Category Archives: Geography

Physical features of Tamil Nadu and Geography of Tamil Nadu Tnpsc

Geography of Tamil Nadu

The Article for written for the topic ‘Geography of Tamil Nadu Tnpsc‘. It is referred from Tamil Nadu Samacheer Kalvi Book. This Article cover the most important points of the physiography of Tamil Nadu and its wildlife.

Tamil Nadu has different traditional and cultural practices. It has exquisite Physiography and climate which makes it unique from other India States.

Tamil land has a variety of flora and fauna that is different plants and animals species, Several exotic hill station, Huge forest, beautiful waterfalls and long beaches and coastline which is the lifeline of millions.

Location and size of Tamil Nadu

Tamil Nadu is located in the southernmost part of the Indian Peninsula. Its location is 8°4’N to 13°35’N latitudes and from 76°18’E to 80°20’E longitudes.

Its eastern boundary is Point Calimere and its western Boundary is Anaimalai Hills. Similarly, its northern boundary is marked by Pulicat lake and its southernmost point is Cape Comorin.

Compared to India, Tamil Nadu has 4% of its total size.

Tamil Nadu neighbouring states and Boundaries

Tamil Nadu has the Bay of Bengal in the east, the Indian Ocean in the South. Her Neighbouring states are Kerala in the West and Andra Pradesh in the North and Karnataka in the Northeast.

Also she has the second longest coastline in India after Gujarat which is 1076 Km.

Since Tamil Nadu is present in the southernmost tip of the Indian Mainland, it shares its border in another country called Sri Lanka.

Administrative divisions of Tamil Nadu

Just after Independence, Tamil Nadu has only 13 districts. The state administrative divisions were reorganised many times. As of now, Tamil Nadu has 35 districts.

The newly formed districts are Kallakurichi, Tenkasi and Chengalpet.

Physiography of Tamil Nadu

Tamil Nadu Districts Map 2021
Tamil Nadu Districts Map 2021 – By Jaishink – Own work, CC BY-SA 4.0,

Physical features of Tamil Nadu

Tamil Nadu is located on the Indian Peninsular plateau will is also called Deccan Plateau. It was part of the ancient Gondwana land which broke away 135 million year ago during the Cretaceous Period.

Tamil Nadu physical features include high eroded mountains, shallow deep valleys and plains. Overall its slopes towards the east.

Tamil Nadu Physiography is divided into West Ghats, Eastern Ghats, Plateaus, Coastal and Inland Plains. Let us see the description of east Physiography.

Eastern, Western Ghats and its Hills of Tamil Nadu

Western Ghats

West Ghats By Mdmadhu – Own work, CC BY-SA 4.0,

The Western Ghats is present on the Western border of Tamil Nadu alongside Kerala. It extends from Nilgiris in the North to Maruthuvazh Malai at Swamithope in the Kanyakumari district in the South.

Its height ranges from 2000 to 3000 metres and covers an area of about 2500 sq Km. The Western Ghats is a continuous range but it also has some passes.

Passes in Geography

Passes are generally a gap or break in a continuous range of hills, terrains, mountains etc.

The Passes found in the Western Ghats are Palghat, Shencottah, Aralvaimozhi and Achankoil and the Major hills of Western Ghats are Nilgiris, Anaimalai, Palani Hills, Cardamom Hills, Varusanadu, Andipatti and Agasthiyar Hills.

Nilgiri Hills

Nilgiri Hills By Enchant me –, CC BY 2.0,

Nilgiri Hills are part of the western ghats which is located in the northwestern part of Tamil Nadu. It consists of 24 peaks of a height of more than 2000 metres.

Its highest peak is Doddabetta with a height of 2637 metres and it is followed by Mukkuruthi peak with a height of 2554 metres.

Nilgiri Hills is famous for a hill station that attracts millions of tourist worldwide. The major hill station located on Nilgiris is Coonoor and Ooty.

Nilgiris is natural wonder, it home to more than 2700 species of flowering plants. Tamil Nadu state animal is Nilgiri Tahr which are found on these hills.

For several years its natural montane grasslands and shrublands are damaged or disturbed by cattle grazing and tea plantations.


Anaimalai Hills in Western Ghats
Anaimalai By Jaseem Hamza, CC BY 3.0,

Anaimalai or Elephant Mountains is a range of mountain that forms the southern portion of western ghats. It is located on Palghat Gap, the border of Tamil Nadu and Kerala.

Important places of Anaimalai are Anaimalai Tiger Reserve, Aliyar Reserved Forest, Valparai Hill station, Kadamparai Hydroelectric Power plant.

Two dams namely Aliyar and Tirumurthy are located in the foothills of this range.

Palani Hills

palani hills on western ghats
Palani Hills in Western Ghats By DRUID1962 – Own work, CC BY-SA 4.0,

Palani Hills are the eastward extension of the western ghats. These hills are located in the Dindigul district except for its western side.

Its highest peak is Vandaravu which is of the height of 2533 metres and its second-highest peak is Vembadi Shola which is of height of 2505.

Kodaikanal is the famous hill station present in these hills. Its height is 2150 metres and lies in the south-central portion of this range.

Cardamom Hills

Cardamom Hills in the western ghats
Cardamom Hills By Anand2202 – Own work, CC BY-SA 4.0,

The Cardamom Hills is also Yela Malai. It is located in the south western part of Tamil Nadu.

Yela Malai gets its name from the spice named Cardamom which is commonly grown here, Also Pepper and Coffee are cultivated here.

Cardamom hills meet the Anaimalai Hills in the northwest, the Palani Hills in the northeast and Varusanadu and Andipatti hills in the southeast.

Varusanadu and Andipatti Hills


Varusanadu and Andipatti Hills are the other eastward extensions of Western Ghats. Megamalai (highway mountain), Kalugumalai, Kurangani Hill station and Suruli and Kumbakarai waterfalls are found on these hills.

Srivilliputhur Grizzled Squirrel Wildlife Sanctuary is located on the southern slope of these hills in Virudhunagar district.

Vaigai River and its tributaries originate from this region.

Pothigai Hills

Pothigai Hills By Rakesh – Own work, CC BY-SA 3.0,

The most part of Pothigai Hills lies in Tirunelveli district, with its southern slope lies in the Kanyakumari district. Pothigai Hills called by different names such as Shiva Jothi Parvath, Agasthiyar Hills, and Southern Kailash.

Pothigai area is known for its evergreen forest, ancient temples and waterfalls. Kalakkad Mundanthurai Tiger Reserve is located in this region.

Mahendragiri Hills

Mahendragiri Hills are a continuous range, which is situated along the border of the Kanyakumari and Tirunelveli districts. Mahendragiri Hills are part of the southern range of the Western Ghats and its average height is 1645 metres.

ISRO Propulsion complex is a test facility for the ISRO to launch space vehicles that are situated on the lower slopes of this mountain.

The Eastern Ghats

The Eastern Ghats By Wikipedia

The Eastern Ghats are discontinuous and irregular. It is dissected at many places by river and these rivers drains into the Bay of Bengal.

The height of these ranges are 1,100 to 1,600 metres. These hills separate the plains from plateaus.

The major hills of the Eastern Ghats of Tamil Nadu are Javadhu, Servarayan, Kalrayan, Kollimalai and Pachaimalai. These are located in the northern districts of Tamil Nadu.

Javadhu Hills

Javadhu Hills By Karthik Easvur – Own work, CC BY-SA 4.0,

Javadhu Hill are an extension of the eastern ghats which are spread over the parts of Vellore and Tiruvannamalai Districts. These hills separates these two districts as well.

The average height of these peaks ranges from 1100-1150 metres. Its heighest peak is Melpattu. The Vainu Bappu Observatory (VBO) Kavalur is located on these hills. This observatory have started its observations in 1967.

Bluish-Grey Granites are covered many parts of this range. These hills are covered with fruit bearing trees, Medicinal herbs and Sandalwoods.

The illegal logging of Tree such as Sandalwood is a major concern here.

Kalvarayan Hills

Kalvarayan Hills
Kalvarayan Hills By Thamizhpparithi Maari – Own work, CC BY-SA 4.0,

It got its name from ancient tribes called Karalar. It is one of the major ranges of eastern ghats in Tamil Nadu. This range along with Pachaimalai, Aralvaimalai, Javadhu and Servarayan hills, separates the river basins of Cauvery and Palar.

The height of these Hills ranges from 600 to 1220 metres. Kalvarayan Hill has two sections. They are Chinna Kalvarayan in the northern section and the Periya Kalvarayan in the southern section.

The average height of Chinna Kalvarayan is 825 metres and the Periya Kalvarayan is 1,220 metres.

Servarayan Hills

Servarayan Hills By Wikipedia : Parvathisri

It is located near Salem City and its height ranges from 1200 to 1620 metres. It gets its name from a local deity known as Servarayan. The highest peak Solaikaradu in the southern part of Eastern Ghats is located in this range.

Its height is 1620 metres. The hill station named Yercaud is located on this range. Yercaud is also known as Poor man Ooty. Servarayan temple is its highest point (1623 metres).

Kolli Hills

kolli hills
Kolli Hills By Chinchu.c – Own work, CC BY 4.0,

Kolli hills is a small mountain range located in the Namakkal district. It covers an area of about 2800 Its average height is up to 1300 metres.

This mountain range runs almost parallel to the east coast of South India. Important Pilgrim Centre in this range is Arpaleeswarar temple.

Kolli Hills has the largest cover of evergreen or shola forest compared to other parts of the eastern ghats. On the commercial side many coffee plantations, fruits, flowers and silver Oak estates are found in this region.



Pachaimalai is the lowest hill range and is spread over the Perambalur, Tiruchirapalli and Salem districts. In the Tamil language, Pachai means Green colour.

The vegetative cover of this region is green than other vegetative covers of this region and hence it is named ‘Pachai Malai‘. Jackfruit is a popular seasonal agricultural product of these hills.

Plateau of Tamil Nadu

Plateaus of Tamil Nadu are located between the Western and Eastern Ghats. It is roughly triangular in shape and covers an area of about 60000

It height increases from east to west and its height ranges between 150 to 600 metres. This plateau is broader in the north and very narrow in the south. It has many subdivisions.

List of plateaus in Tamil Nadu

1.Bharamahal Plateau

Bharamahal plateau is a part of the Mysore plateau and is situated in the northwestern part of Tamil Nadu. Its height ranges from 350 to 710 metres. Dharmapuri and Krishnagiri districts are located in this region.

2.Coimbatore Plateau

It lies between Nilgiris and Dharmapuri District and its height ranges from 150 to 450 metres. Salem, Coimbatore and Erode districts are located in this region. This area spans about 2560 sq. km.

3.Sigur Plateau

Moyar River separates this plateau from the Mysore plateau. Rivers like Bhavani, Noyyal and Amaravathi, which originate from the Western Ghats, from valleys in this region.

Its height varies from 353 to 710 metres. Many intermontane plateaus are found in the region of the Nilgiris.

4.Madurai Plateau

This plateau found in the Madurai district extends up to the foothills of the western ghats. Vaigai and Thamirabarani basin are located in this zone.


The plains in Tamil nadu is divided into two they are inland plains and coastal plains. Inland plains are are drained by Palar, Ponnaiyar, Cauvery and Thamirabarani.

Cauvery plains are the most fertile plains of the state. The plains of Cauvery is found in Salem, Erode, Karur, Tiruchirapalli, Pudukottai, Thanjavur, Tiruvarur and Nagapattinam districts.

The coastal plains of Tamil Nadu are also called Coromandel or Cholamandalam plain. It extends from Chennai to Kanyakumari.

These coastal plains are formed by rivers that flows towards east and drains in the Bay of Bengal and in some places it is more than 80 km wide.

Tamil Nadu coastal plains are emerging coast, still some parts are submerged into the sea.

The sand dunes formed along the coast of Ramanathapuram and Thoothukudi districts are called Teri. Coral rocks are found at the head of the Gulf of Mannar in the eastern coastal plain.


Beaches in Tamil Nadu

The Coromandel coast along the Bay of Bengal consists of beautiful and exotic beaches. The golden sands of Tamil Nadu beaches are scattered with palm and casuarinas groves. Marina and Elliot beaches of Chennai, Kovalam and Silver beaches of Kanyakumari are some of the famous beaches in Tamil Nadu.

Drainage (Rivers in Tamil Nadu)

Natural Vegetation

The total forest cover of Tamil Nadu is lower than the National Forest Policy, 1988 that say a minimum of one-third of total geographical area should be under the forest cover.

Tamil Nadu forest cover is 2.99 and its types vary from wet evergreen to scrub forest.

The Western Ghats, the longest hill range in the state is one of the 25 global hotspots of biodiversity and one of the three mega centres of endemism in India.


This article we have discussed the Geography of Tamil Nadu, including its physiography, hill, plateau, plains, beaches and Natural vegetation of Tamil Nadu.

Non Conventional Sources of Energy Upsc

Non-conventional sources of energy

Non Conventional sources of energy are the ones which are renewable, eco-friendly, pollution-free and they are alternative to conventional energy sources such as Coal, Petroleum etc. Examples are Wind, Solar, Hydro, Tidal-Wave, Biomass Energy etc.

Use of Non-conventional Sources of Energy

India heavily depends on Thermal Power, which uses Fossil fuels as its energy source. This creates huge environmental and as well as health effects to all the living beings.

The gases released by thermal power plant are Sulphur Dioxide (SO ), Carbon Monoxide (CO), Oxides of Nitrogen (NOx) and Ozone (O) and also Suspended Particulate Matter (SPM), Lead and Non-Methane Hydrocarbons.

Also, Hydropower Power, even though its Non-conventional energy sources, still its largely affects the environment as Huge forest were destroyed for the construction of dams.

Due to such environmental effects, the need of hour is Non-Convention Sources of Energy.

Solar Power

Solar Panel producing solar energy: Non-Conventional Sources of energy Upsc
Solar Panels for producing electricity By Abengoa Solar – Abengoa Solar, CC BY 1.0,

Solar Power is produced by using solar panel, which is a large number of Photovoltaic cell or solar cell which are arranged in a particular manner to yield maximum power.

The Terrace of homes and offices can be effectively used to produce Solar energy using Solar Panels and Solar inverters. These systems designed to reduce the electricity bills and also one could earn money by giving the excess electricity produced at Home or Office to the Local Power Distribution Centre or EB.

Solar Power is the fast-growing sector in India as India has a huge advantage over it. Tamil Nadu state has the highest installed solar capacity in India. (Kindly Check the Latest One)

Tamil Nadu’s total installed solar energy is 1697 MW.

The Solar thermal energy programme is being implemented by the Ministry of Non-Conventional Energy Source (MNES) and its main objective is market development, commercialisation and utilisation of heat energy in Industries, Institutions and domestic applications.

Andhra Pradesh, Gujarat, Rajasthan, Maharashtra and Madhya Pradesh are the major solar power producers.

Hydro power

Dams Producing Hydro Electricity By allen watkin, CC BY-SA 2.0,

Hydro Power is one, where the power is generated using the free-flowing water from the Hills, Dams etc. This is regarded as one of the most economical and environmentally friendly methods of power generation. Still it has its own disadvantages, as the construction of dams needs a large area and mostly forest is cleared build such reservoirs and also Hydropower is seasonal as most of the rivers in India are non-perennial.

This method contributes 7% of global power production and the cost of production is also relatively low which makes it a good renewable energy method.

In India, the nodal agency for Hydro Power production is NHPC Limited which is an Indian government hydropower board under the ownership of the Ministry of Power, Government of India that was incorporated in the year 1975 and the first hydroelectric power station in India is established in 1987 at Darjeeling.

Distribution of Hydro Electric Power

  • River of Assam, Arunachal Pradesh, Manipur, Nagaland and Tripura accounts for 30.4%
  • Eastward flowing rivers of peninsular India – 20.9%,
  • Westward flowing rivers of the Western Ghats (South of the Tapti) – 10.5%
  • The Ganga Basin – 11.7%
  • Indus Basin – 16%
  • The rivers of central India – 10.5%

Wind Energy

Will Mill Producing Electricity By Matthew T Rader,, CC BY-SA 4.0,

Wind Mills are erected, to harvest the energy from the natural Air Flow using the Wind Turbines. It is a cheap source of power, plentiful, renewable, clean, eco-friendly and does not give out any unwanted gases such as greenhouse gas during its operation.

Apart from producing electricity, wind energy is used for pumping water and Sail propel ships.

As these Winds Mill occupy less space, a number of Wind Mill unit can be built in a small area. In India, Tamil Nadu has the largest installation, Muppandal-Perungudi area, near Kanniyakumari has the largest concentration of wind farm capacity in a single location in the world.

In 1986, development of wind power in India began. The first wind farm was set up in the coastal areas of Okha, Gujarat, Ratnagiri in Maharashtra and Thoothukudi in Tamil Nadu with 55 KW Vestas Wind Turbines.

The wind energy production capacity has increased greatly in the past few years and currently, India is the fourth-largest producer of Wind Energy in the World. The National Institute of Wind Energy (NIWE), Chennai was established in Tamil Nadu in 1998 as an autonomous institution under the administrative control of the Ministry of New and Renewable Energy.

CIWE main activities include resource assessment and testing & certification.

d) Biomass Energy

The Bioenergy are obtained by the bio-degradable materials such as Animal dung, Kitchen waste, Water Hyacinth, agricultural residue and other wastes etc. Biomass energy is a clean and cheap source of energy.

At the moment India has a high potential to obtain energy from biomass and it is estimated about 18 GW of power can be obtained from biomass in India. And Currently, 32% of the total primary energy used in India is obtained from Biomass.

Currently the energy derived from the biomass is mostly used for domestic purposes.

e) Tidal and wave Energy

Tidal Power Plant By Kches16414 – Own work, CC BY-SA 4.0,

Ocean tides and Ocean waves are the two main sources of Ocean energy and it is estimated that India has 8,000-9,000 MW potential on its coasts. The gulf of Cambay or Gulf of Khambhat in the Arabian Sea in Gujarat is the most suited area for tidal energy with a potential 7,000 MW.

And Followed by by the Gulf of Kachch with potential of 1,000MW and Sunderbans with the potential of 100MW.

At present, a 900mw tidal power plant is proposed to be set up in the Gulf of Kachch region. Also, Wave energy potential in India is estimated to be 40,000 MW. A wave energy power plant of 150 KW(maximum) has been installed at V-izhinjam near Thiruvananthapuram.

Information communication revolution Upsc

Information communication revolution

Evolution of communication technology

Production of and trade in commodities are the basis of the economy of any country. For these to go on, smoothly and with efficiency, the most basic need is information exchange.

The amount of information exchange depends very much on economic development. With the increase in demand for more information and exchange, the means of exchange also develop.

Letters are a vital element in the exchange of information for a long. The means of transport of letters depends on the distances to which they are transported. For short distances, they are sent through the roads. For distant places, they are sent by the railways. And for still farther distances, they are sent either by sea or by air.

Speed posts and the letters that should reach in a short while are being sent through the air. Until now, letters were carried in India by the Government Department alone.

Now, there are private courier services, too. The Government Postal Services have introduced ‘speed post’ to facilitate quick delivery of letters to distant places.

Information exchange is not only through letters but also through various other means such as the telephones, electronic equipment such as telefaxes. In sum, people, products, and information are transferred through roads, postal services, sea routes, and airways. The transfer is done through one or more of the transport modes.

Therefore, there is a competition between the carriers or interdependence among them. As such, development in one leads to developments in another. This is because there are merits and demerits to each of these transport modes and vehicles.

Information Explosion: Information explosion is very much like the population explosion of recent times. Several geographical information systems have been developed to store the data from the information explosion, index, and analyze them for development purposes.

It has become possible to handle different types of data easily through computers. Thus, there is no doubt now that the communication techniques and information revolution have acted in the union to prove the idea that ‘knowledge is power.

What are their impacts? How did they make for a change in geography? What developments occurred in geography as a result of these changes?

Technological, Technical Development: The world around us is changing fast. This change has made transformations on the earth possible. Methods have been devised in geographical science which analyses this change towards an understanding of the earth phenomena.

These have ushered in new perspectives and paradigmatic understanding of geography. In the 1950s, for example, number and quantity brought in a scientific revolution in geography.

Measurements and gathering of statistical data for understanding the world and to resolve problems that face the earth had become day-to-day activities. In course of time, mapping, cartographic research, and mathematical methods have come into use.

At the beginning of the 1960s, there were several descriptions and explanations which have now become established geographical ideas.

Continuous developments in information technologies increased field-based activities, voluminous data collected at the local and regional levels, the use of computers, and mathematical algorithms – all have impacted to increase the information manifold.

Information has multiplied ten times, hundreds of times, and million-fold. In order to take advantage of the exploding information, there came other, forward-looking developments during the 1970s and 1980s.

Although remotely sensed data have been received from the aerial photographs even before, satellite images have now supplemented even better information.

The traditional tool of cartography has now provided support in integrating human skills with the computing skills of computers and this has developed into modern geographical information systems.

Computers have now turned into devices, directly storing data from the fieldwork. They have now become not only the instant processors of arithmetic solutions and maps but also print them out as hard copies.

Space and satellite telecommunications, manual and computer mapping technology, and analytical mathematical algorithms have all been pooled to provide us with the Geographical Information Systems (GIS) that could accommodate and meet the challenges of information explosion in the world in the 1990s.

In several western countries, hundreds of the GISs have come into use. It is estimated that there is now a total of 2,000 such GISs in use in the world.

They have already been in intensive use in the departments of development and management. They have come into use, in our own country as well. The wings of the Survey of India and in the Departments of Universities, have now been used to the extent we could cope with the information explosion.

Importance of Information Technology: The developments in information technology have now paved the way for the new axiom ‘New scales, new worlds’.

Relations between data need, provision and handling have risen as a reflection of technological development. Nevertheless, the technology and the techniques are within certain limits, in operational terms.

Particularly, there is still a limit to the quantum of data that can be handled. The value of information technology depends upon the following is beginning to dawn in our midst:

Nature and type of sensing of information. Its spatial and temporal resolution. Our capability for processing data into information, storing and handling them in terms of computer facility.

The analytical capability with us and the corresponding interpretative capability amongst us. Classifying the conclusions and solutions from the information obtained by us and bringing them into use in a beneficial manner.

The five above, there is no doubt, will give us clarity of what we know of the world.

It is always a question in the area of communication as to how to deliver the news and ideas that arise from these to a majority. In today’s world, there are several communication types of equipment in daily use.

It is also true that some of them are still beyond the reach of a majority of people in this country because of their prices. For example, it is humanly impossible to make available newspapers to every citizen of India.

Similarly, radios and televisions cannot be made available to all of them, either. But there is no doubt that the impact of these media is widespread, throughout the world.

According to one source, radios provide vital information to 90 percent of the Indian population. Television acts in a way useful to 70 percent of the Indians.

They play a vital role in entertainment. Telephones have started functioning in remote villages, besides the towns and cities.

But in western countries, telecommunications have already become a basic need. The day is not far off for it to happen in India, as well. Let us now turn to learn the developments that have come about in the fields
of telecommunication and its technologies.

Communication Revolution: The world is under the grip of a ‘communication revolution’ that is seen in many ways. This revolution is considered the ‘third wave’ of global revolution. The ‘first wave’ of revolution is the ‘green revolution’ while the ‘second wave of revolution is that of the ‘industrial revolution.

The two revolutions (agricultural, industrial) have made a revolutionary change in the development of humankind.

It is expected that the third revolution of communication would bring about changes in the world that would surpass all changes that occurred in the earlier revolutions.

It has made possible the belief that it is ‘One World’.

It would also integrate people of all world, in all directions, is talked about throughout.

As the first impact of the appropriate activities of information technology, the world has begun to shrink. It has now become possible to send the information contained in ten books in a few seconds to a distant place: broadcasting has given way to narrow-casting.

How has this been possible? Let us now look at the historical developments in information and telecommunications, as they are useful to us.

Never before in human history has knowledge been so enormous. Also, we have never possessed such communication abilities as we do now.

We may consider these information and telecommunications technologies as problem-solving strategies and facilities.

It is even possible to integrate the wealthy North countries with the poverty-stricken South countries in the good cause of amenity expansion, catalyzing development, increasing literacy, alleviation of poverty through altruism, nature restoration, world management, promoting peace, and humanizing the world through these technologies.

Language and New Technologies: In human history, the languages were split and developed as the populations spread and multiplied.

Some cultures have gifted their cultures and languages to the outsiders and brought to themselves laurels.

Language has alone become the vehicle of communication. Some of these languages have now become the languages of law, administration, and official use through speech, writing, and printing.

Telecommunication Technologies

In some cultures, languages have been identified as ‘human identities’. English, French, Spanish, Russian, Chinese, and Arabic is being used by the multitude. Similarly, some of the regional and local dialects are being used as the languages of communication among the peoples.

All of these languages offer information through newspapers, radios, and television. All new innovations in technology use languages as the interfaces in the information exchange.

Some signal languages are used in communication with computers.

Ancient Telecommunications:

In telecommunications, all information is conveyed through symbols. The African drummers communicated messages through sound. Smoke signals were in use among some tribes as a means of telecommunications.

Flags and pictorials were used as auxiliaries to telecommunications.

Printing Revolution:

Then came printing techniques. The machine-published books became the primary sources of information besides reaching most of the world population.

The 19th-century steam-driven printing press gave way to the machines which operated with electricity and depended on composing. Next came litho press.

Photocopying created a revolution in copying. This is even now in use. In this computer age, printing has become simple through desktop publication.

The book in your hands has been published using computer publishing.

Telegraph and Telephones

The first-ever electrically operated telegraphic equipment came into use in the year 1837. Subsequently, in 1867, the telephone was born.

These have served humankind for more than a century in the exchange of information. Joining with the computers and satellites in telecommunications, the telephones have revolutionized the internal and international information exchanges.

As a ‘two-way communication’ and a ‘communication without codes’, telephones have become a communication link with no match to its versatility.

Radio: Radio broadcasting –

Especially continuous one – came into vogue in the year 1922. Radio has acquired the epithet ‘the vehicle of social change’ in a few years’ time. It had a very distinctive role in the green revolution of the developing countries.

It is also being used as the primary communication link in population control. It is not only useful to the educated but even more so to the uneducated. But this is under Government control. In some western countries, it is also being used as the communication medium in the private sector radio broadcasting.

With the telephone, this has made history in individual-related communication, too.


Sound and light-based communication was first begun in 1936. This is the television era, which has made possible a ‘reception room revolution’, using cinematographic techniques.

Yet, in some countries, it has earned the name ‘the idiot box, which it does not deserve. This is now an instrument changing the perception of the world population.

However, television has coverage of a mere 15 percent of the population in the poor South countries which hold 75 percent of the world population. In northern countries, it is rare to see a place or a home without television. In some countries, the telecast is through more than 100 channels.

The necessary information they provide, recreational and entertainment fares they offer, and the knowledge-based telecasts are numerous. Yet, where the cinema impacts more readily on the population as in the developing countries, the hold of the television on the population is minimal.

Deep-Sea Telegraphic Lines: These are a communication link among the many countries which have developed quite fast in both telegraphic and telephonic communication.

A deep-sea line in 1980 carried some 5,000 telephonic links. Now there have been several developments. Many countries are not only connected by the deep sea telegraphic lines but they use them in an important way, too.

The Satellite Power

The first-ever satellite is Sputnik 1. This was launched in 1957. It is estimated that over 15,000 satellites have orbited the earth in space. Some have burnt themselves while returning to the earth, in the atmosphere.

The 180 satellites sent up by the United States of America are all in use. The 100 satellites sent up by the former Soviet Union are still in operation. Among the 16 satellites launched by India, none failed.

They have completed successfully their mission, besides helping with the resources appraisal and in international communication. As for geography, the images received from these satellites play a vital role in the assessment of resources.

They form the spatial database for mapping through the GIS. It is not only easy to analyze the problems that the country faces but also develop solutions using the products of maps and their interpretations.

In the operation of satellites, computers have a significant role. It would be otherwise difficult to receive images from the satellites and process them in the lab was it not for the development of computers.

In resources appraisal, the images that we receive from the satellites have a large role to play. Generations of Computers: Computers have been developed in very rapid succession. Present-day computers are considered the Fifth Generation computers.

The first used simple valves. The second-generation computers used transistors. The third has been developed using integrated circuits. And the fourth uses microchips.

Microchips are still being used in fifth-generation computers; there are also other technologies in the field of computers.

Computers are useful in telecommunications in two important ways.

  1. They act as storages and retrieval media when required.
  1. They have a major role in international information exchange through Electronic Mail (E-mail) and international telecommunications.

Climate change and its Consequences Tnpsc

climate change and its consequences

Climate change Definition

Climate change in IPCC usage refers to a change in the state of the climate that can be identified (e.g. using statistical tests) by changes in the mean and/or the variability of its properties, and that persists for an extended period, typically decades or longer.

Climate change definition by Ipcc

Climate change refers to seasonal changes over a long period with respect to the growing accumulation of greenhouse gases in the atmosphere.

Recent studies have shown that human activities since the beginning of the industrial revolution have contributed to an increase in the concentration of carbon dioxide in the atmosphere by as much as 40%, from about 280 parts per million in the pre-industrial period, to 402 parts per million in 2016, which in turn has led to global warming.

Several parts of the world have already experienced the warming of coastal waters, high temperatures, a marked change in rainfall patterns, and increased intensity and frequency of storms. Sea levels and temperatures are expected to be rising.

Climate change and its consequences

Climate change and its consequences are nothing but the negative effects of climate changes, It includes the Failure of the Monsoons. In-country like India, where the majority of the population depend on the Monsoon rainfall for drinking and agriculture.

As most of the rivers in India are non-perennial, People always expects of Monsoon as a source of water. If one season is failed it will be a huge disaster in India. It results in the drying of rivers, lakes and putting a lot of pressure on the groundwater resources.

This in turn puts a lot of pressure on the groundwater. This results in excessive usage of groundwater for agriculture and drinking water that results in groundwater depletion.

Some crops which are planted in Tamil Nadu such as Paddy requires a lot of water to grow. When the monsoon fails it is difficult to depend on groundwater. When the groundwater depletes it results in crop failure.

The crop failure results in famine and diseases.

Another Climate change and its Consequences is an increase in the level of the sea. When the sea level increase just by one inch several Islands and low-lying cities such Chennai, or other coastal regions may submerge into the sea.

As we get news regarding rising sea level is submerging several Pacific Islands If cannot stop the climate change most part of Tamil Nadu might submerge into the sea.

Climate change and its Consequences on Biodiversity

The effects of climate change on Biodiversity is another important topic we need to address. The increase in atmospheric temperature increases the temperature of the sea. This affects the growth of Coral reefs and the breeding of fishes.

The coral reef needs water of temperature 23°–29°Celsius for its growth. When the temperature of seawater increases, it directly affects the growth of Coral. Thousand of species depend directly on the Coral reefs.

The increase in seawater temperature directly affects sea species.

It also affects several birds and animals. An increase in temperature affects Polar Ice Caps that affect Polar Bear, Penguin, etc. The Polar bear population is decreasing at a rapid rate.

The increase in temperature results in frequent forest fires, that kills a lot of wild animals and plants.

Climate change mitigation

Climate change mitigation is a set of activities that need to be taken to reduce the impact of climate change. These include using renewable energy sources such as Solar power plants, wind energy, etc.

Reducing the Co2 discharge, using public transport rather than using Individual vehicles such as Motor Bike, cars, etc.

The latest improvement in climate mitigation is the increased usage of E-Vehicles and Bio Fuels. These are some of the climate change solutions.

The latest climate change news is Treats to tropical forests, Melting glaciers, Global food shortage.

Climate change causes

  • Global warming is the current increase in temperature of the Earth’s surface (both land and water) as well as its atmosphere.

  • Average temperatures around the world have risen by 0.75ºC (1.4ºF) over the last 100 years.

  • About two-thirds of this increase has occurred since 1975.

  • Carbon dioxide, methane, Chlorofluoro Carbon, nitrous oxides are the greenhouse gases warming the earth’s surface. So it is also called the greenhouse effect.

  • The CO2 is the most important of the greenhouse gases contributing to 50% of global warming.

  • The burning of fossil fuel, and other biomass, deforestation result in CO2.

  • In the past, when the Earth experienced increases in temperature it was the result of natural causes but today it is being caused by human activities.


Climate change and Global warming adversely affect agriculture, horticulture, and the ecosystem. Reduced rainfall, higher temperature, and increased pest/weed growth hamper farming.

Threats to health arise due to an increase in disease-carrying vectors such as mosquitoes resulting in malaria, dengue fever, encephalitis, and yellow fever.

An increase in the global average surface air temperature of such magnitude will bring about alarming changes in rainfall patterns and other climatic conditions, resulting in serious ecological disequilibrium.

Minerals and natural resources Tnpsc

Natural resources of India

Natural resources of India include coal, where India has the fourth largest coal reserve in the world, also several other important mineral reserves such as Iron ore, manganese ore (7th largest reserve), bauxite (5th largest), thorium etc.

The most important natural resources are Oil, coal, natural gas, metals, stone and sand. Of this India has abundant natural resources.

Metallic are of two types: Ferrous and Non-Ferrous. Ferrous minerals have iron content such as iron, manganese, nickel, cobalt, tungsten, etc.

Non-Ferrous Minerals- do not have iron content such as gold, silver, copper, bauxite, etc.

Non-Metallic minerals

Nonmetallic minerals do not contain metals, such as mica, limestone, gypsum, potash, and coal. Non-metallic minerals are also called mineral fuels, such as coal and petroleum.

Distribution of natural resources in India

It is estimated that about 100 different minerals are known to be produced in India, out of the 30 are important.

Most of the metallic minerals are found in the peninsular plateau regions, especially in old crystalline rocks. Mineral distribution is concentrated in three belts. Maybe some occurrence here and there is in isolated pockets.

The three belts are the northeastern plateau, southwestern plateau, and northwestern region.

Metallic Minerals

Iron Ore

Iron is not found in pure form, it is often mixed with lime, magnesium, phosphorous, silicon, etc. There are four types of iron ore Haematite, Magnetite, Limonite, and Siderite.

Haematite is reddish in colour, also known as red ochre. It contains 60-70% of iron.


The ore colour is dark brown to blackish and is called black ore. It has magnetic properties. It contains 70% of iron.


It is an inferior variety of iron ore and has many impurities and is also called iron carbonate. It contains 20 to 40% of iron.


It is yellow or light brown in colour, it is called hydrated iron oxide when the iron ore is mixed with oxygen and water. Its mining is cheaper and easier. It contains 40 to 60% of iron.

Iron ore reserves

India has 20% of the world’s total iron reserves. About 75% of the total reserves of iron ore in India are of haematite grade.

Jharkhand, Orissa, Karnataka, Madhya Pradesh, Chattisgarh, and Goa, have 97% of the total iron ore reserves of India.


It is a silver-grey element and it is very hard and brittle. Manganese is always available as a combination with iron, laterite, and other minerals.


It is widely used in iron and steel manufacturing. Also used for making various alloys. Used in making of batteries, bleaching powder, insecticides, paints, etc.

Manganese ore reserves

Found in Odisha (44%), Karnataka (22%), Madhya Pradesh (12%), Maharashtra(7%), Goa (7%), Andra Pradesh (4%), Jharkhand (2%).

Also found in Rajasthan Gujarat, Telangana, and West Bengal. The leading producers of Manganese Ore are the Nagpur, Bhandara, Ratnagiri districts of Maharastra.

Madya Pradesh

Balaghat, Chhindwara districts.


Sundargarh, Kalahandi, Koraput, and Bolangir districts are the major ones.

Other producers are:

Andhra Pradesh (13%)

Srikakulam, Visakhapatnam, Cuddapah, and Guntur districts.

Karnataka (6%)

Districts of Shimoga, Bellary, Chitradurga, and Tumkur.


Copper is an important metal that is used by prehistoric men. Bronze is an alloy of Copper, Zinc, and tin. Copper is used for making Electrical wires, Cooking utensils, etc.

Copper Ore Reserves

Rajasthan state has the largest copper reserve in the country that provides 53.81% of the total produce. It is followed by Jharkhand with 19.54% and Madhya Pradesh with 18.75%.

Other producers are Andhra Pradesh, Gujarat, Haryana, Karnataka, Maharashtra, Meghalaya, Nagaland, Odisha, Sikkim, Tamil Nadu, Telangana, Uttarakhand, and West Bengal. Together these states account for 7.9%.


Khetri, Alwar, and Bhilwara districts.


Dehradun and Garhwal Districts

Andra Pradesh

Guntur, Kurnool, and Nellore districts


Chitradurga and Hassan districts.


Bauxite is an important ore of Aluminium. This ore is found in rocks consisting mainly of hydrated aluminium. It is distributed in the areas of laterite soil.

Aluminium is lightweight and is used in the manufacturing of aircraft, automobile engines, manufacture of cement, various chemicals, etc.

Bauxite deposits are mainly found in Odisha (50.2%), Gujarat(15.8%), Jharkhand(11.9%), Maharashtra(9.9%), Chhattisgarh (6.2%) and Tamil Nadu (2.7%).

Non-Metallic Minerals

The Non-Metallic Minerals include Mica, limestone, gypsum, nitrate, potash, dolomite, coal, petroleum, etc


Mica is used in the electrical industry, as insulating material as it withstands high voltage and has a low power loss factor. Abhrak is a top-quality mica. Mica is translucent. It can be easily split into thin sheets.

It is also used in making lubricants, medicines, paints, and varnishes.

Mica Ore Reserves

Mica deposits are found in Andhra Pradesh(41%), Rajasthan(21%), and Odisha (20%).

Andra Pradesh

Nellore, Visakhapatnam, West Godavari, and Krishna


Bhilwara, Jaipur, and Ajmer districts


Rayagada, Bolangir, and Sundargarh districts


Palamu, Ranchi, and Singhbum districts.


These are rocks that are composed of calcium carbonate or the double carbonate of calcium and magnesium or both. The limestones also contain little silica, alumina, iron oxides, phosphorous, and sulphur.

These are used in making soda ash, caustic soda, bleaching powder, cement, steel plants, glass, fertilizers, and paper.

Limestone Ore Reserves

Andra Pradesh and Telangana produce the most limestone ores with 20% each. Rajasthan (20%), Madhya Pradesh (12%), Tamil Nadu (8.4%), and Karnataka has the most limestone reserves (27%), followed by Andra Pradesh and Rajasthan (12% each), Gujarat (10%), Meghalaya (9%), Telangana (8%), Chhattisgarh and Madhya Pradesh (5% each) and the remaining by other states.

Andra Pradesh

Cuddapah, Kurnool, and Guntur districts


Nalgonda, Adilabad, Warangal and Karimnagar


Jodhpur, Ajmer, Bikhaner and Kota

Madhya Pradesh

Jabalpur and Satna Districts


Salem, Kancheepuram, Tiruchirappalli, Thoothukkudi, Tirunelveli, and Virudhunagar districts.


Gypsum is hydrated sulphate of calcium. It is white, and opaque. These are found in the beds of sedimentary rocks such as limestone, sandstone, and shale.

It is used in the manufacture of cement, fertilizers, plaster of Paris, etc. It is also used in conditioning soil.

Gypsum Ore Reserve

Rajasthan state accounts for 81% of the total reserve in the country. Also, there is a 14% reserve in Jammu and Kashmir and a 2% Reserve in Tamil Nadu.

Also, 3% of resources were present in the states of Gujarat, Himachal Pradesh, Karnataka, Uttarakhand, Andhra Pradesh, and Madhya Pradesh.

Rajasthan produces 82% of the country, Jammu and Kashmir produce 14%, and other states such as Gujarat, Uttarakhand, Andhra Pradesh, and Tamil Nadu produces 4% each.


Jodhpur, Bikaner and Jaisalmer

Jammu and Kashmir

Baramula, Doda and Uri


Bhavnagar and Jamnagar


Dehradun and Mussourrie

Andhra Pradesh

Nellore, Guntur, and Prakasam District

Development of Road Rail Water and Air routes in India Upsc

Development of Road Rail Water and Air routes in India Upsc

Development of road rail water and air routes

The transport system is considered the lifeline of the country and the development of transport in India is the primary goal of both the state and centre.

There are three major means of transport

  • Land (Roadways, Pipelines, Railways),
  • Water (Inland, Waterways, Ocean Routes),
  • Air (Domestic, International).

This article discusses transport in India, and the development of roads, rail, water, and air routes.

Development of transport in India

India has good transport Infrastructure such as roads, railways, airways, and waterways.

Road Infrastructure in India

An important mode of transport for goods and passengers for short, medium, and long distances. The road is easy, and cheap to construct build and maintain.

Asia’s largest tunnel is Patnitop Tunnel, It is also India’s longest road tunnel with a length of 9.28 km (5.8 mi), and the country’s first tunnel with a fully integrated tunnel control system.

India has the second-longest road network with a total length of 56,03,293 Km as of 2016. About 85% of passengers and 70% of freight traffic are carried out every year.

Road Network of India

The road network in India is classified based on the purpose of construction, maintenance, etc. into National Highways (NH), State Highways (SH), District Roads, Rural Roads (Village Roads), Border Roads, and International Highways.

1. National Highways (NH)

  • These highways connect the capital of states, major ports, rail junctions, and industrial and tourist centres.
  • The Ministry of Road Transport and Highways of India is responsible for the development and maintenance of the National Highways in India. The total length is 1,01,011 km which is 1.8% of the total road network in 2016.
  • The longest National Highway is NH-7, which runs from Varanasi in UP to Kanniyakumari in TN covering a distance of 2369 km.
  • The shortest National Highway in India is NH-47A which runs from Ernakulum to Kochi Port (Willington Island) covering a distance of 6km. The total number of national highways in India is 200.

2. State Highways (SH)

  • SH are roads that connect important cities, towns, and district headquarters within the state and connect them with the National highways or Highways of neighbouring states.
  • These roads are financed and administered by the State government. State Highway runs to the length of 1,76,166 km as of 2016.

3. District Road

  • District roads connect the district and taluk headquarters with the state highway and national highways.
  • District roads are constructed and maintained by the Public Works Department of states and Zila Parishad. The total length of the district road is 5,61,940 km (16.81%) in 2016.

4. Rural Road

  • This connects different villages with neighbouring towns. Maintained by Village Panchayats. The total length is 39,35,337 Km as of 2016.
  • Rural roads consist of Panchayat roads ( Zilla Parishad, Panchayat Samiti, Gram Panchayat); roads of the Pradhan Mantri Gram Sadak Yojana (PMGSY), and those constructed by the state PWDs.

5. Border Roads

  • These roads are of strategic importance and are constructed and maintained by Border Road Organization (BRO).
  • BRO was established in 1960, for the development of roads of strategic importance in Northern and Northeastern Borders areas.
  • BRO has constructed the world’s highest road joining Chandigarh and Leh in Ladakh. Border road runs at an average altitude of 4270 meters.

6. Expressways

  • Expressways are multi-lane good quality highways for high-speed traffic.
  • Important expressways are Mumbai-Pune Road, Kolkata-Dumdum Airport Road, Durgapur-Kolkata Road, and Yamuna Expressway between Delhi and Agra.

7. International Highway

  • It links India with neighbouring countries for the promotion of harmonious relationships with them.
  • These highways are constructed with aid from the World Bank under an agreement with the Economic and Social Commission for Asia-Pacific (ESCAP).
  • These highways connect India with Pakistan, Nepal, Bhutan, Bangladesh, and Myanmar.
  • In India, the densest road network is found in the northern plains where it is relatively easy to construct the road. In the mountainous areas, it is difficult to construct roads. Road density is highest in Kerala and lowest in Jammu & Kashmir.
  • The total number of national highways in India is 6, they run from Moreh in Manipur, India, to Maesot in Thailand via Myanmar’s Tamu, Mandalay, and Myawaddy. 
  • Shershah suri built the shahi (Royal) road, from the Indus Valley to Sonar Valley in Bengal. This road from Kolkata to Peshawar was renamed as Grand Trunk(GT) road during the British era. At present, it extends from Amritsar to Kolkata and it is bifurcated into two segments: NH-1 from Delhi to Amritsar and NH-2 from Delhi to Kolkata.

National Highway Authority of India (NHAI), established in 1995. It is an autonomous body under the Ministry of Surface Transport

Tamil State board books

Golden Quadrilateral: Also referred to as the golden highway of India that extends about 5,846 km long road of 4/6 lanes connecting, India’s four metropolitan cities: Delhi-Kolkata-Chennai-Mumbai-Delhi was launched in 1999.

North-South and East-West Corridors: North-South corridor aims at connecting Srinagar in Jammu and Kashmir with Kanyakumari in Tamil Nadu (including Kochi-Salem Spur) with a 4,076 km long road.

The East-West corridor has been planned to connect Silchar in Assam with the port town of Porbandar in Gujarat with 3,640km of road length. The two corridors intersect at Jhansi.

Railway Infrastructure in India (Railway infrastructure upsc)

Railways are considered the backbone of the surface transportation system of India. Indian railways network is the largest in Asia and the second-largest in the world.

Length is 67,368 km with 7349 railway stations as of 2017. The history of rail transport in India started 160 years ago, the first passenger train ran between Bori Bunder (Bombay) and Thane, a distance of 34 km.

The highest-speed train in India is Gatimaan Express.

The light rail system in India is a type of city train public transportation that generally has a lower seating capacity and lower speed than heavy rail. It is called MRTS or Metro Trains in India or Urban Rail transit in India. An example is Chennai Metro, Chennai MRTS, etc.

Importance of rail transport in India

It is considered the cheapest and fastest means of Public Transport for the general public and it is a lifeline for a country like India, where the Land is huge, with tough terrains.

Generally, rail transport is considered the safest means of transport.

The development of rail transport in India is done by the Indian Railways. For ease of operation and management, the Indian Railways is organized into 16 zones (railway zones in India UPSC).

  1. Northern Railway – Delhi,
  2. North-Western Railway – Jaipur,
  3. North-Central Railway- Allahabad,
  4. North-Eastern Railway – Gorakhpur,
  5. North-East Frontier Railway – Guwahati,
  6. Eastern Railway – Kolkatta,
  7. East Coast Railway – Bhubaneswar,
  8. East-Central Railway – Hazipur
  9. West-Central Railway – Jabalpur
  10. Central Railway – Mumbai (VT)
  11. Western Railway-Mumbai (Churchgate)
  12. Southern Railway – Chennai
  13. South-Central Railway – Secunderabad
  14. South-Eastern Railway – Kolkatta
  15. South-Western Railway – Hubball
  16. South East Central Railway – Bilaspur

The Northern Railway accounts for the longest route length followed by the Western Railway.

On the basis of the track, the Indian railway’s categories are Broad Gauge with a width of 1.676 meters, Meter Gauge with a width of 1 meter, Narrow gauge with a width of 0.762 meters, and light gauge with 0.610 meters.

The arrival of Konkan Railways Corporation (KRC), Mass Rapid Transit System (MRTS), Metro, and Sub-Urban railways give easy means of transport.

a) Konkan Railway

The construction of Konkan Railways was completed in 1998. It connects Roha in Maharashtra to Mangaluru in Karnataka on a length of 760km.

On its routes railway crosses 146 rivers, and streams, nearly 2000 bridges, and 73 tunnels. Asia’s longest tunnel is nearly 6.44 km long on this route.

The states of Maharashtra, Goa, and Karnataka are partners in this undertaking The rail link between Banihal in the Jammu region and Qazigund in Kashmir valley was opened in 2013, this rail passes under the Pir Panjal Range through an 11.2 km long tunnel.

b) Metro Railway in India
  • 8 cities with Metro rail in India.
  • Kolkatta, Chennai, Delhi, Bengaluru, Gurgaon, Mumbai, Jaipur, and Kochi.
  • Kolkatta is the first city in India to have metro rail, it is also called as Mass Rapid Transit System (MRTS).
  • As of September 2018, India has 507 km of operational metro lines and 381 stations.

The state of Meghalaya has no railway network

The first train in India is from Mumbai to Thane in 1853 covering a distance of 34 km. In 1951, the railway was nationalized as one unit

“The Indian Railways headquartered at New Delhi.”

“the first suburban railway started in 1925 in Mumbai.”

“Chennai becomes the 6th Indian city with the metro railway.”

“Gatiman express is the fastest operational train in India, that connects New Delhi and Agra and touches 160 km/h. This train takes a travel time of 105 minutes to cover a 200 km journey.”

Pipeline Transport in India

The pipeline is a convenient mode of transport to oil and natural gas fields, refineries, and to markets. Also used to transport water.

The initial cost of laying the pipeline is high but the maintenance cost is less. Its advantages are a steady supply of goods and reduced transhipment losses and delays.

Important networks of pipeline transportation in India are:

Oil field in upper Assam to Kanpur, From Salaya in Gujarat to Jalandhar in Punjab, and Gas pipeline from the Hazira in Gujarat to Jagadispur in Uttar Pradesh

Water Transport System in India

It is a fuel-efficient and eco-friendly mode of transport. The oldest and cheapest mode of transport.

Two types of waterways are Inland Waterways and Ocean Waterways (see routes)

History of water transport in India

Although India is using water transport for thousands of years, officially Inland Waterways Authority of India (IWAI) came into existence on 27 October 1986 to improve and develop Inland water transport.

Inland Waterways in India

India has an extensive network of inland waterways in the form of rivers, canals, lakes, and backwaters.

The total navigable length in India is 14,500 km, out of which 5200km lengths of rivers and 4000 km length of canals are used by mechanized crafts.

The total cargo carried by inland waterways is just about 0.1% of the total inland traffic in India. The Inland Waterways Authority was set up in 1986.

The Major national waterways are :

National Waterway 1: Between Haldia and Allahabad measures 1620 km and includes stretches of the Ganga-Bhagirathi- Hooghly river system. It is the longest national waterway in India.

National Waterway 2: a stretch of the Brahmaputra river between Dhubri and Sadiya a distance of 891 km.

National Waterway 3: extends between Kollam and Kottapuram in Kerala, it is the first national waterway in the country with 24-hour navigation facilities along its entire stretch of 205 km.

Oceanic Routes

About 95% of India’s foreign trade by volume and 70% by value moves by ocean routes. There are 13 major and 200 minor or intermediate ports in India.

The major ports are administered by the central government and minor ports are managed by various state governments.

The major ports on the east coast are Kolkata (including Haldia Dock), Paradip, Visakhapatnam, Chennai, Ennore, and Tuticorin.

The major ports on the west coast are Kandla, Mumbai, Nhava Seva (Jawaharlal Nehru Port), New Mangalore, Marmagao, and Kochi.

India has four major shipyards, the Hindustan Shipyard in Vishakhapatnam, the Garden Reach workshop in Kolkatta, Mazagaon Dock in Mumbai, and Kochi Shipyard in Kochi.

India is the second-largest ship-owning country in Asia and 16th in the world.

Air Transport in India

Air transport in India started on 18th February 1918, when Henry Piquet carried mail from Allahabad to Naini. In 1953, eight different airlines operating in India were nationalized.

Domestic airways fly within the country and international airways connect major cities of the world. Indian Air Lines and Air India are the two airline services run by the Indian Government.

Indian Air Lines provides domestic air services and Air India provides international air services. At present, there are 19 designated international airports.

These airports are managed by the Airport Authority of India,

Examples Netaji Subhash Chandra Bose International Airport, Kolkata, Chennai International Airport, Chennai, Indira Gandhi International Airport, Delhi, Chhatrapati Shivaji International Airport, Mumbai, etc

There are 80 domestic airports and 25 civil enclaves at defence airfields.

Pavan-Hans Helicopter Ltd

Pavan-Hans Helicopter Ltd provides Helicopter support to the petroleum sector, such as ONGC and Oil India Ltd.

It is a public sector company based in New Delhi. Its operation is based at the Juhu Aerodrome in Vile Parle (West) Mumbai.

Pavan-Hans is a Mini Ratna-I category public sector undertaking. It also provides services to state governments in India particularly North East India, Inter-Island, Ferry Services in Andaman & Nicobar Islands, services to Lakshadweep Island, etc.

Airport Authority of India (AAI)

Constituted in 1995

It provides security to Indian Airports.

AAI under the Ministry of Civil Aviation is responsible for creating, upgrading, maintaining, and managing civil aviation infrastructure in India.

Transport in India geography project pdf

Physical Geography

Geography optional – Physical Geography

Physical geography of Oceans and Continents

  • The continents cover 29% of the total area of the earth and the rest is filled with water.
  • The continent that appears today is not the same in the past.
  • The continents and oceans in today’s form will appear different in the future.

Continent Drift Theory

  • The shape of the Atlantic ocean coastline seems to symmetrical.
  • The two Americas that is North and South America, Europe and Africa were once joined together.
  • A Dutch Map Maker, Abrahan Ortelius first to propose joining of continents in 1596.
  • Antonio Pellegrini drew a picture of the continent in the map showing three-continent were once joined together.
  • A German meteorologist, Alfred Wegener proposed the “Continental Drift Theory” in 1912.
  • According to Alfred Wegener, “All the continents formed a single continental mass and mega ocean surrounded the same“.
  • PANGAEA was named for the supercontinent that means all the whole earth.
  • PANTHALASSA was the name given to the ocean when the continents were together that means all water
  • As per Continental Drift theory, around 200 million years ago, the continent which was joined together called the supercontinent called as Pangaea began to move from each other or began to split.
  • Initially, the Pangaea broke up into two parts of large continents one is called Laurasia and another one Gondwanaland.
  • The Laurasia is the northern part and Gondwanaland in the southern part.
  • After that, the Gondwanaland and Laurasia were further broken down into many pieces which we see today.

Evidence that supports Continental Drift Theory

Jig Saw Fit Puzzle of Continents

  • Just like a Jig-Saw-Fit Puzzle, Africa and South America’s shorelines fit like, once it was joined together.
  • The fit of the Atlantic margin was first shown in computer drawing in 1964 by Bullard.
  • This fit was done in 1000 fathom, instead of shoreline which we sea.

Age of Rocks Across Oceans

  • The age of the rocks was determined by Radiometric dating.
  • The rocks of Brazil coast and Western Africa were aged the same about 2000 million.
  • The South America and Africa’s earliest marine deposits were from the Jurassic Age, this makes us come to conclusion that ocean is formed before this time.

The Sedimentary called Tillite

  • Tillite is a type of Sedimentary rock formed from the glaciers deposits.
  • India’s, Tillite from Gondwanana are similar to the Southern Hemispheres six different landmasses.
  • There is thick Tillite in the base of the continent that shows extensive and prolonged glaciation, similarly found in Falkland Island, Australia, Madagascar, Africa and Antarctica.
  • This makes a conclusion that this Gondawana type sediments of these landmass had similar histories.
  • The Tillite provides great pieces of evidence of palaeoclimates and drifting of continents.

Placer Deposits

  • The Ghana coast, there is an occurrence of rich placer deposits of gold and there is a absolute absence of source rock.
  • The type is present in gold-bearing veins in Brazil.
  • This show Ghana is derived from the plateau of Brazil.

Fossils Distribution

  • The distribution of similar type plant and animals found in the landmass which is divided by marine barriers shows there lands were once together.
  • For example, the Lemurs found in Madagascar, Africa and India, led some to come to the conclusion that these three lands were once together by landmass called ‘Lemuria’.
geography optional - lemur present three continents separate by oceans
  • The skeletons of Mesosaurus (a shallow brackish water reptile), found only two places, one is Iraver of Brazil and Southern Cape province of South Africa which was seperated by 4800 km and marine boundaries between them.

Force of Drifting

  • The continental Drift is due to the tidal force and pole-fleeing force as per Wegener.
  • Pole fleeing force is due to rotation of earth. The earth is not a perfect sphere and it has a bulge at equator which is due to rotation of earth.
  • The tidal force is due to sun and moon that developed ocean tides.
  • Alfred Wegner believed that these two forces are responsible for the continental drift and some scholars rejects the Alfred Wegners force of Drifting saying these forces are inadequate to move the continents.

Post-Drift Studies

  • The post-world war -II period added new information regarding the continents.
  • In particular, the ocean floor mapping, gave new dimensions in field of study of oceans and continents.
Convectional Current Theory
  • The convection currents operating in the mantle portion was discussed by Arthur Holmes in the 1930’s.
  • These currents are caused by radioactive elements in the mantle that create Thermal Differences.
  • Holmes suggested that this force existed throughout the Mantle that was responsible for continental drifts.
Mapping of the Ocean Floor
  • The ocean floor consists of not only floors or plains and consists of reliefs, mountains etc just like what that in lands.
  • The survey of the ocean floor started after the world war-2, that gave results such as the existence of mountains, deep trenches were mostly closer to continent margins.
  • The volcanic eruption is mostly active, found at the mid-oceanic ridges.
  • From the result of dating, the result is that the rocks from the oceanic crust are much younger than the continental areas.
  • The age and constituent of rocks are almost the same for the rocks of two sides of the crest of oceanic ridges and equidistant from the crest location.

Ocean Floor Configuration

  • The major division of ocean floor based on type of relief and depth are continental margins, deep-sea basins and mid-ocean ridges.
geography optional- Physical geography of Ocean Floor
Ocean Floor -Physical Geography

Continental Margins

  • The continental margins form the transition between deep sea basins and continental shores.
  • The continental margins consists of continental shelf, continental rise and deep oceanic trenches.

Abyssal Plains

  • Abyssal Plains lie between the mid-oceanic ridges and continental margins.
  • Continental sediments move beyond the margins and get deposited in the Abyssal Plains.

Mid-Oceanic Ridges

  • Mid-Oceanic regions form a chain of mountains inside the ocean.
  • Mid-Oceanic ridges are longest on the surface of the earth, which is under the sea.
  • “Mid-Oceanic ridges are characterized by a central rift system at the crest, fractionated plateau and flank zone all along its length“.
  • The zone of intense volcanic activity is at the rift system at the crest.

Earthquakes and Volcanoes Distribution

geography optional - Physical Geography of distribution of earthquakes and volcanoes
Distribution of Earthquakes and Volcanoes-Physical Geography Courtesy:Ncert
  • The above map shows the volcanoes and earthquakes distribution across the world.
  • The line of dots in the Atlantic ocean is almost parallel to the coastlines
  • The line of dots further extends into the Indian Ocean and bifurcates a small part of the Indian subcontinent with two branches, one branch moves into East Africa and another other meeting a similar line from Myanmar to New Guiana.
  • “The shaded belt showing another area of concentration coincides with the Alpine-Himalayan system and the rim of the Pacific Ocean”.
  • The foci of the earthquakes in the areas of mid-oceanic ridges are at shallow depths whereas, along the Alpine-Himalayan belt as well as the rim of the Pacific, the earthquakes are deep-seated ones”.
  • The volcanoes in the map also has a similar pattern.
  • The rim of the Pacific is also called as “Rim of Fire” due to large number of active volcanoes present in this area.

Sea Floor Spreading Concept

The mapping of oceans and palaeomagnetic studies from oceans gives the some facts such as:

  • A large amount of volcano eruption brings a lot of lava along the mid-oceanic ridges.
  • The characteristics such as age, chemical composition, and magnetic properties are similar among the rocks which are present in the equidistant on either side of the crest of mid-oceanic ridges.
  • Rocks which are close to mid-oceanic ridges are youngest and has normal polarity.
  • The rock’s age increases as moves away from the crest.
  • The ocean crust rocks are younger(200 million years) that the rocks seen in the land (continental rocks – 3200 million years).
  • The sediment on the ocean floor is very thin, nowhere the sediment column found are older than 200 million years.
  • The deep trenches have deep-seated earthquakes.
  • In mid-oceanic ridge, the earthquake foci have shallow depths.
  • These facts led Hess (1961) to propose a hypothesis known as the “Seafloor spreading”.
geography optional - sea floor spreading
Sea floor spreading – Physical Geography Courtesy: Ncert
geography optional - Position of the continents
Position of the Continents-Physical Geography Courtesy:Ncert

Plate Tectonics

  • The plate tectonics was a concept termed by Mckenzie, Parker and Morgan in 1967.
  • The lithospheric plate is a massive plate also called a tectonic plate, irregularly shaped slab of solid rock. It is both continental and oceanic lithosphere.
  • The tectonic plates move horizontally over asthenosphere.
  • The lithosphere includes the crust and upper mantle.
  • The thickness of the oceanic parts of the lithosphere is in the range between 5 and 100 km.
  • The thickness of continental areas is about 200 km.
  • A plate called a continental plant or oceanic plate based on the proportion of area occupied in the continent or in the ocean.
  • The Eurasian plate is continental plate as its large portion is part of the land whereas the Pacific plate is oceanic plate as its large portion is the ocean.
  • As per plate tectonics theory, the earth lithosphere is divided into seven major plates and some minor plates.
  • The young fold mountain ridges, trenches and faults surround these major plates.

Major Plates

  1. Antarctica and the surrounding oceanic plate.
  2. North American Plate (western Atlantic floor separated from the South American plate along the Caribbean islands)
  3. South American Plate (western Atlantic floor sperated from the North American plate along the Caribbean Islands)
  4. Pacific plate
  5. India-Australia-New Zealand plate
  6. Africa with the eastern Atlantic floor plate.
  7. Eurasia and the adjacent oceanic plate.

Important Minor plates

  • Cocos plate – Between Central America and the Pacific Plate.
geography optional - cocos plate
Cocos Plate

  • Nazca Plate: Between South America and Pacific Plate
geography optional - Nazca plate
Nazca Plate
  • Arabian Plate: Mostly the Saudi Arabian Landmass
geography optional - Arabian plate
Arabian Plate
  • Philippine Plate: Between the Asiatic and Pacific Plate, Caroline Plate: Between the Philippine and Indian plate (North of New Guinea)

geography optional - philippine plate
  • Fuji Plate: North-East of Australia
geography optional - Fuji plate

Fuji Plate

geography optional - Physical Geography of major and minor plates
Major and Minor Plates:Physical Geography Courtesy: Ncert
  • The plates move constantly, and the continents move as they are part of the plate and all the plates move.
  • Alred Wegner though all the continent existed as supercontinent called Pangea, and by later studies, all the plates wander everywhere continuously through the time, and supercontinent called Pangea, was once convergent of all plates.
  • Using Palaeomagnetic studies researchers determined the position of the continent from time to time.
  • The position of Indian plates was determined from rock of Nagpur area.

The plate boundaries are of three types:

  1. Divergent Boundaries
  2. Convergent Boundaries
  3. Transform Boundaries

Divergent Boundaries

  • Whenever the plates move from each other, new crust is generated.
  • The spreading sites are sites where the plates move away from each other.
  • Example: the Mid-Atlantic Ridge divergent boundaries, as a result of American plate separated front he Eurasian and African Plates.
geography optional - divergent boundaries
Divergent Boundary – Physical Geography

Convergent Boundaries

  • One plate dived under another where the crust is destroyed, Sub-duction zone is the location where the sinking of a plate occurs.
  • The convergence can occur in three ways, these are 1. Between an oceanic and continental plate; 2. between two oceanic plates; 3. between two continental plates
geography optional - convergent boundaries

Transform Boundaries

geography optional - Transform boundaries
  • Plates horizontally slide over each other, the crust is neither created nor destroyed.
  • Transform faults are the planes of separation generally perpendicular to the mid-oceanic ridges.
  • The eruption does not take all along the entire crest at the same time, there is a differential movement of a portion of the plate away from the axis of the earth and also the earth rotation has effects on the separated block of the plate“.

Plate Movement Rate

  • The rate of the plate movement is determined by the strips of normal and reverse magnetic field that are parallel to the mid-oceanic ridges.
  • The slowest plate movement rate is found in Arctic Ridge at less than 2.5cm/yr.
  • The fastest plate movement rate is found in East pacific rise near Easter Island in the south pacific about, west of Chile about 3400 km.

Plate Movement Force

  • When Alred Wegner proposed the Continental Drift Theory, most scientists believed that earth was static and motion solid object but after various studies such as seafloor spreading, Plate Techtonic, etc, scientists found earth was continuously moving and dynamic one. Now plate movement is accepted by everyone.
  • Below the Rigid plate, the mobile rock is believed to moving in a circular manner.
  • The heated material is rise above, spreads, and gets cooled and sinks to greater depths and this cycle is repeated continuously and called convection cell or convection flow.
  • The two main sources of heat within the earth are Radioactive decay and residual heat.
  • This idea is first proposed by Arthur Holmes’s 1930s, later Harry Hess went about Seafloor Spreading.
  • The slow movement of hot, softened mantle responsible for the force behind the plate movement.

Indian Plate Movement

  • The Indian Plate consists of India Peninsular and Australian continental portions.
  • “The subduction zone along the Himalayas forms the northern plate boundary in the form of continent-continent convergence.
  • In the east, it extends through Rakinyoma Mountains of Myanmar towards the island arc along the Java Trench.
  • In the East, the margin is a spreading site lying to the east of Australia in the form of an oceanic ridge in SW Pacific.
  • The Western Margin follows Kirthar Mountain of Pakistan and further extends along the Makrana coast and joins the spreading site from the Red Sea rift southeastward along the Chagos Archipelago.
  • The boundary between India and the Antarctic plate is also marked by an oceanic ridge (divergent boundary) running in roughly W-E direction and merging into the spreading site, a little south of New Zealand.”
geography optional - Movement of India plate
Movement of India Plate
  • India was once a large island off the Australian coast.
  • Until about 225 million years ago, the Tethys Sea separated India from the Asian continent.
  • About 200 million years ago India started its journey towards the north, at the same time when Pangaea broke.
  • About 40-50 million years ago India collided with Asia, producing rapid uplift of Himalayas.
  • About 140 million years ago, the Indian subcontinent was located as south as 50 degrees south latitude.
  • The two major plates were separated by the Tethys sea and the Tibetian block was close to the Asiatic landmass.
  • During the movement of the Indian plate towards the Eurasian plate, a major event that occurred was the outpouring of lava and formation of Deccan traps. This started somewhere around 60 million years ago and continued for a long period of time.
  • This started somewhere around 60 million years ago and continued for a long period of time.
  • From 40 million years ago and thereafter, the event of formation of the Himalayas took plate and scientist believe that this process is still continuing and the height of the Himalayas is still rising.

Physical Geography of Minerals and Rocks

Minerals and Rocks

  • The elements are in solid form in the outer layer and in hot molten form in the interior of the earth.
  • Oxygen, silicon, aluminium, iron, calcium, sodium, potassium and magnesium form the 98% of total element on earth crust.
  • The rest of 2% of elements are formed by titanium, hydrogen, phosphorous, manganese, sulphur, carbon, nickel and other elements.
  • Minerals are substances that are elements in the earth crust that are rarely found combined with other elements to make various substances.
  • The mineral can be organic and inorganic substances with definite chemical composition, physical properties and orderly atomic structure.
  • A mineral is composed of two or more elements, but sometimes single element minerals like sulphur, copper, silver, gold, graphite etc are found.
  • There are 2000 elements have been identified and named and six major mineral groups that are known as major rock-forming minerals.
  • The basic source of all minerals is the hot magma in the interior of the earth.
  • When magma cools, the crystal of minerals appear and a systematic series of minerals are formed in sequence to solidify to form rocks.

Physical Characteristics of Minerals and Rocks

  • External crystal Form- Molecular-level structure such as cubes, hexagonal prism etc
  • Cleavage- Tendency to break in a given direction
  • Fracture – Crystal will break in an irregular manner
  • Lustre – Regardless of colour each mineral has a unique lustre like metallic, silky, glossy etc.
  • Colour – the colour is determined by a molecular structure such as malachite, azurite, chalcopyrite etc and some coloured by impurities such quartz which may be white, green, red etc.
  • Streak – the color of mineral changes when powdered. Example Malachite is green when powdered gives green whereas fluorite is purple or green but gives a white streak.
  • Transparency – Mineral are either Translucent or opaque.
  • Structure-Based on the arrangement of crystal it is fine, medium or coarse-grained; fibrous – separable, divergent, radiating.
  • Hardness – Degree of Hardness of material is determined by the Mohs scale. The Mohs scale ranges from 1-10. Based on Mohs scale 10 minerals are selected such as Talc-1, Gypsum-2, calcite-3, fluorite-4, apatite-5, feldspar-6, quartz-7, topaz-8, corundum-9, diamond-10.

Metallic Minerals

Metallic minerals is divided into three types:

  • Precious Metals – Platinum, Gold, Silver etc
  • Ferrous Metals – Iron and other metals usually mixed with Iron to form various types of steel.
  • Non-Ferrous Metals – These includes metals like copper, lead, zinc, tin, aluminium etc.

Non-Metallic Minerals

  • Sulphur, Phosphates and Nitrates are some of the examples of non-metallic minerals, that does not contain any metal content.


  • A Rock is composed of one or more mineral, it will soft or hard and different in colour.
  • Example Granite is hard and soapstone is soft.
  • Example Gabbro is black and quartzite is milky white
  • Feldspar and quartz are the most common minerals found in rocks.
  • Petrology is the study of rocks and Petrologist studies the rocks based on characteristics such as mineral composition, texture, structure, origin etc.
  • Geographer studies the rocks for landforms, soil etc.

The rocks are of three types

  1. Igneous Rocks
  2. Sedimentary Rocks
  3. Metamorphic Rocks

Igneous Rocks

  • These are called as Primary rocks formed out of Lava and Magma from the interior of the earth.
  • The Magma from interior of earth, solidifies on cooling. This process happens in crust or on the surface of earth.
  • Igneous rocks are classified based on Texture, Texture depends upon size and arrangement of grains or other physical characteristics.
  • If the magma is cooled slowly in the greater depths, the grain size will be large.
  • Rapid cooling of Magma on the surface produces small and smooth grains.
  • Intermediate cooling results in intermediate size of grains.
  • Example of Igneous rock are Tuff, volcanic breccia, basalt, pegmatite,gabbro, Granite.

Sedimentary Rocks

  • It is derived from Latin word Sedimentum which means settling.
  • The rocks of various types are broken up into fragments of various size due to various denudation agents.
  • Such fragments are transported to exogenous agencies and deposited and these deposits turn rocks by compaction. This process is called Lithification.
  • The number of layers of varying thickness in sedimentary rocks like sandstone, shale etc.
  • Sedimentary are classified into three types that are Mechanically formed, Organically formed, Chemically formed.
  • Mechanically formed sedimentary rocks are Sandstone, conglomerate, limestone, shale, loess etc
  • Organically formed sedimentary rocks are geyserite, chalk, limestone, coal etc
  • Chemically formed sedimentary rocks are chert, limestone, halite, potash etc.

Metamorphic rocks

  • Metamorphic means change of form.
  • These rocks are formed by pressure, volume and temperature (PVT).
  • When the rocks are subjected to great pressure by tectonic processes or molten magma comes into contact with crustal rocks, Metamorphism occurs.
  • Metamorphism is a process by which already consolidated rocks are subjected to re-crystallisation and reorganisation within original rocks.
  • Dynamic Metamorphism means without any remarkable chemical changes there occurs a mechanical disruption and reorganisation of the original minerals within rocks sue to breaking and crushing.
  • There are two types of thermal metamorphism, contact metamorphism and regional metamorphism.
  • The rocks come into the contact with hot intruding molten lava or magma and recrystallise under high temperature is called Contact Metamorphism.
  • The rock materials recrystallise due to the deformation caused by tectonics shearing with high temperature or pressure or both. This is a regional metamorphism.
  • Foliation or lineation is the term used to mention the arrangement of minerals or grains in metamorphic rocks.
  • Sometimes minerals or materials of different groups are arranged into alternating thin to thick layers appearing in light and dark shades, such a structure in metamorphic rocks is called banding and rocks displaying banding are called banded rocks.
  • Metamorphic rocks are divided into two groups, foliated rocks and non-foliated rocks.
  • Examples of metamorphic rocks are Gneissoid, granite, syenite, slate, schist, marble, quartzite etc.

Rocks Cycle

geography optional - Physical geography of rock cycle
Rock Cycle : Physical Geography
  • Rocks do not remain the same, they transform this called Rock Cycle.
  • Igneous rocks are the primary rocks, metamorphic and sedimentary rocks are other forms of these primary rocks.
  • The igneous and metamorphic rocks are can be fragmented and turn into sedimentary rocks.
  • Sedimentary rocks also fragment further to become new sedimentary rocks.
  • The crustal rocks such as Metamorphic and Igneous rocks can sub-duct due to various movement, moves slowly to the mantle and due to high temperature it gets molten down to lava and the rocks cycle continues.

Geomorphic Processes: Physical Geography

  • Why the earth surface is uneven?. The answer is earth crust is dynamic and it is subjected to continuous changes. The changes are due to various external and internal forces.
  • The external forces such as sunlight etc are called as exogenic forces.
  • The internal forces are called as endogenic forces.
  • The exogenic forces create degradation or wearing down of relief or elevations and aggradation or filling up of depressions or basins.
  • The wearing down of relief variation due to erosion is called gradation.
  • The endogenic forces continuously raise or elevate the earth surfaces and exogenic forces fail to make to even surface on the reliefs or surface of the earth.
  • Generally, exogenic forces are land wearing forces and endogenic forces are land building forces.

Geomorphic Process

  • The endogenic and exogenic forces that bring a change in the configuration of the earth by various physical and chemical action is called as Geomorphic Process.
  • Diastrophism and volcanism are endogenic geomorphic processes and erosion, deposition, mass wasting and weathering are exogenic processes.
  • The geomorphic agent is any natural exogenic element such as Ice, wind, water etc that can acquire and transport earth materials.
  • These geomorphic agents become mobile due to gradients there remove the material and transport, and deposit them to lower-level over the slopes.
  • Geomorphic processes and geomorphic agents are almost the same.
  • The geomorphic process is a force that is applied to the earth materials whereas the geomorphic agents are elements such as water, ice, wind etc.
  • The gravity is very important for geomorphic process or geomorphic agent is responsible for all process happens on the earth such as carrying slits from the slope using water, water flowing over slopes, stress on rocks etc. The gravitational force plays a vital role.
  • All the movement with the earth or outside the side are due to gradients from a higher level to lower levels, from high pressure to low-pressure areas etc.

Endogenic Processes

  • The force from inside the earth is responsible for Endogenic process.
  • The Endogenic energy is radioactivity, tidal friction, rotational friction and primordial heat.
  • This energy due to geothermal gradients and heat flow within induces diastrophism and volcanism in the lithosphere.
  • The actions of endogenic forces are uneven due to the difference in geothermal gradients and heat flow from inside, crustal thickness, strength. Therefore the surface is uneven.


  • Anything that move, build up or elevate the parts of the earth crust comes under Diastrophism.
  • Diastrophism includes i)Orogenic processes that involve mountain building by severe folding and changes long and narrow belts of the earth’s crust, ii) Epeirogenic process that is uplifting or warping large parts of earth’s crust, iii) earth tremors or quakes involving minor movements iv) plate tectonics responsible for horizontal crustal plate movements.
  • “Orogeny is a mountain building process whereas Epeirogeny is continental building process”.
  • The faulting and fracturing of crust are caused by orogeny, epeirogeny, earthquakes and plate tectonics.
  • Each and every of these process cause PVT (Pressure, Volume, Temperature) changes such as metamorphism of rocks.

Exogenic Processes

  • It gets the energy from the sun and also the gradients created by tectonic factors.
  • Gravitational force acts on all the objects and produce movement slope direction.
  • Force applied per unit area is called stress, it is produced by pushing or pulling and induces deformation.
  • Forces acting along the faces of earth materials are shear stresses/ separating forces, this stress that breaks rocks and other earth materials.
  • The shear stresses result in angular displacement or slippage.
  • Apart from that earth materials are subjected to molecular stress due to temperature, changes, crystallisation and melting are most common.
  • These chemical reactions make loosening of bonds between grains, dissolving of soluble mineral or cementing materials.
  • There we can come to the conclusion that the reason that leads to weathering, mass movements and erosion is the development of stress in earth materials.
  • The precipitation and temperature are important climatic elements.
  • Weathering, mass movements, erosion and transportation are part of denudation.
  • Also, different climatic regions add variations in thermal gradients by latitudinal, seasonal and land and water spread on the surface of the earth.
  • The density type and vegetation also depend on precipitation and temperature influence indirectly on exogenic geomorphic processes.
  • There is also a variation of insolation received by north and south-facing slopes as compared to east and west-facing slopes.
  • Moreover, the velocity and direction of the wind, type of precipitation (snow/water rain), rain intensity, the connection between precipitation and evaporation, daily changes in temperature, freezing and thawing frequency, frost penetration depth, these also affect geomorphic processes.
  • The intensity of action of exogenic processes depends upon the structure of rocks such as folds, faults, orientation and inclination of bed, presence or absence of joints, bedding planes, hardness or softness o constituent minerals, chemical of a mineral constituent, permeability or impermeability.


  • It is the action of weather and climate the acts on earth materials and reduce them to fragments.
  • It is also referred as mechanical disintegration and chemical decomposition of rocks by various element of climate or weather.
  • No motion takes place during weathering, It is on site or in-situ process.
geography optional  - weathering of rocks
Depth of Weathering mantles and climatic regimes
  • Weathering processes differ from different climatic regions and also the depth of the weathering mantle.

Chemical Weathering Processes

  • A group of weathering processes viz; solution, carbonation, hydration, oxidation and reduction act on the rocks to decompose, dissolve, or reduce them to a fine clastic state through chemical reaction by oxygen, surface and /or soil water and other acids.

Types of Forest and Vegetations

Forest and wildlife in India Upsc

Forest and wildlife in India

India is one of the world’s richest in biological diversity. Also, several numbers of species are yet to be discovered. Some estimate that 10% of wild flora and 20% of its mammals are on the threatened list.

Natural Vegetation and Planted Vegetation

Natural vegetation is something that certain plant species left undisturbed over some time. For example, in a forest or mountain terrain, these plant communities start to adapt themselves to the conditions, might be soil or climate, etc.

On the other hand, Planted vegetation, is growing a specific plant from the forest or some source and planting it in the farm/garden under some human supervision.

India’s land is huge and it is so large that it is called the Indian subcontinent, which has a large variety of natural vegetation. Also, India has got so many types of vegetation that differ from one place to another. Due to this, there are great variations in climate and soil in India.

For example, the Himalayas has temperate vegetation. This is in the North part of India. On the other hand in places such as Andaman and Nicobar, Western Ghat, etc. These two places are separated by hundreds of miles of sea but still, these two has similarity in vegetation. These two are Tropical Rain Forest.

To completely contrast the above two vegetation we find yet another type of vegetation that is desert and semi-deserts of Rajasthan. It is known as Cactii, it is a kind of busy or thorny vegetation.

You will find tropical forests and mangroves in the deltaic regions.

 Types of Forest in the India

  1. Tropical Evergreen and Semi-Evergreen Forest
  2. Tropical Deciduous Forest
  3. Tropical Thorn Forest
  4. Montane Forest
  5. Littoral and Swamp Forest

Tropical Evergreen and Semi-Evergreen Forest

Forest and wildlife Types of Forest-Evergreen Forest
Photo by Brady Knoll on

Ok, these Woods are found in Andaman Nicobar Is, Northeastern regions, and Western Ghats slopes.

As far as climate is concerned these are generally in warm and humid places, where there are rainfall of excess of 200 cm and an annual mean temperature of almost 22 degrees Celcius.

The tropical evergreen forest is well arranged with a layer that is nearer to land and is well sheltered with creepers, and shrubs. A unique pattern is found, a short tree along with a variety of tall trees in this vegetation.

These trees of evergreen forests reach up to 60 meters and above. You know another exciting fact about this vegetation, there is a definite period these trees for fruition, flowering, or shedding their leaves.

It appears green throughout the year. Examples of Evergreens are ebony, aini, mahogany, rosewood, etc. Next, the other one is found in the less rainy area which has an amalgamation of moist deciduous trees and evergreen that is known as a semi-evergreen forest.

Another characteristic feature is the presence of Climbers.

The main examples of semi-evergreen forests are white cedar, kail, and hollock.

Someone might have known the value of these forests, Yes that someone is the British, who knows the commercial value of the woods, they replace Oak forest with Pine in Kumaon and Garhwal.

Oakwood was used to lay rails and for constructions as woods were insulators. Also, Brits cleared forests for the plantations of rubber, tea, coffee.

Tropical Deciduous Forest in India

Types of Forest-Tropical Deciduous Forest
Photo by Pixabay on

These are like viruses, like everywhere in India, it’s widespread and also called monsoon forests. They found where the precipitation was around 70-200 cm.

Based on the amount of water and moist presence, these are further divided into moist and dry deciduous.

Moist Deciduous found in heavy precipitated areas with 100-200 cm, found in the Himalayan foothill in the northeastern Indian states.

Also found in eastern ranges of the western ghats and parts of Odisha. Some of the tree species are Teak, Sandalwood, sal, Kusum, etc. Dry Deciduous found in margins of wetter areas where there is the transition, moist to drier to thorns. The precipitated areas with 70-100 cm.

Cover vast regions of the country. Found in the Indian peninsula, UP plains, and Bihar and also in higher Peninsular plateau and north Indian plains.

These have striking characteristics such as patches of grass in common, with trees scatter between other things and mixed with teak. Another common feature is, these trees shed their leaves and become leafless in dry seasons

Some of the tree species are Axlewood, tendu, palas, etc. Due to low rainfall and perhaps overgrazing to some extent, this vegetation is found very low in the western Rajasthan and southern Rajasthan.

Tropical Thorn Forests in India

Types of Forest-Tropical Thorn Forest
Photo by Tomas Anunziata on

From the word thorn, you might have concluded this kind of vegetation is found in dry areas. Thorn forests are found in areas where there is very low precipitation of about less than that of 50 cm.

Thorn vegetation, yes it consists of a variety of Shrubs, grasses, thorns, etc. In India, as you know it is found Northwestern part of the country, where the land is semi-arid.

Prominent areas of Tropical Thorn are southwestern Punjab that borders Punjab and Rajasthan, and of course Rajasthan, Gujarat, MP, and UP. In thorn vegetation, the plants are leafless throughout or most of the year.

Examples of Thorn vegetation are Babool, Ber, Wild Date, Palas, etc. A kind of grass grows up to 2m called Tussocky grass.

Montane Forest in India

These forests are classified based on altitude and amount of rainfall. Accordingly two different types of forest namely the Eastern Himalayas Forest and the Western Himalayas forest.

Eastern Himalayas

Found on the slopes of the mountains in northeast states. These forests receive rainfall of more than 200 cm. The vegetation of the eastern Himalayan forest is evergreen type.

The altitude is between 1200- 2400 m found in this type of forest Sal, Oak, Laurel, Amura, Chestnut, Cinnamon are the main trees. At the altitude of 2400 to 3600m, oak, birch, silver, fir, fine, spruce and juniper are found.

Western Himalayas

In this region rainfall is moderate. Western Himalayas forest is found in the states of Jammu and Kashmir, Himachal Pradesh, and Uttarakhand.

Up to 900m altitude semi-desert vegetation is found. This region is known for bushes and small trees. At an altitude of 900 to1800m, chir tree is most common. Other important trees of this region are sal, semal, dhak, Jammun, and jujube.

At the altitude of 1800 to 3000m, is covered with semi temperate coniferous forest, Chir, Deodar, Blue pine, poplar, birch, and elder.


Alpine is found all along the Himalayas with above 2400m altitude. They purely have coniferous trees. Oak, Silver fir, pine, and Juniper are the main trees of the Alpine forest.

The eastern parts of the Himalayas have a large extent of these forests.

Tidal Forest

Tidal forests are found in and around the deltas, estuaries, and creeks prone to tidal influences. The tidal forest is also called Delta Forest or Swamp Forest.

The delta of Ganga – Brahmaputra has the largest tidal forest. The deltas of Mahanadi, Godavari and Krishna rivers are also known for Tidal forests. These are also known as Mangrove Forest.

Coastal Forest

These are littoral forests. Coastal Forest is found in coastal areas. Casurina, palm, and coconut are the dominant trees. Both the eastern and western coasts have this kind of forest.

The coast of Goa and Kerala is known for its coastal forest.

Riverine Forest

Riverine forests are found along the rivers in Khadar Area. These are known for Tamarisk and Tamarind Trees. The rivers of great plains are more prominent for this type of natural vegetation.


Wildlife includes Animals of any habitat in nature. The non-domesticated animals are wild animals. The wild animals include vertebrates such as fish, amphibians, reptiles, birds, and mammals and invertebrates such as bees, butterflies, moths, etc.

Flaura means plants and Fauna means animals. India has a fauna of about 81,251 species out of 1.5 million species in the world.

India has 6500 species of invertebrates, 5000 species of mollusks, 2546 species of fishes, 1228 species of birds, 458 species of mammals, 446 species of reptiles, 204 species of amphibians, 4 species of panthers, and 6000 species of insects.

India is home to tigers, lions, leopards, snow leopards, pythons, wolves, foxes, bears, crocodiles, rhinoceroses, camels, wild dogs, monkeys, snakes, antelope species, deer species, bison, and the mighty Asian elephant.

Various human activities caused troubles to various species that led them to decrease in population and even cause extinction.

A conversation of biodiversity is necessary to maintain ecological balance. IBWL (Indian board for wildlife) was created in 1952 to suggest ways of protection, conservation, and management of wildlife to the government.

In 1972, the union government passed the Wildlife (Protection) Act. The objective of the Wildlife (Protection) Act 1972 is to effectively protect the wildlife and control poaching, smuggling, and illegal trade of wildlife.

UN Convention on Biological Diversity (CBD) in 1992 recognizes the sovereign rights of states to use their Biological Resources. India developed 102 National Park and 515 Wildlife Sanctuaries to preserve the wildlife.

Biosphere Reserves

Biosphere Reserves are protected areas of the land, coastal environment, where the people are also part of the system. There are 18 Biosphere reserves established by the Indian government.

Biosphere reserves protect a large area of natural habitat and usually include one or more National parks along with buffer zones. Buffer zones are open to some economic uses.

Eleven of the Eighteen biosphere reserves in India are under the list of Man and Biosphere programme of UNESCO. They are Gulf of Mannar, Nandadevi, Nilgiris, Nokrek, Pachmarhi, Simlipal, Sundarbans, Agasthiyamalai, Great Nicobar, Kanjanjunga and Amarkantak.

Biosphere ReservesState
Achanakmar-AmarkantakChattisgarh, Madya Pradesh
Dibru SaikhowaAssam
Dihand DibangArunachal Pradesh
Great NicobarAndaman and Nicobar Islands
Gulf of MannarTamil Nadu
Nanda DeviUttarakhand
NilgirisTamil Nadu
PachmarhiMadya Pradesh
SundarbansWest Bengal
Cold DesertHimachal Pradesh
Sesahachalam HillsAndra Pradesh
PannaMadya Pradesh

Project Tiger launched in April 1973. Its object is to conserve the tiger population, especially in Tiger Reserves in India. The project increased over 60% population of Tiger from 1979 consensus put the population at 3015.

Other species like barasingha (swamp deer), rhino, and elephants population also increased parallel due to this project.

forest and wildlife resources in india

forest and wildlife sanctuaries in india

forest and wildlife laws in india

forest conservation laws in india


  1. Samacheer Kalvi Geography Class X, 2019 Edition.
Geographical features of India

Location and physical features of India Tnpsc

Location and physical features of India

The geographical features of India consist of the peninsula which is surrounded by water on three sides, the world’s highest mountain ranges in the north, the desert in Rajasthan etc.

Coast and Land Boundary of India

India shares a 15,200 Km land frontier in the west with Pakistan, northwest with Afghanistan, Nepal-China-Bhutan in the north, and Bangladesh-Myanmar in the east. India shares the longest border with Bangladesh with 4156 km. India shares the shortest border with Afghanistan at 106 km.

India has a coastline of 6100 km with three sides, namely the Indian Ocean, and its two arms lie on the Arabian Sea in the west, and in the east, it is the Bay of Bengal. The total length of India’s coastline including the islands is 7516.6 km.

India and Sri Lanka are separated by the Palk Strait which is a narrow and shallow sea called Palk Strait.

India’s Geographic Location in the World

India’s landmass is centrally located between East and West Asia. India has a southward extension to the Asian continent and the Indian Ocean. India has a strategic location as it is located in the trans-Indian Ocean route that connects Europe and East Asia.

This helps in establishing contact with West Asia, Africa, and Europe

India: A Subcontinent

India along with Myanmar, Bangladesh, Pakistan, Nepal, Bhutan, and Sri Lanka is called an Indian Subcontinent. This area is separated from Asia by a chain of mountains in the northwest, north, and northeast. Also separated by Sea in the South.

This region also has unique continental characteristics in Physiography, climate, natural vegetation, minerals, etc Therefore India is called a Subcontinent.

The physical features of India

  • Geographically India’s physical features are divided into five physiographic divisions:
    • Himalayas
    • Great Northern Plains
    • Peninsular Plateau
    • Great India Desert
    • Coastal Plains
    • Islands

The Himalayan mountains

The Himalayan mountains (northern mountains) are the youngest and the loftiest mountain chains in the world. The Himalayas have formed only a few million years ago. They were formed because of the folding of the earth’s crust due to tectonic activity.

Himalaya stretches for a distance of about 2,500 Km from the Indus Gorge in the west to Brahmaputra gorge in the east. The width of the Himalayas varies from 500 km in Kashmir to 200 Km in Arunachal Pradesh.

Pamir Knot is famously referred to as the “Roof of the World”, is the link connecting the Himalayas and high ranges of central Asia. From the Pamir Knot, the Himalayas extend eastwards in like an arc.

Pamir Knot in India Map

The term Himalaya means “Abode of Snow” in the Sanskrit language. The Himalayas acts as a great wall are classified into three divisions:

  • Trans Himalayas
  • Himalayas
  • Eastern or Purvanchal Hills

Aravalli range is the oldest fold mountain range in India.

  1. The Trans-Himalayas

The Trans-Himalayas is also known as the western Himalayas. The western Himalayas lies to the north of the great Himalayan Range. It lies in the Tibetian plateau and Jammu-Kashmir. The western Himalayas are about 40km wide in eastern and western extremities.

It is about 225 km wide in its central part. The trans-Himalayas contain the Tethys sediments. The rock of this region contains fossil-bearing marine sediments which are underlain by ‘Tertiary granite‘. It also has partly metamorphosed sediments and constitutes the core of the Himalayas axis.

The prominent ranges of Trans-Himalayas are Zaskar, Ladakh, Kailash, and the Karakoram.

The Himalayas

The Himalayas constitutes the core part of the northern mountains. The Himalayas are young fold mountains. The Himalayas were formed by the movement of Angara landmass in the north and Gondwana landmass in the south.

The Tethys sea found between these two landmasses was uplifted by the compression and the resultant landform was the Himalayas. The Himalayas consists of many ranges.

  • Greater Himalayas
  • Lesser Himalayas
  • Siwaliks
PeakCountryHeight in metres
Mt. EverestNepal8848
Mt.K2 or Godwin AustenIndia8611
Nanga ParbatIndia8126
Nanda DeviIndia7817
Namcha BarwaIndia7756
Gurla MandhataNepal7728

Himalayan Mountain Ranges with its Height and country

Himalaya is the home of several high peaks. However, it holds the record of having the maximum number of highest peaks among any mountain range in the world. Out of the 14 highest peaks in this world, the Himalayas holds 9.

The Greater Himalayas or the Himadri

The Himadri rises abruptly like a wall north of the lesser Himalayas. It is 25 km wide and the average height is about 6000m. The Greater Himalayas receive lesser rainfall compared to the lesser Himalayas and the Siwaliks. Physical weathering is not effective over the Greater Himalayas (Himadri) compared to the other ranges.

Almost all the lofty peaks of the Himalayas are located in this range. The famous ones are Mt.Everest (8,848m) and Kanchenjunga (8,586m). Mt.Everest is located in Nepal and Kanchenjunga is located between Nepal and Sikkim.

This range is the most continuous of all ranges. It is a region of permanent snow cover. It has many glaciers, Gangothri, Yamunotri and Siachen are famous ones.

The Lesser Himalayas or The Himachal

The Himachal (Lesser Himalayas) is in the middle range of the Himalayas. The height of this range varies from 3,700 to 4,500m. Its width varies up to 80 km. The major rocks of the Himachal ranges are slate, limestone, and quartzite.

This region is exposed to extensive erosion due to heavy rainfall, deforestation, and urbanization. Pir Panjal, Dhauladhar, and Mahabharat are the mountain ranges found in this part. Major hill stations of the Himalayas are located in Lesser Himalayas (Himachal). Shimla, Mussourie, Nainital, Almora, Ranikhet, and Darjeeling are the famous ones.

Major Passes in the Himalayan
  • Karakoram Pass in Jammu Kashmir.
  • Zojila Pass, Shipkila pass in Himachal Pradesh
  • Bomdila Pass in Arunachal Pradesh
  • Nathala Pass and Jhelepla Pass in Sikkim
  • Khyber pass which connects Pakistan and Afghanistan
  • Bolan Pass in Pakistan is important passes of the Indian Subcontinent.

The Siwaliks or Outer Himalayas

The Siwaliks extend from Jammu and Kashmir to Assam. It is partly made by the debris brought by the Himalayas rivers. The altitude varying between 900-1100 meters elevation of this range is 1300m. The width of Siwaliks varies from 10km in the east to 50km in the west.

It is the most discontinuous range.

Duars and Duns

The longitudinal valleys found between the Siwaliks and the Lesser Himalayas are Duns in the west. In the east it is Duars. These are the ideal sites for settlements in this region.

Features of Purvanchal Hills

Purvanchal Hills are the eastern offshoot of the Himalayas. These ranges extend to the northeastern states of India. The states lying in the Purvanchal hill ranges are Arunachal Pradesh, Nagaland, Manipur, Mizoram, Tripura, and eastern Assam.

Most of the Purvanchal hills are located along the border of India and Myanmar and some inside India.

The collection of Dafla Hills, Abor Hills, Mishmi Hills, Patkai Bum Hills, Naga Hills, Manipur Hills, Mizo Hills, Tripura Hills, Mikir Hills, Garo Hills, Khasi Hills, and Jaintia Hills are known as Purvanchal Hills or Purvanchal Ranges.

Importance of Himalayas

The Himalayas blocks southwest monsoon winds and causes heavy rainfall in north India. It forms a natural barrier to the subcontinent. It is the source of many perennial rivers like the Indus, Ganges, Brahmaputra, etc. The Northern Mountains are described as the paradise of tourists due to their natural beauty.

Many hill stations and pilgrim centers like Amarnath, Kedarnath, Badrinath, and Vaishnavidevi temples are situated here. It provides the raw material for many forest-based industries.• It prevents the cold winds blowing from Central Asia and protects India from severe cold.

The Himalayas are renowned for their rich biodiversity.

Longitudinal Divisions of Himalayas

Longitudinal division of Himalayas

  1. The Kashmir Punjab Himachal Himalayas- Located between the rivers of Indus and Sutlej.
  2. The Kumaun Himalayas- Located
    between the rivers of Sutlej and Kali.
  3. The Central-Nepal Himalayas are located between the rivers of Kali and Tista.
  4. The Assam Eastern Himalayas are located between the rivers of Tista and Dihang.

The Great Northern Plains

The fertile land extending across seven north Indian states forms the great northern plains. These extensive plains lie to the south of the northern mountains. This plain is one of the most extensive stretches of alluvium in the world and is deposited by the river Indus, Ganga, Brahmaputra, and its tributaries.

The length of the plain is about 2400 km and the width varies from 240 to 320 km. Its width increases from east to west. It covers an area of over 7 lakh sq. km. The great plains of India are formed mostly by the depositional process of the Himalayan and Vindhyan rivers.

These rivers deposit sediments along the foothills and flood plains. The important characteristics and features of sediment deposition in the plains areas are as follows.

1. The Bhabar Plain

This plain is made of unassorted sediments and gravel deposited by the rivers of the Himalayas. Small stream flow disappears in this region due to the high porosity of this plain. Bhabar Plain lies to the south of the Siwalik from west to east (Jammu Division to Assam).

The width of the Bhabar Plain varies from 8 to 15km. It is wider in the western plains (Jammu Division) than in the east (Assam). This plain is not suitable for cultivation, and only big trees with large roots thrive in this region.

2. The Tarai Tract or Teraje Region of India

The Tarai Tract is a zone of excessive dampness with thick forests and rich wildlife. It is located in the south of Nepal and northern India which is parallel to the lower Himalayas. It is stretched from the Brahmaputra in the east and Yamuna in the west.

It lies south of the Bhabar plains. The width of the Tarai Tract is 15 to 30 Km. The Tarai is wider in the eastern of the Great Plains especially in the Brahmaputra Valley because of the heavy rainfall.

The Tarai forest is cleared for farming in many states. The Tarai region is important as it provides connectivity to Eastern Himalayas across Nepal. The ecological importance of the Tarai region has Tiger, Elephant, Asian Rhino, etc.

In Nepal, the Tarai region is referred to as the “Granary of Nepal”, as the soil in this region is very fertile and receives good rainfall and a suitable climate for agriculture.

3. The Bhangar Plains

The Bhangar represents the upland alluvial tracts of the Great Plains of India. It is formed by the older alluvium. The Bhangar land lies above the flood limits of the rivers. This soil is dark in colour, rich in humus content, well-drained, and useful for agriculture.

4. The Khadar Plains

The new alluvium tracts along the courses of the rivers are known as Khadar or Bet lands. The Khadar tracts are enriched by fresh deposits of silt every year during rainy seasons. The Khadar land consists of sand, silt, clay, and mud. It is highly fertile soil.

5. Delta Plains

The deltaic plain is an extension of the Khadar land. It covers 1.9 Lakh sq. km in the lower reaches of the Ganga River. It is an area of deposition as the river flows in this tract sluggishly.

Chars and Bils

The deltaic plains consist of old mud, new mud, and marsh. In the delta region, the uplands are called ‘Chars‘. And the marshy areas are called ‘Bils’.

The Peninsular Plateaus

It lies to the south of the Great Northern Plains. This is the largest Physiographic division in India. Peninsular Plateaus cover about 16 lakh sq. km (about half of the total area). It is an old rocky plateau region. The topography has a series of plateaus and hill ranges interspersed with rivers.

Aravalli hills mark the north-western boundary of the plateau region. Its northern and northeastern boundaries are marked by the Bundelkhand upland, Kaimur, and Rajmahal hills. The Western Ghats and the Eastern Ghats mark the western and eastern boundaries respectively.

The altitude of a large portion of the plateau is more than 600m from the mean sea level. The peak of Anaimudi is the highest point in the plateau, its height is 2695m and is located in Anaimalai. The general slope of this plateau is towards the east.

The Great Plateau is a part of the Gondwana landmass. Due to old age, rivers in this region attained their base level and developed broad and shallow valleys. The river Narmada divides the plateau region of India broadly into two parts.

The region lying to the north of Narmada is called the Central Highlands, and the region lying to the south of Narmad is called the Deccan Plateau. All the major rivers such as Mahanadi, Godavari, Krishna, Kaveri, etc. lie to the south of the Vindhyas that flow eastwards and fall into the Bay of Bengal. Narmada and Tapti are the two rivers situated to the south of the Vindhyas flow westward.

Their movement towards the west is due to the presence of a rift valley in the region.

1. Central Highlands

The Central Highlands lies between the Narmada River and the Northern Great Plains. The Aravallis form the west and northwestern edge of the Central Highlands. These hills extend from Gujarat, through Rajasthan to Delhi in the Northwesterly direction for a distance of about 700km.

The height of these hills is about 1500m in the southwest while near Delhi the height is hardly 400m. Guru Shikhar with 1722m is the highest peak of this range. The western part of the central highland is known as the Malwa Plateau. It lies to the southeast of Aravallis and to the north of the Vindhyachal range.

The rivers Chambal, Betwa, and Ken drain the Malwa plateau before they join the river, Yamuna.

  • The part of the Central Highlands which extends to the east of Malwa Plateau is known as Bundelkhand and its further extension is known as Bagelkhand.
  • The eastern part of the central Highlands which lies in the north-eastern part of the Indian plateau is known as Chhota-Nagpur Plateau.
  • It covers much of Jharkhand, adjacent parts of Odisha, West Bengal, Bihar and Chhattisgarh.
  • This region is very rich in mineral resources, particularly iron ore and coal.

2. Deccan Plateau

It is the largest part of the plateau region of India. The shape of this plateau is almost triangular. On the sides of the triangle is marked by a line joining Kanyakumari with Rajmahal Hills and this line passes through the Eastern Ghats.

The second arm is marked by Satpura Range, Mahadeo Hills, Maikal Range, and the Rajmahal Hills. The third arm is marked by the Western Ghats. The total area is about 7 lakh square km and the height ranges from 500 to 1000m above sea level.

The Western Ghats form the western edge of the Peninsular Plateau and run parallel to the Arabian Sea Coast. The northern part of this range is called Sahyadris. The height of the Sahyadris increases from north to south. Anaimudi is a sort of tri-junction of the Anaimalai range, the cardamom hills, and the Palani hills.

Kodaikanal is a hill resort situated on the Palani Hills. The Eastern Ghats run from southwest to northeast from the eastern edge of this plateau. This range is also called Poorvadri. The Eastern ghats join the western ghats at the Nilgiri hills, bordering Karnataka and Tamil Nadu.

The Eastern ghats are not continuous like the Western ghats. The rivers of Mahanadi, Godavari, Krishna, Pennar, and Kaveri have dissected this range in many places.

The Indian Desert

The Thar desert, also known as the Great Indian Desert is a large arid region in the northwestern part of the Indian subcontinent that covers an area of 2,00,000 sq. km and forms a natural boundary between India and Pakistan. It is the world’s 7th largest desert and the world’s 9th largest subtropical desert located in the western part of India.

The desert lies in the western part of the Aravali range and covers 2/3 of Rajasthan state. There are two major divisions in the Thar desert and they are the Actual desert region called Marusthali and the semi-desert region called Bhangar. And different types of sand dunes and salt lakes called Dhands are seen here.

The Coastal Plains

The Peninsular Plateau of India is flanked by narrow coastal plains of varied width from north to south known as the Western Coastal Plains and the Eastern Coastal Plains. They were formed by the depositional action of the river and the erosional and depositional actions of the sea waves.

The Indian coastal plains are divided into Western and Eastern Coastal Plains.

1. The Western Coastal Plain

It lies between the Western Ghats and the Arabian Sea. It extends from Rann of Kutch in the North to Kanyakumari in the south and its width varies from 10 to 80 km. It is mainly characterized by Sandy beaches, coastal sand dunes, mudflats, lagoons, estuary, laterite platforms, and residual hills.

The northern part of the west coastal plain is known as the Konkan plain. The middle part of this plain is known as Kanara. The southern part of the plain is known as the Malabar coast which is about 550km long and 20-100 km wide.

This part of the coast is characterized by sand dunes. Along the coast, there are numerous shallow lagoons and backwaters called Kayals and Teris. Vembanad is a famous backwater lake found in this region.

2. The Eastern Coastal Plain

It lies between the eastern ghats and the Bay of Bengal and it stretches along with the states of West Bengal, Odisha, Andhra Pradesh, and Tamil Nadu. These plains are formed by the alluvial fillings of the littoral zone by the east-flowing rivers of India. The coastal plain consists mainly of the recent alluvial deposits.

This coastal plain has a regular shoreline with well-defined beaches.

  • The coastal plain between the Mahanadi and Krishna Rivers is known as the Northern Circars and the southern part lies between the Krishna and Kaveri Rivers is called the Coromandel Coast.
  • The Marina beach on this coast in Chennai and is the second-longest beach in the world.

Important Lakes in the Eastern Coastal Plain

Among the backwater lakes of this coast, lake Chilka (Odisha) is the largest lake in India located to the southwest of the Mahanadi delta, the Kolleru Lake lies between the deltas of Godavari and Krishna, and the Pulicat Lake lies on the border of Andhra Pradesh and Tamil Nadu are the well-known lakes in the eastern coastal plain.

The Islands of India

There are two major island groups namely Andaman-Nicobar and Lakshadweep. Andaman and Nicobar Islands consist of 572 islands and are located in the Bay of Bengal. Lakshadweep Islands are located in the Arabian Sea and have 27 islands that are mainly of coral origin.

The Andaman and Nicobar Islands are of largely tectonic and volcanic origin. India’s only active volcano is found on Barren Island in Andaman and Nicobar Islands.

1.Andaman and Nicobar Islands

Andaman and Nicobar Islands are located in an elevated portion of the submarine mountains. It lies close to the equator, as a result, it remains hot and wet throughout the year and has a dense forest. The area of the island group is about 8249 sq km.

The entire group of islands is divided into two, which are Andaman in the North and Nicobar in the South. Andaman and Nicobar Islands are of great strategic importance for the country. Port Blair is the capital of Andaman and Nicobar Islands.

The Ten Degree Channel separates Andaman from the Nicobar group. The southernmost tip, Indira Point is a part of Nicobar Island

The southernmost tip of India, which is Indira Point is located at the latitude of 6°45’N or 6-1/2 N which is part of Nicobar Island.

2. Lakshadweep Islands

Lakshadweep archipelago is a group of coral islands situated off the west coast of the Indian Subcontinent. The administrative capital of Lakshadweep is Kavaratti. The Eight Degree Channel separates the Lakshadweep from the Maldives Islands.

Their uninhabited Island is known as Pitt Island, which has a bird sanctuary. Lakshadweep has three divisions earlier namely Laccadive, Minicoy, and Amindivi. It was named Lakshadweep in 1973.

3. Offshore Islands

Besides Andaman-Nicobar and Lakshadweep islands, India has a number of Islands along the Western Coast, Eastern Coast, in the delta region of Ganga, and in the Gulf of Mannar. Many of these islands are uninhabited and are administered by the adjacent states.

India Location

The latitude and longitude extent of India

India extends from  8°4 ‘N to 37°6 ‘N latitude and 68°7 ‘E to 97°25 ‘E longitudes. India is located in the North-Eastern Hemisphere. The Southernmost part of India is Indira Point or 6-1/2 N latitude is 6°45’N latitude and is located in the Andaman and Nicobar Islands.

The southernmost point of the mainland is Cape Comorin or Kanyakumari. The north-south extent of India is 3214 km, it extends from Indira Col in Jammu and Kashmir to Kanyakumari in Tamil Nadu. The east-west extension is 2933 km, it extends from Rann of Kutch in Gujarat in the west to Arunachal Pradesh in the east.

The tropic of Cancer at 23°30′ N passes through the centre of the country and divides the country into two halves. One half is northern temperate and the other half is southern tropical lands. India is politically divided into 28 states and 8 union territories as of 16-11-2020.

The newly formed union territories are Jammu and Kashmir, and Ladakh after the removal of Article 370. Total union territories along the west coast are Diu Daman-Dadra Nagar Haveli, Mahe (Pondicherry), and Lakshadweep. Totally three.

The number of union territories on the eastern coast is Puducherry and Andaman Nicobar Islands. Totally two. The smallest state in India is Goa. The largest state in India is Rajasthan.

The smallest union territory in India is Lakshadweep. The largest union territory is the Andaman & Nicobar Islands. The largest district in India is Kachchh (Gujarat). The smallest district in India is Mahe (Pondicherry).

The states that do not have an international border or lie on the largest state Rajasthan are Haryana, Uttar Pradesh, and Madya Pradesh. The states that do not have an international border or lie on international coastal boundaries are Haryana, Jharkhand, Madhya Pradesh, Chhattisgarh, and Telangana.


This post is for the topic ‘Location – Physical Features of India‘ for the Tnpsc exam. These notes are taken from Samacheer Kalvi’s book 10th Standard. It is also useful for Upsc and other state service exams.



Rivers in India Tnpsc notes

This article discusses the Indian rivers and their tributaries. It also covers west and east flowing rivers in India and types of rivers in India.

Rivers in India

Rivers in India is an important topic in Civil services, often a number of questions asked from its topic. There are seven major rivers namely Indus, Brahmaputra, Narmada, Tapi, Godavari, Krishna, and Mahanadi. Along with its tributaries, it makes the river system of India.

It is important to know the river as about most as India is an agriculture-dependent country, and most of the politics, interstate disputes happen because of it.

Also, it is important to know about climate-related to the river, which helps in Agriculture and also disaster management.

A river system or drainage system is an integrated system of tributaries and a trunk stream that collects and drains surface water into the sea, lake, or some other water bodies.

The total area drained by a river and its tributaries is known as the drainage basin. The drainage pattern of an area is the result of the geological structure of the respective areas.

It provides irrigation, drinking water, navigation, and helps in power generation to the people.

Types of rivers in India

The Indian drainage system is classified into Himalayan, and Peninsular rivers based on their location.

Let us see what are Himalayan and peninsular drainage systems?

Himalayan Rivers

Himalayan rivers are found in North India. These rivers originate from the Himalayas. Thereby they are called Himalayan rivers.

Himalayan rivers are perennial rivers, that is there is constant water flow throughout the year. Examples of Himalayan rivers are Indus, Ganga, Brahmaputra, etc.

Types of Rivers in India
types of rivers in India

The Indus River System

Indus river is one of the largest rivers in the world. Indus river originates from a northern slope of the Kailash range in Tibet near Manasarovar Lake at a height of 5150 metres above sea level.

The length of the Indus is about 2880km but it flows only 709 km in India. The Indus river has a total drainage area extending 11,65,500 sq km in which 321,289 sq km areas are drained in India.

Its flows through the Indian state Ladakh. It flows through Zaskar ranges and creates deep gorges.

The river runs through formerly called Jammu and Kashmir, turns south near Chillar, and enters Pakistan.

Indus major tributaries are Jhelum, Chenab (Largest tributary of Indus), Ravi, Beas, and Sutlej. It enters the Arabian Sea.

The Ganga River System

The Ganga river has the largest drainage system in India. It extends over an area of 8,61,404 sq km in India.

The Ganga plain is the densely populated plain in India. The Ganga River originates as Bhagirathi from the Gangotri Glacier in Uttar Khasi District of Uttarkhand, at an elevation of 7010 metres.

The length of the Ganga river is 2525 km. The major tributaries of Ganga from the north are Gomti, Gandak, Kosi, and Ghaghra and from the south, the Yamuna which is the largest tributary of Ganga, Son, Chambal, etc.

The Ganga river is called the Padma in Bangladesh. The Ganga and Brahmaputra together create the world’s largest delta known as Sundarbans in Bangladesh before joining the Bay of Bengal.

Brahmaputra River System

Brahmaputra river originates from the Chemayungdung Glacier of the Kailash range to the east of Lake Manasarovar in Tibet at a height of 5150 metres about sea level.

The Brahmaputra is also known as Tsangpo (Purifier) in Tibet. The total drainage area of the Brahmaputra river is about 5,80,000 sq. km.

Its total drainage area in India is 1,94,413 sq. km. The total length of the Brahmaputra rivers is about 2900 km. The total length of the Brahmaputra river in India is 900 km.

Brahmaputra river enters India through a gorge in Arunachal Pradesh namely Dihang. The tributaries of Brahmaputra river are Tista, Manas, Barak, Subansiri etc. Brahmaputra river is called Jamuna in Bangladesh.

Brahmaputra river joins with Ganga river in Bangladesh. The resultant river is called Meghna.

Characteristics of Himalayan Rivers

a.Originate from the Himalayas
b.Long and wide
c.Perennial in nature
d.Unsuitable for hydropower generation
e.Middle and lower courses are navigable

Peninsular Rivers of India

The south Indian rivers are called the Peninsular rivers. Most of the Peninsular rivers originate from the Western Ghats.

Peninsular rivers are non-perennial rivers. The peninsular rivers are non-perennial rivers because of large seasonal fluctuation in the volume of water as they are solely fed by rain.

These rivers flow in the valley with steep gradients. Based on the direction of flow, the peninsular rivers are divided into West flowing and East flowing rivers.

East Flowing Rivers


Mahanadi river originates near Sihawa in the Raipur district of Chattisgarh. It flows through Odisha and its length is 851 km.

Seonath, Telen, Sandur, and Ib are its major tributaries. The mainstream of Mahanadi is divided into several distributaries such as Paika, Birupa, Chitartala, Genguti and Nun.

All these distributaries form the Delta of Mahanadi which is one of the largest deltas in India. The Mahanadi empties its water in the Bay of Bengal.


The Godavari is the longest among the Peninsular rivers and its length is 1465km. Its drainage area is 3.13 lakh sq. km. The Godavari river is also called Vridha Ganga.

This river originates in the Nasik district of Maharashtra, a portion of Western Ghats. Godavari river flows through Telangana and Andra Pradesh before joining the Bay of Bengal.

The Major Tributaries of the Godavari river are Purna, Penganga, Pranitha, Indravati, Tal, and Salami.

The Godavari river gets divided into two channels called Vasistha and Gautami near Rajahmundry. Then it forms one of the largest deltas in India. Kolleru, a freshwater lake is located in the deltaic region of the Godavari.


The Krishna river originates from a spring at Mahabaleshwar in the Western Ghats of Maharashtra. The length of the Krishna River is 1400 km.

Its drainage area is 2.58 lakh sq. km. Krishna is the second-longest Peninsular river.

The major tributaries of the Krishna river are Bhima, Peddavagu, Musi, Koyna, and Tungabhadra. Krishna river flows through Andra Pradesh and joins the Bay of Bengal at Hamasaladeevi.


The Kaveri river originates at Talakaveri, from Kudagu hills of Karnataka. Its length is 800km.Kaveri river is called Dhaksin Ganga or Ganga of South Harangi.

The major tributaries of the Kaveri river are Hemavati, Kabini, Bhavani, Arkavathy, Noyyal, Amaravathi, etc.

In Karnataka, the river bifurcates twice, forming the sacred islands of Srirangapatnam and sivasamudram.

While entering Tamil Nadu, Kaveri continues through a series of twisted wild gorges until it reaches Hogenakkal Falls and flows through a straight, narrow gorge near Salem.

The Kaveri breaks at Srirangam Island with two channels, river Coleroon and Kaveri. At last, it empties into the Bay of Bengal at Poompuhar.


rivers in india
rivers in india map

West Flowing Rivers


Narmada river rises in Amarkantak Plateau in Madhya Pradesh at an elevation of 1057 metres. It flows for a distance of about 1312 km.

Narmada drainage area is about 98796 sq. km. It forms a 27 km long estuary before entering the Arabian Sea through the Gulf of Cambay.

Narmada is the largest among the west-flowing rivers of Peninsular rivers. The major tributaries of Narmada are Burhner, Halon, Heran, Banjar, Dudhi, Shakkar, Tawa, Barna and Kolar.


The Tapti is one of the major rivers of Peninsular India with a length of about 724 km. It covers an area of 65,145 sq km.

Tapti river rises near Multai in the Betul district of Madhya Pradesh at an elevation of about 752 m.

It is one of only the three rivers in Peninsular India that run from east to west – the others being the Narmada and the Mahi. The major tributaries are Vaki, Gomai, Arunavati, Aner, Nesu, Buray, Panjhra, and Bori.

It outfalls into the Arabian Sea through the Gulf of Cambay.

east and west flowing rivers in india map
east and west flowing rivers in India map

Characteristics of South Indian Rivers

• Originate from the Western Ghats
• Short and narrow
• Non-perennial in nature
• Suitable for hydropower generation
• Not useful for navigation

In which river the Gerosappa (jog) fall is found?


  2. Geography of India for Civil Services by Majid Husain