Physiographic Divisions of India and the Himalayas Notes for UPSC

India has a very varied landscape, from snow-covered mountains and fertile plains to old plateaus, long coastlines and islands. Geographers divide India into six physiographic divisions: the Northern Mountains (Himalayas), the Northern Plains, the Peninsular Plateau, the Indian Desert, the Coastal Plains and the Islands. For UPSC, this chapter is the base of Indian Geography: you must know the features, important peaks, passes, ranges and their importance. This note explains each division in simple language with easy tables.

The Six Physiographic Divisions at a Glance

1. The Northern Mountains: The Himalayas

The Himalayas form an arc about 2,400 km long, running from the Indus river in the west to the Brahmaputra in the east. Their width is about 400 km in Kashmir and 150 km in Arunachal Pradesh. They are young fold mountains, formed by the collision of the Indian plate with the Eurasian plate over the old Tethys Sea, and they are still rising, which is why earthquakes and landslides are common. The Himalayas have a clear division from north to south:

Trans-Himalaya

This region lies north of the main Himalayas and includes the Karakoram, Ladakh and Zanskar ranges. The Karakoram has K2 (Godwin Austen), the second highest peak in the world (8,611 m), and long glaciers such as the Siachen glacier and the Baltoro glacier.

Greater Himalaya (Himadri)

This is the highest and most continuous range, with an average height of about 6,000 m, and has a granite core with snow throughout the year. The glaciers of the Ganga and Yamuna (Gangotri and Yamunotri) are here. Important peaks include Mount Everest (8,849 m, in Nepal), Kanchenjunga (8,586 m, the highest in India, on the Sikkim-Nepal border), Nanga Parbat and Nanda Devi (7,816 m, the highest peak entirely in India).

Lesser Himalaya (Himachal)

This range lies south of the Himadri and has heights of about 3,700 to 4,500 m. It includes the Pir Panjal (the longest), Dhauladhar and Mussoorie ranges. Many hill stations, like Shimla, Mussoorie, Nainital and Darjeeling, and beautiful valleys such as Kashmir, Kangra and Kullu are located here.

Outer Himalaya (Shiwaliks)

The Shiwaliks are the lowest (900 to 1,100 m) and youngest range, made of loose sediments washed down from higher mountains. The wide valleys between the Lesser Himalaya and the Shiwaliks are called Duns in the west (Dehradun) and Duars in the east.

Eastern Hills (Purvanchal)

These hills run along the India-Myanmar border and include the Patkai, Naga, Manipur and Mizo hills. The Garo, Khasi and Jaintia hills of Meghalaya are, geologically, an extension of the Peninsular Plateau.

Regional Division and Important Passes

Sir Sidney Burrard divided the Himalayas by rivers: the Punjab Himalaya (Indus to Sutlej), Kumaon Himalaya (Sutlej to Kali), Nepal Himalaya (Kali to Teesta) and Assam Himalaya (Teesta to Dihang). The main passes are: Karakoram Pass, Khardung La and Zoji La (Ladakh and Jammu and Kashmir), Banihal (Jammu-Kashmir highway), Rohtang (Himachal), Shipki La (Himachal-Tibet), Lipulekh and Niti (Uttarakhand), and Nathu La and Jelep La (Sikkim).

2. The Northern Plains

The Northern Plains lie between the Himalayas and the Peninsular Plateau and are formed by the deposition of silt from the Indus, Ganga and Brahmaputra. They are about 2,400 km long and 240 to 320 km wide. They are the most fertile and densely populated region of India. Their regional divisions are the Punjab plains, the Ganga plains and the Brahmaputra plains. From north to south, the plains have the following belts:

• Bhabar: a narrow belt of pebbles at the foot of the Shiwaliks where streams disappear underground.
• Terai: a wet and marshy belt south of the Bhabar where the streams re-emerge; it has thick forests and wildlife.
• Bhangar: older alluvium, slightly higher, with kankar nodules.
• Khadar: newer, fertile alluvium found in the flood plains.

3. The Peninsular Plateau

This is the oldest and most stable landmass of India, made of ancient crystalline rocks and part of the old Gondwana land. It has the following parts:

• Central Highlands: Aravalli, Malwa Plateau, Bundelkhand and Baghelkhand. The Aravalli is one of the oldest fold mountains in the world, with Guru Shikhar (1,722 m) at Mount Abu as its highest peak.
• Vindhya and Satpura Ranges: central Indian ranges between the Narmada and the Tapi, with Dhupgarh (Pachmarhi) as the highest peak of the Satpura.
• Chota Nagpur Plateau: rich in coal, iron ore and mica, often called the "Ruhr of India".
• Deccan Plateau: a triangular plateau made of volcanic basalt (the Deccan Trap), which gives black soil.

The two Ghats meet at the Nilgiri hills, where Doddabetta (2,637 m) is the highest peak. Important passes of the Western Ghats include Thal Ghat, Bhor Ghat and the Palghat Gap.

4. The Indian Desert

The Thar Desert (also called Marusthali) lies west of the Aravalli in Rajasthan and gets less than 150 mm of rainfall. It has sand dunes (barchans), salty lakes (such as Sambhar) and the seasonal Luni river. The Indira Gandhi Canal now brings water to part of it.

5. The Coastal Plains

The western coastal plain is narrow, lying between the Western Ghats and the Arabian Sea, and is divided into the Konkan (Maharashtra), the Karnataka coast and the Malabar coast (Kerala) with its lagoons called kayals or backwaters. The eastern coastal plain is wider, lying between the Eastern Ghats and the Bay of Bengal, with large deltas of the Mahanadi, Godavari, Krishna and Kaveri. It is divided into the Northern Circars and the Coromandel Coast.

6. The Islands

The Andaman and Nicobar Islands in the Bay of Bengal are the tops of an underwater mountain range and are separated by the Ten Degree Channel. They have India's only active volcano, Barren Island, and the southernmost point of India, Indira Point. The Lakshadweep Islands in the Arabian Sea are made of coral, and are small atolls.

How the Himalayas Were Formed

About 50 million years ago, the Indian plate, which had been moving north after breaking from the old Gondwana land, collided with the Eurasian plate. The thick layers of sediments in the Tethys Sea between the two plates were squeezed and pushed up to make the Himalayas. Since the Indian plate is still moving north by a few centimetres every year, the mountains continue to rise and the region keeps facing earthquakes. This plate tectonic story explains why the Himalayas are young, folded and full of fossils of sea animals, and why the Peninsular Plateau, which lies on the old, stable part of the plate, is much less shaken by earthquakes.

How to Study Physiography for UPSC

1. Draw an outline map of India and mark the six divisions in different colours.
2. Memorise peaks, passes and ranges in a table with their location and state.
3. Link relief with rivers, soil, climate and population: this makes the facts logical and easy to remember.
4. Solve previous year questions on peaks, ranges, passes and landforms like the Bhabar and Terai.

Importance of the Himalayas (Mains Angle)

You can write the following points: the Himalayas shape the monsoon and protect India from cold winds; they are the source of perennial rivers; they have forests and rich biodiversity; they provide hydropower, minerals, tourism and fertile soil to the plains; and they serve as a natural boundary for defence. At the same time, the region faces earthquakes, landslides, glacial lake floods, melting glaciers due to climate change and risks from unplanned development. A good conclusion stresses sustainable development, eco-sensitive zones and disaster preparedness.

Practice Statements and Common Mistakes

• "Nanda Devi is the highest peak of India." Wrong in the strict sense. Kanchenjunga is the highest, while Nanda Devi is the highest entirely within India.
• "The Shiwaliks are the oldest Himalayan range." Wrong. They are the youngest.
• "The Aravalli is an old fold mountain." Correct.
• Do not mix up the Bhabar (porous pebbles) and the Terai (swampy).

Quick Revision

• Himalayas: Trans-Himalaya, Himadri, Himachal and Shiwaliks; Purvanchal in the east.
• Plains: Bhabar, Terai, Bhangar and Khadar.
• Plateau: Aravalli, Vindhya-Satpura, Chota Nagpur, Deccan and the Ghats.

Physiography is the base of all geography. Use a map to locate each range and peak, learn the Himalayan divisions in order, and compare the Western and Eastern Ghats in a table, and you will find this topic easy and scoring.

Related Notes to Read Next

Continue your preparation with these related notes from the same subject:

• Indian Agriculture and Green Revolution Notes for UPSC
• Natural Vegetation and Forests of India Notes for UPSC
• Indian Minerals, Industries and Energy Resources Notes for UPSC
• All Indian Geography notes

Frequently Asked Questions (FAQ)

What are the six physiographic divisions of India?

They are the Northern Mountains (Himalayas), the Northern Plains, the Peninsular Plateau, the Indian Desert, the Coastal Plains and the Islands.

What are the main divisions of the Himalayas?

From north to south they are the Trans-Himalaya, the Greater Himalaya (Himadri), the Lesser Himalaya (Himachal) and the Outer Himalaya (Shiwaliks), with the Purvanchal hills in the east.

Which is the highest peak in India?

Kanchenjunga (8,586 m) on the Sikkim-Nepal border is the highest peak in India. Nanda Devi (7,816 m) is the highest peak located entirely within India.

What are the Shiwaliks?

The Shiwaliks are the outermost and youngest range of the Himalayas, made of loose sediments, with heights of about 900 to 1,100 metres.

What are Duns?

Duns are long valleys between the Lesser Himalaya and the Shiwaliks, such as Dehradun, Kotli Dun and Patli Dun.

What are Bhabar and Terai?

Bhabar is a porous pebble belt at the foot of the Shiwaliks where streams disappear. Terai is a marshy belt to its south where streams reappear.

What is the difference between Bhangar and Khadar?

Bhangar is old alluvium found on higher land with kankar nodules, while Khadar is new, fertile alluvium found in flood plains and renewed every year.

Which is the highest peak of peninsular India?

Anamudi (2,695 m) in the Anaimalai hills of the Western Ghats in Kerala is the highest peak of peninsular India.

What is the difference between the Western and Eastern Ghats?

The Western Ghats are higher and continuous with only a few gaps, while the Eastern Ghats are lower, discontinuous and cut by rivers.

Which is the oldest mountain range in India?

The Aravalli range is one of the oldest fold mountain ranges in the world, with Guru Shikhar (1,722 m) as its highest point.

What is the Palghat Gap?

The Palghat Gap is a break in the Western Ghats between the Nilgiris and the Anaimalai hills in Kerala and Tamil Nadu, used by roads and railways.

Which Indian island has an active volcano?

Barren Island in the Andaman Sea, part of the Andaman and Nicobar Islands, is India’s only active volcano.