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Chapter 2: Physical Features of India

India’s diverse landscape includes all major physical features: mountains, plains, plateaus, deserts, and islands. This chapter explores the six major physiographic divisions, their geological origins, and their significance. The Peninsular Plateau is ancient and stable, while the Himalayas and Northern Plains are recent and dynamic.

1. The Himalayan Mountains

Overview: Young, fold mountains stretching 2,400 km from Indus to Brahmaputra, forming an arc. Width varies from 400 km (Kashmir) to 150 km (Arunachal Pradesh), with greater altitude variations in the east.

Three Parallel Ranges:

• Great Himalayas (Himadri): Northernmost, continuous range with peaks averaging 6,000 m (e.g., Everest, Kanchenjunga). Granite core, snow-bound, with glaciers (e.g., Gangotri, Siachen).
• Lesser Himalayas (Himachal): South of Himadri, 3,700–4,500 m, 50 km wide. Composed of compressed rocks, includes Pir Panjal, Dhaula Dhar, Mahabharat ranges, and valleys like Kashmir, Kangra, Kullu. Famous hill stations: Mussoorie, Nainital, Ranikhet (Uttarakhand).
• Shiwaliks: Outermost, 10–50 km wide, 900–1,100 m. Made of unconsolidated sediments, with valleys called Duns (e.g., Dehra Dun, Kotli Dun).

Regional Divisions:

• Punjab Himalaya (Indus to Satluj): Kashmir, Himachal Himalaya.
• Kumaon Himalaya (Satluj to Kali).
• Nepal Himalaya (Kali to Teesta).
• Assam Himalaya (Teesta to Dihang).

Purvachal: Eastern hills beyond Dihang gorge, running south along India’s eastern boundary. Comprises Patkai, Naga, Manipur, and Mizo hills, made of sedimentary sandstones, covered with dense forests.

Significance: Forms a rugged barrier, influences climate, and provides river sources.

2. The Northern Plains

Formation: Formed by alluvial deposits from Indus, Ganga, Brahmaputra, and tributaries over millions of years. Covers 7 lakh sq km, 2,400 km long, 240–320 km wide.

Features: Fertile, densely populated, agriculturally productive due to rich soil, water, and climate. Includes riverine islands (e.g., Majuli, world’s largest inhabited) and distributaries in lower courses.

Divisions:

• Punjab Plains: Western, formed by Indus and tributaries (Jhelum, Chenab, Ravi, Beas, Satluj). Dominated by doabs (land between two rivers).
• Ganga Plains: Central, from Ghaggar to Teesta, covering Haryana, Delhi, UP, Bihar, Jharkhand, West Bengal.
• Brahmaputra Plains: Eastern, in Assam.

Relief Features:

• Bhabar: Narrow 8–16 km belt of pebbles parallel to Shiwaliks, where streams disappear.
• Terai: South of Bhabar, wet and marshy, once forested, now agricultural (e.g., Dudhwa National Park).
• Bhangar: Older alluvium above floodplains, terrace-like, with kankar (calcareous) deposits.
• Khadar: Newer, fertile floodplain deposits, renewed annually, ideal for intensive farming.

3. The Peninsular Plateau

Overview: Ancient tableland of crystalline, igneous, and metamorphic rocks, part of Gondwana land. Features broad, shallow valleys and rounded hills.

Divisions:

• Central Highlands: North of Narmada, includes Malwa plateau. Bounded by Satpura (south), Aravalis (northwest), merging with Rajasthan desert. Rivers (Chambal, Sind, Betwa, Ken) flow southwest to northeast. Includes Bundelkhand, Baghelkhand, and Chotanagpur plateau (drained by Damodar).
• Deccan Plateau: Triangular, south of Narmada, flanked by Satpura (north), Mahadev, Kaimur, Maikal (east). Higher in west, slopes east. Extends to Meghalaya, Karbi-Anglong, North Cachar Hills. Hill ranges: Garo, Khasi, Jaintia.

Western and Eastern Ghats:

• Western Ghats: Continuous, 900–1,600 m, parallel to western coast, crossed by passes (Thal, Bhor, Pal). Cause orographic rain. Highest peaks: Anai Mudi (2,695 m), Doda Betta (2,637 m). Local names vary, height increases southwards.
• Eastern Ghats: Discontinuous, 600 m, stretch from Mahanadi to Nilgiris. Dissected by rivers (e.g., Godavari). Highest peak: Mahendragiri (1,501 m). Includes Shevroy, Javadi hills.

Deccan Trap: Black soil area of volcanic origin, formed by denuded igneous rocks.

Aravali Hills: Highly eroded, broken hills from Gujarat to Delhi, on plateau’s western margin.

Hill Stations: Ooty (Udagamandalam), Kodaikanal (Tamil Nadu).

4. The Indian Desert

Location: West of Aravali Hills, an undulating sandy plain with dunes.

Climate: Arid, rainfall below 150 mm/year, low vegetation. Streams appear briefly in rainy season, disappearing into sand.

Features: Barchans (crescent-shaped dunes) dominate, with longitudinal dunes near Indo-Pakistan border. Luni is the only major river.

Example: Jaisalmer showcases barchans.

5. The Coastal Plains

Overview: Narrow strips flanking Peninsular Plateau along Arabian Sea (west) and Bay of Bengal (east).

Western Coast: Narrow, between Western Ghats and Arabian Sea.

• Konkan: Northern, Mumbai to Goa.
• Kannad Plain: Central.
• Malabar Coast: Southern.

Eastern Coast: Wider, level, with deltas from rivers (Mahanadi, Godavari, Krishna, Kaveri).

• Northern Circar: Northern part.
• Coromandel Coast: Southern part.

Key Feature: Chilika Lake (Odisha), India’s largest saltwater lake, south of Mahanadi delta.

6. The Islands

Two Groups:

• Lakshadweep: Coral islands off Kerala’s Malabar coast, 32 sq km. Formerly Laccadive, Minicoy, Amindive; renamed in 1973. Kavaratti is the administrative headquarters. Pitti island has a bird sanctuary. Rich in flora and fauna.
• Andaman and Nicobar: In Bay of Bengal, larger, with volcanic origins. Diverse ecosystems, including coral reefs.

Corals: Formed by calcium carbonate secretions of coral polyps in shallow, warm waters. Types: barrier reefs, fringing reefs, atolls (e.g., Lakshadweep).

7. Summary Table

Division	Key Features	Examples
Himalayan Mountains	Young, fold mountains, 2,400 km, three ranges (Himadri, Himachal, Shiwalik), Purvachal	Everest, Kanchenjunga, Dehra Dun, Mizo Hills
Northern Plains	Alluvial, 7 lakh sq km, fertile, divided into Punjab, Ganga, Brahmaputra plains	Majuli, Dudhwa National Park
Peninsular Plateau	Ancient, crystalline rocks, Central Highlands, Deccan Plateau, Western/Eastern Ghats	Anai Mudi, Chotanagpur, Ooty
Indian Desert	Sandy, arid, barchans, low rainfall	Luni River, Jaisalmer
Coastal Plains	Narrow west (Konkan, Kannad, Malabar), wide east (Northern Circar, Coromandel)	Chilika Lake
Islands	Lakshadweep (coral), Andaman and Nicobar (volcanic)	Kavaratti, Pitti Island

8. Summary and Key Takeaways

Diversity: India’s physiographic divisions showcase varied landforms, from young Himalayas to ancient plateaus.

Geological Contrast: Himalayas are unstable, Northern Plains are alluvial, and Peninsular Plateau is stable.

Significance: Each division supports unique ecosystems, agriculture, and human settlements, shaping India’s geography.