upscvision.org
upscvision.org/
3️⃣
NCERT Notes/
✅Class 7: Social Science: Our Environment: Textbook in Geography for Class VII, 2007
Search

✅Class 7: Social Science: Our Environment: Textbook in Geography for Class VII, 2007

Chapter 1 - Environment
Introduction
Understanding Environment
  1. Basics of Environment
      • Serves as the foundational life support system.
      • Provides essential elements for life: air, water, food, and shelter.
  1. Human Interaction with Environment 2.1. Humans modify the natural environment in various ways. 2.2. Examples:
      • Cars produce emissions that pollute the air.
      • The land is repurposed to construct buildings and factories.
      • Manufacturing processes produce goods, containers, etc.
  1. Definitions 3.1. Environment: The collective surroundings (including places, people, objects, and nature) that affect living organisms. 3.2. Natural Environment:
      • Biotic (living) and abiotic (non-living) conditions on Earth. 3.3. Human Environment:
      • Covers human activities, creations, and interactions.
      Image
      notion image
Natural Environment
Natural Environment and Ecosystems
  1. Natural Environment Components 1.1. Lithosphere: Solid crust of the earth, consists of:
      • Rocks and minerals.
      • Surface covered by soil.
      • Landforms like mountains, plateaus, plains, and valleys.
      • Provides forests, grasslands, agricultural land, settlements, and minerals. 1.2. Hydrosphere: Water domain, comprises:
      • Various water sources: rivers, lakes, seas, oceans.
      • Essential for all life forms. 1.3. Atmosphere: Thin layer of air surrounding the earth.
      • Protects from harmful solar rays.
      • Composed of gases, dust, and water vapor.
      • Influences weather and climate. 1.4. Biosphere: Living world, includes:
      • Plant and animal kingdoms.
      • The zone where land, water, and air interact to support life.
  1. Ecosystem 2.1. Definition: Interrelation between living organisms and their surroundings. 2.2. Examples: Rain forests, grasslands, deserts, mountains, lakes, rivers, oceans, ponds. 2.3. Significance:
      • Organisms depend on their surroundings and often on each other.
      • Ecosystems can range in size from large forests to small ponds.
  1. Interactions & Variations
      • Different regions (e.g., Kerala's heavy rainfall vs. Jaisalmer's desert conditions) have unique ecosystems.
      • Flora and fauna vary based on the environment they are in.
      • Ecosystems dictate the way of life for organisms, including humans.
Human Environment
  1. Human Interaction with Environment 1.1. Early humans adapted to their surroundings. 1.2. As needs evolved, humans modified the environment accordingly.
  1. Evolution of Human Activities 2.1. Early Adaptations:
      • Simple life with nature-provided necessities. 2.2. Agricultural Evolution:
      • Learned to grow crops and domesticate animals.
      • Settled life began. 2.3. Commercial Evolution:
      • Invention of the wheel.
      • Production of surplus food.
      • Emergence of barter system.
      • Start of trade and commerce. 2.4. Industrial Revolution:
      • Large-scale production became possible.
      • Faster transportation methods. 2.5. Information Revolution:
      • Speedy and easy global communication.
  1. Harmony with Environment
      • Balance is crucial between natural and human environments.
      • Adapting to seasonal changes, e.g., eating watermelon in summer and peanuts in winter.
      • The importance of coexisting with nature is indicated by Nurie's story.
  1. Awareness and Appreciation:
      • Emphasis on understanding the beauty of diverse landscapes and appreciating the balance of nature, as showcased by the classroom activity.
Glossary
Key Definitions
  1. Environment
      • Origin: Derived from the French word "Environer/Environner".
      • Meaning: Refers to the "neighborhood" or surroundings.
  1. Ecosystem
      • Definition: A system where all living organisms interact with each other and with their physical and chemical environment.
      • Components: Interaction involves the transfer of energy and material.
  1. Barter System
      • Definition: A trading method where goods are exchanged directly without the use of money.
Chapter 2 - Inside our Earth
Interior of the Earth
  1. Layers of the Earth (Similar to an onion's concentric layers)
      2. 1.1. Crust
      • Thickness: 35 km (continental masses), 5 km (ocean floors).
      • Composition:
        • Continental Crust (Sial): Mainly silica (Si) and alumina (Al).
        • Oceanic Crust (Sima): Mainly silica (Si) and magnesium (Ma).
      1.2. Mantle
      • Location: Beneath the crust.
      • Depth: Extends up to 2900 km below the crust.
      1.3. Core
      • Radius: About 3500 km.
      • Composition (Nife): Mainly nickel (Ni) and iron (Fe).
      • Conditions: Very high temperature and pressure.
Image
notion image
Image
notion image
Rocks and Minerals
  1. Rocks
      • Definition: Natural mass of mineral matter making up the earth’s crust.
      • Characteristics: Can differ in color, size, and texture.
      1.1. Types of Rocks
      1.1.1. Igneous Rocks - Formation: From the cooling of molten magma. - Types: - Extrusive Igneous Rocks: Formed from rapidly cooled lava on the earth's surface. - Example: Basalt (Deccan plateau). - Intrusive Igneous Rocks: Formed from magma that cools inside the earth’s crust. - Example: Granite (used for grinding stones).
      1.1.2. Sedimentary Rocks - Formation: From compressed and hardened sediments. - Example: Sandstone (formed from sand grains). - May contain fossils.
      1.1.3. Metamorphic Rocks - Formation: From igneous or sedimentary rocks that have undergone heat and pressure.
      1.2. Rock Cycle
      • Continuous transformation of rocks from one type to another.
      • Sequence: Igneous → Sedimentary → Metamorphic → Magma → Igneous.
  1. Minerals
      • Definition: Naturally occurring substances with specific physical properties and a definite chemical composition.
      • Importance: Used as fuels, in industries, medicine, and fertilizers.
      • Examples: Coal, natural gas, petroleum, iron, aluminum, gold, and uranium.
Image
notion image
Glossary
Earth's Depths and Terminology
  1. Earth's Depth and Composition
      2. 1.1. Mines and Holes
      • World's deepest mine: Located in South Africa, approximately 4 km deep.
      • Deepest hole for oil exploration: About 6 km deep.
      1.2. Reaching Earth's Centre
      • Requires a hole about 6,000 km deep if starting from the ocean floor.
      1.3. Composition by Volume
      • Crust: 1% of earth's volume.
      • Mantle: 84% of earth's volume.
      • Core: 15% of earth's volume.
      1.4. Earth's Radius
      • Approximately 6,371 km.
  1. Terminology
      2. 2.1. Igneous
      • Origin: Latin word "Ignis", meaning "fire".
      2.2. Sedimentary
      • Origin: Latin word "sedimented", meaning "settle down".
      2.3. Metamorphic
      • Origin: the Greek word "metamorphose", meaning "change of form".
      2.4. Fossils
      • Definition: Remains of dead plants and animals trapped in rock layers.
Chapter 3 - Our Changing Earth
Introduction
Lithosphere, Earth Movements, and Earthquakes
  1. Lithospheric Plates
      2. 1.1. The earth's lithosphere is divided into lithospheric plates. 1.2. These plates move very slowly, a few millimetres each year. 1.3. Movement is due to molten magma circulating inside the earth.
  1. Forces Acting on Earth
      2. 2.1. Endogenic Forces
      • Act inside the earth.
      • Can produce both sudden and slow movements.
      2.2. Exogenic Forces
      • Work on the surface of the earth.
  1. Natural Disasters
      2. 3.1. Volcanoes
      • An opening in the earth's crust.
      • Molten material erupts suddenly through this vent.
      3.2. Earthquakes
      • Vibrations on the earth's surface due to lithospheric plate movement.
      • Origin point: Focus.
      • Surface point directly above focus: Epicentre.
      • Vibrations radiate from the epicentre as waves.
      • Maximum damage near the epicentre.
  1. Earthquake Preparedness
      2. 4.1. Can't predict earthquakes, but the impact can be minimized with preparedness. 4.2. Local prediction methods include observing animal behavior's.
Chart
notion image
Image
notion image
Image
notion image
Earthquake Preparedness
Earthquake Preparedness and Bhuj Earthquake
  1. Earthquake Preparedness
      2. 1.1. Safe Spots
      • Under kitchen counters.
      • Under tables or desks.
      • Inside corners or walls.
      1.2. Danger Zones
      • Fireplaces.
      • Areas around chimneys.
      • Near windows, mirrors, and picture frames that can shatter.
      1.3. Awareness
      • Spread knowledge about safety measures among friends and family.
  1. Bhuj Earthquake (26th January 2001)
      2. 2.1. Intensity: 6.9 on the Richter scale.
      2.2. Consequences
      • Fires due to overturned charcoal cookers.
      • School buildings collapsed: An estimated 971 students and 31 teachers lost their lives.
      • Infrastructure damage: Phone lines, water pipelines, and power stations were affected.
      2.3. Response
      • State of emergency declared.
      • Gujarat Chief Minister appealed for financial aid from the Centre.
      • Concerns rose three days post-quake regarding the distribution of food, blankets, and medical supplies.
  1. Measuring Earthquakes
      2. 3.1. Instrument: Seismograph.
      3.2. Richter Scale
      • 2.0 or less: Barely noticeable.
      • Over 5.0: Can cause damage due to falling objects.
      • 6.0 or higher: Very strong.
      • 7.0: Classified as a major earthquake.
Major Land Forms
Major Landforms and Their Formation
  1. Weathering and Erosion
      2. 1.1. Weathering: Breaking up of rocks on the earth's surface.
      1.2. Erosion: Wearing away from the landscape by agents like water, wind, and ice.
      1.3. Erosion and deposition work together to create various landforms.
  1. Work of a River
      2. 2.1. Erosion by running water.
      2.2. Waterfall: Formed when a river tumbles over hard rocks or down steep valleys.
      2.3. Meanders: Large bends in a river.
      2.4. Ox-bow Lake: Formed when a meander loop gets cut off from the river.
      2.5. Floodplain: Flat fertile land formed by deposition of sediments when a river overflows its banks.
      2.6. Levees: Raised banks of a river.
      2.7. Delta: Formed when a river splits into distributaries before entering the sea, depositing sediments at each mouth.
  1. Work of Sea Waves
      2. 3.1. Coastal landforms arise from erosion and deposition by sea waves.
      3.2. Sea Caves: Hollow caves formed by waves hitting rocks.
      3.3. Sea Arches: Formed when only the roof of a sea cave remains.
      3.4. Stacks: Wall-like structures formed after sea arches lose their roofs.
      3.5. Sea Cliff: Steep rocky coast rising vertically above seawater.
      3.6. Beaches: Formed by the deposition of sediments along shores.
  1. Work of Ice
      2. 4.1. Glaciers: "Rivers of ice" that erode the landscape.
      4.2. Glacial Lakes: Deep hollows filled with water after glaciers melt.
      4.3. Glacial Moraines: Deposits formed by materials carried by glaciers.
  1. Work of Wind
      2. 5.1. Active agent in deserts.
      5.2. Mushroom Rocks: Rocks eroded by wind with a narrow base and wide top.
      5.3. Sand Dunes: Hill-like structures formed by deposition of sand.
      5.4. Loess: Large areas of fine sand deposited by wind (e.g., in China).
Additional Concepts
Lithospheric Plates, Earthquake Waves, and Waterfalls
  1. Lithospheric Plates
      2. 1.1. Earth's crust is divided into large and small, rigid plates.
      1.2. These plates carry both continents and the ocean floor.
  1. Earthquake Waves
      2. 2.1. Three main types of earthquake waves:
      2.1.1. P waves (Longitudinal waves)
      2.1.2. S waves (Transverse waves)
      2.1.3. L waves (Surface waves)
      2.2. Note: Check encyclopedias for specific properties of these waves.
  1. Famous Waterfalls
      2. 3.1. Angel Falls: The highest waterfall is located in Venezuela, South America.
      3.2. Niagara Falls: Situated on the border between Canada and the USA, North America.
      3.3. Victoria Falls: Found on the borders of Zambia and Zimbabwe, Africa.
       
Chapter 4 - Air
Introduction
Earth's Atmosphere
  1. Atmosphere
      2. 1.1. A vast blanket of air that surrounds Earth.
      1.2. Essential for the survival of all living beings.
  1. Functions
      2. 2.1. Provides the air we breathe.
      2.2. Offers protection from harmful sun rays.
  1. Temperature Regulation
      2. 3.1. Makes Earth's temperature liveable.
      3.2. Without it, we would experience extreme heat during the day and freezing temperatures at night.
Composition of the Atmosphere
  1. Atmospheric Composition
      2. 1.1. Mixture of various gases.
      1.2. Main Gases: Nitrogen and oxygen (the bulk of the atmosphere).
      1.3. Minor Gases: Carbon dioxide, helium, ozone, argon, hydrogen.
      1.4. Contains tiny dust particles.
  1. Nitrogen (N₂)
      2. 2.1. Most abundant gas in the atmosphere.
      2.2. Inhaled and exhaled by humans without absorption.
      2.3. Plants require nitrogen but cannot absorb it directly from the air.
      2.4. Bacteria in soil and plant roots convert atmospheric nitrogen for plant use.
  1. Oxygen (O₂)
      2. 3.1. Second most abundant gas.
      3.2. Vital for respiration in humans and animals.
      3.3. Produced by green plants during photosynthesis.
  1. Carbon Dioxide (CO₂)
      2. 4.1. Used by plants in photosynthesis.
      4.2. Released by humans and animals during respiration.
      4.3. Balance maintained between CO₂ uptake by plants and released by animals.
      4.4. Imbalance Concern: Burning fuels (coal, oil) releases additional CO₂, impacting weather and climate.
Image
notion image
Structure of the Atmosphere
  1. Layers of Atmosphere
      • The atmosphere is divided into five main layers.
  1. Troposphere
      2. 2.1. Closest to Earth's surface.
      2.2. Average height: 13 km.
      2.3. Contains breathable air.
      2.4. Weather phenomena (rainfall, fog, hailstorm) occur here.
  1. Stratosphere
      2. 3.1. Lies above the troposphere, up to 50 km.
      3.2. Mostly free from clouds and weather events.
      3.3. Ideal for flying airplanes.
      3.4. Contains the ozone layer which protects from harmful sun rays.
  1. Mesosphere
      2. 4.1. Above the stratosphere, up to 80 km.
      4.2. Meteorites burn up in this layer upon entering from space.
  1. Thermosphere
      2. 5.1. Temperature rises rapidly with height.
      5.2. Contains the Ionosphere (between 80-400 km).
      5.3. Important for radio wave transmission.
      5.4. Radio waves are reflected back to Earth by this layer.
  1. Exosphere
      2. 6.1. The uppermost atmospheric layer.
      6.2. Contains very thin air.
      6.3. Light gases (helium, hydrogen) float into space from here.
Image
notion image
Weather and Climate
  1. Weather vs. Climate
      2. 1.1. Weather: Hour-to-hour, day-to-day atmospheric conditions.
      1.2. Climate: Average weather condition of a place over a longer period.
  1. Temperature
      2. 2.1. Degree of hotness or coldness of air.
      2.2. Insolation: Incoming solar energy intercepted by Earth.
      2.2.1. Decreases from equator to poles.
      2.2.2. Causes temperature variation.
      2.3. Urban areas (cities) generally have higher temperatures than rural areas (villages).
  1. Air Pressure
      2. 3.1. Pressure exerted by the weight of air on Earth's surface.
      3.2. Highest at sea level; decreases with height.
      3.3. Influenced by temperature: high temperature = low pressure, low temperature = high pressure.
      3.4. Air moves from high to low-pressure areas.
  1. Wind
      2. 4.1. Movement of air from high to low pressure.
      4.2. Types:
      4.2.1. Permanent winds: Constant direction (e.g., trade winds, westerlies).
      4.2.2. Seasonal winds: Change direction seasonally (e.g., monsoons).
      4.2.3. Local winds: Specific to certain times and areas (e.g., land and sea breeze, loo).
  1. Moisture and Precipitation
      2. 5.1. Humidity: Amount of water vapor in the air.
      5.2. Clouds: Masses of water droplets formed from condensed water vapor.
      5.3. Precipitation:
      5.3.1. Liquid form = rain.
      5.3.2. Rainfall types: convectional, orographic, cyclonic.
      5.3.3. Importance: Provides fresh water, essential for life.
  1. Significance
      2. 6.1. Weather and climate influence daily activities, ecosystems, and lifestyles.
Image
notion image
Image
notion image
Additional Concepts
Atmospheric Phenomena and Weather Instruments
  1. Greenhouse Effect & Global Warming
      2. 1.1. Greenhouse Gas: Carbon dioxide traps heat; vital for maintaining Earth's temperature.
      1.2. Global Warming: Excessive CO2 (from factories, and cars) retains more heat, raising Earth's temperature.
      1.2.1. Effects: Melting snow, rising sea levels, flooding in coastal areas, climate changes, extinction risk for certain species.
  1. Air Circulation
      2. 2.1. Heated air expands, rises, and is replaced by cold, denser air, creating air circulation.
  1. Sun's Energy & Earth
      2. 3.1. Earth receives 1 in 2,000,000,000 parts of the sun’s energy.
  1. Weather Instruments
      2. 4.1. Thermometer: Measures temperature (standard unit: Celsius; water freezes at 0°C, boils at 100°C).
      4.2. Barometer: Measures atmospheric pressure.
      4.3. Rain Gauge: Measures rainfall amount.
      4.4. Wind Vane: Indicates wind direction.
  1. Moon & Atmospheric Pressure
      2. 5.1. No air or atmospheric pressure on the moon.
      5.2. Astronauts wear special suits filled with air to counteract body pressure, preventing blood vessels from bursting.
  1. Wind Naming Convention
      2. 6.1. Winds are named after their origin direction (e.g., westerly wind blows from the west).
  1. Cyclone: Case Study of Odisha, 1999
      2. 7.1. Odisha faced two significant cyclones in October 1999.
      7.2. Supercyclone on 29 October 1999 had winds up to 260 km/h, causing widespread destruction.
      7.3. Cyclone resulted from a depression in the Gulf of Thailand, impacting 13 million people and causing extensive agricultural and infrastructural damage.
      7.4. Mangrove forests between Paradeep and Konark were decimated.
  1. Forms of Precipitation
      2. 8.1. Rain, snow, sleet, and hail.
Chapter 5 - Water
Introduction
Water and Its Forms
  1. Introduction to Water
      2. 1.1. Water is associated with rivers, waterfalls, rain, and taps.
      1.2. Evaporation and condensation processes contribute to the water's transient nature in puddles.
  1. Water Cycle
      2. 2.1. Evaporation: The Sun's heat turns water into vapor.
      2.2. Condensation: Cooled water vapor forms clouds.
      2.3. Precipitation: Water returns to earth as rain, snow, or sleet.
      2.4. Cycle: Continuous change and circulation of water forms among oceans, atmosphere, and land.
  1. Water's Eternal Nature
      2. 3.1. Earth's water has been consistent and unchanging over centuries.
      3.2. Water used in one location might have existed in a completely different location years ago.
  1. Sources of Fresh Water
      2. 4.1. Rivers, ponds, springs, and glaciers.
      4.2. Oceans and seas contain saline water.
  1. Saline Water
      2. 5.1. Oceans have salty water due to dissolved salts.
      5.2. Main salt: Sodium chloride (common table salt).
Image
notion image
Map
notion image
Distribution of Water Bodies
  1. Earth's Water Composition
      2. 1.1. 75% of the earth's surface is covered by water.
  1. Water Scarcity Paradox
      2. 2.1. Despite abundant water coverage, many countries face water scarcity.
      2.2. Not all water on earth is readily accessible or usable.
  1. Water Distribution
      2. 3.1. The specific distribution of water across different reservoirs and sources was mentioned (exact percentages from the table are not provided here).
      3.2. Demonstrations and activities can help in understanding this distribution.
  1. Importance of Water
      2. 4.1. Essential for survival and irreplaceable for quenching thirst.
      4.2. Careless usage of water wastes a valuable and precious resource
Chart
notion image
Ocean Circulation
  1. Ocean's Charm
      • Walking barefoot on the seashore provides a unique experience.
      • Features: wet sand, seabirds, salty air, music of the waves.
      • Ocean water is always in motion, never still.
  1. Ocean Movements
      2. 2.1. Waves - Alternating rise and fall of the ocean surface. - Caused by wind; stronger winds during storms create larger waves. - Tsunami: Massive tidal wave due to underwater disturbances (e.g., earthquake). - Can reach speeds > 700 km/h. - The 2004 tsunami affected coastal India; and submerged Indira Point in Andaman and Nicobar.
      2.2. Tides - Rhythmic rise and fall of ocean water twice a day. - High Tide: Water rises to its maximum height. - Low Tide: Water recedes to its lowest point. - Caused by the gravitational pull of the moon and sun. - Spring Tides: Highest tides during full moon and new moon days (sun, moon, earth aligned). - Neap Tides: Lowest tides during the moon's first and last quarter (gravitational forces of the sun and moon pull water in different directions). - Benefits of Tides: - Aid in navigation (raising water level near shores). - Assist in fishing (bringing more fish closer to shore). - Potential for generating electricity.
  1. Utility of Ocean Movements
      • High tides facilitate shipping and fishing.
      • Tidal movements can be harnessed for electricity generation.
Ocean Currents
  1. Definition
      • Ocean currents are continuous, directed movements of seawater on the ocean surface.
  1. Types of Currents
      2. 2.1. Warm Currents - Originate near the equator. - Flow towards the poles. - Example: Gulf Stream.
      2.2. Cold Currents - Originate in polar or higher latitudes. - Move towards tropical or lower latitudes. - Example: Labrador Ocean current.
  1. Effects of Ocean Currents
      2. 3.1. Temperature Influence - Warm currents raise land temperature. - Cold currents lower land temperature.
      3.2. Fishing Grounds - Confluence of warm and cold currents creates fertile fishing grounds. - Examples: Seas around Japan, the eastern coast of North America.
      3.3. Navigation Challenges - Meeting point of warm and cold currents often leads to foggy conditions, complicating navigation.
Map
notion image
Additional Concepts
  1. Definitions & Concepts
      2. 1.1. Terrarium - Artificial enclosure for small house plants.
      1.2. Salinity - Amount of salt in water. - Average ocean salinity: 35 parts per thousand. - Example: Dead Sea's salinity: 340 grams per liter.
      1.3. Waves - Formed by winds across the ocean surface. - Strength depends on wind speed.
      1.4. Tsunami - Japanese: "Harbour waves". - Caused by underwater disturbances (e.g., earthquakes).
  1. Tsunami of 26 December 2004
      2. 2.1. Causes - Result of an earthquake near Sumatra. - Magnitude: 9.0 on the Richter scale. - Ocean floor displacement & water movement.
      2.2. Effects - Speed: Up to 800 km/h. - Submerged islands, including Indira Point in Andaman and Nicobar. - Affected: Andhra Pradesh, Tamil Nadu, Kerala, Puducherry, Andaman and Nicobar.
      2.3. Warning Systems - The Pacific Ocean has early warning systems. - The Indian Ocean lacked these due to lesser seismic activity.
      2.4. Destruction on Tamil Nadu Coast - Massive damage due to lack of monitoring and awareness. - Rapid water withdrawal indicated tsunami approach. - Casualties due to public ignorance and curiosity.
  1. Important Dates & Events
      2. 3.1. World Water Day - Celebrated on March 22 to reinforce water conservation.
      3.2. Tsunami – The Earth’s Pandemonium - Tsunami's impact on coastlines and aftermath.
Chapter 6 - Human Environment Interactions: The Tropical and Subtropical Region
Life in the Amazon Basin
  1. Geographical Location
      2. 1.1. Tropical Region - Close to the equator (between 10°N and 10°S). - Known as the equatorial region.
      1.2. Amazon River - Originates from mountains in the west. - Empties into the Atlantic Ocean in the east.
      1.3. River's Mouth - The place where a river flows into another body of water.
      1.4. Amazon Basin - Formed by the Amazon River and its tributaries. - Drains parts of Brazil, Peru, Bolivia, Ecuador, Columbia, and a small portion of Venezuela.
  1. Countries through which Equator Passes in the Basin
      2. To be filled in based on map reference (Fig. 6.2).
Map
notion image
Climate
Climate of the Amazon Basin
  1. Location
      • Situated directly on the equator.
  1. Temperature
      2. 2.1. Day - Hot with high humidity. - Sticky sensation on the skin.
      2.2. Night - Slight decrease in temperature. - High humidity remains constant.
  1. Rainfall
      • Occurs almost daily.
      • Unexpected, without much warning.
Rainforests
Rainforests of the Amazon Basin
  1. Environment Characteristics
      2. 1.1. Heavy Rainfall - Results in dense forests.
      1.2. Sunlight Penetration - Forests are so thick that sunlight doesn't reach the ground. The ground remains dark and damp.
  1. Vegetation
      2. 2.1. Shade Tolerant Vegetation - Due to limited sunlight.
      2.2. Parasitic Plants - Orchids and bromeliads grow as plant parasites.
  1. Fauna
      2. 3.1. Birds - Toucans, hummingbirds, and macaws. - Distinguished by brilliant colors and loud sounds.
      3.2. Mammals - Monkeys, sloths, and tapirs.
      3.3. Reptiles & Snakes - Crocodiles, anacondas, boa constrictors, and pythons.
      3.4. Insects - Thousands of species present.
      3.5. Aquatic Life - Numerous fish species, including the flesh-eating Piranha.
  1. Biodiversity
      • Extremely rich variety of life.
People of the Rainforests
  1. Agriculture & Food
      2. 1.1. Farming Method - Practice "slash and burn agriculture". - Clear trees in the forest for small farming patches.
      1.2. Crops - Main crops: Tapioca, pineapple, sweet potato. - Staple food: Manioc (cassava). - Cash crops: Coffee, maize, cocoa.
      1.3. Diet - Queen ants and egg sacs in addition to crops.
  1. Housing
      2. 2.1. Materials - Wood from rainforests.
      2.2. Types - Thatched houses resembling beehives. - Large "Maloca" apartments with steep roofs.
  1. Lifestyle Changes
      2. 3.1. Transport & Accessibility - Earlier: Access mainly via rivers. - 1970: Introduction of Trans Amazon highway. - Use of aircraft and helicopters.
      3.2. Impact on Indigenous Population - Pushed out due to developmental activities. - Forced to settle in new areas with their farming practices.
  1. Environmental Concerns
      2. 4.1. Destruction of Rainforests - Development leading to loss of biologically diverse forests. - Large areas disappearing annually in the Amazon basin.
      4.2. Consequences - Topsoil erosion due to rainfall. - Lush forests transforming into barren landscapes.
Life in the Ganga-Bramhaputra Basin
  1. Geographical Overview
      2. 1.1. Location - Lies in the sub-tropical region between 10°N to 30°N latitudes. - Basin drains via tributaries of Ganga and Brahmaputra.
      1.2. Main Features - Plains of Ganga and Brahmaputra. - Himalayan mountains and foothills. - Sundarbans delta. - Oxbow lakes in the plain area.
      1.3. Climate - Dominated by monsoon climate. - Hot summers, cool winters, and heavy rainfall from mid-June to mid-September.
  1. Population & Habitation
      2. 2.1. Distribution - Fewer people in mountain areas due to inhospitable terrain. - High population density in plains due to fertile soil.
      2.2. Agriculture & Food - Main crop: Paddy (requires high rainfall). - Other crops: Wheat, maize, sorghum, gram, millets. - Cash crops: Sugarcane, jute, banana. - Special crops: Tea (West Bengal, Assam), silk (Bihar, Assam). - Terrace farming on gentle mountain slopes.
  1. Vegetation & Wildlife
      2. 3.1. Vegetation - Tropical deciduous trees (teak, sal, peepal) in plains. - Bamboo groves in Brahmaputra plain. - Mangrove forests in the delta area. - Coniferous trees (pine, deodar, fir) in cooler regions with steep slopes.
      3.2. Wildlife - Common animals: Elephants, tigers, deer, monkeys. - Special: One-horned rhinoceros (Brahmaputra plain), Bengal tiger, crocodiles (delta). - Aquatic life: Rohu, catla, hilsa fish. Fish and rice as the staple diet.
  1. Urbanization & Development
      2. 4.1. Major Cities - Cities along the Ganga: Allahabad, Kanpur, Varanasi, Lucknow, Patna, Kolkata.
      4.2. Environmental Concerns - Pollution due to wastewater from towns and industries.
      4.3. Transport - Roadways, railways, waterways, and airports are developed. - Kolkata is an important port on the River Hooghly.
      4.4. Tourism - Notable sites: Taj Mahal (Agra), Allahabad, Buddhist stupas, Lucknow's Imambara, wildlife sanctuaries in Assam, and tribal culture in Arunachal Pradesh.
Map
notion image
Additional Concepts
Amazon River, Cultivation Techniques, and Conservation Efforts
  1. Amazon River's Naming
      • Named by Spanish explorers after being attacked by tribes resembling ancient Roman 'Amazons'.
  1. Geographical Definitions
      • Tributaries: Smaller rivers joining a main river.
      • River Basin: Main river + its tributaries that drain an area.
        • Amazon Basin is the world's largest.
      • Population Density: Number of persons per sq. km.
        • Examples: Uttarakhand (189), West Bengal (1029), Bihar (1102).
  1. Flora and Fauna
      • Bromeliads: Plants storing water in leaves; used by frogs for laying eggs.
      • River Ganga and Brahmaputra: Home to Susu (blind dolphin) which indicates river health.
  1. Cultivation Techniques
      • Slash and Burn:
        • Trees/bushes are cut down and burnt to release nutrients.
        • The land is used for a few years and then left to restore fertility.
        • Cultivation is resumed after soil restoration.
      • Terracing: Creating flat surfaces on steep slopes to grow crops.
  1. Case Study: Lake as a Livelihood
      • Location: Matwali Maun village, Bihar.
      • Fishermen cleaned ox-bow lake (maun) for fish cultivation.
      • The land around the lake is fertile; and used for paddy, maize, and pulses.
      • Buffalo helps in plowing.
      • The community sells fish to neighboring towns.
      • Pollutants are a threat to fish cultivation.
  1. Conservation Initiatives in India
      • Swachh Bharat Mission: Launched in 2014 to focus on sanitation and universal sanitation coverage.
      • Namami Ganga Programme: To conserve the River Ganga.
Chapter 7 - Life in the Deserts
The Hot Desert - Sahara
Sahara Desert
  1. Introduction
      • Located in North Africa.
      • The world's largest desert with 8.54 million sq. km.
      • Touches 11 countries: Algeria, Chad, Egypt, Libya, Mali, Mauritania, Morocco, Niger, Sudan, Tunisia, and Western Sahara.
  1. Geography
      • Predominantly sandy, but also has gravel plains and rocky plateaus.
      • Some plateaus rise over 2500m in height.
  1. Climate
      • Extremely hot and dry.
      • Short rainy season with cloudless skies.
      • Day temperatures can reach 50°C.
      • Night temperatures can approach 0°C.
  1. Flora and Fauna
      • Vegetation: cactus, date palms, acacia.
      • Oases are green islands amid the desert.
      • Animals: camels, hyenas, jackals, foxes, scorpions, snakes, and lizards.
  1. People and Culture
      • Inhabited by nomadic tribes like Bedouins and Tuaregs.
        • Livestock: goats, sheep, camels, horses.
        • Products: milk, leather, mats, carpets, clothes, blankets.
      • Settled populations near oases and Nile Valley.
        • Cultivation: date palms, rice, wheat, barley, beans.
        • Egyptian cotton is world-renowned.
  1. Resources and Development
      • Valuable minerals: iron, phosphorus, manganese, uranium.
      • Major oil reserves in Algeria, Libya, and Egypt.
      • Modern developments: skyscrapers, superhighways, trucks in salt trade.
      • Cultural shift: Tuaregs as tourist guides; nomads moving to cities for oil/gas jobs.
Map
notion image
The Cold Desert - Ladakh
Cold Desert - Ladakh
  1. Location and Geography
      • Located in the Great Himalayas, eastern Jammu and Kashmir.
      • Enclosed by the Karakoram Range (north) and Zanskar Mountains (south).
      • Rivers: Mainly Indus, forming deep valleys and gorges.
      • Altitude: Ranges from 3,000m in Kargil to over 8,000m in Karakoram.
      • Glaciers: e.g., Gangri glacier.
  1. Climate
      • Extremely cold and dry due to high altitude.
      • Intense sun heat; the air is thin.
      • Summer: Day temperatures just above 0°C; Night temperatures below –30°C.
      • Winter: Often below –40°C.
      • Rainfall: Minimal (around 10 cm annually).
      • Unique Experience: Sunstroke and frostbite simultaneously (sunlit upper body, shaded feet).
  1. Flora and Fauna
      • Sparse vegetation: Scanty grasses, shrubs, willows, and poplars in valleys.
      • Summer fruits: Apples, apricots, walnuts.
      • Birds: Robins, redstarts, Tibetan snowcock, raven, hoopoe (some migratory).
      • Animals: Wild goats, sheep, yak, specific dogs. Used for milk, and meat hides.
      • Yak products: Cheese and butter.
      • Wool: Derived from sheep and goat hair.
  1. People and Culture
      • Resemblance: Inhabitants of Tibet and Central Asia.
      • Religions: Mainly Muslims and Buddhists.
      • Notable structures: Buddhist monasteries (e.g., Hemis, Thiksey, Shey, Lamayuru).
      • Summer activities: Cultivation of barley, potatoes, peas, beans, turnip.
      • Winter activities: Festivities and ceremonies.
      • Women’s role: Domestic work, fieldwork, business, and shops.
      • Connectivity: Leh (capital) is connected by road (National Highway 1A) and air.
      • Tourism: Visits to gompas, treks, ceremonies, and festivities.
      • Modernization impact: Balanced lifestyle; reverent and careful resource usage.
Map
notion image
Additional Concepts
Desert Knowledge
  1. Definition of Desert
      • The arid region with high or low temperatures.
      • Limited vegetation.
  1. Sahara Desert
      • Once a lush green plain.
      • Cave paintings depict rivers with crocodiles, elephants, lions, giraffes, ostriches, sheep, cattle, and goats.
      • Climate change turned it into a dry region.
      • Al Azizia recorded its highest temperature of 57.7°C in 1922.
      • Skeletons of fish are found, hinting at a past aquatic environment.
      • Depressions: Formed when wind blows away sands.
        • Oasis: Formed in depressions with underground water; fertile land for crops.
        • Example: Tafilalet Oasis in Morocco, covering 13,000 sq. km.
  1. Ladakh
      • Name: "La" (mountain pass) + "Dak" (country).
      • Drass: One of the coldest inhabited places on earth.
      • Also known as Khapa-chan (snow land).
      • Wildlife: Chiru (Tibetan antelope) is endangered; hunted for shahtoosh wool.
      • Vegetation: Willow trees are used for cricket bats.
      • Manali-Leh highway: Crosses four passes (Rohtang la, Baralacha la, Lungalacha la, Tanglang la); open between July and September.
  1. Desert Game (Classroom Activity)
      • Aim: Understand desert creatures.
      • Creatures are categorized into mammals, birds, and reptiles.
      • Students are assigned a desert creature and write three characteristics.
      • A class was divided into groups to guess the animal based on clues.
      • Points are awarded for correct answers.
 
Copyright 2022 UPSC Vision