Major Physiographic Regions of India – UGC NET – Geography – Notes

• India has a unique culture and is one of the oldest and greatest civilizations in the world. It stretches from the snow-capped Himalayas in the north to Sun-drenched coastal villages of the south and the humid tropical forests on the south-west coast, from the fertile Brahmaputra valley in its east to the Thar Desert in the west.
• India shares its border from Afghanistan and Pakistan to the north-west, China, Bhutan, and Nepal to the north, Myanmar to the far East, and Bangladesh to the east. Sri Lanka is separated from India by a narrow channel of sea formed by the Palk Strait and the Gulf of Mannar. The country can be divided into six zones mainly North, South, East, West, and Central and Northeast zone. It has 28 states and eight union territories.

Physiography of India

1. The Geological Structure of India is very diverse because an Indian rock belongs to different geologic periods, dating as far back as the Eoarchean Era. Its geographical land area can be classified into Archaean System; Dharwar System, Cuddapah System; Vindhyan System; Gondwana System, Deccan Trap; Tertiary System; Quarternary System.
2. India is located latitudinally in the Northern Hemisphere and longitudinally in the Eastern Hemisphere. It extends from 8°4′ north and 37°6′ North in length (latitudes). And between 68°7′ East and 97°25′ East in width (longitudes). Because of this great longitudinal extent, the difference in local time between the eastern and western extremes of our country is about two hours.
3. The local time along 82° 30′ E longitudes is taken as the standard time of India i.e. Indian Standard Time (IST). This meridian is known as the Standard Meridian of India. It has an area of 3.28 million square km. It is the seventh-largest country in the world. It accounts for nearly 2% of the world’s total area. It is situated in the northern hemisphere.
4. India has a coastline of 7516.6 km of total land frontier 15200 km and Tropic of Cancer passes almost through its middle crossing over the states of Gujarat, Rajasthan, Madhya Pradesh, Chhattisgarh, Jharkhand, West Bengal, Tripura and Mizoram.
5. India lies largely on the Indian Plate, the northern portion of the Indo-Australian Plate, whose continental crust forms the Indian subcontinent Physical divisions, are marked by natural configuration. India is divided into six physiographic divisions on basis of the varied physiographic features: units as follows: Northern and North-eastern Mountain; Northern Plain; Peninsular Plateau; Indian Desert; Coastal Plains; and Islands.
6. The Himalayas are one of the youngest fold mountain ranges in the world of tectonic origin and comprise mainly sedimentary rocks. They stretch from the Indus River in the west to the Brahmaputra River in the east. It consists of three parallel ranges such as Himadri (Greater Himalayas), Himachal (Lesser Himalaya), and Shiwaliks (Outer Himalaya).
7. Himadri (Greater Himalayas): It has an average elevation of 6100m includes some of the highest peaks and some of the important passes like Jalep La in the Chumbi Valley in Sikkim and Shipki La in the Sutlej Valley. Mt. Everest or Sagarmatha, the highest peak of the world, lies in Nepal.
8. Himachal (Lesser Himalaya): It has an average height of 3700-4500 m. The important ranges are Dhauladhar, Pir Panjal, Nag Tibba and Musoorie. Important hill resorts are Shimla, Ranikhet, Almora, Nainital and Darjiiling Valley plains and ‘Doon or Doar’ are special features of this range bordering the outer Himalayas.
9. Shiwaliks (Outer Himalaya): It is recent origin with an average elevation of 900-1200 m, giving a hogback appearance with relatively steeper slope towards the south.
10. Trans Himalayan Zones lies to the North of the Great Himalayas bordering Tibet. Some important ranges of this zone are Karakoram, Ladakh, and Zaskar. This is the largest snow field outside the polar region.
11. The Northern Plains are formed by the alluvial deposits brought by the rivers the Indus, the Ganga and the Brahmaputra. These plains extend approximately 3,200 km from the east to the west. The average width of these plains varies between 150-300 km. The maximum depth of alluvium deposits varies between 1,000-2,000 m. From the north to the south, these can be divided into three major zones: the Bhabar, the Tarai and the alluvial plains.
12. The Indian Desert is located to the north-west of the Aravali hills lies the Great Indian Desert. It is a land of undulating topography dotted with longitudinal dunes and barchans. This region receives low rainfall below 150 mm per year; hence, it has an arid climate with low vegetation cover. It is because of these characteristic features that this is also known as Marusthali.
13. The Plateau of India is roughly triangular in shape with its base parallel to the Ganga Valley and its apex pointing towards the southern tips of the country. It is hard old mass of igneous and metamorphic rocks being part of the tectonic plate called the Gondwanaland.
14. Peninsular Plateau is bordered by the Western Ghats in the west, Eastern Ghats in the east and the Satpura, Maikal range and Mahadeo hills in the north. Western Ghats are locally known by different names such as the Sahyadri in Maharashtra, Nilgiri hills in Karnataka and Tamil Nadu and Anaimalai hills and Cardamom hills in Kerala.
15. The Eastern Ghats Mountain Ranges are extending from Orissa to Tamil Nadu. It is more eroded than the Western Ghats. It is drained by the Godavari and the Krishna River. Vishakhapatnam Peak is the highest peak of this range. Mahendragiri is the second highest peak of this range. It continues as the Javadi and Shevaroy hills in the south-west of Chennai, beyond which they merge with the Western Ghats.
16. The Western Ghat Mountain Range or Sahyadri Range is the India’s largest mountain range after the Himalayas, which extend from the Tapi river valley to the Nilgiri. It is divided into two parts- the North Sahyadri and the south Sahyadri. This range is the home of many hill stations like Matheran, Lonavala-Khandala, Mahabaleshwar, Panchgani, Amboli Ghat, Kudremukh and Kodagu.
17. The Western Ghats Coastal Plain extends from Surat to Kanyakumari which is divided into four parts: Gujarat Plain- Coastal area of Gujarat; Konkan Plain-between Daman and Goa; Kannad Plain- between Goa and Mangalore; and Malabar Plain- between Mangalore and Kanyakumari.
18. The Eastern Coastal Plains lies between the Eastern Ghats and the sea coast from the Subarnarekha River to Kanyakumari. As compared to the Western Coastal Plain It is wider because the rivers like Godavari, the Krishna and the Kaveri formed the delta over there. The continental shelf extends up to 500 km into the sea, which makes it difficult for the development of good ports and harbours. In Eastern Coastal plain, there is the Kolleru Lake which situated in the delta region of the Godavari and the Krishna Rivers. Chilka Lake and Pulicat Lake is the best example of lagoon which is also found in this region.
19. There are two major island groups in India one in the Bay of Bengal and the other in the Arabian Sea.
20. The Bay of Bengal island groups consists of about 572 islands/islets. These are situated roughly between 6°N-14°N and 92°E -94°E. The two principal groups of islets include the Ritchie’s archipelago and the Labyrinth Island. The entire group of island is divided into two broad categories – the Andaman in the north and the Nicobar in the south. They are separated by a water body which is called the 10° channel.
21. The islands of the Arabian Sea include Lakshadweep and Minicoy. These are scattered between 8°N-12°N and 71°E -74°E longitude. These islands are located at a distance of 280 km-480 km off the Kerala coast. The entire island group is built of coral deposits. There are approximately 36 islands, of which 11 are inhabited. Minicoy is the largest island with an area of 453 sq. km. The entire group of islands is broadly divided by the 11° channel, north of which is the Amini Island and to the south of the Canannore Island.

On the basis of physical features,India can be divided into following six divisions:

1. The Northern & North – Eastern Mountains
2. The Northern Plains
3. The Indian Desert
4. The Peninsular Plateau 
5. The Coastal Plains 
6. The Islands

The Northern & North-Eastern Mountains

The North and Northeastern Mountains are made up of two mountain ranges: the Northern and Eastern Mountains. The Himalayas are made up of a succession of mountain ranges that run parallel to each other. The typical orientation of these mountains in the northwestern section of India is from northwest to southeast. The Himalayas run east-west in the Darjeeling and Sikkim areas, whereas they run southwest-northwest in Arunachal Pradesh. They are in the north-south direction in Nagaland, Manipur, and Mizoram.

• The North and Eastern Mountains are made up of the Himalayas and the Northeastern highlands.
• The Himalayas consist of a series of mountain ranges that run parallel to one another.
• The Greater Himalayan range, which encompasses the Great Himalayas and the Trans-Himalayan range, the Middle Himalayas, and the Shiwalik are some of the most important ranges.
• The Greater Himalaya, the Lesser/Middle Himalaya, and the Siwalik Range are all Himalayan Ranges.
• The typical orientation of these mountains in the northwestern section of India is from northwest to southeast.
• The Himalayas run east-west in the Darjeeling and Sikkim areas, whereas they run southwest-northwest in Arunachal Pradesh.
• They are in the north-south direction in Nagaland, Manipur, and Mizoram. The Great Himalayan range, also known as the central axial range, is approximately 2,500 kilometres long from east to west, and its breadth ranges between 160 and 400 kilometres north to south.
• These mountains may be found in India’s northeastern states.
• The Himalayan orogeny gave rise to these mountains, which vary in size and relief.
• Sandstones make up the majority of them. The lush trees cover these mountains.
• To the west, the Purvanchal hills are convex.
• Within the Himalayas, there are large-scale regional variances. The Brahmaputra forms the Himalayas’ eastern boundary.
• The Himalayas curve dramatically to the south and from the eastern highlands of Purvanchal beyond the Dihang canyon.

Views on Origin of Himalayas

Edward Suess:

• According to Suess the folding of the Himalayas has been caused by the compressional forces which have worked from the north and led to the folding of the detritus deposited in the bed of the Tethys.
• In this process the land mass of Angara land lying north of the Tethys acted as backland whereas Gondwana land along the southern margin of the Tethys behaved as foreland and remained stationary.
• Due to the southward movement of Angaraland the Tethyan sediment was compressed against the Peninsular mass yielding place to three successive arc like ranges from west to east owing to two 2 extended horns of the peninsula (the Aravallis and Delhi ridge in the west and Meghalaya plateau in the east). The southward bend in the Himalayan ranges is cited as a strong argument in support of this theory.

Kober:

• Famous german geologist Kober has presented a detailed and systematic description of the surface features of the earth in his book ‘Der Bau der Erde’ in which he has tried to establish a relationship between ancient rigid masses and orogeny (mobile zones or geosynclines).
• Thus he has tried to explain the origin of mountains on the basis of his geosynclinals theory. According to this theoryTethys geosyncline occupied the present day place of the Himalayas and was bordered by Angaraland in the north and Gondwanaland in the south both of which acted as foreland.
• During the Eocene period both these rigid masses (kratogens) started converging as a result of which folds were formed along the northern and southern borders of the Tethys sediments giving birth to the Kunlun mountains in the north and Himalayas in the south.
• Tibetan plateau as median mass between these two mountains remained unaffected by the folding, althoughit was slightly raised due to intense nature of the compressional forces.

Northern Mountains

The Himalayan Mountains make up India’s northern mountain range. They are the world’s tallest mountain ranges.

Trans Himalayas:

• The Great Himalayan Range is immediately to the north.
• Because the majority of this Himalayan range is located in Tibet, it is also known as the Tibetan Himalaya.
• In the Zaskar Range, the Nanga Parbat (8126 m) is a significant range.
• The Ladakh Range is located north of the Zaskar Range and runs parallel to it. Only a few peaks in this range exceed 6000 metres in elevation.
• The Kailas Range (Gangdise in Chinese) is a branch of the Ladakh Range in western Tibet. Mount Kailash is the highest point in the area (6714 m). The Indus River rises on the Kailash range’s northern slopes.
• The Great Karakoram Range, also known as the Krishnagiri Range, is India’s northernmost Trans-Himalayan Range.
• The Karakoram Range stretches for around 800 kilometres east of the Pamir.
• The Karakoram Range is to the north-east of the Ladakh Plateau. It’s been divided into several plains and mountains.