Physical Features of India Notes Class 9 Geography CBSE

Notes of the Chapter ‘Physical Features of India’ are given here. The Notes are meant for revision of the chapter ‘Physical Features of India’ chapter of class 10 geography. The notes are properly written with proper headings to make them more comprehensible.

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Physical Features of India Notes

Syllabus

Theme

Major Physiographic Divisions –

  • Himalayan Mountains, Northern Plains,
  • Peninsular Plateau, Indian Desert,
  • Coastal Plains, Island

Learning Objectives

Understand the major landform features and the underlying geological structure; their association with various rocks and minerals as well as nature of soil types.


India’s Major Physiographic Divisions

India is a geographically diverse country and comprises all the major physical features like mountains, plateaus, plains, valleys, islands, etc. The diversity in the terrain is the result of various geological processes in the past.

There are six physical features of India as given below:

  • The Himalayan Mountains
  • The Northern Plains
  • The Peninsular Plateau
  • The Indian Desert
  • The Coastal Plains
  • The Islands

1. The Himalayan Mountains

  • The Himalayas bound India in the northwest, north, and northeast.
  • These mountain ranges run from west (River Indus) to the east (River Brahmaputra).
  • The Himalayas are young fold mountains.
  • The Himalayas are known to be the most rugged and loftiest mountains in the world.
  • The Himalayas stretch over 2,400 kms.
  • The width of the Himalayas is greatest at Kashmir (400 kms) and the narrowest at 150 kms in Arunachal Pradesh.

Himalayas consist of three parallel ranges:

  1. Greater or Inner Himalayas, or the Himadri
  2. Lesser Himalayas, or the Himachal
  3. Outer Himalayas, or the Shivalik

Himadri, or Greater Himalayas

  • They form the northernmost Himalayan range with an average height of 6,000 metres.
  • This range of Himalayas consists of some of the world’s highest peaks, such as Nanga Parbat, Mount Everest, and Kanchenjunga, etc.
  • The Himadri range is the source of many glaciers, such as Biafo, Siachen, and Baltoro. Glaciers are a massive, slow-moving mass of ice formed due to the accumulation of ice.
  • The glaciers, one of the biggest outside the polar region, are the source of water for many important rivers flowing in the country.
  • The folds of this range of the Himalayas are asymmetrical.
  • The mountain ranges of Himadri are mainly composed of granite.
  • Several passes ( navigable gap in the mountain terrain) in the Himalayan range like Zoji La, Shipki La, Nathu La, and Pir Panjal have been used since ancient times to enter India.

Himachal, or Lesser Himalayas

  • The Himachal lies to the south of the Himadri range.
  • The average height of mountains in this range is 3,700 to 4,500 metres.
  • The average width of this range is 50 kms.
  • This range is composed of highly compressed and altered rocks.
  • Pir Panjal range is the longest range in Himachal. Some other ranges are the Dhaula Dhar and the Mahabharat.
  • The famous valley of Kashmir, Kangra, and Kullu Valley lie in the Himachal range.
  • Hills stations such as Nainital, Dharmshala and Dalhousie are also located here.

Shiwaliks, or Outer Himalayas

  • The southernmost Himalayan range is known as the Shiwalik.
  • The height of the mountains varies between 900 and 1,100 metres.
  • The width varies between 10 and 50 kms. 
  • Rivers flowing from the Himalayas carry sediments and cover the valleys of Shiwaliks with thick layers of gravel and alluvium.
  • The longitudinal, flat-bottomed valleys that lie between the Lesser Himalayas and Shiwaliks are known as duns, for example, Dehradun, Kotlidun, and Patlidun.
  • The southern part of the range is flat marshy area and is referred to as terai.

Himalayas from West to East

There is an east to west division of Himalayas. River valleys demarcate these divisions.

  1. Punjab Himalayas or Kashmir and Himachal Himalayas, between Indus and Satluj rivers
  2. Kumaon Himalayas, between Satluj and Kali rivers
  3. Nepal Himalayas, between Kali and Teesta rivers
  4. Assam Himalayas, between Teesta and Dihang rivers

Purvanchal or Eastern Hills

·      These mountains are spread across the eastern boundary of India, beyond the Dihang gorge.

·      They cover the northeastern states extending from Arunachal Pradesh to Mizoram.

·      These hills are composed of sedimentary rocks, mainly sandstones.

·      They are covered with thick forests.

·      Some famous hills from this region are the Patkai hills, the Naga hills, the Manipur hills and the Mizo hills.


2. The Northern Plains of India

Q. Hint: What are the distinctive characteristics of the Northern Plains and the Indian Desert?

The Northern Plains

  • The deposition of alluvium at the foothills of the Himalayas by the rivers Indus, Ganga, Brahmaputra, and their tributaries over millions of years has caused the formation of the Northern Plains of India.
  • The Northern Plains cover an area of 7 lakh million sq km, with a length of 2,400 kms and a width of 240 to 320 kms.
  • The Northern Plains are highly productive due to the vast fertile soil cover, ideal climatic conditions, and adequate water supply.
  • It is a densely populated region in the country.

Divisions of Northen Plain

The Northern Plain of India has been divided into three plains.

Punjab Plains

  • The Northern Plains of India can be categorised based on location into three broad categories.
  • The western section of the northern plains is called the Punjab plains.
  • This region is drained by the river Indus and its five main tributaries Jhelum, Chenab, Satluj, Beas, and Ravi.
  • These rivers have their source in the Himalayas.
  • A significant part of this plain lies in Pakistan.
  • Doabs (land lying between two rivers) are common in the part of the plains that lie in Pakistan.

Ganga Plains

  • This section of the plains covers the area between the Ghaggar and Teesta rivers.
  • The Ganga Plain includes many North Indian states such as Haryana, Delhi, Uttar Pradesh, Bihar, parts of Jharkhand, and West Bengal.

Brahmaputra Plains

  • The easternmost section of the Northern Plains comprises states like Assam and Arunachal Pradesh.
  • It is an agricultural plain formed by the Brahmaputra and its tributaries.

Classification of Northern Plains

The Northern Plains do not have uniform relief features throughout. Based on variation in relief features, they can be divided into four regions: Bhabar, Terai, Bhangar, and Khadar.

Bhabar

  • This plain lies south of the Shiwalik range.
  • It is a narrow, 8 to 16 km wide belt composed of pebbles brought down by rivers from the Himalayas.
  • The rivers and streams disappear from the surface and flow underground due to the high porosity of the pebbles in the river beds.

Terai

  • This region of the Northern Plains lies south of the Bhabar belt and is composed of fine deposits.
  • Streams start re-appearing on the surface in this region.
  • The land is wet, swampy, and marshy. It is covered with thick forests and has a variety of wildlife.

Bhangar

  • North of the floodplains and south of the Terai region is the Bhangar region.
  • This plain is made up of older alluvium.
  • The region presents a terrace-like feature.
  • The soil has a high concentration of calcium carbonate, regionally known as ‘kankar.’

Khadar

  • The younger and newer deposits of the floodplains form the Khadar plain.
  • River floods deposit new layers of alluvium every year.
  • It is highly fertile and optimum for practicing intensive agriculture.

3. The Great Indian Desert

  • The Great Indian Desert, or the Thar Desert, lies in the western part of India, in Rajasthan.
  • The Aravali hills lie to the east of the desert.
  • The Indian Desert is a sandy plain with sand dunes spread across it.
  • This region experiences a dry climate due to high temperatures and scanty rainfall below 150 mm per year.
  • The vegetation cover is very sparse and thinly distributed. Cactus, acacia, babool are some of the trees that can thrive in this desert.
  • Due to insufficient water and a high rate of evaporation, most streams dry up along their course.
  • Luni is the only major river flowing through the region.
  • A large part of the desert is covered with crescent-shaped sand dunes, called ‘barchan.’
  • As one moves towards the Indo-Pakistan border, the longitudinal sand dunes are more prominent.

4. Landforms of Peninsular India

Q. Hint: How are peninsular plateaus formed and how are they divided from north to south?

Peninsular Plateau

  • The Peninsular Plateau is one of the oldest landforms that was formed by the breaking and drifting of the Gondwana land.
  • It is composed of old crystalline, igneous and metamorphic rocks.
  • The black soil area or the Deccan Traps of the peninsular plateau was formed due to the denudation of igneous rock of volcanic origins.
  • The peninsular plateau consists of two divisions: the Central Highlands and the Deccan Plateau.

Central Highlands

  • Central Highland lies to the north of the river Narmada.
  • They cover a significant part of the Malwa plateau.
  • The Vindhya range and the Satpura range lie in the south.
  • The Aravali range with extensively eroded hills lies in the northwest.
  • Rivers such as Chambal, the Sind, the Betwa and the Ken drain this region from the southwest to northeast direction due to the slope of the land.
  • The eastward extensions of this Highland are called Bundelkhand and Baghelkhand.
  • The highland narrows towards the east.
  • The Chhotanagpur Plateau lies further east. It is drained by the Damodar river.

Deccan Plateau

  • Deccan plateau is a triangular landmass.
  • The extension of this plateau region is bordered by:
    • The Satpura range and Narmada River in the north
    • The Mahadev, the Kaimur hills and the Maikal range in the east
  • The Deccan Plateau gradually slopes towards the east.
  • The Meghalaya, Karbi-Anglong Plateau and North Cachar Hills are the northeast extensions of the plateau.
  • It is separated from the Chhotanagpur Plateau through a fault.
  • The Garo, the Khasi and the Jaintia Hills are the three prominent hills of the region.
  • The Deccan Plateau is bounded by the Western Ghats and the Eastern Ghats on the west and east, respectively.
  • The region consists of fertile black soil.

Western Ghats

  • The Western Ghats run parallel to the western coast of India.
  • The average elevation of the Western Ghats is 1,600 metres.
  • The height gradually increases from north to south.
  • Since it is a continuous range, it can be crossed only through passes such as Kasara ghat, Naneghat.
  • Western ghats receive orographic rainfall as they face the rain-bearing moist winds from the Arabian Sea and the Indian Ocean.
  • The highest peaks here are the Anai Mudi (2,695 metres) and the Doda Betta (2,637 metres).
  • The Godavari, Krishna and Kaveri are the three main rivers originating in the Western Ghats.
  • The Western Ghats are known by local names in different states — Sahyadri in Maharashtra, Nilgiri Hills in Tamil Nadu and Kerala and Cardamom Hills in Kerala.

Eastern Ghats

  • The Eastern Ghats extend from the Mahanadi Valley in the north to the Nilgiris in the south.
  • The Eastern Ghats are intersected by many rivers that drain into the Bay of Bengal.
  • The average height of the ghats is 600 metres.
  • The highest peak is Mahendragiri (1,501 metres).
  • To the southeast lie Shevroy Hills and Javadi Hills.

Distinctive features of the Peninsular plateau

  • The peninsular plateau has a black soil area called the Deccan Traps.
  • Due to volcanic activities millions of years ago, igneous rocks were formed.
  • These igneous rocks weathered over time and formed the black soil found in the region today.
  • The highly eroded and broken hills of the Aravali range lies along the western and north-western boundary of the peninsular plateau.

5. Coastal Plains of India

Q. Hint: How are the coastal plains and the island groups important for India?

Coastal Plains of India: A coastal plain is characterised by a flat, low-lying stretch of land near oceans or seas. The western coastal plains and the eastern coastal plain of India lie on either side of the peninsular plateau.

Western Coastal Plains

The western coastal plain lies between the Arabian Sea and the western ghats. It is narrower than the eastern coastal plain. It is divided into three regions:

  • Konkan coast (Mumbai- Goa) in the north
  • Kannad plain in the centre
  • Malabar coast in the south

Eastern Coastal Plains

  • The eastern coastal plains lie between the Eastern Ghats and the Bay of Bengal.
  • The east coastal area can be divided into two – the Northern Circar in the north and the Coromandel Coast in the south.
  • The eastern coastal plains are wider and much more level than the western coastal plains.
  • Large rivers such as Mahanadi, Godavari, Krishna, and Kaveri flowing through the eastern coastal plains have formed extensive deltas.
  • The famous brackish water lake Chilika in Odisha lies in the eastern coastal plains.

6. Island Groups of India

  • An island is a land surrounded by water.
  • India has two major groups of islands – the Lakshadweep and the Andaman and Nicobar Islands.
  • The Lakshadweep Islands were known as Laccadive, Minicoy, and Amindive until 1973.

Lakshadweep Islands

  • The Lakshadweep group of islands are located in the Arabian Sea, close to the Malabar coast of Kerala.
  • These are a group of coral islands covering a small area of 32 sq. kms.
  • Kavaratti Island is the administrative headquarters.
  • This island group has a great diversity of flora and fauna.
  • A bird sanctuary is located on the uninhabited Pitti Island.

Andaman and Nicobar Islands

  • These are a chain of islands extending from north to south in the Bay of Bengal.
  • Most islands in Andaman and Nicobar are elevated portions of submerged mountains.
  • These islands are comparatively bigger and more scattered than Lakshadweep Islands.
  • The chain of islands is divided into two groups, the Andaman in the north and the Nicobar in the south.
  • Andaman and Nicobar Islands have rich and diverse flora and fauna.
  • Due to proximity to the equator, these islands experience an equatorial climate.
  • Thick forests cover these islands.

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