November 24, 2021
November 17, 2021
- The Peninsular plateau constitutes one of the ancient landmass on the earth’s surface (composed of igneous rock and metamorphic rocks).
- The Himalayas and the northern plains are the most recent landmass. The northern plain is composed of alluvial soil.
Major Physiographic Divisions
- The Himalayan region
- The Northern plains
- The Peninsular Plateau
- The Indian Desert
- The Coastal Plains
- The Islands
The Himalayan region
- These mountain ranges run in a west-east direction from the Indus to the Brahmaputra.
- They form an arc, which covers a distance of about 2,400 Km. Its width varies from 400 Km in Kashmir to 150 Km in Arunachal Pradesh.
- The Himalaya consists of three parallel ranges (Himadri, Himachal and Shiwalik) in its longitudinal extent.
- The northern-most range is known as the Great or Inner Himalayas or the Himadri. It is the most continuous range consisting of the loftiest peaks with an average height of 6,000 metres. It contains all prominent Himalayan peaks.
|The northern-most range is known as the Great or Inner Himalayas or the||The range lying to the south of the Himadri forms the most rugged mountain system and is known as Himachal or lesser Himalaya.||The outer-most range of the Himalayas is called the Shiwalik.|
|It is the most continuous range consisting of the loftiest peaks with an average height of 6,000 metres.||The altitude varies between 3,700 and 4,500 metres and the average width is of 50 Km||Width of 10-50 Km Altitude varying between 900 and 1100 metres|
|Glaciers:Gangotri,Bhagirathi,Satopanth,Kamet,Chaturangi,Pindari||Ranges: Pir Panjal range, the Dhaula Dhar, Mahabharata ranges||The longitudinal valley lying between lesser Himalaya and the Shiwalik are known as Duns.|
|Passes:Karakoram Pass,Shipkilla,Nathula||Dehra Duns,Kotli Duns, Patli Duns|
The Northern plains
- The northern plain has been formed by the interplay of the three major river systems, namely — the Indus, the Ganga and the Brahmaputra along with their tributaries.
- This plain is formed of alluvial soil. It spreads over an area of 7 Lakh sq. km. The plain being about 2400 km long and 240 to 320 km broad, is a densely populated physiographic division.
- The rivers coming from northern mountains are involved in depositional work. In the lower course, due to gentle slope, the velocity of the river decreases, which results in the formation of riverine islands (Majuli).
- The Northern Plain is broadly divided into three sections :
|Punjab Plains||Ganga Plains||Brahmaputra Plains|
|Formed by the Indus and its tributaries, the larger part of this plain lies in Pakistan.||The Ganga plain extends between Ghaggar and Teesta rivers.||This plain has been formed by deposition of alluvium brought down by river Brahmaputra and its tributaries.|
|The Indus and its tributaries — the Jhelum, the Chenab, the Ravi, the Beas and the Satluj originate in the Himalaya.||It is spread over the states of North India, Haryana, Delhi, U.P., Bihar, partly Jharkhand and West Bengal to its East, particularly in Assam lies the Brahmaputra plain.||After the floods, the river generally changes its course. This process has led to the formation of various islands in the river. Majuli (1250 sq.km.) in the Brahmaputra river is the world’s largest river island.|
|This section of the plain is dominated by the doabs.||Bangladesh is situated on this plain and the delta jointly formed by Ganga and Brahmaputra and their distributaries.|
Based on the Relief features; the Northern Plains can be divided into Four regions:
- Bhabar: The Rivers, after descending from the mountains deposit pebbles in a narrow belt of about 8 to 16 km in width lying parallel to the slopes of the Shiwalik. All the streams disappear in this Bhabar belt
- Terai: South of this belt, the streams and rivers re-emerge and create a wet, swampy and marshy region known as Terai.
- Bhangar: The largest part of the northern plain is formed of older alluvium. It lies above the floodplains of the rivers and presents a terrace like feature. The soil in this region contains calcareous deposits, locally known as kankar.
- Khadar: The newer, younger deposits of the floodplains are called Khadar. They are renewed almost every year and so are fertile, thus, ideal for intensive agriculture.
The Peninsular Plateau
- The Peninsular plateau is a tableland composed of the old crystalline, igneous and metamorphic rocks.
- It was formed due to the breaking and drifting of the Gondwana land and thus, making it a part of the oldest landmass. The plateau has broad and shallow valleys and rounded hills.
- This plateau consists of two broad divisions.
|Central Highlands||Deccan Plateau|
|The part of the Peninsular plateau lying to the north of the Narmada river, covering a major area of the Malwa plateau.||The shape of this plateau is triangular. One of the sides of this triangle is marked by the line joining KanyaKumari with Rajmahal Hills and this line passes through the Eastern Ghats.|
|The Aravallis form the west-north-western edge of the Central Highlands.||The Satpura range flanks its broad base in the north, while the Mahadev, the Kaimur hills and the Maikal range from its eastern extensions.|
|Malwa plateau forms the dominant part of the Central Highlands. It lies to the southeast of Aravallis and to the north of Vindhyachal Range.||The Deccan Plateau is higher in the west and slopes gently eastwards. An extension of the Plateau is also visible in the northeast, locally known as the Meghalaya, Karbi-Anglong Plateau and North Cachar Hills.|
|The part of the Central Highlands which extends to the east of Malwa Plateau is known as Bundelkhand and is further followed by Baghelkhand and the well known Chhotanagpur Plateau.||The Western Ghats and the Eastern Ghats mark the western and the eastern edges of the Deccan Plateau.|
|Western Ghats||Eastern Ghats|
|The range extends northward to the Tapti River and southward almost to Cape Comorin at India’s southern tip.||The Eastern Ghats include several discontinuous and dissimilar hill masses that generally trend northeast-southwest along the Bay of Bengal.|
|The mountains reach elevations of 3,000 to 5,000 feet (900 to 1,500 metres) in the north, rise less than 3,000 feet in the area south of Goa, and are higher again in the far south, reaching 8,652 feet (2,637 metres) at Doda Betta mountain.||The narrow range has an average elevation of about 2,000 feet (600 metres), with peaks reaching 4,000 feet (1,200 metres) and higher; the high point is Arma Konda (5,512 feet [1,680 metres]) in Andhra Pradesh .|
|The Palghat Gap separates the Western Ghats proper from their southward extension, known as the Southern Ghats. The Western Ghats, because they receive extremely heavy rainfall from the southwest monsoon, comprise peninsular India’s principal watershed; rainfall is much lighter inland on the plateau.||There is a gap in the chain 100 miles (160 km) wide through which the Krishna and Godavari rivers reach the coast; the Godavari runs through a gorge 40 miles (65 km) long|
|The high rainfall has produced dense forests on the seaward slopes, with bamboo, teak, and other valuable trees.||Farther southwest, beyond the Krishna River, the Eastern Ghats appear as a series of low ranges and hills|
|Some rivers among the Western Ghats have been dammed to produce electric power. A number of hill resorts are located in the mountains||Southwest of Chennai (Madras), the Eastern Ghats continue as the Javadi and Shevaroy hills, beyond which they merge with the Western Ghats.|
The Indian Desert
- The Indian desert lies towards the western margins of the Aravallis Hills. It is an undulating sandy plain covered with sand dunes.
- This region receives very low rainfall below 150 mm per year. It has arid climate with low vegetation cover.
- Streams appear during the rainy season. Soon after they disappear into the sand as they do not have enough water to reach the sea.
- Luni is the only large river in this region.
The Coastal Plains
- The western coast, sandwiched between the Western Ghats and the Arabian Sea, is a narrow plain.
- It consists of three sections.
- The northern part of the coast is called the Konkan (Mumbai – Goa); the central stretch is called the Kannad Plain, while the southern stretch is referred to as the Malabar Coast.
- The plains along the Bay of Bengal are wide and level. In the northern part, it is referred to as the Northern Circar, while the southern part is known as the Coromandel Coast.
- Large rivers, such as the Mahanadi, the Godavari, the Krishna and the Kaveri have formed extensive delta on this coast.
- Lake Chilika is an important feature along the eastern coast.
- This group of islands is composed of small coral islands. Earlier they were known as Laccadive, Minicoy and Amindive.
- In 1973, these were named as Lakshadweep. It covers small area of 32 sq km. Kavaratti Island is the administrative headquarters of Lakshadweep. This island group has great diversity of flora and fauna.
- The Pitti Island, which is uninhabited, has a bird sanctuary.
- The elongated chain of islands located in the Bay of Bengal extending from north to south. These are Andaman and Nicobar islands.
- They are bigger in size and are more numerous and scattered. The entire group of islands is divided into two broad categories – The Andaman in the north and the Nicobar in the south. It is believed that these islands are an elevated portion of submarine mountains.
- These island groups are of great strategic importance for the country.
- There is great diversity of flora and fauna in this group of islands too.
- These islands lie close to equator and experience equatorial climate and have thick forest cover.