NCERT Notes for Class 7th Geography

NCERT Notes Class 7th Geography






Chapter.1: Environment

NCERT Notes Class 7th Geography





1.Natural Environment

Biotic:

The world of living organisms.

Examples: Plants & animals.

Abiotic:

The world of non- living elements.

Examples: Land, rocks, air etc.

2.Environment:

Whatever we see in our surrounding is known as the environment.

3.Major domains of the environment:

1.Lithosphere.

2.Hydrosphere.

3.Atmosphere.

4.Biosphere.

Among these domains, life exists on Biosphere.

Lithosphere: It is the solid crust or the hard top layer of the earth.

Hydrosphere: It comprises various sources of water and different types of water bodies like rivers, lakes, seas, oceans etc.

Atmosphere: It is the thin layer of the air that surrounds the earth.

Biosphere: Plants & animal kingdom together makes the biosphere.

OR

It is a narrow zone of the earth where land, water, and air interact with each other to support life.

4.Natural Environment: Where land, water, air, plants and animals comprise is known as the natural environment.

5.Ecosystem :

The relationship between living organisms with each other and even with their surroundings in known as Ecosystem

Chapter.2: Inside Our Earth






1. The earth, our Homeland is a dynamic planet. It is constantly undergoing changes inside and outside

2.Three layers of the earth:

1.Crust.

2.Mental

3.Core

3. The main mineral constituents of the mass are silica and alumina.It is this called sial.(si= silica & al= alumina)

4. The oceanic crust mainly consists of silica & magnesium.It is therefore called sima (si= silica & ma= magnesium)

5. The Earth's crust is made up of various types of rocks.

6.Rock: Any natural mass of mineral matter that makes up the earth's crust is called a rock.

7. There are three major types of rocks:

1.Igneous rocks.

2.Sedimentary rocks.

3.Metamorphic rocks.

Igneous rocks are also called primary rocks.

8. There are two types of igneous rocks:

1.Intrusive rocks.

2.Extrusive rocks.

9. Magma that comes out from the interior of the earth’s surface rapidly cools down and becomes solid. Rocks formed in such a way on the crust is called extrusive igneous rocks. Example: Basalt.

Deccan plateau is made up of basalt rocks.

10. When molten magma cools down deep inside the earth’s crust then solid rocks are formed called intrusive igneous rocks. Example: Granite.

11. Rocks which roll down, crack and hit each other and are broken down into small fragments. These smaller particles are called sediments.

The loose sediments are compressed and hardened to form layers of rocks. These types of rocks are called sedimentary rocks.

12. Rocks are used for making roads, houses, and buildings.

13. The process of transformation of the rock from one to another is known as rock cycle.

14. When the igneous and sedimentary rocks are subjected to heat and pressure they change into metamorphic rocks.

Chapter.3: Our Changing Earth






1.Lithospheric plates: The lithosphere is broken into a number of plates known as lithospheric plates.

2. Earth movements are of two types of forces:

1.Endogenic forces.

2.Exogenic forces.

1.Endogenic forces: The forces which act in the interior of the earth.

2.Exogenic forces: The forces that work on the surface of the earth.

3.Volcano: It is a vent (opening) in the earth's crust through which molten magma erupts suddenly.

4.Earthquake: Sudden vibration of the earth due to movement of lithospheric plates is known as an earthquake.

5.Focus: The place in the crust where the movements of earthquake start are called the focus.

6.Epicenter: The place on the surface above the focus is known as an epicenter.

7. Earthquake is measured with a machine called seismograph.

8. The magnitude of the earthquake is measured on the Richter scale.

9. Landscapes are being continuously worn away by two processes:

1.Weathering

2.Erosion

1.Weathering: It is the breaking up of the rocks on the earth’s surface.

2.Erosion: It is the wearing away of the landscape by different agents like water, wind & ice.

10. Work on a river: The running water in the river erodes the landscape. When the river trembles at a steep angle over very hard rocks or down a steep valley side it forms a waterfall.

11.Meanders: As the river enters the plain it twists and turns, forming larger blends know as meanders.

12.Due to continuous erosion and deposition along the sides of the meander the ends of the meander loop come closer and closer. In due courses of time, the meander loops cut off from the river and form a cutoff lake, also known as the ox-bow lake.

13.Distributaries: The river begins to break up into a number of streams called distributaries.

The collection of sediments from all the mouths forms the delta.

14.Sea caves: The hollow like caves are formed on the rocks They are called sea caves.

As these cavities become bigger and bigger only the roof of the caves remain,t his forming sea arches.



The steep rocky coast rising almost vertically above seawater is called a sea cliff.

15.Glaciers: Glaciers are rivers of ice which too erode the landscape by bulldozing soil and stones to expose the solid rock below.

The material carried by the glacier such as rocks big and small, sand & slit gets deposited. These deposits form Glacier moraines.

16. An active agent of erosion and deposition in the deserts is wind.

In deserts, we can see rocks in the shape of mushrooms commonly called mushroom rocks.

17.When the wind blows it lifts and transport sand from one place to another. When it stops blowing the sand falls gets deposited in the low hill- like structure. These are called sand dunes.

18. The plates move because the molten magma inside the earth moves in a circular motion.

Chapter.4: Air






 Composition of air:

~78% nitrogen

~21% oxygen

~0.93% argon

~0.03% carbon dioxide

~0.04% all others.

2.Weather instruments:

1.Thermometer: Measures temperature.

2.Barometer: Measure atmospheric pressure

3.Rain gauge: Measure the amount of rainfall.

4.Wind vane: Shows the direction of the wind.

3. Nitrogen is the most plentiful gas in the air.

4. The atmosphere is divided into five layers:

1 Troposphere

2.Stratosphere

3.Mesosphere

4.Thermosphere

5.Exosphere.

1.Troposphere: All the weather phenomena like rainfall, fog & hailstorm occur in this layer.

2.Stratosphere: Most ideal for flying airplanes. It contains a layer of ozone gas.

3.Mesosphere: Meteorites burn-up in this layer on entering from space.

4 Thermosphere: This layer helps in radio transmission.

5.Exosphere: The uppermost layer of the atmosphere.

5.Weather: It is hour-to-hour day to day condition of the atmosphere.

6.Climate: The average weather condition of a place for a longer period of time represents the climate.

7.Temperature: The degree of hotness or coldness of the air is called temperature.

8.Insolation: It is the incoming solar energy intercepted by the earth.

9.Air Pressure:

1. It is defined as the pressure exerted by the weight of air on the earth's surface.

2. As we go up the layers of the atmosphere, the pressure falls rapidly.

3. The air pressure is highest at sea level and decreases with height.

4. Horizontally the distribution of air pressure is influenced by the temperature of the air at a given place.

5. The air always moves from the high-pressure area to a low-pressure area.

10.Wind: The movement of air from a high-pressure area to a low-pressure area is called wind.

11. There are three types of winds:

1.Permanent wings.eg.Tradewinds.

2.Seasonal winds - Monsoon in India

3.Local winds-Loo

12. Moisture in the air at any time is known as humidity.

~As the air gets warmer, it's capacity to hold the water vapors increases and so it becomes more & more humid.

13. There are three types of rainfall:

1.Convectional rainfall.

2.Orographic rainfall.

3.Cyclonic rainfall

14.Atmosphere: The blanket if air which surrounds the earth is known as atmosphere.

~Carbon Dioxide creates the greenhouse effect.

~Ozone gas protect us from harmful sun rays.

Chapter.5: Water






1.Water Cycle: The process by which water continually changes its form and circulates between oceans, atmosphere, and land is known as the water cycle.

2.•The ocean bodies and seas contain salty water.

  • The water of the ocean is salty or saline as it contains a large amount of dissolved salt.

  • Most of the salt is sodium chloride or the common table salt that we eat.

3.Terrarium:  It is an artificial enclosure for keeping small house plants.

4.¾ of the earth is covered by water.

5. March 22 is celebrated as World Water Day.

6. Tsunami is a Japanese word that means harbor waves as the harbors get destroyed whenever there is a tsunami.

7.Waves: When the water on the surface of the ocean rises and falls alternately they are called waves.

Tsunami: Huge tidal waves called the tsunami.

Tide: The rhythmic rise and fall of ocean water twice in a day is called a tide.

Causes of tides: The strong gravitational pull exerted by the sun and the moon on the earth's surface cause tides.

8. A major source of freshwater are: Rivers, ponds, springs, and glaciers

9. During the full moon & the new moon days the sun, moon & earth are in the same line and tides are highest. These tides are called spring tides.

When the moon is in its first & last quarter, the ocean water gets drawn in diagonally opposite directions by the gravitational pull of sun & earth, resulting in low tides. These are called neap tides.

10.Ocean currents: Ocean currents are streams of a water flowing constantly on the ocean surface in definite directions.

~The ocean currents may be warm or cold. Generally, the warm ocean currents originate near the equator and move towards the poles.

~The cold currents carry water from polar or higher latitudes to tropical or lower latitudes.

~The Labrador ocean current is cold while the gulf stream is a warm current.

~The ocean currents influence the temperature conditions of the area.

~Warm currents bring about warm temperature over the land surface.

~The areas where the warm and cold currents meet provide the best fishing ground of the world.

The sea around Japan and the Eastern coast of North America are such examples.

NCERT Notes Class 7th Geography continue

Chapter.6: Natural Vegetation And Wildlife






1.The growth  of vegetation depends upon factors:

1.Temperature.

2.Moisture.

2.Natural vegetation is generally classified into three broad categories:

1.Forest.         2.Grassland       3.Shrubs.

3.Forests are classified into six categories:

1.Tropical evergreen forest:

1.Also called tropical rainforest.

2.Found near the equator and close to the tropics.

3.Forest is hot and receives heavy rainfall throughout the year.

4.Trees shed their leaves at different times.

5.Important trees are Rosewood, ebony, mahogany.

2.Tropical deciduous forests:

1.Also called monsoon forest.

2.These regions experience seasonal changes.

3.Important trees are Sal, teak, neem, and shisha.

4.Found in northern Australia, India, and Central America.

3.Temperate Evergreen forests:

1.Located in the mid-latitudinal coastal regions.

2.Both hard & softwood trees are found here.

3.Examples: Oak, pine, eucalyptus etc.

4.Temperate Deciduous  forests:

1.Found in the north-eastern part of USA, China, New Zealand, Chile and Western Europe.

2.Trees shed their leaves in dry season.

3.Common trees are oak, ash, beech etc.

4.Animals are deer, foxes, wolves commonly found.

5. Mediterranean Vegetation:

1.Found in the areas around the mediterranean sea in Europe, Africa & China.

2.These regions are marked for hot dry summers and mild rainy winters.

3.Citrus fruits such as orange, figs, olives, and grapes are cultivated.There is not much wildlife.

6.Coniferous Forests:

1.Found area near between latitudes (50°-70°) of northern-hemisphere.

2.These forests are also called Taiga.

3.Trees are tall, softwoods which are used for making paper and newsprint.

4.Trees are Chir, pine, cedar etc.

7.Grasslands:

There are two types of grasslands:

1.Tropical.           2.Temperate

8.Grasslands are known as different names in different regions.

1.Tropical grasslands:

East Africa: Savanna

Brazil: Campos

Venezuela: Llanos

2.Temperate grasslands:

Argentina: Pampas

N.America: Prairie

S.Africa: Veld

C.Asia: Steppe

Australia: Down

8.Thorny bushes:

1.These are found in the regions like dry deserts.

2.Tropical deserts are located on the western margins of the continents.

9.Tundra type of vegetation found in Polar regions.

Chapter.7: Human Environment- Settlement, Transport, And Communication






1.Settlements: These are places where people build their homes.

2.Two types of Settlements:

1.Permanent settlements

2.Temporary settlements

1. In a permanent settlement, people build homes to live in.

2. Temporary settlements are occupied for a short period of time.

3.Site: The place where a building or a settlement develops is called site.

Natural conditions for selection of an ideal site are:

  1. Favorable climate.

2. Availability of water.

3.Suitable land.

4.Fertile land.

4. Transport: It means by which people or goods move.

5. There are four major means of transport:

  1. Roadways.

2.  Railways.

3. Waterways.

4.Airways

1.Roadways: Most commonly used means of transport.

These are of two types:

1.Metalled(pucca)

2.Unmatteled(kutcha)

Road built undergrounds are called subways underpants.

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

2.Railways: The railways carry heavy goods and people move over long distances, quickly and cheaply.

Indian railways network is largest in Asia.

The trans-Siberian, railways is the world's largest railway system connecting St. Petersburg in Western Russia to Vladivostok on the Pacific coast.

3.Waterways:  These are the cheapest for carrying heavy and bulky loads over long distances.

Two types of waterways:

1.Inland Waterways.

2.Sea routes.

1.Inland waterways: Navigable rivers and lakes.

Eg. Ganga- Brahmaputra river system.

2.Sea routes: Used for transporting merchandise and goods from one country to another.

4.Airways: The fastest way of transport.

Important airports are Delhi, Mumbai, New York, London, Paris etc.

6.Communication: It is the process of conveying messages to others.

7.Mass media: The process through which a large number of people can communicate together is known as mass media.

Eg. Emails, Newspapers, Radio, Tv, and the Internet.

8.The activities practiced by the people:

Agriculture, fishing, foresting, craftwork and trading etc.

Chapter.8: Human-Environment Interactions The Tropical and the Subtropical Region






1.The Spanish explorers discovered:

Amazon River

Amazon river flows through the equator region.

It falls in the Atlantic ocean.

2. The place where a river flows into another body of water is called the river mouth.

3.Tributaries: These are small rivers that join the main river.

4.River Basin: The main river along with all area forming a river basin or coastal areas.

5. Amazon basin is the largest river basin in the world. It drains in portions of Brazil, parts of Peru, Bolivia, Colombia and a small parts of Venezuela.

6.Climate : ( Amazon Basin)

  1. Hot and wet climate throughout the year.

2. Due to the high humidity, the skin feels sticky.

3. It rains almost every day.

4. Thick forests grow.

5. The ground remains dark and damp due to dense forest.

6. Orchids, bromeliads grow as a plant parasite.

7. Fauna & fauna: Hummingbirds animals like monkey, sloth and Rent-A-Car tapir are found.

7.People in the rainforest:

1.M en hunt fish along the rivers, whereas women take care of the crops.

2.T hey mainly grow tapioca, pineapple, and sweet potatoes.

3.T hey practice slash & burn agriculture.

4.T he staple food is manioca also known as cassava.

5.T here are large apartments like houses called maloca with steep roofs.

6.T he development activities are leading to the gradual destruction of the biologically diverse rainforests.

8. Slash and burn is a way of cultivating land where farmers clear a piece of land by cutting down trees and bushes.

  1. The Ganga-Brahmaputra Basin:

1.T he tributaries of Ganga- Brahmaputra together form Ganga-Brahmaputra basin.

2.T he basin lies in the Sub-Zero call region (10°N to 30°N Latitude)

3.T he tributaries of Ganga are Ghagra, son, Chambal, Gandak, Kosi etc.

The main features of this basin are:

1.The plains of the Ganga-Brahmaputra.

2.The mountains and the foothills of the Himalayas.

3.The Sunderban delta.

Climate:

This region experience monsoon type of climate (rain from mid - June to mid-September )

People & region:

1.T his region has a very high density of population.

2. It provides the most suitable land for human habitation.

3.T he soil is fertile and suitable for the cultivation.

4.M ain crop of this region is peddy and the other crops are wheat, maize, sorghum, gram, and millet.

5.C ash crops are sugarcane and just.

6.T he delta area is covered with the mangrove forest.

7.T here is a variety of wildlife in the basin.

10.MAIN cities on the bank of river Ganga are Allahabad, Kanpur, Varanasi, Lucknow, and Patna.

11.Population density: It means the number of persons that live in one square km of area.

12. Kolkata is an important port on the river Hooghly.

One-horned rhinoceros found in the Brahmaputra plains.

13. Kaziranga & Manas  Wildlife sanctuaries are in Assam.

Chapter.9: Life in the Temperate Grasslands






1.Two broad categories of world’s grasslands:

  1. Which found in tropical regions.

2. Which found in temperate regions.

2.The Prairies.

1. These are the temperate grasslands of the North-America.

2.T he prairies are bound by the rocky mountains in the west and the Great lake in the east.

3. Prairies cover parts of USA & parts of Canada.

4. An area in South is drained by the tributaries of river Mississippi & Canadian prairies are drained by the tributaries of Saskatchewan river.

5.T he grasslands of Prairies were homes of American-Indians more popularly known as Blackfoot Indians.

3.Chinook: It is a hot wind that blows in winter and therefore raises the temperature in a short time.

4.The cattle farms in the North-American grasslands known as Ranches.

Ranches look after by sturdy men called cowboys.

5. Bison or the American buffalo is the most important animal of this region.

6. The Prairies are known as the Granaries of the World due to the huge surplus production of wheat.

7.Velds:

1.The temperate grasslands of South-Africa.

2. It is bound by the Drakensberg mountains on the east.

3. Kalahari desert lies to its west.

4. The tributaries of rivers Orange and Limpopo drain this region.

2.Climate:

1. The welds have a mild climate due to AN Influence of Indian ocean.

2. Summers are short and warm.

3.Johannesburg records about 20°C temperature in the summers.

4. The velds receive rainfall in the

summer months from November to February.

3.Flora & Fauna.

1. The vegetation cover is sparse

2. Red grass grows in bush velds.

3. Animals are lions, leopards, cheetah, and kudu.

4.People:

1. Velds are known for cattle rearing and mining.

2. Sheep rearing is the most important occupation of the people.

3. Sheep is the breed for the wool and has given rise to wool industry the Velds.

4. Merino sheep is a popular species and their wool is very warm.

5. Iron & steel industry has developed where coal and iron are present.

6.J Johannesburg is known for being the gold capital of the world.

7.K Kimberly is famous for its diamond mines.

Chapter.10: Life in the Deserts






1. Deserts are of two types:

1. Hot desert

2. Cold desert.

1. Hot desert: Sahara

1. It is situated in North Africa.

2. It is the world's largest desert.

3. It has an area of around 8.54 million sq.km.

4. The Sahara desert touches 11 countries.

2.Climate:

1.Scorching hot & parch dry.

2. Short rainy season.

3. The sky is cloudless or dry.

4. The day temperature may soon as high as 50°C.

5. The nights are freezing cold.

3.Flora & Fauna.

1. Some common plants, trees are:

Cactus, dates, palms, acacia etc.

2. Some common animals are:

Camels, hyenas, foxes, scorpions and many varieties of lizards.

4.People:

1. Group of people is Bedouins and Tuaregs.

2. They wear heavy robes as protection against dust storms and hot winds.

2.The Cold Desert: Ladakh

1. Lying in the Great Himalayas on the Eastern side of Jammu and Kashmir.

2. The Karakoram range in the north and Zanskar mountain in the south enclose it.

3. Indus is the most important river.

4. Gangri glacier is important.

5. The day temperature in the summer is just above zero degrees & night temperature well below -30°.

6. There is a little rainfall.

2.Flora & Fauna:

1. Some common animals are Robins, red stars, Tibetan snowcock, reven and hoopoe, wild goat & sheep, yak and special kinds of dogs.

2. Yak’s milk is used to make cheese and butter.

3.People

1. People here are either Muslims or Buddhists.

2. Leh, the capital of Ladakh is well connected both by road & air.

3. National highway 1A connects Leh to the Kashmir valley through Zoji la pass.

4. Ladakh is also known as Khapa- Chan which means snow land.

~Finest cricket bats are made from the wood of the willow tree.

~Chiru or the antelope is an endangered species.

4. Tourists visits to the Gompass, treks to see the meadows and glaciers, witnessing ceremonies and festivals are important activities.

NCERT Notes Class 7th Geography(End)


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NCERT Notes Class 7th Geography

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