The Earth in the Solar System
Full moon(Poornima): Once in a month
New moon(Amavasya): after a fortnight of full moon,no moon at all.
Celestial bodies: The sun, the moon and all those objects shining in the night sky are called celestial bodies.
Stars:Some celestial bodies are very big and hot. They are made up of gases. They have their own heat and light, which they emit in large amounts. These celestial bodies are called stars. The sun is a star.
Constellations : various patterns formed by different groups of stars. ex. Ursa Major(Big Bear),Saptarishi(Sapta-seven, rishi-sages) forms a part of Ursa Major constellation.
Pole star: The North star indicates the north direction. It is also called the Pole Star.
Planet: Some celestial bodies do not have their own heat and light. They are lit by the light of the stars. Such bodies are called planets. The word ‘planet’ comes from the Greek word “Planetai” which means ‘wanderers’.
Satellite : The moon that we see in the sky is a satellite. It is a companion of our earth and moves round it. Like our earth, there are eight other planets that get heat and light from the sun. Some of them have their moons too.
Solar System : The sun, eight planets, satellites and some other celestial bodies known as asteroids and meteoroids form the solar system.
The Sun (Roman mythology 'sol' ::Sungods, Solar:: related to sun): The sun is in the centre of the solar system. It is huge and made up of extremely hot gases. It provides the pulling force that binds the solar system. The sun is the ultimate source of heat and light for the solar system.The sun is about 150 million km away from the earth.Light travels at the speed of about 300,000 km per second. Yet, even with this speed, the light of the sun takes about eight minutes to reach the earth.
Planet: There are eight planets in our solar system. In order of their distance from the sun, they are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
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Orbits : All the eight planets of the solar system move around the sun in fixed paths. These paths are elongated. They are called orbits.Mercury is nearest to the sun. It takes only about 88 days to complete one round along its orbit. Venus is considered as ‘Earth’s-twin’ because its size and shape are very much similar to that of the earth.Pluto was considered a planet till August 2006 but removed by International Astronomical Union.
Dwarf planets : Pluto like other celestial objects (Ceres, 2003 UB313) discovered in recent past may be called ‘dwarf planets'.
Earth : The earth is the third nearest planet to the sun. In size, it is the fifth largest planet. It is slightly flattened at the poles. That is why, its shape is described as a Geoid. Geoid means an earth-like shape.
Geography : Greek words, ge::'earth', 'graphia':: 'writing'
Geology : 'logy':: Logia, study of the earth
Geometry: 'metry'::metrial, measurement of the earth
Geoid: 'oid':: oeides, resembling the shape or form of the earth.
The Moon: Our earth has only one satellite, that is, the moon. Its diametre is only one-quarter that of the earth. It appears so big because it is nearer to our planet than other celestial bodies. It is about 3,84,400 km away from us. The moon moves around the earth in about 27 days. It takes exactly the same time to complete one spin. As a result, only one side of the moon is visible to us on the earth. The moon does not have conditions favourable for life. It has neither water nor air.
Satellite: A Satellite is a celestial body that moves around the planets in the same way as the planets move around the sun.
Human-made Satellite : A Human-made Satellite is an artificial body. It is designed by scientists to gather information about the universe or for communication. It is carried by a rocket and placed in the orbit around the earth.ex. INSAT,IRS,EDUSAT etc.
Asteroids: there are numerous tiny bodies which also move around the sun. These bodies are called asteroids. They are found between the orbits of Mars and Jupiter.
Meteoroids : The small pieces of rocks which move around the sun are called meteoroids. Sometimes these meteoroids come near the earth and tend to drop upon it. During this process due to friction with the air they get heated up and burn. It causes a flash of light. Sometimes, a meteor without being completely burnt, falls on the earth and creates a hollow.
Milky Way galaxy : a cluster of millions of stars. This band is the Milky Way galaxy. Our solar system is a part of this galaxy.In ancient India, it was imagined to be a river of light flowing in the sky. Thus, it was named Akash Ganga.
Galaxy : A galaxy is a huge system of billions of stars, and clouds of dust and gases.
Universe:Millions of galaxies that make the Universe.
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Globe : Latitudes & Longitudes
Globe : Globe is a true model (miniature form) of the earth.
Axis: Imginary line around which earth moves.
Equator : Another imaginary line running on the globe divides it into two equal parts. This line is known as the equator. The northern half of the earth is known as the Northern Hemisphere and the southern half is known as the Southern Hemisphere. Both are equal halves. The equator is an imaginary circular line and is a very important reference point to locate places on the earth. All parallel circles from the equator up to the poles are called parallels of latitudes. Latitudes are measured in degrees.
The equator represents the zero degree latitude.Since the distance from the equator to either of the poles is one-fourth of a circle round the earth, it will measure 1/4th of 360 degrees, i.e. 90°. Thus, 90 degrees north latitude marks the North Pole and 90 degrees south latitude marks the South Pole.
All parallels north of the equator are called ‘north latitudes.’ Similarly all parallels south of the equator are called ‘south latitudes'. The value of each latitude is, therefore, followed by either the word north or south. Generally, this is indicated by the letter ‘N’ or ‘S’.
By measuring the angle of the Pole Star from your place, you can know the latitude of your place.
Important Parallels of Latitudes :
Equator : 0'
North Pole : 90'N
South Pole : 90'S
(i) Tropic of Cancer (23½° N) in the Northern Hemisphere.
(ii) Tropic of Capricorn (23½° S) in the Southern Hemisphere.
(iii) Arctic Circle at 66½° north of the equator.
(iv) Antarctic Circle at 66½° south of the equator.
Heat Zones of the Earth
Torrid Zone : The mid-day sun is exactly overhead at least once a year on all latitudes in between the Tropic of Cancer and the Tropic of Capricorn. This area, therefore, receives the maximum heat and is called the Torrid Zone.
Temperate Zones: The mid-day sun never shines overhead on any latitude beyond the Tropic of Cancer and the Tropic of Capricorn. The angle of the sun’s rays goes on decreasing towards the poles. As such, the areas bounded by the Tropic of Cancer and the Arctic Circle in the Northern Hemisphere, and the Tropic of Capricorn and the Antarctic Circle in the Southern Hemisphere, have moderate temperatures. These are, therefore, called Temperate Zones.
Frigid Zones : Areas lying between the Arctic Circle and the North Pole in the Northern Hemisphere and the Antarctic Circle and the South Pole in the Southern Hemisphere, are very cold. It is because here the sun does not rise much above the horizon. Therefore, its rays are always slanting and provide less heat. These are, therefore, called Frigid Zones (very cold).
Longitudes:We must find out how far east or west places are from a given line of reference running from the North Pole to the South Pole. These lines of references are called the meridians of longitude.
Prime Meridian : Unlike parallels of latitude, all meridians are of equal length. Thus, it was difficult to number the meridians. Hence, all countries decided that the count should begin from the meridian which passed through Greenwich, where the British Royal Observatory is located. This meridian is called the Prime Meridian.
The Prime Meridian and 180° meridian divide the earth into two equal halves, the Eastern Hemisphere and the Western Hemisphere. Therefore, the longitude of a place is followed by the letter E for the east and W for the west. It is, however, interesting to note that 180° East and 180° West meridians are on the same line.
Fig : Timezone of the world
Longitude and Time
As the earth rotates from west to east, those places east of Greenwich will be ahead of Greenwich time and those to the west will be behind it. The rate of difference can be calculated as follows. The earth rotates 360° in about 24 hours, which means 15° an hour or 1° in four minutes. Thus, when it is 12 noon at Greenwich, the time at 15° east of Greenwich will be 15 × 4 = 60 minutes, i.e., 1 hour ahead of Greenwich time, which means 1 p.m. But at 15° west of Greenwich, the time will be behind Greenwich time by one hour, i.e., it will be 11.00 a.m. Similarly, at 180°, it will be midnight when it is 12 noon at Greenwich.
In India, the longitude of 82½° E (82° 30'E) is treated as the standard meridian. The local time at this meridian is taken as the standard time for the whole country. It is known as the Indian Standard Time (IST).
India located east of Greenwich at 82°30'E is 5 hours and 30 minutes ahead of GMT.
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Motion of the Earth
Rotation : Rotation is the movement of the earth on its axis.
Revolution: The movement of the earth around the sun in a fixed path or orbit is called Revolution. It takes 365 and 1/4 days to revolve around the sun.It is clear that the earth is going around the sun in an elliptical orbit. Six hours saved every year are added to make one
day (24 hours) over a span of four years.A year with 366 days is called a leap year.
Seasons: A year is usually divided into summer, winter, spring and autumn seasons. Seasons change due to the change in the position of the earth around the sun.
Orbital plane : The axis of the earth which is an imaginary line, makes an angle of 66½° with its orbital plane. The plane formed by the orbit is known as the orbital plane.
Aryabhata had stated that ‘the earth is round and rotates on its own axis.’
Circle of Illumination : The circle that divides the day from night on the globe is called the circle of illumination.Due to the spherical shape of the earth, only half of it gets light from the sun at a time. The portion facing the sun experiences day while the other half away from the sun experiences night.
Summer Solstice : You will see that on 21st June, the Northern Hemisphere is tilted towards the sun. The rays of the sun fall directly on the Tropic of Cancer. As a result, these areas receive more heat. The areas near the poles receive less heat as the rays of the sun are slanting. The North Pole is inclined towards the sun and the places beyond the Arctic Circle experience continuous daylight for about six months. Since a large portion of the Northern Hemisphere is getting light from the sun, it is summer in the regions north of the equator. The longest day and the shortest night at these places occur on 21st June. At this time in the Southern Hemisphere all these conditions are reversed. It is winter season there. The nights are longer than the days. This position of the earth is called the Summer Solstice.
Winter Solstice: On 22nd December, the Tropic of Capricorn receives direct rays of the sun as the South Pole tilts towards it. As the sun’s rays fall vertically at the Tropic of Capricorn (23½° S), a larger portion of the Southern Hemisphere gets light. Therefore, it is summer in the Southern Hemisphere with longer days and shorter nights. The reverse happens in the Northern Hemisphere. This position of the earth is called the Winter Solstice.
Equinox : On 21st March and September 23rd, direct rays of the sun fall on the equator. At this position, neither of the poles is tilted towards the sun; so, the whole earth experiences equal days and equal nights. This is called an equinox.On 23rd September, it is autumn season in the Northern Hemisphere and spring season in the Southern Hemisphere. The opposite is the case on 21st March.when it is spring in the Northern Hemisphere and autumn in the Southern Hemisphere.
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Maps
Map : A map is a representation or a drawing of the earth’s surface or a part of it drawn on a flat surface according to a scale. But it is impossible to flatten a round shape completely.
Physical Maps: Maps showing natural features of the earth such as mountains, plateaus, plains, rivers, oceans etc. are called physical or relief maps.
Political Maps: Maps showing cities, towns and villages, and different countries and states of the world with their boundaries are called political maps.
Thematic Maps : Some maps focus on specific information; such as road,maps, rainfall maps, maps showing distribution of forests, industries etc. are known as thematic maps.
Componets of Maps : Distance, direction and symbols.
Distance :
Scale is the ratio between the actual distance on the ground and the distance shown on the map.
Small scale map: When large areas like continents or countries are to be shown on a paper, then we use a small scale. For example 5 cm. on the map shows 500 km. of the ground. It is called a small scale map.
Large scale map : When a small area like your village or town is to be shown on paper, then we use a large scale that is 5 cm. on the map shows 500 metres only on the ground. It is called a large scale map.Large scale maps give more information than small scale maps.
Direction :
Most maps contain an arrow marked with the letter ‘N’ at the upper right hand corner.This arrow shows the north direction. It is called the north line. Four major directions(cardinal points) : North, South, East and West. Other four intermediate directions are north-east (NE), south east( SE), south-west (SW) and north-west (NW).
Compass : an instrument used to find out main directions. Its magnetic needle always points towards north-south direction.
Symbols : Maps have a universal language that can be understood by all. There is an international agreement regarding the use of these symbols. These are called conventional symbols.
Sketch: A sketch is a drawing mainly based on memory and spot observation and not to scale. Sometimes a rough drawing is required of an area to tell where a particular place is located with respect to other places.
Plan : A plan is a drawing of a small area on a large scale. A large-scale map gives lot of information, but there are certain things which we may sometimes want to know for example the length and breadth of a room, which can’t be shown in a map.
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Major Domains of the Earth
Human beings can live here because the life sustaining elements of land, water and air are present on the earth. The surface of the earth is a complex zone in which three main components of the environment meet, overlap and interact.
Lithosphere : The solid portion of the earth on which we live is called the Lithosphere.
Two major divisions of the earth's surface: i) Continents ii) Ocean basins
Continents : The large landmasses. These continents are – Asia, Europe, Africa, North America, South America, Australia and Antarctica.
Asia: Asia is the largest continent. It covers about one third of the total land area of the earth. The continent lies in the Eastern Hemisphere. The Tropic of Cancer passes through this continent. Asia is separated from Europe by the Ural mountains on the west.
Europe: Europe is much smaller than Asia. The continent lies to the west of Asia. The Arctic Circle passes through it. It is bound by water bodies on three sides.
The combined landmass of Europe and Asia is called the Eurasia.
Africa: Africa is the second largest continent after Asia. The Equator or 00 latitude runs almost through the middle of the continent. A large part of Africa lies in the Northern Hemisphere.Only continent through which the Tropic of Cancer, the Equator and the Tropic of Capricorn pass.
The Sahara Desert, the world’s largest hot desert, is located in Africa. The continent is bound on all sides by oceans and seas.The world’s longest river the Nile, flows through Africa.
North America : North America is the third largest continent of the world. It is linked to South America by a very narrow strip of land called the Isthmus of Panama. The continent lies completely in the Northern and Western Hemisphere. Three oceans surround this continent.
Strait : A strait is a narrow passage of water connecting two large woterbodies like seas and oceans.
Isthmas: A narrow strip of land joining two landmasses.
South America : South America lies mostly in the Southern Hemisphere. The Andes, world’s longest mountain range, runs through its length from north to south.South America has the world’s largest river, the Amazon.
Australia : Australia is the smallest continent that lies entirely in the Southern Hemisphere. It is surrounded on all sides by the oceans and seas. It is called an island continent.
Antarctica : Antarctica, completely in the Southern Hemisphere, is a huge continent. The South Pole lies almost at the centre of this continent. As it is located in the South Polar Region, it is permanently covered with thick ice sheets. There are no permanent human settlements. Many countries have research stations in Antarctica. India also has research stations there. These are named as Maitri and Dakshin Gangotri.
Ocean basins : the huge water bodies.All the oceans of the world are connected with one another.The level of seawater remains the same everywhere. Elevation of land is measured from the level of the sea, which is taken as zero.
The highest mountain peak Mt. Everest is 8,848 metres above the sea level. The greatest depth of 11,022 metres is recorded at Mariana Trench in the Pacific Ocean.
Edmund Hillary (New Zealand) and Tenzing Norgay Sherpa (India) were the first men to climb the highest mountain peak Mt. Everest on the planet earth on 29th May, 1953. Junko Tabei (Japan) was the first woman to reach the summit on 16th May, 1975. The first Indian woman to climb the highest peak on 23rd May, 1984 was Bachendri Pal.
Atmosphere : The gaseous layers that surround the earth, is the Atmosphere,where oxygen, nitrogen, carbon-dioxide and other gases are found.It provides us with the air we breathe and protects us from the harmful effects of sun’s rays. The atmosphere extends up to a height of about 1,600 kilometres. The atmosphere is divided into five layers based on composition, temperature and other properties. These layers starting from earth’s surface are called the troposphere, the stratosphere, the mesosphere, the thermosphere and the exosphere. Nitrogen 78 per cent, oxygen 21 per cent and other gases like carbondioxide, argon and others comprise 1 per cent by volume.
Oxygen is the breath of life while nitrogen helps in the growth of living organisms. Carbon dioxide, though present in minute amount, is important as it absorbs heat radiated by the earth, thereby keeping the planet warm. It is also essential for the growth of plants. The density of the atmosphere varies with height , it is maximum at sea level and decreases rapidly as we go up. The temperature also decrease as we go up.Air moves from high pressure to low pressure, movind air is known as wind.
Hydrosphere : Water covers a very big area of the earth’s surface and this area is called the Hydrosphere. The Hydrosphere comprises water in all its forms, that is, ice, water and water vapour.
The earth is called the blue planet due huge amount of water. More than 97% of the Earth’s water is found in the oceans and is too salty for human use.a very small percentage is available as fresh water for human use in the form of rivers, icesheets and glaciers or under the ground.
Ocean : Oceans are the major part of hydrosphere. They are all interconnected. The ocean waters are always moving. The three chief movements of ocean waters are the waves, the tides and the ocean currents. The five major oceans are the Pacific Ocean, the Atlantic Ocean, the Indian Ocean, the Southern Ocean and the Arctic Ocean, in order of their size.
Pecific ocean: The Pacific Ocean is the largest ocean. It is spread over one-third of the earth. Mariana Trench, the deepest part of the earth, lies in the Pacific Ocean. The Pacific Ocean is almost circular in shape. Asia, Australia,North and South Americas surround it.
Atlantic ocean : The Atlantic Ocean is the second largest Ocean in the world. It is ‘S’ shaped. It is flanked by the North and South Americas on the western side, and Europe and Africa on the eastern side. The coastline of Atlantic Ocean is highly indented. This irregular and indented coastline provides ideal location for natural harbours and ports. From the point of view of commerce, it is the busiest Ocean.
India ocean: The Indian Ocean is the only ocean named after a country, that is, India. The shape of ocean is almost triangular.In the north, it is bound by Asia, in the west by Africa and in the east by Australia.
Southern Ocean : The Southern Ocean encircles the continent of Antarctica and extends northward to 60 degrees south latitude.
Arctic Ocean : The Arctic Ocean is located within the Arctic Circle and surrounds the North Pole. It is connected with the Pacific Ocean by a narrow stretch of shallow water known as Berring strait. It is bound by northern coasts of North America and Eurasia.
Biosphere : The Biosphere is the narrow zone where we find land, water and air together, which contains all forms of life. Several species of organisms that vary in size from microbes and bacteria to huge mammals. All the living organisms including humans are linked to each other and to the biosphere for survival.The organisms in the biosphere may broadly be divided into the plant kingdom and the animal kingdom.Increase in the amount of CO2 leads to increase in global temperatures. O2 This is termed as global warming.
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Major Landforms of the Earth
Within the earth, a continuous movement is taking place.
Internal process :leads to the upliftment and sinking of the earth’s surface at several places.
External process : the continuous wearing down and rebuilding of the land surface.
Erosion : wearing away of the earth's surface
Deposition : The surface is being lowered by the process of erosion and rebuilt by the process of deposition.
These two processes are carried out by running water, ice and wind.
Hiils : A hill is a land surface that rises higher than the surrounding area. Generally, a steep hill with an elevation of more than 600 metres is termed as a mountain.
Mountains : A mountain is any natural elevation of the earth surface. The mountains may have a small summit and a broad base. It is considerably higher than the surrounding area. Some mountains are even higher than the clouds. As you go higher, the climate becomes colder.
There are some mountains you cannot see as they are under the sea. Mauna Kea (Hawaii) in the Pacific Ocean is an undersea mountain. It is higher than Mount Everest being 10,205 metres high.
Types of Mountains :
i) Fold Mountains:: rugged relief and high conical peaks. Ex (young fold mountains)The Himalayan & the Alps, (old fold mountains) The Aravali range(oldest), the Appalachians(North America), Ural mountains(Russia).
ii) Block Mountains:: Block Mountains are created when large areas are broken and displaced vertically. The uplifted blocks are termed as horsts and the lowered blocks are called graben. Ex. the Rhine valley(Europe) and the Vosges mountains(Europe).
iii)Volcanic Mountains:: Formed due to volcanic activity. Ex. Mt. Kilimanjaro(Africa), Mt. Fujiyama(Japan)
Importance of Mountains : Storehouse of water, glaciers, river valleys and terrace, rich variety of flora and fauna, forest, tourist site.
Range : Arrangement of the mountains, many mountain systems consist of a series of parallel ranges extending over hundreds of kilometres. The Himalayas(Asia), the Alps(Europe) and the Andes(South America) are some of the examples.
Glaciers : In some mountains, there are permanently frozen rivers of ice. They are called glaciers.
Plateaus : A plateau is an elevated flat land. It is a flat-topped table land standing above the surrounding area. Height varies from few hundred metres to several thousand metres. Ex the Deccan plateau, East African plateau(Kenya), Tanzania, Uganda and the Western plateau(Aus). Highest plateau in the world: Tibet plateau(height 4000-6000 metres). Plateaus are rich in mineral deposits.
African plateau : gold and diamond mining.
Indian Plateau : iron, coal and mangese(all are found in Chhotanagpur plateau).
Importance of Plateau: minerals, waterfallls:Hundru falls(Chhotanagpur plateau,river : Subarnarekha ), Jog falls(Karnataka), lava plateaus: black soil
Plains : Plains are large stretches of flat land. They are, generally, not more than 200 metres above mean sea level. most of the plains are formed by rivers and their tributaries.Plains are very fertile. Ex. Asia(Ganga & Brahmaputra in India,Yangize in China) and North America.
.Alluvial deposits : very fine soils brought by rivers and deposited in the river basins,
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INDIA : In the north, it is bound by the lofty Himalayas. The Arabian Sea in the west, the Bay of Bengal in the east and the Indian Ocean in the south, wash the shores of the Indian peninsula.
Area : 3.28 million sq. km. North-south (Kashmir to Kanyakumari is abt 3200km), east-west 2900km(Arunchal Pradesh to Kuchchh). Second most populated country.
Large countries which stretch extensively from east to west do not have a single Standard Time for the whole country. The USA and Canada have seven and six time zones respectively. Russia have 11 time zones.
Location : India is located in the northern hemisphere. Tropic of Cancer(23°30'N),
south to north : 8°4'N and 37°6'N latitudes. West - east : 68°7'E and 97°25'E longitudes
India's Neighbours : Seven countries : Pakistan, Nepal, Bhutan,Bangladesh, Myanmar, China, Shri Lanka(Palk strait).
Division of India(On the basis of languages mainly)29 states , 7 Unon Territories. Telangana became the 29th state of India on 2 June 2014.
Capital : Delhi
Fig : Political map of India
Physical Division:
Himalaya : Him + alaya mean 'the abode of snow.'
Himalayan mountains are divided into three main parallel ranges.:
i) Great Himalaya(Himadri): World's highest peaks are located in this range.
ii)Middle Himalaya(Himachal) : Lies to to the south of Himadri. Popular hill stations.
iii) The Shiwalik: The southmost ranges.
The Northern Indian plains : lie to the south of the Himalayas. They are generally level and flat. These are formed by the alluvial deposits laid down by the rivers– the Indus, the Ganga, the Brahmaputra and their tributaries.
The Great Indian desert : In the western part of of india, dry , hot and sandy stretch of land, very little vegetation.
Peninsular plateau : to the south of northern plains, triangular in shape, relief is highly uneven. Region of many hill ranges (Vindhyas & Satpuras) and valleys ex Aravali hills(1 of the oldest), river Narmada & Tapi(west flowing drain into the Arbian Sea).
The Western Ghats or Sahyadris border the plateau in the west and the Eastern Ghats provide the eastern boundary. While the Western Ghats are almost continuous, the Eastern Ghats are broken and uneven.
Delta : The Ganga and the Brahma putra form the world’s largest delta, the Sundarbans delta. The delta is triangular in shape.The Sunderban delta is formed where the Ganga and Brahmaputra flow
into the Bay of Bengal.
Coastal plains : To the West of the Western Ghats and the East of Eastern Ghats lie the Coastal plains. The western coastal plains are very narrow. The eastern Coastal plains are much border. East flowing river : Mahanadi, Godavari, Krishna and Kaveri.
Lakshadweep Island: Located in the Arabian Sea. These are coral islands located off the coast of Kerala.
Andaman & the Nicobar Island : lie to the southeast of the Indian mainland in the Bay of Bengal.
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Climate, Vegetation and Wildlife
Weather : weather is about day to day changes in the atmosphere. It includes changes in temperature, rainfall and sunshine etc.
Broadly, the major seasons recognised in India are:
• Cold Weather Season (Winter) December to February: Sun rays do not fall directly on in the region.
• Hot Weather Season (Summer) March to May: More or less direct sun rays.
loo : hot and dry winds during the day.
• Southwest Monsoon Season (Rainy) June to September: The winds blow from Arabian Sea and Bay of Bengal towards the land. They carry moisture with them. When these winds strike the mountain barriers, rainfall occurs.
• Season of Retreating Monsoon (Autumn) October and November : Winds move back from the mainland to the Bay of Bengal. This is the season of the retreating monsoons. Rainfall in Tamil Nadu and Andhra Pradesh.
Monsoon : Arabic word 'mausim' : Seasons.
The climate of a place is affected by its location, altitude, distance from the sea, and relief.
Jaisalmer and Bikaner in the desert of Rajasthan are very hot, while Drass and Kargil in Jammu and Kashmir are freezing cold. Coastal places like Mumbai and Kolkata experience moderate climate.
Mawsynram in Meghalaya receives the world’s highest rainfall, while in a particular year it might not rain at all in Jaisalmer in Rajasthan.
Natural Vegetation : The grasses, shrubs and trees, which grow on their own without interference or help from human beings are called natural vegetation.
Vegetation of India can be divided into five types :
i) Tropical evergreen forest: Heavy rainfall, forest are dense i.e. no sunlight to the ground,many species of tree which shed their leaves at different times of the year hence always appear green. imp trees : mahogany, ebony and rosewood. Andaman and Nicobar Islands, parts of North-Eastern states and a narrow strip of the Western slope of the Western Ghats are home of these forests.
ii) Tropical deciduous forest : In large part of country, also called monsoon forests, dense, shed leaves at a particular time of the year. imp tree : sal, teak, peepal,neem,shisham. MP,UP,Bihar,Jharkhand, Chattishgarh, Odisha and in parts of Maharashtra.
iii)Thorny bushes : dry areas of the country. leaves are in the form of spines to reduce the loss of water. Trees: Cactus, khair, babool, keekar. Area : Rajasthan, Punjab, Haryana, Eastern slopes of Western Ghats and Gujarat.
iv) Mountain vegetation : variation in the height of the trees, increasing height falling temperature.At a height 1500-2500m most of the trees are conical in shape(called coniferous trees). imp trees : Chir, Pine, Deodar.
v) Mangrove forest : saline water forest, found mainly in Sunderbans in West Bengal and in the Andaman and Nicobar Islands. imp tree : Sundary after which Sunderbans have been named.
Wild Life : Forests are home to a variety of wild life. There are thousands of species of animals and a large variety of reptiles, amphibians, mammals, birds, insects and worms which dwell in the forest.
National Animal : Tiger
National Bird : Peacock
Government initiative : Project Tiger and Project Elephant
Full moon(Poornima): Once in a month
New moon(Amavasya): after a fortnight of full moon,no moon at all.
Celestial bodies: The sun, the moon and all those objects shining in the night sky are called celestial bodies.
Stars:Some celestial bodies are very big and hot. They are made up of gases. They have their own heat and light, which they emit in large amounts. These celestial bodies are called stars. The sun is a star.
Constellations : various patterns formed by different groups of stars. ex. Ursa Major(Big Bear),Saptarishi(Sapta-seven, rishi-sages) forms a part of Ursa Major constellation.
Pole star: The North star indicates the north direction. It is also called the Pole Star.
Planet: Some celestial bodies do not have their own heat and light. They are lit by the light of the stars. Such bodies are called planets. The word ‘planet’ comes from the Greek word “Planetai” which means ‘wanderers’.
Satellite : The moon that we see in the sky is a satellite. It is a companion of our earth and moves round it. Like our earth, there are eight other planets that get heat and light from the sun. Some of them have their moons too.
Solar System : The sun, eight planets, satellites and some other celestial bodies known as asteroids and meteoroids form the solar system.
The Sun (Roman mythology 'sol' ::Sungods, Solar:: related to sun): The sun is in the centre of the solar system. It is huge and made up of extremely hot gases. It provides the pulling force that binds the solar system. The sun is the ultimate source of heat and light for the solar system.The sun is about 150 million km away from the earth.Light travels at the speed of about 300,000 km per second. Yet, even with this speed, the light of the sun takes about eight minutes to reach the earth.
Planet: There are eight planets in our solar system. In order of their distance from the sun, they are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
"MY VERY EFFICIENT MOTHER JUST SERVED US NUTS."
Orbits : All the eight planets of the solar system move around the sun in fixed paths. These paths are elongated. They are called orbits.Mercury is nearest to the sun. It takes only about 88 days to complete one round along its orbit. Venus is considered as ‘Earth’s-twin’ because its size and shape are very much similar to that of the earth.Pluto was considered a planet till August 2006 but removed by International Astronomical Union.
Dwarf planets : Pluto like other celestial objects (Ceres, 2003 UB313) discovered in recent past may be called ‘dwarf planets'.
Earth : The earth is the third nearest planet to the sun. In size, it is the fifth largest planet. It is slightly flattened at the poles. That is why, its shape is described as a Geoid. Geoid means an earth-like shape.
Geography : Greek words, ge::'earth', 'graphia':: 'writing'
Geology : 'logy':: Logia, study of the earth
Geometry: 'metry'::metrial, measurement of the earth
Geoid: 'oid':: oeides, resembling the shape or form of the earth.
The Moon: Our earth has only one satellite, that is, the moon. Its diametre is only one-quarter that of the earth. It appears so big because it is nearer to our planet than other celestial bodies. It is about 3,84,400 km away from us. The moon moves around the earth in about 27 days. It takes exactly the same time to complete one spin. As a result, only one side of the moon is visible to us on the earth. The moon does not have conditions favourable for life. It has neither water nor air.
Satellite: A Satellite is a celestial body that moves around the planets in the same way as the planets move around the sun.
Human-made Satellite : A Human-made Satellite is an artificial body. It is designed by scientists to gather information about the universe or for communication. It is carried by a rocket and placed in the orbit around the earth.ex. INSAT,IRS,EDUSAT etc.
Asteroids: there are numerous tiny bodies which also move around the sun. These bodies are called asteroids. They are found between the orbits of Mars and Jupiter.
Meteoroids : The small pieces of rocks which move around the sun are called meteoroids. Sometimes these meteoroids come near the earth and tend to drop upon it. During this process due to friction with the air they get heated up and burn. It causes a flash of light. Sometimes, a meteor without being completely burnt, falls on the earth and creates a hollow.
Milky Way galaxy : a cluster of millions of stars. This band is the Milky Way galaxy. Our solar system is a part of this galaxy.In ancient India, it was imagined to be a river of light flowing in the sky. Thus, it was named Akash Ganga.
Galaxy : A galaxy is a huge system of billions of stars, and clouds of dust and gases.
Universe:Millions of galaxies that make the Universe.
Globe : Latitudes & Longitudes
Globe : Globe is a true model (miniature form) of the earth.
Axis: Imginary line around which earth moves.
Equator : Another imaginary line running on the globe divides it into two equal parts. This line is known as the equator. The northern half of the earth is known as the Northern Hemisphere and the southern half is known as the Southern Hemisphere. Both are equal halves. The equator is an imaginary circular line and is a very important reference point to locate places on the earth. All parallel circles from the equator up to the poles are called parallels of latitudes. Latitudes are measured in degrees.
The equator represents the zero degree latitude.Since the distance from the equator to either of the poles is one-fourth of a circle round the earth, it will measure 1/4th of 360 degrees, i.e. 90°. Thus, 90 degrees north latitude marks the North Pole and 90 degrees south latitude marks the South Pole.
All parallels north of the equator are called ‘north latitudes.’ Similarly all parallels south of the equator are called ‘south latitudes'. The value of each latitude is, therefore, followed by either the word north or south. Generally, this is indicated by the letter ‘N’ or ‘S’.
By measuring the angle of the Pole Star from your place, you can know the latitude of your place.
Important Parallels of Latitudes :
Equator : 0'
North Pole : 90'N
South Pole : 90'S
(i) Tropic of Cancer (23½° N) in the Northern Hemisphere.
(ii) Tropic of Capricorn (23½° S) in the Southern Hemisphere.
(iii) Arctic Circle at 66½° north of the equator.
(iv) Antarctic Circle at 66½° south of the equator.
Heat Zones of the Earth
Torrid Zone : The mid-day sun is exactly overhead at least once a year on all latitudes in between the Tropic of Cancer and the Tropic of Capricorn. This area, therefore, receives the maximum heat and is called the Torrid Zone.
Temperate Zones: The mid-day sun never shines overhead on any latitude beyond the Tropic of Cancer and the Tropic of Capricorn. The angle of the sun’s rays goes on decreasing towards the poles. As such, the areas bounded by the Tropic of Cancer and the Arctic Circle in the Northern Hemisphere, and the Tropic of Capricorn and the Antarctic Circle in the Southern Hemisphere, have moderate temperatures. These are, therefore, called Temperate Zones.
Frigid Zones : Areas lying between the Arctic Circle and the North Pole in the Northern Hemisphere and the Antarctic Circle and the South Pole in the Southern Hemisphere, are very cold. It is because here the sun does not rise much above the horizon. Therefore, its rays are always slanting and provide less heat. These are, therefore, called Frigid Zones (very cold).
Longitudes:We must find out how far east or west places are from a given line of reference running from the North Pole to the South Pole. These lines of references are called the meridians of longitude.
Prime Meridian : Unlike parallels of latitude, all meridians are of equal length. Thus, it was difficult to number the meridians. Hence, all countries decided that the count should begin from the meridian which passed through Greenwich, where the British Royal Observatory is located. This meridian is called the Prime Meridian.
The Prime Meridian and 180° meridian divide the earth into two equal halves, the Eastern Hemisphere and the Western Hemisphere. Therefore, the longitude of a place is followed by the letter E for the east and W for the west. It is, however, interesting to note that 180° East and 180° West meridians are on the same line.
Longitude and Time
As the earth rotates from west to east, those places east of Greenwich will be ahead of Greenwich time and those to the west will be behind it. The rate of difference can be calculated as follows. The earth rotates 360° in about 24 hours, which means 15° an hour or 1° in four minutes. Thus, when it is 12 noon at Greenwich, the time at 15° east of Greenwich will be 15 × 4 = 60 minutes, i.e., 1 hour ahead of Greenwich time, which means 1 p.m. But at 15° west of Greenwich, the time will be behind Greenwich time by one hour, i.e., it will be 11.00 a.m. Similarly, at 180°, it will be midnight when it is 12 noon at Greenwich.
In India, the longitude of 82½° E (82° 30'E) is treated as the standard meridian. The local time at this meridian is taken as the standard time for the whole country. It is known as the Indian Standard Time (IST).
India located east of Greenwich at 82°30'E is 5 hours and 30 minutes ahead of GMT.
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Motion of the Earth
Rotation : Rotation is the movement of the earth on its axis.
Revolution: The movement of the earth around the sun in a fixed path or orbit is called Revolution. It takes 365 and 1/4 days to revolve around the sun.It is clear that the earth is going around the sun in an elliptical orbit. Six hours saved every year are added to make one
day (24 hours) over a span of four years.A year with 366 days is called a leap year.
Seasons: A year is usually divided into summer, winter, spring and autumn seasons. Seasons change due to the change in the position of the earth around the sun.
Fig: Revolution of Earth and Seasons
Orbital plane : The axis of the earth which is an imaginary line, makes an angle of 66½° with its orbital plane. The plane formed by the orbit is known as the orbital plane.
Aryabhata had stated that ‘the earth is round and rotates on its own axis.’
Circle of Illumination : The circle that divides the day from night on the globe is called the circle of illumination.Due to the spherical shape of the earth, only half of it gets light from the sun at a time. The portion facing the sun experiences day while the other half away from the sun experiences night.
Summer Solstice : You will see that on 21st June, the Northern Hemisphere is tilted towards the sun. The rays of the sun fall directly on the Tropic of Cancer. As a result, these areas receive more heat. The areas near the poles receive less heat as the rays of the sun are slanting. The North Pole is inclined towards the sun and the places beyond the Arctic Circle experience continuous daylight for about six months. Since a large portion of the Northern Hemisphere is getting light from the sun, it is summer in the regions north of the equator. The longest day and the shortest night at these places occur on 21st June. At this time in the Southern Hemisphere all these conditions are reversed. It is winter season there. The nights are longer than the days. This position of the earth is called the Summer Solstice.
Winter Solstice: On 22nd December, the Tropic of Capricorn receives direct rays of the sun as the South Pole tilts towards it. As the sun’s rays fall vertically at the Tropic of Capricorn (23½° S), a larger portion of the Southern Hemisphere gets light. Therefore, it is summer in the Southern Hemisphere with longer days and shorter nights. The reverse happens in the Northern Hemisphere. This position of the earth is called the Winter Solstice.
Equinox : On 21st March and September 23rd, direct rays of the sun fall on the equator. At this position, neither of the poles is tilted towards the sun; so, the whole earth experiences equal days and equal nights. This is called an equinox.On 23rd September, it is autumn season in the Northern Hemisphere and spring season in the Southern Hemisphere. The opposite is the case on 21st March.when it is spring in the Northern Hemisphere and autumn in the Southern Hemisphere.
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Maps
Map : A map is a representation or a drawing of the earth’s surface or a part of it drawn on a flat surface according to a scale. But it is impossible to flatten a round shape completely.
Physical Maps: Maps showing natural features of the earth such as mountains, plateaus, plains, rivers, oceans etc. are called physical or relief maps.
Political Maps: Maps showing cities, towns and villages, and different countries and states of the world with their boundaries are called political maps.
Thematic Maps : Some maps focus on specific information; such as road,maps, rainfall maps, maps showing distribution of forests, industries etc. are known as thematic maps.
Componets of Maps : Distance, direction and symbols.
Distance :
Scale is the ratio between the actual distance on the ground and the distance shown on the map.
Small scale map: When large areas like continents or countries are to be shown on a paper, then we use a small scale. For example 5 cm. on the map shows 500 km. of the ground. It is called a small scale map.
Large scale map : When a small area like your village or town is to be shown on paper, then we use a large scale that is 5 cm. on the map shows 500 metres only on the ground. It is called a large scale map.Large scale maps give more information than small scale maps.
Direction :
Most maps contain an arrow marked with the letter ‘N’ at the upper right hand corner.This arrow shows the north direction. It is called the north line. Four major directions(cardinal points) : North, South, East and West. Other four intermediate directions are north-east (NE), south east( SE), south-west (SW) and north-west (NW).
Compass : an instrument used to find out main directions. Its magnetic needle always points towards north-south direction.
Symbols : Maps have a universal language that can be understood by all. There is an international agreement regarding the use of these symbols. These are called conventional symbols.
Sketch: A sketch is a drawing mainly based on memory and spot observation and not to scale. Sometimes a rough drawing is required of an area to tell where a particular place is located with respect to other places.
Plan : A plan is a drawing of a small area on a large scale. A large-scale map gives lot of information, but there are certain things which we may sometimes want to know for example the length and breadth of a room, which can’t be shown in a map.
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Major Domains of the Earth
Human beings can live here because the life sustaining elements of land, water and air are present on the earth. The surface of the earth is a complex zone in which three main components of the environment meet, overlap and interact.
Lithosphere : The solid portion of the earth on which we live is called the Lithosphere.
Two major divisions of the earth's surface: i) Continents ii) Ocean basins
Continents : The large landmasses. These continents are – Asia, Europe, Africa, North America, South America, Australia and Antarctica.
Asia: Asia is the largest continent. It covers about one third of the total land area of the earth. The continent lies in the Eastern Hemisphere. The Tropic of Cancer passes through this continent. Asia is separated from Europe by the Ural mountains on the west.
Europe: Europe is much smaller than Asia. The continent lies to the west of Asia. The Arctic Circle passes through it. It is bound by water bodies on three sides.
The combined landmass of Europe and Asia is called the Eurasia.
Africa: Africa is the second largest continent after Asia. The Equator or 00 latitude runs almost through the middle of the continent. A large part of Africa lies in the Northern Hemisphere.Only continent through which the Tropic of Cancer, the Equator and the Tropic of Capricorn pass.
The Sahara Desert, the world’s largest hot desert, is located in Africa. The continent is bound on all sides by oceans and seas.The world’s longest river the Nile, flows through Africa.
North America : North America is the third largest continent of the world. It is linked to South America by a very narrow strip of land called the Isthmus of Panama. The continent lies completely in the Northern and Western Hemisphere. Three oceans surround this continent.
Strait : A strait is a narrow passage of water connecting two large woterbodies like seas and oceans.
Isthmas: A narrow strip of land joining two landmasses.
South America : South America lies mostly in the Southern Hemisphere. The Andes, world’s longest mountain range, runs through its length from north to south.South America has the world’s largest river, the Amazon.
Australia : Australia is the smallest continent that lies entirely in the Southern Hemisphere. It is surrounded on all sides by the oceans and seas. It is called an island continent.
Antarctica : Antarctica, completely in the Southern Hemisphere, is a huge continent. The South Pole lies almost at the centre of this continent. As it is located in the South Polar Region, it is permanently covered with thick ice sheets. There are no permanent human settlements. Many countries have research stations in Antarctica. India also has research stations there. These are named as Maitri and Dakshin Gangotri.
Ocean basins : the huge water bodies.All the oceans of the world are connected with one another.The level of seawater remains the same everywhere. Elevation of land is measured from the level of the sea, which is taken as zero.
The highest mountain peak Mt. Everest is 8,848 metres above the sea level. The greatest depth of 11,022 metres is recorded at Mariana Trench in the Pacific Ocean.
Edmund Hillary (New Zealand) and Tenzing Norgay Sherpa (India) were the first men to climb the highest mountain peak Mt. Everest on the planet earth on 29th May, 1953. Junko Tabei (Japan) was the first woman to reach the summit on 16th May, 1975. The first Indian woman to climb the highest peak on 23rd May, 1984 was Bachendri Pal.
Atmosphere : The gaseous layers that surround the earth, is the Atmosphere,where oxygen, nitrogen, carbon-dioxide and other gases are found.It provides us with the air we breathe and protects us from the harmful effects of sun’s rays. The atmosphere extends up to a height of about 1,600 kilometres. The atmosphere is divided into five layers based on composition, temperature and other properties. These layers starting from earth’s surface are called the troposphere, the stratosphere, the mesosphere, the thermosphere and the exosphere. Nitrogen 78 per cent, oxygen 21 per cent and other gases like carbondioxide, argon and others comprise 1 per cent by volume.
Oxygen is the breath of life while nitrogen helps in the growth of living organisms. Carbon dioxide, though present in minute amount, is important as it absorbs heat radiated by the earth, thereby keeping the planet warm. It is also essential for the growth of plants. The density of the atmosphere varies with height , it is maximum at sea level and decreases rapidly as we go up. The temperature also decrease as we go up.Air moves from high pressure to low pressure, movind air is known as wind.
Hydrosphere : Water covers a very big area of the earth’s surface and this area is called the Hydrosphere. The Hydrosphere comprises water in all its forms, that is, ice, water and water vapour.
The earth is called the blue planet due huge amount of water. More than 97% of the Earth’s water is found in the oceans and is too salty for human use.a very small percentage is available as fresh water for human use in the form of rivers, icesheets and glaciers or under the ground.
Ocean : Oceans are the major part of hydrosphere. They are all interconnected. The ocean waters are always moving. The three chief movements of ocean waters are the waves, the tides and the ocean currents. The five major oceans are the Pacific Ocean, the Atlantic Ocean, the Indian Ocean, the Southern Ocean and the Arctic Ocean, in order of their size.
Pecific ocean: The Pacific Ocean is the largest ocean. It is spread over one-third of the earth. Mariana Trench, the deepest part of the earth, lies in the Pacific Ocean. The Pacific Ocean is almost circular in shape. Asia, Australia,North and South Americas surround it.
Atlantic ocean : The Atlantic Ocean is the second largest Ocean in the world. It is ‘S’ shaped. It is flanked by the North and South Americas on the western side, and Europe and Africa on the eastern side. The coastline of Atlantic Ocean is highly indented. This irregular and indented coastline provides ideal location for natural harbours and ports. From the point of view of commerce, it is the busiest Ocean.
India ocean: The Indian Ocean is the only ocean named after a country, that is, India. The shape of ocean is almost triangular.In the north, it is bound by Asia, in the west by Africa and in the east by Australia.
Southern Ocean : The Southern Ocean encircles the continent of Antarctica and extends northward to 60 degrees south latitude.
Arctic Ocean : The Arctic Ocean is located within the Arctic Circle and surrounds the North Pole. It is connected with the Pacific Ocean by a narrow stretch of shallow water known as Berring strait. It is bound by northern coasts of North America and Eurasia.
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Major Landforms of the Earth
Within the earth, a continuous movement is taking place.
Internal process :leads to the upliftment and sinking of the earth’s surface at several places.
External process : the continuous wearing down and rebuilding of the land surface.
Erosion : wearing away of the earth's surface
Deposition : The surface is being lowered by the process of erosion and rebuilt by the process of deposition.
These two processes are carried out by running water, ice and wind.
Hiils : A hill is a land surface that rises higher than the surrounding area. Generally, a steep hill with an elevation of more than 600 metres is termed as a mountain.
Mountains : A mountain is any natural elevation of the earth surface. The mountains may have a small summit and a broad base. It is considerably higher than the surrounding area. Some mountains are even higher than the clouds. As you go higher, the climate becomes colder.
There are some mountains you cannot see as they are under the sea. Mauna Kea (Hawaii) in the Pacific Ocean is an undersea mountain. It is higher than Mount Everest being 10,205 metres high.
Types of Mountains :
i) Fold Mountains:: rugged relief and high conical peaks. Ex (young fold mountains)The Himalayan & the Alps, (old fold mountains) The Aravali range(oldest), the Appalachians(North America), Ural mountains(Russia).
ii) Block Mountains:: Block Mountains are created when large areas are broken and displaced vertically. The uplifted blocks are termed as horsts and the lowered blocks are called graben. Ex. the Rhine valley(Europe) and the Vosges mountains(Europe).
iii)Volcanic Mountains:: Formed due to volcanic activity. Ex. Mt. Kilimanjaro(Africa), Mt. Fujiyama(Japan)
Importance of Mountains : Storehouse of water, glaciers, river valleys and terrace, rich variety of flora and fauna, forest, tourist site.
Range : Arrangement of the mountains, many mountain systems consist of a series of parallel ranges extending over hundreds of kilometres. The Himalayas(Asia), the Alps(Europe) and the Andes(South America) are some of the examples.
Glaciers : In some mountains, there are permanently frozen rivers of ice. They are called glaciers.
Plateaus : A plateau is an elevated flat land. It is a flat-topped table land standing above the surrounding area. Height varies from few hundred metres to several thousand metres. Ex the Deccan plateau, East African plateau(Kenya), Tanzania, Uganda and the Western plateau(Aus). Highest plateau in the world: Tibet plateau(height 4000-6000 metres). Plateaus are rich in mineral deposits.
African plateau : gold and diamond mining.
Indian Plateau : iron, coal and mangese(all are found in Chhotanagpur plateau).
Importance of Plateau: minerals, waterfallls:Hundru falls(Chhotanagpur plateau,river : Subarnarekha ), Jog falls(Karnataka), lava plateaus: black soil
Plains : Plains are large stretches of flat land. They are, generally, not more than 200 metres above mean sea level. most of the plains are formed by rivers and their tributaries.Plains are very fertile. Ex. Asia(Ganga & Brahmaputra in India,Yangize in China) and North America.
.Alluvial deposits : very fine soils brought by rivers and deposited in the river basins,
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INDIA : In the north, it is bound by the lofty Himalayas. The Arabian Sea in the west, the Bay of Bengal in the east and the Indian Ocean in the south, wash the shores of the Indian peninsula.
Area : 3.28 million sq. km. North-south (Kashmir to Kanyakumari is abt 3200km), east-west 2900km(Arunchal Pradesh to Kuchchh). Second most populated country.
Large countries which stretch extensively from east to west do not have a single Standard Time for the whole country. The USA and Canada have seven and six time zones respectively. Russia have 11 time zones.
Location : India is located in the northern hemisphere. Tropic of Cancer(23°30'N),
south to north : 8°4'N and 37°6'N latitudes. West - east : 68°7'E and 97°25'E longitudes
India's Neighbours : Seven countries : Pakistan, Nepal, Bhutan,Bangladesh, Myanmar, China, Shri Lanka(Palk strait).
Division of India(On the basis of languages mainly)29 states , 7 Unon Territories. Telangana became the 29th state of India on 2 June 2014.
Capital : Delhi
Physical Division:
Himalaya : Him + alaya mean 'the abode of snow.'
Himalayan mountains are divided into three main parallel ranges.:
i) Great Himalaya(Himadri): World's highest peaks are located in this range.
ii)Middle Himalaya(Himachal) : Lies to to the south of Himadri. Popular hill stations.
iii) The Shiwalik: The southmost ranges.
The Northern Indian plains : lie to the south of the Himalayas. They are generally level and flat. These are formed by the alluvial deposits laid down by the rivers– the Indus, the Ganga, the Brahmaputra and their tributaries.
The Great Indian desert : In the western part of of india, dry , hot and sandy stretch of land, very little vegetation.
Peninsular plateau : to the south of northern plains, triangular in shape, relief is highly uneven. Region of many hill ranges (Vindhyas & Satpuras) and valleys ex Aravali hills(1 of the oldest), river Narmada & Tapi(west flowing drain into the Arbian Sea).
The Western Ghats or Sahyadris border the plateau in the west and the Eastern Ghats provide the eastern boundary. While the Western Ghats are almost continuous, the Eastern Ghats are broken and uneven.
Delta : The Ganga and the Brahma putra form the world’s largest delta, the Sundarbans delta. The delta is triangular in shape.The Sunderban delta is formed where the Ganga and Brahmaputra flow
into the Bay of Bengal.
Coastal plains : To the West of the Western Ghats and the East of Eastern Ghats lie the Coastal plains. The western coastal plains are very narrow. The eastern Coastal plains are much border. East flowing river : Mahanadi, Godavari, Krishna and Kaveri.
Lakshadweep Island: Located in the Arabian Sea. These are coral islands located off the coast of Kerala.
Andaman & the Nicobar Island : lie to the southeast of the Indian mainland in the Bay of Bengal.
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Climate, Vegetation and Wildlife
Weather : weather is about day to day changes in the atmosphere. It includes changes in temperature, rainfall and sunshine etc.
Broadly, the major seasons recognised in India are:
• Cold Weather Season (Winter) December to February: Sun rays do not fall directly on in the region.
• Hot Weather Season (Summer) March to May: More or less direct sun rays.
loo : hot and dry winds during the day.
• Southwest Monsoon Season (Rainy) June to September: The winds blow from Arabian Sea and Bay of Bengal towards the land. They carry moisture with them. When these winds strike the mountain barriers, rainfall occurs.
• Season of Retreating Monsoon (Autumn) October and November : Winds move back from the mainland to the Bay of Bengal. This is the season of the retreating monsoons. Rainfall in Tamil Nadu and Andhra Pradesh.
Monsoon : Arabic word 'mausim' : Seasons.
The climate of a place is affected by its location, altitude, distance from the sea, and relief.
Jaisalmer and Bikaner in the desert of Rajasthan are very hot, while Drass and Kargil in Jammu and Kashmir are freezing cold. Coastal places like Mumbai and Kolkata experience moderate climate.
Mawsynram in Meghalaya receives the world’s highest rainfall, while in a particular year it might not rain at all in Jaisalmer in Rajasthan.
Natural Vegetation : The grasses, shrubs and trees, which grow on their own without interference or help from human beings are called natural vegetation.
Vegetation of India can be divided into five types :
i) Tropical evergreen forest: Heavy rainfall, forest are dense i.e. no sunlight to the ground,many species of tree which shed their leaves at different times of the year hence always appear green. imp trees : mahogany, ebony and rosewood. Andaman and Nicobar Islands, parts of North-Eastern states and a narrow strip of the Western slope of the Western Ghats are home of these forests.
ii) Tropical deciduous forest : In large part of country, also called monsoon forests, dense, shed leaves at a particular time of the year. imp tree : sal, teak, peepal,neem,shisham. MP,UP,Bihar,Jharkhand, Chattishgarh, Odisha and in parts of Maharashtra.
iii)Thorny bushes : dry areas of the country. leaves are in the form of spines to reduce the loss of water. Trees: Cactus, khair, babool, keekar. Area : Rajasthan, Punjab, Haryana, Eastern slopes of Western Ghats and Gujarat.
iv) Mountain vegetation : variation in the height of the trees, increasing height falling temperature.At a height 1500-2500m most of the trees are conical in shape(called coniferous trees). imp trees : Chir, Pine, Deodar.
v) Mangrove forest : saline water forest, found mainly in Sunderbans in West Bengal and in the Andaman and Nicobar Islands. imp tree : Sundary after which Sunderbans have been named.
Wild Life : Forests are home to a variety of wild life. There are thousands of species of animals and a large variety of reptiles, amphibians, mammals, birds, insects and worms which dwell in the forest.
National Animal : Tiger
National Bird : Peacock
Government initiative : Project Tiger and Project Elephant
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