India — Relief Features
"India has every landscape Earth can offer — from the highest mountains to the flattest plains, from the driest desert to the wettest rainforest. This is our GEOGRAPHY."
1. The Six Physiographic Divisions
India's physical landscape is divided into SIX major divisions, each formed by different GEOLOGICAL PROCESSES over billions of years.
2. The Himalayas (Northern Mountains)
Formation
YOUNG FOLD MOUNTAINS. Formed ~50 million years ago when the INDIAN PLATE collided with the EURASIAN PLATE. The TETHYS SEA sediments were folded UP → the Himalayas. 'They are STILL RISING — at about 5 mm per year. The collision continues.'
Extent
Arc-shaped. 2,400 km long (Indus gorge, west → Brahmaputra gorge, east). Width: 400 km (Kashmir) to 150 km (Arunachal).
Three Parallel Ranges
| Range | Altitude | Key Features |
|---|---|---|
| Himadri (Greater/Inner Himalayas) | Average 6,000 m | HIGHEST range. Mount Everest (8,849 m) — Nepal. Kanchenjunga (8,586 m) — India's highest (Sikkim). Glaciers (Gangotri, Yamunotri → source of major rivers). |
| Himachal (Lesser/Middle Himalayas) | 3,700–4,500 m | Pir Panjal, Dhauladhar ranges. Famous HILL STATIONS: Shimla, Mussoorie, Nainital, Darjeeling. |
| Shiwaliks (Outer Himalayas) | 900–1,200 m | YOUNGEST range. Made of unconsolidated sediments. DUNS: flat-floored valleys (Dehradun, Patli Dun). |
Importance
CLIMATIC BARRIER: Blocks cold Central Asian winds → Keeps North India warmer. Forces monsoon winds to RISE → OROGRAPHIC RAINFALL. Source of PERENNIAL RIVERS (glaciers). Strategic DEFENCE (natural northern wall).
3. The Northern Plains
Formation
Formed by ALLUVIUM deposited by the INDUS, GANGA, and BRAHMAPUTRA river systems over millions of years. 'These plains are a DEEP TROUGH filled with sediment — one of the deepest alluvial fills in the world.'
Extent
~7 lakh km². Very FLAT. Very FERTILE. DENSELY POPULATED — 'The Granary of India.'
Divisions
| Section | Region | Main Rivers |
|---|---|---|
| Punjab Plains | WEST | Indus and tributaries (Jhelum, Chenab, Ravi, Beas, Satluj) |
| Ganga Plains | CENTRAL | Ganga and tributaries (Yamuna, Ghaghara, Gandak, Kosi) |
| Brahmaputra Plains | EAST | Brahmaputra |
Key Features
Bhabar (8-16 km belt at Himalayan foot. Coarse pebbles. Rivers DISAPPEAR underground — porous). Terai (South of Bhabar. Marshy. Rivers RE-EMERGE. Thick forests — now largely cleared). Khadar (NEWER alluvium. Replenished by annual floods. VERY FERTILE). Bhangar (OLDER alluvium. Higher terraces. Has KANKAR nodules — calcareous deposits).
4. The Peninsular Plateau
Formation
ANCIENT crystalline, igneous, and metamorphic rocks — some of the OLDEST on Earth (3+ billion years). Part of GONDWANALAND. 'This is India's geological CORE — stable, ancient, rich in minerals.'
Divisions
Central Highlands (NORTH of Narmada River): Malwa Plateau. Bundelkhand. Baghelkhand. Aravalli Range (oldest fold mountains in India — highly eroded).
Deccan Plateau (SOUTH of Narmada): LARGEST plateau. Slopes EASTWARD (rivers flow West → East — Godavari, Krishna). BLACK SOIL (regur — volcanic origin, excellent for cotton). Bordered by: Western Ghats (continuous, higher — average 900-1,600 m. Anaimudi, Kerala — highest peak in Peninsular India, 2,695 m. Cause OROGRAPHIC RAIN on windward side. Rain-shadow on leeward side). Eastern Ghats (discontinuous, lower. Cut by rivers — Godavari, Krishna, Kaveri). The two Ghats MEET at the Nilgiri Hills.
5. The Indian Desert (Thar)
Location: Western Rajasthan. LOW rainfall (<15 cm/year). Sandy plains with SAND DUNES (barchans, longitudinal). Luni River: ONLY significant river. INLAND DRAINAGE (doesn't reach the sea — evaporates). Sparse xerophytic vegetation (cacti, Khejri, thorn bushes). 'The Thar is a COLD-WEATHER desert — the monsoon doesn't reach it. It's also the MOST DENSELY POPULATED desert in the world.'
6. The Coastal Plains
| Feature | Western Coastal Plain | Eastern Coastal Plain |
|---|---|---|
| Width | NARROW (50-80 km) | WIDER (100-130 km) |
| Coast Type | SUBMERGED → natural HARBOURS (Mumbai, Kochi, Marmagao) | EMERGENT → DELTAS (Mahanadi, Godavari, Krishna, Kaveri) |
| Rivers | SHORT, FAST (drain directly into Arabian Sea) | LONG, form LARGE DELTAS |
| Sub-divisions | Konkan (Mumbai-Goa). Malabar (Kerala). | Northern Circars (north). Coromandel (south). |
| Lagoons | Fewer | Chilika (Odisha — LARGEST coastal lagoon in India). Pulicat. |
7. The Islands
Andaman & Nicobar (Bay of Bengal): 572 islands. Volcanic origin (extension of Arakan Yoma mountains of Myanmar). Barren Island: India's ONLY ACTIVE VOLCANO. Indira Point (Great Nicobar): SOUTHERNMOST point of India.
Lakshadweep (Arabian Sea): 36 CORAL islands. Atoll formations. Small. Low-lying. India's smallest Union Territory.
8. Common Mistakes
- 'Western Ghats are higher in the north' — They are HIGHEST in the south (Nilgiris, Anaimudi). Height INCREASES southward.
- 'Eastern Coastal Plain has natural harbours' — WESTERN coast (submerged) has natural harbours. Eastern coast (emergent) has DELTAS — not ideal for harbours.
- 'Khadar is older than Bhangar' — KHADAR = NEW (replenished by floods). BHANGAR = OLDER (higher terraces, kankar).
9. AP SSC Exam Focus
| Topic | Marks |
|---|---|
| Himalayan ranges (3) | 3-4 |
| Northern Plains — Bhabar, Terai, Khadar, Bhangar | 3-4 |
| Peninsular Plateau — Western vs Eastern Ghats | 3-4 |
| Coastal Plains — West vs East | 3-4 |
| Map work — mountains, rivers, coasts | 4-5 |
10. The Himalayas — In-Depth Study
Longitudinal Divisions of the Himalayas
Besides the THREE PARALLEL RANGES (Himadri, Himachal, Shiwaliks), the Himalayas are also divided into FOUR longitudinal divisions from west to east:
| Division | Extent | Key Features |
|---|---|---|
| Punjab Himalayas | Indus to Satluj (Kashmir, Himachal) | Also called 'Kashmir Himalayas.' Beautiful valleys — Kashmir, Kullu, Kangra. Famous LAKES — Dal, Wular. |
| Kumaon Himalayas | Satluj to Kali (Uttarakhand) | Nanda Devi (7,816 m — India's 2nd highest). Valley of Flowers. Hill stations — Nainital, Mussoorie. |
| Nepal Himalayas | Kali to Teesta (Nepal) | Mount EVEREST (8,849 m — world's highest). Kanchenjunga (8,586 m — India's highest, in Sikkim). Most GLACIERS. |
| Assam Himalayas | Teesta to Brahmaputra (Darjeeling, Arunachal, Sikkim, Bhutan) | NARROWER and LOWER than other sections. Heavy rainfall. Dense forests. |
The Himalayas — Ecological Importance
- Biodiversity Hotspot: Eastern Himalayas — incredible species richness. Red panda, snow leopard, one-horned rhinoceros, Bengal tiger.
- Medicinal Plants: Yarshagumba (caterpillar fungus — expensive, used in traditional medicine), Brahmi, Ashwagandha.
- Carbon Sink: Forests of the Himalayas absorb significant CO₂.
- Tribal Cultures: Home to diverse indigenous communities (Ladakhis, Sherpas, Bhutias, Lepchas, Nagas).
11. Peninsular Plateau — In Detail
Central Highlands
Located NORTH of the Narmada River. Includes: Malwa Plateau (central MP — black soil, cotton). Bundelkhand (south UP — rugged terrain, drought-prone). Baghelkhand (east MP). Aravalli Range (Rajasthan — HIGHLY ERODED, oldest fold mountains in India. Guru Shikhar — highest peak, 1,722 m).
Deccan Plateau
Located SOUTH of the Narmada River. The LARGEST plateau in India. Composed of VERY OLD crystalline and metamorphic rocks. Slopes EASTWARD — all major rivers flow west to east (Mahanadi, Godavari, Krishna, Kaveri).
Black Soil (Regur) : Formed from DECCAN TRAP (volcanic lava). Rich in: calcium, magnesium, iron, alumina. Excellent for COTTON (cotton grows best in black soil). Found mainly in: Maharashtra, Madhya Pradesh, Gujarat, Karnataka, Telangana, AP.
Western Ghats (Sahyadris) — Detailed
| Feature | Detail |
|---|---|
| Length | 1,600 km (from Gujarat to Kanyakumari) |
| Average height | 900-1,600 m |
| Highest peak | Anaimudi (2,695 m) — Kerala |
| Continuity | CONTINUOUS — can only be crossed through passes (Thal, Bhor, Palghat) |
| Rainfall | WINDWARD side (west): VERY heavy (200-500+ cm). LEEWARD side (east): LOW (rain-shadow — 50-80 cm) |
| Biodiversity | UNESCO World Heritage Site. One of the 8 'hottest' biodiversity hotspots. Thousands of ENDEMIC species |
Eastern Ghats — Detailed
| Feature | Detail |
|---|---|
| Length | ~1,750 km (from Odisha to Tamil Nadu) |
| Average height | 300-800 m (LOWER than Western Ghats) |
| Highest peak | Jindhagada Peak (1,690 m) — in Arma Konda, Vishakhapatnam district, AP |
| Continuity | DISCONTINUOUS — cut by major rivers (Godavari, Krishna, Penna, Kaveri) |
| Geology | OLDER than Western Ghats. Composed of ancient crystalline rocks |
| Key ranges in AP | Nallamala Hills, Papikonda, Seshachalam, Palakonda |
Western Ghats vs Eastern Ghats — Comparison
| Feature | Western Ghats | Eastern Ghats |
|---|---|---|
| Height | HIGHER (900-1,600+ m) | LOWER (300-800 m) |
| Continuity | CONTINUOUS | DISCONTINUOUS |
| Highest peak | Anaimudi (2,695 m) | Jindhagada (1,690 m) |
| Rivers crossed by | Very few passes | MANY (Godavari, Krishna, Kaveri) |
| Rainfall | VERY HIGH (windward) | MODERATE |
| Biodiversity | EXTREMELY RICH | Rich but less documented |
| UNESCO status | World Heritage Site | NOT declared |
12. Coastal Plains — Extended Detail
Western Coastal Plain
Konkan Coast (Mumbai to Goa): NARROW offshore strip. CREEKS and ESTUARIES. Mangroves. Behind the coast: the SAHYADRIS (Western Ghats) rise steeply. Rice, coconuts, cashew, and spices are grown.
Malabar Coast (Karnataka to Kerala): WIDER and more fertile than Konkan. Lagoons and BACKWATERS (Kerala's famous houseboat destinations — Alleppey, Kumarakom). SPICES — pepper, cardamom, cloves — historically traded with Romans and Arabs. Rice, tapioca, coconut, rubber, and tea.
Eastern Coastal Plain
Northern Circars (Odisha to Andhra's Krishna district): Wide, fertile alluvial plains formed by the Mahanadi, Godavari, and Krishna deltas. RICE BOWL OF INDIA. Orissa coast: Chilika Lake (largest coastal lagoon in India — 1,100+ km² — Ramsar site, home to migratory birds and Irrawaddy dolphins).
Coromandel Coast (from Krishna delta to Kanyakumari): NARROWER than the Northern Circars. Lower rainfall. Important for AQUACULTURE. Includes the delta of the Kaveri River (Tamil Nadu — fertile rice-growing region).
13. Islands — Extended Detail
Andaman & Nicobar Islands (572 islands, 31 inhabited)
- Location: Bay of Bengal. 1,200 km from Chennai.
- Origin: VOLCANIC (extension of the Arakan Yoma range of Myanmar).
- Capital: Port Blair.
- Cellular Jail (Kala Pani) : British used it for EXILING POLITICAL PRISONERS. Now a National Memorial.
- Indira Point: SOUTHERNMOST point of India (Great Nicobar Island). Submerged in the 2004 tsunami — lighthouse was damaged.
- Barren Island: India's ONLY ACTIVE VOLCANO. Last eruption in 2024.
- Tribes: Sentinelese (isolated, hostile to outsiders). Jarawas. Onges. Shompens. Great Andamanese.
- Economy: Tourism, fisheries, timber, coconut. Limited to PROTECT tribal areas.
Lakshadweep (36 CORAL islands, 10 inhabited)
- Location: Arabian Sea. 200-400 km off the Kerala coast.
- Origin: CORAL — ATOLL formations (ring-shaped coral reefs enclosing a lagoon).
- Capital: Kavaratti.
- Area: 32 km² — India's SMALLEST UNION TERRITORY.
- Population: ~70,000. Predominantly MUSLIM. Culture similar to Kerala's Mappila Muslims.
- Economy: Coconut cultivation. FISHING (tuna — major export). Tourism (scuba diving, water sports — Agatti, Bangaram). Limited environmental impact due to small scale.
14. AP-Specific: Eastern Ghats and Coromandel Coast
'Eastern Ghats and Coromandel Coast are ESPECIALLY RELEVANT for AP Board students. These features DEFINE the geography of Andhra Pradesh.'
Eastern Ghats in AP
The Eastern Ghats pass through the DISTRICTS of Srikakulam, Vizianagaram, Visakhapatnam, East Godavari, West Godavari, Krishna, Guntur, Prakasam, Kadapa, Kurnool, Chittoor, and Nellore. They are RESPONSIBLE for: (a) Forests and biodiversity (Nallamala, Seshachalam — red sanders). (b) Water catchment (all AP rivers originate in or flow through them). (c) Mineral deposits (barytes, limestone, bauxite). (d) Tourism (Araku Valley, Borra Caves, Talakona Waterfalls).
Coromandel Coast in AP
The Coromandel Coast stretches from the Krishna delta to the Tamil Nadu border in AP. Key features: (a) Nellore and Prakasam districts lie on the Coromandel Coast. (b) Lower rainfall than the Godavari-Krishna deltas. (c) Groundwater is SALINE in some coastal areas. (d) Important for AQUACULTURE — shrimp and fish farming. (e) Pulicat Lake — second largest brackish water lake in India (shared with Tamil Nadu). A Ramsar site. Important for migratory birds.
15. Self-Test Questions
- Name the SIX PHYSIOGRAPHIC DIVISIONS of India. Describe any TWO.
- Draw a labelled diagram showing the THREE PARALLEL RANGES of the Himalayas.
- Explain the formation of the NORTHERN PLAINS. Differentiate between BHABAR, TERAI, KHADAR, and BHANGAR.
- Differentiate between the WESTERN GHATS and the EASTERN GHATS (5 points).
- Compare the WESTERN COASTAL PLAIN and the EASTERN COASTAL PLAIN.
- Describe the ANDAMAN & NICOBAR ISLANDS. Why is the Cellular Jail significant?
- What are LAKSHADWEEP ISLANDS? How were they formed?
- What is the significance of the PENINSULAR PLATEAU for India's mineral wealth?
- How do the HIMALAYAS affect India's climate?
- What is the importance of the Eastern Ghats and the Coromandel Coast for ANDHRA PRADESH?
Answers to Selected Questions: Q3: BHABAR (Himalayan foot — coarse pebbles, rivers disappear). TERAI (marshy, rivers re-emerge). KHADAR (new alluvium, very fertile, floodplains). BHANGAR (older alluvium, higher terraces, contains kankar nodules). Q7: Lakshadweep is made of CORAL ISLANDS — formed by the skeletons of coral polyps (tiny marine animals). They are ATOLLS — ring-shaped reefs enclosing a lagoon. Ministry of Environment regulates all development to protect fragile coral ecosystems.
