Introduction
India’s landmass shows great physical diversity.
- The Himalayas in the north → high, snow-covered peaks.
- The Northern Plains → flat, fertile, and densely populated.
- The Peninsular Plateau → ancient, stable landmass rich in minerals.
- The Coastal Plains and Islands → provide natural harbours and maritime advantages.
India’s physical features are broadly grouped into six major divisions:
- The Himalayan Mountains
- The Northern Plains
- The Peninsular Plateau
- The Indian Desert
- The Coastal Plains
- The Islands
1. Geological Structure of India
India’s physical features are a result of plate tectonics.
- India was once part of Gondwana land (supercontinent in the Southern Hemisphere).
- Gondwana broke apart → Indian plate drifted northwards.
- About 50 million years ago, Indian Plate collided with Eurasian Plate.
- Result: Himalayan ranges were formed due to folding and uplift.
- The Peninsular Plateau is one of the oldest landmasses → stable since Precambrian times.
- Northern Plains formed by alluvial deposits from Himalayan rivers.
Thus, India’s relief reflects both old and young landforms.
2. The Himalayan Mountains
2.1 General Features
- Geologically young, fold mountains.
- Extend along the north of India for about 2,400 km.
- Width: 400 km in Kashmir to 150 km in Arunachal Pradesh.
- Three parallel ranges: Himadri, Himachal, Shiwalik.
2.2 Longitudinal Divisions
- The Himadri (Great Himalaya):
- Northernmost, highest range.
- Average height = 6,000 metres.
- Includes highest peaks: Mount Everest (8848 m, in Nepal), Kanchenjunga (8598 m, in India).
- Snow-covered, source of glaciers and perennial rivers (Ganga, Yamuna, Indus, Brahmaputra).
- The Himachal (Middle Himalaya):
- Lies south of Himadri.
- Average height: 3,700–4,500 metres.
- Famous ranges: Pir Panjal, Dhauladhar, Mahabharat.
- Hill stations: Shimla, Mussoorie, Nainital.
- Valleys: Kashmir, Kangra, Kullu.
- The Shiwalik (Outer Himalaya):
- Southernmost range.
- Height: 900–1,100 metres.
- Composed of unconsolidated sediments → prone to earthquakes, landslides.
- Contains duns (valleys filled with sediments, e.g., Dehradun).
2.3 Regional Divisions of Himalayas
From west to east, Himalayas are divided into:
- Punjab Himalayas – Indus to Sutlej.
- Kumaon Himalayas – Sutlej to Kali.
- Nepal Himalayas – Kali to Tista.
- Assam Himalayas – Tista to Dihang.
2.4 Purvachal Hills (Eastern Hills)
- Extension of Himalayas in northeast.
- Hills: Patkai, Naga, Manipur, Mizo Hills (Lushai).
- Characterised by dense forests, high rainfall, shifting cultivation.
3. The Northern Plains
3.1 Formation
- Formed by alluvial deposits from rivers – Indus, Ganga, Brahmaputra.
- Spread over about 7 lakh sq km.
- Length: 2,400 km; width: 240–320 km.
- Extremely fertile, densely populated.
3.2 Divisions
- Punjab Plains (Indus Basin):
- Formed by Indus and tributaries (Jhelum, Chenab, Ravi, Beas, Sutlej).
- Western part lies in Pakistan.
- Ganga Plains:
- Between Ghaggar and Teesta rivers.
- Covers Haryana, Delhi, UP, Bihar, West Bengal, parts of Jharkhand.
- Brahmaputra Plains:
- In Assam; formed by Brahmaputra river.
3.3 Relief Features
- Bhabar: Narrow belt of pebbles, along foothills. Rivers disappear here.
- Terai: Marshy, forested region south of Bhabar; rich in wildlife.
- Bhangar: Older alluvium, slightly elevated, less fertile.
- Khadar: New alluvium, very fertile, renewed annually by floods.
4. The Peninsular Plateau
4.1 General Features
- One of the oldest landmasses (formed during Gondwana period).
- Irregular triangle shape.
- Surrounded by hills and plateaus.
- Rich in minerals (coal, iron, manganese).
4.2 Divisions
- Central Highlands:
- Between Narmada and northern plains.
- Ranges: Aravallis (old, eroded, extend from Gujarat to Delhi).
- Plateaus: Malwa, Bundelkhand, Baghelkhand.
- Deccan Plateau:
- South of Narmada.
- Triangular shape; slopes eastwards.
- Bounded by Western and Eastern Ghats.
- Rivers: Godavari, Krishna, Kaveri, Mahanadi.
4.3 Ghats
- Western Ghats:
- Height: 900–1600 m.
- Continuous, steep slope to Arabian Sea.
- Origin of west-flowing rivers (Mandovi, Zuari).
- Eastern Ghats:
- Lower, discontinuous.
- Height: 600 m.
- Broken by rivers (Godavari, Krishna).
5. The Indian Desert
- Located in western Rajasthan.
- Known as Thar Desert.
- Low rainfall (<150 mm per year).
- Sand dunes, arid climate, xerophytic vegetation.
- River: Luni (seasonal).
- Rich in wind energy and solar energy.
6. The Coastal Plains
6.1 Western Coastal Plains
- Between Western Ghats and Arabian Sea.
- Narrow (50–100 km).
- Divisions:
- Konkan (Mumbai to Goa).
- Kannad Plain (Goa to Karnataka).
- Malabar Coast (Kerala).
- Features: lagoons, backwaters (Kerala).
6.2 Eastern Coastal Plains
- Between Eastern Ghats and Bay of Bengal.
- Wider, flat, fertile.
- Divisions:
- Northern Circar (Andhra).
- Coromandel Coast (Tamil Nadu).
- Features: deltas of Mahanadi, Godavari, Krishna, Kaveri.
7. The Islands
7.1 Andaman and Nicobar Islands
- Located in Bay of Bengal.
- Around 572 islands.
- Volcanic origin, forested, strategic importance.
- Southernmost point: Indira Point (submerged in 2004 tsunami).
7.2 Lakshadweep Islands
- Located in Arabian Sea.
- Composed of coral deposits (atolls, reefs).
- Smallest UT of India.
8. Importance of Physical Features
- Himalayas: Defence, water resources, climate barrier.
- Northern Plains: Food basket, dense population.
- Plateau: Minerals, energy resources.
- Desert: Solar/wind energy, tourism.
- Coastal Plains: Fishing, trade, ports.
- Islands: Defence outposts, biodiversity, tourism.
Quick Revision (One-Liners)
- Himalayas: Young fold mountains, three parallel ranges.
- Northern Plains: Alluvial deposits, fertile, food bowl.
- Peninsular Plateau: Oldest landmass, mineral-rich.
- Indian Desert: Thar, arid climate, sand dunes.
- Coastal Plains: Western (narrow), Eastern (wide, fertile deltas).
- Islands: Andaman-Nicobar (volcanic, Bay of Bengal), Lakshadweep (coral, Arabian Sea).