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GC06 — Physiography of India

🌎 Indian Geography – GC06 CDS Level ★ High Priority
📌 CDS Focus (2022–2026): This is one of the most tested Indian Geography topics. Exam regularly asks: Himalayan divisions (longitudinal & regional), passes (Shipki La, Nathu La, Zoji La — which state they are in), highest peaks, river origins, Northern Plains (Bhangar vs Khadar), Peninsular Plateau features (Deccan Trap, Eastern & Western Ghats differences), coastal plains (which coast is wider), and Island features (A&N vs Lakshadweep). Average students should master the location + one key fact per feature.

1. India’s Major Physiographic Divisions

Fig. 1.1 — Schematic Cross-Section: North to South Physiographic Zones of India
THE HIMALAYAS Young fold mountains • Runs 2,500 km • Width 150–400 km • Arc from Indus to Brahmaputra GREAT NORTHERN PLAINS Alluvial deposits of Indus, Ganga & Brahmaputra • 2,400 km long • 240–320 km wide • Most fertile region PENINSULAR PLATEAU Ancient Gondwana land • Deccan Trap (basalt) in NW • Includes Central Highlands & Deccan Plateau COASTAL PLAINS W. Ghats on west • E. Ghats on east • Western coast narrower & straight • Eastern coast wider & deltaic ISLANDS: A&N Islands (Bay of Bengal • Volcanic)   |   Lakshadweep (Arabian Sea • Coral Atolls)
💡 The 7 Physiographic Divisions of India (N to S): 1 The Himalayas  |  2 Northern Plains  |  3 Peninsular Plateau  |  4 Indian Desert (Thar)  |  5 Coastal Plains  |  6 Western & Eastern Ghats  |  7 Islands
THE HIMALAYAS

2. The Himalayas

Fig. 2.1 — Longitudinal Divisions of the Himalayas (Cross-Section S to N)
SOUTH (Indo-Gangetic) NORTH (Tibet side) SHIWALIKS (Sub-Himalaya) 600–1,200 m • Outer range Dun valleys here (Dehradun, Patlidun) LESSER HIMALAYA (Himachal / Middle) 1,000–4,500 m Mussoorie, Shimla, Nainital Pir Panjal, Dhauladhar ranges GREATER HIMALAYA (Himadri / Innermost) >6,000 m • Perpetual snow Everest (8,848 m) • K2 • Kanchenjunga Main passes: Shipki La, Nathu La TRANS HIMALAYA (Tibetan / Tethys) Karakoram, Ladakh Zaskar & Kailash ranges K2 (8,611 m) is here Dry, cold; rain-shadow area

A. Longitudinal Divisions (S to N)

DivisionAlso CalledHeight RangeKey Features & CDS Facts
ShiwaliksSub-Himalaya / Outer Himalaya600–1,200 mOutermost & youngest; soft sedimentary rocks; longitudinal valleys = Duns (e.g., Dehradun, Patlidun, Kotlidun). Prone to earthquakes and landslides
Lesser HimalayaHimachal / Middle Himalaya1,000–4,500 mFamous hill stations: Mussoorie, Shimla, Darjeeling, Nainital. Ranges: Pir Panjal, Dhauladhar, Nag Tibba, Mahabharat. Karewas (glacial lake deposits) in Kashmir valley used for saffron cultivation
Greater HimalayaHimadri / Inner Himalaya6,000+ mHighest, oldest, most continuous range; perpetual snow; all major peaks. Everest (8,848 m), Kanchenjunga (8,586 m — India’s highest). Main Himalayan passes for trade
Trans HimalayaTibetan / Tethys Himalaya3,000–7,000 mNorth of main range; Karakoram, Ladakh, Zaskar ranges; K2 (8,611 m) in Karakoram; dry rain-shadow area; Indus and Sutlej rivers originate here (antecedent drainage)

B. Regional Divisions (W to E)

Fig. 2.2 — Regional (West to East) Divisions of the Himalayas
WEST (Indus) EAST (Brah.) Punjab Himalaya Indus to Sutlej J&K, Himachal Dalhousie, Kangra Kumaon Himalaya Sutlej to Kali R. Uttarakhand Nainital, Mussoorie Nepal Himalaya Kali to Tista R. Everest (8,848 m) Widest section Sikkim Himalaya Tista to Dibang R. Kanchenjunga Nathu La pass Assam Himalaya Dibang to Brahmaputra Arunachal Pradesh Densely forested
Topic AHimalayan Passes & Peaks — CDS DirectFrequently Asked
Passes
Zoji La — J&K; connects Srinagar & Leh (NH-1D). Rohtang La — Himachal Pradesh; connects Kullu & Lahul-Spiti. Shipki La — Himachal Pradesh; India-China trade route (Sutlej enters India here). Nathu La — Sikkim; India-China border; reopened for trade 2006. Jelep La — Sikkim; ancient trade route to Tibet. Lipulekh — Uttarakhand; pilgrim route to Kailash-Mansarovar.
Peaks
Mt. Everest (8,848 m) — Nepal Himalaya; world’s highest. K2 / Godwin Austen (8,611 m) — Karakoram; 2nd highest; in Pakistan-administered Kashmir. Kanchenjunga (8,586 m) — Sikkim; India’s highest peak. Nanga Parbat — “Killer mountain”; western end of Himalayas. Namcha Barwa — eastern end of Himalayas.
Rivers
Rivers with antecedent drainage (older than mountains): Indus, Ganga, Brahmaputra. These carved gorges through rising mountains. The Brahmaputra makes a hairpin bend at Namcha Barwa before entering India as Siang → Dihang → Brahmaputra.
GREAT NORTHERN PLAINS

3. The Great Northern Plains

The Northern Plains are formed by the alluvial deposits of three river systems: Indus (west), Ganga (central), and Brahmaputra (east). They extend about 2,400 km east to west and are 240–320 km wide. This is the world’s largest alluvial plain and India’s agricultural heartland.

Fig. 3.1 — Northern Plains: Bhangar vs Khadar & Regional Divisions
Himalayan Foothills Bhabar belt (porous, gravelly) Rivers disappear underground here TERAI Marshy & forested Rivers reappear Dense forests UP, Bihar, Uttarakhand BHANGAR Older alluvium • Higher land Not flooded annually Contains ‘Kankar’ (limestone) Less fertile than Khadar KHADAR Newer alluvium • Flood plain Flooded & renewed annually Very fertile • Fine silt Best for cultivation RIVER Active channel Riverine & deltaic deposits (Delta area) South → (from Himalayas toward river, then south)

🍋 Regional Divisions of Northern Plains

  • Punjab Plains: Formed by Indus & tributaries (5 rivers: Jhelum, Chenab, Ravi, Beas, Sutlej). Doabs (land between two rivers) — most of this is now in Pakistan
  • Ganga Plains: Largest division; stretches from Delhi to West Bengal; Ganga + tributaries (Yamuna, Ghaghra, Gandak, Kosi)
  • Brahmaputra Plains (Assam Valley): Eastern end; extremely fertile; prone to annual flooding; tea gardens
  • Rajasthan Plains: West of Aravalli; semi-arid; merges with Thar Desert

🔭 Key Northern Plains Features

  • Bhabar belt: Porous, rocky belt at Himalayan foothills; rivers sink underground; width 8–16 km
  • Terai belt: Wet, marshy, forested zone south of Bhabar; rivers reappear; fertile agricultural land (sugarcane, rice)
  • Bhangar: Older alluvium above flood level; contains kankar (calcium carbonate nodules); less fertile
  • Khadar: Newer alluvium in flood plains; renewed annually; most fertile; best for cultivation
  • Delta: At river mouths; the Sundarbans delta = world’s largest delta (Ganga-Brahmaputra)
PENINSULAR PLATEAU

4. The Peninsular Plateau

The oldest and most stable landmass of India — a fragment of ancient Gondwana. Composed of ancient crystalline, igneous and metamorphic rocks. Divided into: Central Highlands (north of Narmada) and Deccan Plateau (south of Narmada).

⛰️ Central Highlands (N of Narmada)

  • Malwa Plateau: MP, Rajasthan; formed by Deccan Trap; rivers drain north to Ganga
  • Bundelkhand: UP & MP; granitic rocks; Betwa & Ken rivers
  • Baghelkhand: Eastern MP; limestone plateau; Son River
  • Chota Nagpur Plateau: Jharkhand; rich in minerals (coal, iron, mica, bauxite); “Mineral heartland of India”
  • Aravalli Range: World’s oldest fold mountain; Rajasthan; NE–SW trend; Guru Shikhar (1,722 m) = highest peak in Rajasthan

⛰️ Deccan Plateau (S of Narmada)

  • Triangular block tilted west to east (rivers drain E to Bay of Bengal)
  • Deccan Trap: NW part; formed by extensive lava flows (Cretaceous period); black basaltic soil (Regur) = cotton belt
  • Bounded: Western Ghats (W), Eastern Ghats (E), Satpura range (N), Nilgiris (S junction)
  • Highest peak: Anamudi (2,695 m) in Kerala = highest peak in South India and in peninsular India
  • Rivers: Godavari, Krishna, Mahanadi, Cauvery — all drain east to Bay of Bengal
⚠️ Peninsular Plateau Traps: (1) Anamudi (2,695 m) is the highest peak in peninsular India (Kerala/Cardamom Hills), not a Himalayan peak. (2) Chota Nagpur is the “Mineral heartland of India” — not in South India. (3) Deccan Trap = lava flows from Cretaceous period, NOT Himalayan folding. (4) Narmada & Tapti rivers are unique — they flow westward through rift valleys (unlike other peninsular rivers). (5) Guru Shikhar is Rajasthan’s highest peak (Aravalli hills), not Guru Nanak’s peak.
WESTERN & EASTERN GHATS

5. Western & Eastern Ghats

Fig. 5.1 — Comparison: Western Ghats vs Eastern Ghats
WESTERN GHATS (Sahyadri) Steep ↑ W face Gentle E slope Continuous unbroken range along W coast Length: ~1,600 km • Avg height: 1,000–1,600 m Highest: Anamudi 2,695 m (Kerala) UNESCO WHS • Passes: Thal, Bhor, Pal Ghats EASTERN GHATS Discontinuous; cut by rivers (Mahanadi, Godavari) Lower avg height: 600 m Highest: Mahendragiri 1,501 m (Odisha) Meet at Nilgiri Hills in TN • Doda Betta (2,637 m)
FeatureWestern GhatsEastern Ghats
Other nameSahyadriNo specific name; sometimes called Purva Ghat
ContinuityContinuous, unbroken wall from Gujarat to KeralaDiscontinuous; cut by rivers Mahanadi, Godavari, Krishna, Cauvery
HeightHigher; average 1,000–1,600 mLower; average 600 m
Highest peakAnamudi 2,695 m (Kerala)Mahendragiri 1,501 m (Odisha)
UNESCO WHSYes — Western Ghats declared WHS (2012) and Biodiversity HotspotNo
Meeting pointBoth Ghats meet at Nilgiri Hills (Tamil Nadu). Doda Betta (2,637 m) is the highest point of Nilgiris
COASTAL PLAINS

6. Coastal Plains of India

🌊 Western Coastal Plain

  • Narrower (10–80 km); relatively straight; no major deltas
  • Lies between Western Ghats and Arabian Sea
  • Konkan coast: Maharashtra & Goa (rocky, narrow; Mumbai port)
  • Kanara coast: Northern Karnataka coast
  • Malabar coast: Kerala; backwaters (Kayals) = unique shallow lagoons; cashew & coconut
  • Receives heavy SW monsoon (windward side of W. Ghats)

🌊 Eastern Coastal Plain

  • Wider (100–130 km); deltaic; gentle slope
  • Lies between Eastern Ghats and Bay of Bengal
  • Northern Circars: N. Andhra Pradesh & Odisha coast
  • Coromandel coast: S. Andhra Pradesh & Tamil Nadu; receives NE monsoon
  • Major river deltas: Mahanadi, Godavari, Krishna, Cauvery
  • Chilika Lake (Odisha) = largest coastal lagoon in India
💡 West vs East Coast — Easy Memory: Western = Winding, Wetter (SW monsoon), Wider Ghats but Narrower coast. Eastern = Expansive coast (wider), Enormous deltas, gets NE monsoon. Western coast lacks major deltas because rivers are short & swift. Eastern coast has major deltas from long peninsular rivers.
THAR DESERT & ISLANDS

7. Indian Desert (Thar) & Islands

🏜 Thar Desert

  • Also called Great Indian Desert; located in western Rajasthan & part of Gujarat
  • Area: ~3.2 lakh km² (12th largest desert in world)
  • Arid; receives <150 mm rainfall annually
  • Luni River = only significant river; flows into Rann of Kutch
  • Consists of sand dunes (Erg) and rocky terrain; shifting dunes called barchans
  • Bordered by Aravalli Range on east (no barrier to Arabian Sea on west = dry)
  • Major cities: Jaisalmer (“Golden City”), Barmer, Bikaner

🏖️ Islands of India

  • Andaman & Nicobar Islands: Bay of Bengal; 572 islands; volcanic origin; India’s southernmost point = Indira Point (Great Nicobar). Largest: Middle Andaman. Barren Island = India’s only active volcano. Port Blair = capital
  • Lakshadweep: Arabian Sea; 36 islands (10 inhabited); coral atoll origin; smallest UT of India; Kavaratti = capital. Rich in coconut. Close to Maldives
  • Pamban Island (Rameswaram) — connected to mainland by bridge; Gulf of Mannar
⚠️ Island Traps — Most Tested: (1) Andaman & Nicobar = volcanic islands in Bay of Bengal. (2) Lakshadweep = coral atolls in Arabian Sea. (3) India’s southernmost point = Indira Point (Great Nicobar Island), not Cape Comorin/Kanyakumari (southern tip of mainland). (4) Barren Island (A&N) = India’s only active volcano. (5) Lakshadweep’s capital = Kavaratti, NOT Minicoy. (6) A&N capital = Port Blair (South Andaman Island).

📐 Key Facts Sheet — GC06 Physiography of India

Himalayan Peaks
Everest: 8,848 m (Nepal; world’s highest)
K2: 8,611 m (Karakoram; 2nd highest)
Kanchenjunga: 8,586 m (India’s highest)
Nanga Parbat: western end of Himalayas
Key Passes
Zoji La: J&K (Srinagar – Leh)
Rohtang La: Himachal Pradesh
Shipki La: HP (Sutlej enters India)
Nathu La: Sikkim (India–China trade)
Northern Plains
Length: 2,400 km E–W
Width: 240–320 km
Bhangar = older alluvium (kankar)
Khadar = newer alluvium (most fertile)
Peninsular Plateau Peaks
Anamudi: 2,695 m (highest in peninsular India)
Doda Betta: 2,637 m (Nilgiris, TN)
Mahendragiri: 1,501 m (E. Ghats, Odisha)
Guru Shikhar: 1,722 m (Aravalli, Rajasthan)
Coastal Plains
W. coast: Narrower; Konkan, Kanara, Malabar
E. coast: Wider; N. Circars, Coromandel
Kayals (backwaters): Kerala coast
Chilika Lake: largest coastal lagoon (Odisha)
Islands
A&N Islands: Volcanic; Bay of Bengal
Lakshadweep: Coral atolls; Arabian Sea
Southernmost point: Indira Point (Great Nicobar)
Active volcano: Barren Island (A&N)

📝 Topic-Wise PYQs & Tricky Questions — GC06

Q1. The Nathu La pass is located in which state of India? CDS PYQ
(a) Arunachal Pradesh(b) Himachal Pradesh(c) Sikkim(d) Uttarakhand
✔ Answer: (c) Sikkim
Nathu La (4,310 m) is a mountain pass in the Sikkim Himalayas on the India–China border. It was reopened for trade in 2006 after being closed since the 1962 war. It connects Gangtok (Sikkim) with Tibet. Zoji La is in J&K, Rohtang La and Shipki La are in Himachal Pradesh, and Lipulekh is in Uttarakhand.
Q2. Khadar differs from Bhangar in which of the following ways? CDS PYQ
(a) Khadar is older alluvium found above the flood level(b) Khadar is newer alluvium renewed annually by floods — more fertile(c) Bhangar is found in the active flood plains of rivers(d) Both are equally fertile and occur at the same level
✔ Answer: (b) Khadar is newer alluvium renewed annually by floods — more fertile
Khadar = newer alluvium deposited in active flood plains; renewed by floods each year; fine silt; very fertile; ideal for cultivation. Bhangar = older alluvium; lies above flood level; contains kankar (nodules of calcium carbonate); less fertile than Khadar. This distinction is among the most repeatedly tested Northern Plains facts in CDS.
Q3. Which is the highest peak in South India? ⚡ Tricky
(a) Doda Betta(b) Mahendragiri(c) Anamudi(d) Guru Shikhar
✔ Answer: (c) Anamudi
Anamudi (2,695 m) in Kerala (Cardamom Hills/Anaimalai Hills, part of Western Ghats) is the highest peak in South India and in the entire Peninsular India. Doda Betta (2,637 m) is the highest peak of the Nilgiri Hills (Tamil Nadu). Mahendragiri (1,501 m) is the highest peak of the Eastern Ghats (Odisha). Guru Shikhar (1,722 m) is the highest peak of the Aravalli range (Rajasthan).
Q4. The Lakshadweep Islands are formed by: CDS PYQ
(a) Volcanic activity in the Arabian Sea(b) Coral reef formation (atolls) in the Arabian Sea(c) Submergence of coastal land in the Bay of Bengal(d) River delta deposits
✔ Answer: (b) Coral reef formation (atolls) in the Arabian Sea
Lakshadweep Islands are coral atolls (ring-shaped coral reefs enclosing a lagoon) formed by coral polyps in the warm shallow waters of the Arabian Sea. They are India’s smallest Union Territory. The Andaman & Nicobar Islands, in contrast, are of volcanic origin in the Bay of Bengal. Barren Island in A&N is India’s only active volcano.
Q5. The Duns are longitudinal valleys found in which part of the Himalayas? ⚡ Tricky
(a) Greater Himalaya (Himadri)(b) Lesser Himalaya (Himachal)(c) Shiwalik Hills (Sub-Himalaya)(d) Trans-Himalaya (Karakoram)
✔ Answer: (c) Shiwalik Hills (Sub-Himalaya)
Duns (or Doons) are longitudinal flat-floored valleys found between the Shiwaliks (outermost/southernmost Himalayan range) and the Lesser Himalaya. Famous examples: Dehradun, Kotlidun, Patlidun, Chaukhambu. The word “Doon” in Dehradun comes from this geographical feature. They are formed by river deposits between ridges and are agriculturally fertile.
Q6. The Western Ghats and Eastern Ghats meet at: CDS PYQ
(a) Cardamom Hills(b) Nilgiri Hills(c) Anaimalai Hills(d) Palani Hills
✔ Answer: (b) Nilgiri Hills
The Western Ghats and Eastern Ghats converge at the Nilgiri Hills in Tamil Nadu. The highest point of the Nilgiris is Doda Betta (2,637 m). The Nilgiris are also known for tea cultivation and the Toda tribal community. The Palghat (Palakkad) Gap is a major natural pass in the Western Ghats in this region, connecting Tamil Nadu and Kerala.
Q7. India’s southernmost point, Indira Point, is located on which island? CDS PYQ
(a) Little Andaman(b) Great Nicobar(c) Car Nicobar(d) Katchall Island
✔ Answer: (b) Great Nicobar
Indira Point (also called Pygmalion Point) at the southern tip of Great Nicobar Island is India’s southernmost point (6°45′N latitude). It was submerged slightly due to the 2004 Indian Ocean Tsunami. India’s southernmost point on the mainland is Kanyakumari (Cape Comorin), Tamil Nadu. Do not confuse these two for CDS.
Q8. The Chota Nagpur Plateau is also known as: ⚡ Tricky
(a) Granary of India(b) Mineral heartland of India(c) Garden of India(d) Rice bowl of India
✔ Answer: (b) Mineral heartland of India
Chota Nagpur Plateau (Jharkhand) is called the “Mineral heartland of India” or “Ruhr of India” (like Germany’s industrial Ruhr region) due to its vast deposits of coal, iron ore, mica, bauxite, copper, and uranium. The Damodar Valley is the major coalfield here. Punjab is the “Granary of India”; Kerala is the “Garden of India”; Andhra Pradesh is the “Rice bowl of India.”

🧠 Quick Memory Chart — GC06

🏔️ Himalayan Divisions (S→N)
  • Shiwaliks: outermost; Duns
  • Lesser Himalaya: hill stations
  • Greater Himalaya: highest peaks
  • Trans Himalaya: Karakoram; K2
  • India’s highest: Kanchenjunga
  • World’s highest: Everest (Nepal)
🕔 Key Passes (State)
  • Zoji La: J&K (Srinagar–Leh)
  • Rohtang La: Himachal Pradesh
  • Shipki La: HP (Sutlej enters)
  • Nathu La: Sikkim (China border)
  • Jelep La: Sikkim (Tibet route)
  • Lipulekh: Uttarakhand
🍒 N. Plains Terms
  • Bhabar: porous; rivers sink
  • Terai: marshy; forests
  • Bhangar: old alluvium; kankar
  • Khadar: new alluvium; fertile
  • Length: 2,400 km
  • Largest delta: Sundarbans
⛰️ Plateau Peaks
  • Anamudi: 2,695 m (S. India)
  • Doda Betta: 2,637 m (Nilgiris)
  • Mahendragiri: 1,501 m (E. Ghats)
  • Guru Shikhar: 1,722 m (Aravalli)
  • Chota Nagpur: Mineral heartland
  • Deccan Trap: Black soil; Cotton
🏆 W vs E Coast
  • W. coast: Narrower; No deltas
  • W. coast: Konkan, Kanara, Malabar
  • Kayals (backwaters): Kerala
  • E. coast: Wider; Major deltas
  • E. coast: N. Circars, Coromandel
  • Chilika Lake: largest lagoon (Odisha)
🏖️ Islands
  • A&N: Volcanic; Bay of Bengal
  • Lakshadweep: Coral atolls; Arab Sea
  • Southernmost: Indira Point (Gr. Nicobar)
  • Active volcano: Barren Island
  • A&N capital: Port Blair
  • Lakshadweep capital: Kavaratti
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