Class 9 Chapter 2 | Physical Features of India | Notes
Chapter 2 Notes> class 9 Geography
PHYSICAL FEATURES OF
INDIA
|| Key points || Short notes ||
Introducing
India has all major physical features of the earth i. e. Mountains, plains ,Plateaus , deserts and Islands. India has a great landmass which is formed during different geological periods. Besides geological formations, a number of Processes such as weathering, erosion and deposition also created and modified the relief to its present form.
Earth scientists given different theories to explain the formation of physical features. "Theory of plate Tectonic" Is one of such theories.
Theory of Plate Tectonics :- According to this theory, the crust of the earth has been formed out of seven major and some minor plates.
The movement of the plates results in the building up of stresses within the plates and the continental rocks above leading to folding, faulting and volcanic activity.
These plates movement broadly classified into three types ;
Convergent Boundary
Divergent Boundary
Transform Boundary
• When some plates come towards each Other they form a convergent Boundary.
• When some plates move away from each other they form divergent Boundary.
• When two plates coming together they may either collide and crumble or one may slide under the other then they form Transform Boundary.
Gondwana land : It is the southern part of the ancient super continent Pangea with Angara land in the northern part.
Major Physiographic Divisions
The major Physiographic divisions of India are as follow:-
1) The Himalayan Mountains
2) The Northern Plains
3) The Peninsular Plateau
4) The Indian Desert
5) The Coastal Plains
6) The Islands
The Himalayan mountains
i) The Himalayas are geological young and structurally fold mountains stretch over the northern border of India.
ii) The Himalayas represent the loftiest and most rugged mountain barriers of the world.
iii) They covers a distance of about 2400 km from west-east direction.
iv) Their width varies from 400km in Kashmir to 150 Km in Arunachal Pradesh.
v) Attitudinal variations are greater in the Eastern half than those in western half.
The Himalayas consists of three parallel ranges in its longitudinal extent.
They are :- a. The Greater Himalayas
b. The Lesser Himalayas
c. The Shiwaliks.
The Great Himalayas
i) The inner most ranges of Himalayas are called the Great Himalayas Or 'Himadri'.
ii) It is consisting of the loftiest peaks with an average height of 6,000 metres.
iii) The core of this part of Himalayas is composed of granite.
iv) It is perennially snow bounded.
The Lesser Himalayas
i) This ranges lies to the south of the Himadri.
ii) The ranges are mainly composed of highly compressed and altered rocks.
iii) The altitude varies between 3,700 and 4,500 meters and the average height width is of 50 Km.
iv) Pir Panjal ranges forms the longest and the most important range. The Dhaula Dhar and the Mahabharat ranges are the other prominent ranges .
v) The famous valley of this range are The Kashmir valley, the kangra and kullu valley in Himachal Pradesh. This regions well known for its hill stations.
The Shivaliks
i) The outer most range of Himalayas is called Shivaliks.
ii) They extend over a width of 10-15 Km and have an altitude varying between 900 to 1100 metres.
iii) These valleys are covered with thick gravel and alluvium.
iv) The longitudinal valley lying between lesser Himalaya and the Shiwaliks are known as Duns. Dehra Dun, Kotli Dun and Patil Duns are some of the well-known Duns.
• On the basis of West to east division of the regions has been divided and demarcated by the river Valleys.
- For example ; The part of Himalayas lying between Indus and Satluj has been traditionally known as Punjab Himalayas but is also known regionally as Punjab Himalaya and Himachal Himalaya from West to east respectively.
- The part of Himalayas lying between Satluj and Kali rivers is known as Kumaon Himalayas.
- The Kali and Tista rivers valley is known as Nepal Himalayas.
- The part lying between Tista and Dihang rivers is known as Assam Himalayas.
• Beyond Dihang gorge, the Himalayas bend sharply to the South and spread along the Easter Boundary of India. Known as Purvanchal Or the Eastern hills.
• The Purvanchal compromises the Patkai hills, the Naga hills, Manipur hills and the Mizo hills.
The Northern Plains
i) The northern plains has been formed by the combination of three major rivers systems - The Indus , the Ganga and the Berhampur along with their tributaries.
ii) The northern plains spread over an area of 7 lakh sq. km. 2400 km long and 240 to 320 km broad.
iii) This is the most fertile area in India with adequate water supply and favorable climate.
iv) The rivers in the lower course split in numerous channels due to the deposition of slit. These channels are known as Tributaries.
Northern plains have four regions with different relief features.
a. Bhabar : It lies at the foot of Shivalik , a narrow 8-16 km wide belt of pebbles.
b. Terai : The marshy area with wildlife and forest. Dudhwa National park in this region.
c. Bangar : Older alluvium plain which rises above the level of the flood plains.
d. Khadar : The newer, younger deposits of the flood plains are called Khadar.
The Peninsular Plateau
I) Peninsular plateau is a table land created by breaking and drifting of Gondwana land.
II) The plateau has been divided mainly into two divisions.
a. The central Highlands
b. Deccan plateau
a. Central Highlands
i) The part of Peninsular Plateau lying to the North of the Narmada river covering a major area of the malwa plateau is known as the central Highlands.
ii) The central Highlands are wider in the West but narrow in the east.
iii) The eastward extensions of this plateau are locally known as the Bundelkhand and Baghelkhand.
iv) The chotanagpur plateau marks the further eastward extension, drained by the river Damodar.
b. Deccan plateau
i) The Deccan plateau is a triangular land mass that lies to the South of the river Narmada.
ii) The Eastern and western edges are marked by The Eastern Ghats and Western Ghats.
iii) Western Ghat is lie parallel to the Western coast. The Western Ghats are higher than the Eastern Ghats
iv) The Eastern Ghats stretch from the Mahanadi valley to the Nilgiris in the South.
v) The highest peaks include the Anai Mudi, and the Doda Betta, Mahendra giri is the highest peaks in the Eastern Ghats
A distinct features of this plateau, in its black soil, which is found in the area known as Deccan trap.
The Indian Desert
i) The Indian Desert lies towards the Western margin of the Aravali Hills.
ii) It is a sandy plain covered with sand dues.
iii) This region mainly receives low rainfall, i. e. below 150 mm per year.
iv) Major area is covered by Barchans ( crescent shaped dunes).
v) Luni is the only river in the region.
The Coastal Plains
i) The Peninsula plateau is flanked by the narrow coastal strips which runs along the Bay of Bengal in the east and Arabian sea in the West.
ii) The Western coast is decided into :- konkan ( mumbai - goa) Northern stretch , Kannad plains central stretch, malabar coast southern stretch.
iii) The eastern strips is divided into :- Northern circar, while the Southern part is known as Coromandal Coast.
iv) Lake Chilika is an important feature along the eastern coast.
The Islands
Lakshadweep Islands
i) Group of Islands close to the Malabar coast of Kerala.
ii) They are composed of small coral islands.
iii) It covers a small area of 32 sq. Km
Andaman & Nicobar Islands
i) They are the group of Islands located in the Bay of Bengal, extending from North to South.
ii) They are Bigger in size and are more numerous and scattered. They are divided into two groups - Andaman in the North and Nicobar in the South.
_________________________________
.jpeg)
