Physical Division of India – NDA Geography Notes

India is not a flat, uniform land. It has some of the most varied landscapes in the world. There are towering mountains in the north, vast flat plains, an ancient rocky plateau in the centre, narrow coastal strips on both sides, and island groups far out in the sea.

Understanding these physical divisions is important. They explain India’s rivers, climate, agriculture, and population distribution. NDA has tested this chapter from many angles — the sequence of physical divisions from north to south, the oldest landform, Himalayan peaks and passes, Karewas, zones of the northern plains, lakes, and the island channels.

The Six Physical Divisions of India

India is divided into six major physical regions:

1. The Himalayan Mountains
2. The Northern Plains
3. The Peninsular Plateau
4. The Indian Desert (Thar)
5. The Coastal Plains
6. The Islands

They run roughly from north to south. Mountains are in the north. Plains lie just below them. The plateau is further south. Coastal plains flank the peninsula on both sides. Islands lie offshore in the sea.

The correct sequence from north to south is: Himalayas → Northern Plains → Peninsular Plateau → Coastal Plains. [NDA 2014-I]

1. The Himalayan Mountains

How were the Himalayas formed?

The Himalayas are fold mountains. They were formed when the Indian tectonic plate crashed into the Eurasian plate. [NDA 2008-II]

Before this collision, a large shallow sea called the Tethys Sea existed in this region. As the two plates pushed against each other, the sediments at the bottom of this sea were folded and pushed upward. This formed the Himalayan ranges.

This process began about 70 million years ago and is still continuing. This is why:

• The Himalayas are still rising
• The region has frequent earthquakes
• Marine fossils (remains of ancient sea creatures) are found in the Himalayas — evidence of the old Tethys Sea

The Himalayas are the youngest major mountain range in India. The Peninsular Plateau is far older.

Why are the Himalayas poor in minerals?

The Himalayas are made mostly of sedimentary rocks — rocks formed from compressed sea sediments. Sedimentary rocks are generally poor in metallic minerals. The rugged terrain also makes mineral exploration very difficult and costly. [NDA tested via CDS]

In contrast, the Peninsular Plateau has ancient igneous and metamorphic rocks — which is why it is rich in iron ore, coal, manganese, and copper.

The Three Parallel Ranges of the Himalayas

The Himalayas have three main ranges running parallel to each other from west to east:

Range	Local Name	Height	Key Features
Greater Himalayas	Himadri	Over 6,000 m	Highest range; always snow-covered; contains Everest, K2, Kanchenjunga
Lesser Himalayas	Himachal	3,700–4,500 m	Contains hill stations — Shimla, Mussoorie, Nainital, Darjeeling
Outer Himalayas	Shiwaliks	900–1,100 m	Lowest range; southernmost foothills

Duns are fertile valleys found between the Shiwaliks and the Lesser Himalayas. Dehradun is the most famous Dun. Others include Patli Dun and Kotli Dun.

Pir Panjal Range is part of the Lesser Himalayas. [NDA tested via CDS]

The Himalayas are wider in the west (about 400 km) than in the east (about 150 km). So the statement that “Himalayas are wider in the east” is WRONG. [NDA 2010-II]

The Indus, Sutlej, and Brahmaputra rivers are older than the Himalayas. They existed before the mountains rose. As the mountains rose, these rivers kept cutting through them. This is called antecedent drainage. [NDA 2010-II]

Karewas — A Special Himalayan Feature

In the Kashmir Valley, along the lower slopes of the Pir Panjal range, there are flat-topped terraces. These are called Karewas.

The Kashmir Valley was once a large lake thousands of years ago. As the lake slowly dried up, it left behind layers of sand, clay, silt, and loam. These deposits hardened over time into flat terraces.

Karewas are lacustrine deposits — formed by an ancient lake during the Pleistocene period. [NDA tested via CDS]

Karewas are famous for three crops:

• Saffron — India’s most expensive spice
• Almond
• Walnut

These crops grow well on the dry, well-drained Karewa land. Rice is NOT grown on Karewas — paddy needs waterlogged, flat, low-lying fields.

All three statements about Karewas are correct: they are Pleistocene lacustrine deposits, found along lower slopes of Pir Panjal, and known for saffron, almond, and walnut cultivation.

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Important Himalayan Peaks

Peak	Height	Location
Mount Everest	8,849 m	Nepal-China border — highest in the world
K2 (Godwin Austen)	8,611 m	Pakistan-occupied Kashmir — 2nd highest in world
Kanchenjunga	8,586 m	Sikkim-Nepal border — highest peak in Indian territory
Nanda Devi	7,816 m	Uttarakhand — highest peak entirely within India

Important distinctions:

• Kanchenjunga = highest peak within Indian territory (on the Sikkim-Nepal border)
• Nanda Devi = highest peak lying completely within India’s undisputed boundaries, in Uttarakhand [NDA 2006-II]
• K2 is the second highest in the world but lies in Pakistan-occupied Kashmir — NOT in undisputed Indian territory

Among Dhaulagiri, Namcha Barwa, Nanda Devi, and Nanga Parbat — Dhaulagiri (8,167 m in Nepal) is the highest. [NDA 2007-II]

Peaks located in India (not Nepal or Pakistan): Namcha Barwa and Kamet are located in India. Dhaulagiri and Makalu are in Nepal.

Peak-State Matching:

• Nanga Parbat — Jammu & Kashmir
• Nanda Devi — Uttarakhand [NDA 2006-II]
• Kanchenjunga — Sikkim

Structurally, the Meghalaya region (Shillong Plateau) is part of the Deccan Plateau — not the Himalayas. [NDA 2016-I]

Important Himalayan Passes

A pass is a gap in a mountain range that allows movement across it.

Pass	State/Region	Connects	Notes
Zoji La	Jammu & Kashmir	Srinagar to Leh	In Greater Himalayas
Banihal Pass	J&K	Jammu to Srinagar	In Pir Panjal Range
Rohtang Pass	Himachal Pradesh	Manali to Lahaul-Spiti	—
Shipki La	Himachal Pradesh	India to China	Sutlej enters India here
Bara Lacha Pass	Himachal Pradesh	—	—
Lipulekh	Uttarakhand	India to China	—
Niti Pass	Uttarakhand	India to Tibet	—
Nathu La	Sikkim	India to China (Tibet)	Links Sikkim with Tibet; was main Silk Route artery; reopened in 2006
Jelep La	Sikkim	—	In Sikkim Himalayas
Aghil Pass	Trans Himalayas	—	In Trans Himalayan region
Karakoram Pass	Ladakh	India to China (Xinjiang)	—
Khardung La	Ladakh	—	Near Nubra Valley

Sequence of passes from Kashmir to Sikkim: Zoji La → Shipki La → Nathu La. [NDA 2006-II]

Pass-State matching [NDA 2012-I]:

• Zoji La — Jammu & Kashmir
• Lipulekh — Uttarakhand
• Shipki La — Himachal Pradesh
• Nathu La — Sikkim

Key facts about passes:

• Zoji La is in the Greater Himalayas [NDA 2024-II]
• Banihal Pass is in the Pir Panjal Range [NDA 2024-II]
• Photo La is in the Ladakh Range [NDA 2024-II]
• Nathu La links Sikkim with Tibet; it was the main artery of the ancient Silk Route; reopened in 2006.
• Khardung La is in Ladakh — near Nubra Valley
• Lanak La links Lhasa with Ladakh

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The Purvanchal Hills

In the northeast, the Himalayas bend sharply southward and form lower hills called the Purvanchal. These include the Patkai Hills, Naga Hills, Manipur Hills, and Mizo Hills. They separate northeastern India from Myanmar.

The hill range that separates Manipur from Nagaland is the Barail Hills.

Assam is known as the ‘land of red river and blue hills.’ It contains three of the six physiographic divisions of India and covers about 2.39% of India’s total area.

2. The Northern Plains

Just south of the Himalayas lie the Northern Plains. They are one of the most fertile regions in the world.

They were formed by sediments brought down by three great river systems — the Indus, the Ganga, and the Brahmaputra. Over millions of years these rivers deposited layer upon layer of alluvial soil.

The plains stretch about 3,200 km from east to west. Alluvial deposits reach 1,000 to 2,000 metres deep in some places.

Four zones — moving south from the Himalayas:

Bhabar:
This is the zone right at the base of the Shiwaliks. When rivers come down from the mountains, they drop their load of heavy boulders, pebbles, and coarse gravel here. The ground is very porous. Rivers actually sink underground and disappear in this zone. Wells are very deep. Bhabar is about 8 to 10 km wide. [NDA 2023-II | NDA tested via CDS]

Terai:
Just south of Bhabar, the underground rivers come back to the surface. This creates a wet, marshy, forested belt called the Terai. It was once heavily forested and malarial. Much of it has been cleared for farming today.

Bhangar:
Further south lies older alluvium. This is called Bhangar. It sits a bit higher than the river floodplains and is not regularly flooded. The soil here is older and contains hard deposits of calcium carbonate called Kankar.

Khadar:
The newest alluvium is found in the active floodplains of rivers. This is Khadar. Rivers flood every year and deposit fresh, fine silt — making Khadar the most fertile land in India. It is renewed every year.

Zone	Key Feature	Fertility
Bhabar	Rocky, porous; rivers sink underground	Not fertile
Terai	Marshy, forested; rivers re-emerge	Moderate
Bhangar	Older alluvium; elevated; Kankar deposits	Less fertile
Khadar	New alluvium; active floodplains; renewed annually	Most fertile

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3. The Peninsular Plateau

The Peninsular Plateau is the oldest physical feature of India. [NDA 2016-I]

It is part of the ancient Gondwana supercontinent — the same landmass that once included Africa, South America, Australia, and Antarctica. This makes it hundreds of millions of years old — far older than the Himalayas.

Because it is so old and stable, this region does not experience major earthquakes. The rocks here are ancient igneous and metamorphic rocks, rich in minerals — coal, iron ore, manganese, copper, and mica.

The plateau has an average height of 600 to 900 metres. It slopes gently eastward — which is why most peninsular rivers flow east into the Bay of Bengal.

The Narmada River divides the Peninsular Plateau into two parts:

Central Highlands — North of the Narmada. Includes the Malwa Plateau, Bundelkhand Plateau, and Chota Nagpur Plateau in Jharkhand. The Chota Nagpur Plateau is rich in coal, iron ore, manganese, and bauxite.

Deccan Plateau — South of the Narmada. Bounded by the Western Ghats on the west and Eastern Ghats on the east. Slopes from west to east.

The Aravalli Range is the oldest mountain range in India. [NDA tested via CDS]

Hills of Central India — west to east sequence:
Mahadeo Hills → Maikala Hills → Garhjat Hills. [NDA 2007-II]

Rajmahal highlands consist of lava flow deposits. Bundelkhand gneiss belongs to the oldest Archaean rocks of India. Both statements are correct. [NDA 2016-I]

The southern point of the Peninsular Plateau is formed by the Nilgiri Hills, where the Eastern and Western Ghats meet. [NDA 2023-II]

The Cardamom Hills are a continuation of the Western Ghats — NOT the Eastern Ghats. [NDA 2023-II]

The Shillong Plateau in the northeast is structurally an extension of the Peninsular Plateau (Deccan Plateau). [NDA 2016-I]

The Western and Eastern Ghats

Feature	Western Ghats (Sahyadri)	Eastern Ghats
Continuity	Continuous, unbroken	Discontinuous — broken by rivers
Height	Higher (~1,000 m average)	Lower (~600 m average)
Highest Peak	Anamudi, Kerala (2,695 m)	Mahendragiri, Odisha (1,501 m)
Rainfall	Very heavy (windward of SW monsoon)	Less (leeward side)

Anamudi (2,695 m) in Kerala is the highest peak in South India. It is in the Anaimalai Hills of the Western Ghats.

The west coast of India is a high, rocky, retreating coast dominated by erosional landforms. The east coast is a low sedimentary coast with depositional forms (river deltas).

The western coastal plain is narrow, submerged, and provides natural conditions for ports — but does NOT have well-developed deltas. [NDA 2015-I]

Important peaks of the Peninsular Plateau:

• Dodabetta — Tamil Nadu (Nilgiris)
• Guru Shikhar — Rajasthan (Aravallis) — highest peak of Aravallis
• Kalsubai — Maharashtra (highest peak of Maharashtra)
• Dhupgarh — Madhya Pradesh (highest peak of Satpura) [NDA 2009-I]

Sequence from south to north:
Doddabetta → Vindhyachal → Dhaulagiri → Kailash. [NDA 2014-I]

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The Deccan Trap

A large part of the Deccan Plateau is covered by ancient black lava rock called the Deccan Trap. Millions of years ago, massive volcanic eruptions poured lava over this region. The lava weathered over time to form the famous black cotton soil (regur soil) — ideal for growing cotton.

4. The Indian Desert (Thar)

The Thar Desert lies to the northwest of the Aravalli Hills. It covers most of Rajasthan and extends into parts of Gujarat, Punjab, and Haryana.

The Thar receives very little rainfall — less than 150 mm per year in most areas. The Aravalli Hills run roughly parallel to the monsoon winds instead of across them — so they fail to force the winds upward and cause rainfall.

The shifting sand dunes in the Thar region are locally known as Dhoros. [NDA 2016-I]

The features of North-Western India are deserts, fertile plains, and moderately forested mountains. [NDA 2016-I]

The Indian desert (Marusthali) is believed to have been under the sea during the Mesozoic Era. [NDA tested via CDS]

5. The Coastal Plains

India has two distinct coastal plains.

Western Coastal Plain:

The western coast lies between the Western Ghats and the Arabian Sea. It is narrow — only 10 to 25 km wide. From north to south it is divided into:

• Konkan Coast — Maharashtra and Goa
• Kannad Coast — Karnataka
• Malabar Coast — Kerala

The Malabar Coast in Kerala is famous for its backwaters — a network of lagoons and canals running parallel to the sea, locally called Kayals.

Eastern Coastal Plain:

The eastern coast lies between the Eastern Ghats and the Bay of Bengal. It is much wider — 100 to 130 km. From north to south it is divided into:

• Northern Circars — northern Andhra Pradesh and Odisha
• Coromandel Coast — southern Andhra Pradesh and Tamil Nadu

The eastern coast has the large deltas of the Mahanadi, Godavari, Krishna, and Cauvery rivers.

Feature	Western Coast	Eastern Coast
Width	Narrow (10–25 km)	Wide (100–130 km)
Coastline	Rocky, indented	Smooth, sandy
Natural harbours	Many	Few
Famous feature	Backwaters (Kerala)	River deltas
Major lake	Vembanad (Kerala)	Chilika (Odisha)

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Important Lakes of India

Lakes are tested frequently. Learn these carefully.

Lake	State	Type	Key Fact
Wular Lake	J&K	Freshwater	Largest freshwater lake in India; tectonic lake; Jhelum flows through it
Dal Lake	J&K	Freshwater	Famous for houseboats; NOT the largest freshwater lake
Chilika Lake	Odisha	Brackish	Largest coastal lagoon in India; largest brackish water lake in Asia; Ramsar site
Vembanad Lake	Kerala	Brackish	Longest lake in India; western coast
Loktak Lake	Manipur	Freshwater	Largest freshwater lake in Northeast India; has floating islands called Phumdis; Keibul Lamjao National Park is here
Sambhar Lake	Rajasthan	Saltwater	Largest saltwater lake in India; important source of salt

Wular Lake is the largest freshwater lake in India — not Dal Lake. Wular is a tectonic lake formed by movement of the Earth’s crust.

Loktak Lake in Manipur has floating masses of soil, vegetation, and organic matter called Phumdis. The Keibul Lamjao National Park is built on these floating Phumdis. It is the world’s only floating national park — home to the endangered Sangai deer.

6. The Islands

Lakshadweep Islands (Arabian Sea):

• Located about 200–300 km off the Kerala coast
• Total of 36 islands; only 10 are inhabited
• Coral islands — formed from coral reefs [NDA 2014-I]
• Smallest Union Territory of India by area
• Capital: Kavaratti
• Nine Degree Channel separates Minicoy Island from the rest of Lakshadweep
• Eight Degree Channel separates Lakshadweep from the Maldives

Andaman and Nicobar Islands (Bay of Bengal):

• About 572 islands; only around 38 are inhabited
• Andaman group is in the north; Nicobar group is in the south
• Ten Degree Channel separates Little Andaman from Car Nicobar
• Capital: Port Blair on South Andaman Island [NDA 2008-I]
• Indira Point — southernmost tip of India — is on Great Nicobar Island
• Barren Island — India’s only active volcano — is in the Andaman group
• Narcondam Island — an extinct volcano — is also in the Andaman group
• Duncan Passage separates South Andaman from Little Andaman
• Mount Thuillier is on Great Nicobar Island

Renamed islands [NDA 2019-I]:

• Ross Island → Shaheed Dweep
• Neil Island → Shaheed Dweep — Wait, checking: Ross Island = Netaji Subhas Chandra Bose Dweep; Neil Island = Shaheed Dweep; Havelock Island = Swaraj Dweep. All three renamings are correct. [NDA 2019-I]

Channel	Separates
Ten Degree Channel	Little Andaman from Car Nicobar (Andaman group from Nicobar group)
Nine Degree Channel	Minicoy from rest of Lakshadweep
Eight Degree Channel	Lakshadweep from Maldives
Duncan Passage	South Andaman from Little Andaman