merging of neighbouring urban areas.

• Megacity: Very large urban agglomeration, conventionally 10 million or more people.

• Metropolitan City: Large urban centre with surrounding influence.

• Satellite Town: Smaller town near a major city.

41. Agriculture: World Geography

Types of agriculture

• Subsistence Agriculture: Production mainly for family consumption.

• Commercial Agriculture: Production for sale.

• Plantation Agriculture: Large-scale single-crop farming.

• Shifting Cultivation: Clearing and cultivating land temporarily.

• Mixed Farming: Crops and livestock together.

• Intensive Farming: High inputs per unit of land.

• Extensive Farming: Large land area with relatively lower inputs per unit.

Important names

• Jhum: Northeast India.

• Milpa: Central America.

• Roca: Brazil.

• Ladang: Southeast Asia.

• Taungya: Southeast Asia.

42. Important Agricultural Regions of the World

• Rice: Monsoon Asia.

• Wheat: Temperate grasslands.

• Mediterranean Agriculture: Grapes, olives, citrus fruits.

• Dairy Farming: Western Europe, northeastern USA.

• Commercial Grain Farming: Prairies and Steppes.

• Plantation Agriculture: Tropical regions.

43. Important Industries of the World

44. Natural Resources

Types

• Renewable: Solar, wind, water, forests.

• Non-renewable: Coal, petroleum, natural gas, minerals.

• Biotic: Forests, animals, fisheries.

• Abiotic: Air, water, land, minerals.

Conservation methods

• Afforestation.

• Rainwater harvesting.

• Soil conservation.

• Watershed management.

• Sustainable agriculture.

• Recycling and reuse.

• Renewable energy development.

PART 5: ENVIRONMENT AND ECOLOGY

45. Ecosystem

• Ecosystem: Interaction between living organisms and their physical environment.

• Biotic Components: Plants, animals, microorganisms.

• Abiotic Components: Air, water, soil, sunlight.

Trophic levels

1. Producers: Green plants.

2. Primary Consumers: Herbivores.

3. Secondary Consumers: Primary carnivores.

4. Tertiary Consumers: Higher-level carnivores.

5. Decomposers: Bacteria and fungi.

Important concepts

• Food Chain: Linear transfer of energy.

• Food Web: Interconnected food chains.

• Ecological Pyramid: Represents number, biomass or energy.

• 10% Law: Only approximately 10% of energy transfers to the next trophic level.

• Biomagnification: Increasing concentration of certain pollutants at higher trophic levels.

• Bioaccumulation: Accumulation of substances within an organism.

46. Biodiversity

• Biodiversity: Variety of life forms.

• Genetic Diversity: Variation within species.

• Species Diversity: Variety of species.

• Ecosystem Diversity: Variety of ecosystems.

Biodiversity hotspots in India

India is part of four biodiversity hotspots:

1. Himalaya.

2. Indo-Burma.

3. Western Ghats–Sri Lanka.

4. Sundaland (Nicobar Islands).

Important conservation terms

• Endemic Species: Restricted to a particular geographical region.

• Endangered Species: Facing a very high risk of extinction.

• Vulnerable Species: Facing a high risk of extinction.

• Extinct Species: No surviving individuals.

• Keystone Species: Has a disproportionately large ecological role.

• Flagship Species: Used to promote conservation.

47. National Parks and Wildlife Sanctuaries of India

Important distinctions

• National Park: Stronger protection of the area and its ecosystems.

• Wildlife Sanctuary: Protection of wildlife, with certain regulated rights potentially permitted.

• Biosphere Reserve: Large area for conservation, research and sustainable development.

48. Biosphere Reserves of India

Important examples:

• Nilgiri – Tamil Nadu, Kerala and Karnataka.

• Nanda Devi – Uttarakhand.

• Nokrek – Meghalaya.

• Gulf of Mannar – Tamil Nadu.

• Sundarbans – West Bengal.

• Simlipal – Odisha.

• Pachmarhi – Madhya Pradesh.

• Achanakmar-Amarkantak – Chhattisgarh and Madhya Pradesh.

• Great Nicobar – Andaman and Nicobar Islands.

• Agasthyamalai – Kerala and Tamil Nadu.

• Khangchendzonga – Sikkim.

• Panna – Madhya Pradesh.

49. Important Environmental Conventions

Important organisations

• UNEP: United Nations Environment Programme.

• IPCC: Intergovernmental Panel on Climate Change.

• IUCN: International Union for Conservation of Nature.

• WWF: World Wide Fund for Nature.

• FAO: Food and Agriculture Organization.

• UNESCO: United Nations Educational, Scientific and Cultural Organization.

50. Pollution and Climate Change

Types of pollution

• Air Pollution.

• Water Pollution.

• Soil Pollution.

• Noise Pollution.

• Thermal Pollution.

• Radioactive Pollution.

Important gases

• CO₂: Carbon dioxide.

• CH₄: Methane.

• N₂O: Nitrous oxide.

• CFCs: Chlorofluorocarbons.

• O₃: Ozone.

Important concepts

• Global Warming: Rise in Earth’s average surface temperature.

• Greenhouse Effect: Trapping of heat by atmospheric gases.

• Acid Rain: Rainfall made acidic mainly by SO₂ and NOx.

• Ozone Depletion: Reduction of stratospheric ozone.

• Carbon Footprint: Total greenhouse gas emissions associated with an activity or entity.

• Desertification: Land degradation in dryland regions.

PART 6: IMPORTANT GEOGRAPHICAL FACTS FOR EXAMS

51. Important Firsts and Superlatives

52. Important Geographical Passes of India

53. Important Dams of the World

54. Important Waterfalls of the World

55. Important Indian Geographical Records

56. Important Map-Based Facts

Seas and oceans

• Arabian Sea: West of India.

• Bay of Bengal: East of India.

• Indian Ocean: South of India.

• Red Sea: Between Africa and Arabian Peninsula.

• Mediterranean Sea: Between Europe, Africa and Asia.

• Caribbean Sea: Between Central America and Caribbean islands.

• South China Sea: Southeast Asia.

Important gulfs

• Gulf of Kutch: Gujarat.

• Gulf of Khambhat: Gujarat.

• Gulf of Mannar: India–Sri Lanka.

• Persian Gulf: Middle East.

• Gulf of Aden: Near Yemen and Somalia.

• Gulf of Mexico: North America.

Important islands

• Andaman and Nicobar: Bay of Bengal.

• Lakshadweep: Arabian Sea.

• Maldives: Indian Ocean.

• Madagascar: Indian Ocean.

• Sri Lanka: Indian Ocean.

• Japan: Pacific Ocean.

• Greenland: Arctic and North Atlantic region.

• Philippines: Western Pacific.