GeographyCBSE Class 11 · Structure and Physiography

The Peninsular Plateau, Desert, Coastal Plains and Islands (Class 11 Geography, India: Physical Environment, Chapter 2)

Updated 17 October 2026 · Fact-checked

The Peninsular Plateau is one of the oldest, most stable landmasses with two broad divisions: the Central Highlands and the Deccan Plateau, with the North-eastern (Shillong and Karbi Anglong) plateau as an extension. The Indian Desert lies north-west of the Aravali; the western coastal plain is submerged and narrow, the eastern emergent and broad with deltas; Andaman and Nicobar are elevated submarine mountains while Lakshadweep is entirely of coral.

Understand The Peninsular Plateau, the Indian Desert, the Coastal Plains and the Islands of India

Why this topic matters. Ghats comparison, western versus eastern coast and the two island groups are standard comparison questions with map work.

1. Peninsular Plateau. An irregular triangle rising from 150 m above the river plains to 600 to 900 m, bounded by the Delhi ridge, Rajmahal hills, Gir range and Cardamom hills, with the Shillong and Karbi Anglong plateau as its north-eastern extension. It is one of the oldest and most stable landmasses, with tors, block mountains, rift valleys, hummocky hills and wall-like quartzite dykes; black soil is found in the west and north-west, and the general slope is from west to east.

2. Deccan Plateau. Bordered by the Western Ghats in the west, Eastern Ghats in the east and the Satpura, Maikal and Mahadeo hills in the north. The Western Ghats are higher and more continuous (average 1,500 m, rising north to south), with Anaimudi (2,695 m) the highest peak of the peninsula and Dodabetta (2,637 m) in the Nilgiris; they are the source of most Peninsular rivers. The Eastern Ghats are discontinuous and low, cut by the Mahanadi, Godavari, Krishna and Kaveri. The two meet at the Nilgiri hills.

3. Central Highlands. Bounded west by the Aravali; the Satpura forms the northern boundary of the Deccan; elevation 700 to 1,000 m, sloping north and north-east; the Rajmahal hills are the eastern extension and the Chotanagpur plateau holds large mineral reserves.

4. North-eastern Plateau. An extension of the main plateau, separated by a fault between the Rajmahal hills and the Meghalaya plateau that was later filled by river deposits; Meghalaya and Karbi Anglong are rich in coal, iron ore, sillimanite, limestone and uranium.

5. Indian Desert. North-west of the Aravali: the Marusthali, with longitudinal dunes and barchans, rainfall below 150 mm a year, and arid conditions. It was under the sea in the Mesozoic era (wood fossils at Aakal and marine deposits near Brahmsar). Wind and weathering produce mushroom rocks and shifting dunes, with oases mostly in the south.

6. Coastal plains. The western plain is submerged, narrow, with natural ports (Kandla, Mazagaon, Marmagao, Mangalore, Cochin), no deltas, and the Malabar kayals. The eastern plain is emergent and broader, with well-developed deltas (Mahanadi, Godavari, Krishna, Kaveri) and fewer ports because the continental shelf extends up to 500 km into the sea.

7. Islands. Andaman and Nicobar (Bay of Bengal): about 572 islands, elevated portions of submarine mountains, some volcanic (Barren Island is India's only active volcano), separated by the Ten Degree Channel. Lakshadweep and Minicoy (Arabian Sea): about 36 islands, 11 inhabited, entirely coral; the Eleven Degree Channel divides the Amini and Cannanore groups, and the Nine Degree Channel separates Minicoy, the largest island, from the main group.

The Peninsular Plateau, the Indian Desert, the Coastal Plains and the Islands of India: key facts

Peninsular Plateau: Height 600 to 900 m
Slope west to east
Central Highlands, Deccan Plateau (+ North-eastern extension); Oldest, stable landmass.
Ghats: Western Ghats: average 1,500 m, Anaimudi 2,695 m, Dodabetta 2,637 m
Eastern Ghats: discontinuous, low
Meet at Nilgiri; Compare the two.
Coastal plains: West: submerged, narrow, ports, no deltas | East: emergent, broad, deltas, shelf up to 500 km; West and east.
Islands: Andaman and Nicobar about 572, Ten Degree Channel
Lakshadweep about 36, coral, Eleven Degree Channel between Amini and Cannanore, Nine Degree Channel between Minicoy and the main group
Barren Island: active volcano; Two groups.

How to answer The Peninsular Plateau, the Indian Desert, the Coastal Plains and the Islands of India questions

A west-versus-east comparison is answered in a table.

1Use the same rows for both sides: type, width, ports, deltas.
2Give the reason for ports on the west (submerged, natural harbours).
3Give the reason for fewer ports on the east (wide continental shelf).
4Close with an example of each.

The Peninsular Plateau, the Indian Desert, the Coastal Plains and the Islands of India in real life

The idea, met in an everyday situation. Answer the question in your own words, then compare with the model answer. The one-line hook is what to remember.

Harbour or delta

Suppose a country needs sheltered deep harbours on one coast and fertile river deltas on the other.

Which Indian coasts fit these?

Try it first, then show the solutionSolution

Submerged west coast gives natural harbours.
Emergent east coast has the deltas of the Godavari and Krishna.

Answer: West for harbours; east for deltas.

Memory hook: West ports, east deltas.

Coral island

Suppose a small low island of coral sand lies 300 km off the coast and has storm beaches of pebbles and boulders on its eastern side.

Which Indian island group is this similar to?

Try it first, then show the solutionSolution

Entirely coral deposits and storm beaches on the eastern seaboard.
These are features of Lakshadweep.

Answer: Lakshadweep and Minicoy.

Memory hook: Coral means Lakshadweep.

Tricks to remember The Peninsular Plateau, the Indian Desert, the Coastal Plains and the Islands of India

Short memory aids. Say each one aloud once, then use it on a question the same day.

Anaimudi 2,695
Highest peak of the peninsula; Dodabetta 2,637
Use it when: Peaks.
West submerged, East emergent
Ports on the west, deltas on the east
Use it when: Coasts.
10 and 9
Ten Degree Channel for Andaman, Nine Degree for Lakshadweep
Use it when: Channels.

The Peninsular Plateau, the Indian Desert, the Coastal Plains and the Islands of India: solved examples

Ordered from board level to HOTS. Try each one before you open the solution.

Example 1: Active volcano · 1 mark · MCQBoard level

India's only active volcano is on:
(A) Great Nicobar
(B) Barren Island
(C) Minicoy
(D) Saddle Peak

Try it first, then show the solutionSolution

Barren Island is the only active volcano (1 mark).

Answer: (B)

Example 2: Two Ghats · 2 marks · Very short answerBoard level

Name two differences between the Western and Eastern Ghats. (2 marks)

Try it first, then show the solutionSolution

Western Ghats are higher and continuous (1 mark).
Eastern Ghats are discontinuous and low, cut by rivers (1 mark).

Answer: The Western Ghats are higher (average 1,500 m) and continuous, while the Eastern Ghats are low and discontinuous, eroded by the Mahanadi, Godavari, Krishna and Kaveri.

Example 3: Western versus eastern coastal plains · 3 marks · Short answerHarder board level

Compare the western and eastern coastal plains on type, ports and deltas. (3 marks)

Try it first, then show the solutionSolution

West is submerged and narrow; east is emergent and broader (1 mark).
West has natural ports and harbours; east has fewer ports as the continental shelf extends up to 500 km (1 mark).
West has no deltas; east has well-developed deltas of the Mahanadi, Godavari, Krishna and Kaveri (1 mark).

Answer: The western plain is submerged and narrow, with natural harbours such as Kandla, Marmagao and Cochin, and has no deltas. The eastern plain is emergent and broader, has fewer ports because the continental shelf extends up to 500 km into the sea, and has well-developed deltas of the Mahanadi, Godavari, Krishna and Kaveri.

Example 4: Assertion and reason: Lakshadweep · 1 mark · Assertion-reasonHarder board level

Assertion (A): Lakshadweep is made entirely of coral deposits.
Reason (R): The Andaman and Nicobar group is made of elevated portions of submarine mountains.
(A) Both true, R explains A
(B) Both true, R does not explain A
(C) A true, R false
(D) A false, R true

Try it first, then show the solutionSolution

Both statements are true but R describes a different group and does not explain the coral origin (1 mark).

Answer: (B)

Example 5: HOTS: desert under the sea · 5 marks · Long answerHOTS / competency

The Indian Desert shows wood fossils at Aakal about 180 million years old and marine deposits near Brahmsar, yet it is arid today. Explain what this tells us, how the present surface features formed, and why the rock below is still linked to the Peninsular plateau. (5 marks)

Try it first, then show the solutionSolution

Marine deposits show the area was under the sea in the Mesozoic era (1 mark).
Wood fossils show land conditions at times, about 180 million years ago (1 mark).
Present arid conditions with rainfall below 150 mm (1 mark).
Wind and physical weathering carved mushroom rocks, shifting dunes and oases (1 mark).
The underlying rock is an extension of the Peninsular plateau (1 mark).

Answer: Marine deposits near Brahmsar show that the area was once under the sea in the Mesozoic era, and the 180-million-year-old wood fossils at Aakal record earlier life there. Today it is arid, with rainfall below 150 mm. Physical weathering and wind have carved the surface into mushroom rocks, longitudinal dunes and barchans, with oases mostly in the south. The underlying rock, however, is an extension of the Peninsular plateau.

Where students lose marks in The Peninsular Plateau, the Indian Desert, the Coastal Plains and the Islands of India

The slips examiners see most often, and what to write instead.

Mistake: Saying the Eastern Ghats are higher than the Western Ghats
Order swapped.
Wrong working
Eastern Ghats are higher and continuous.
Right working
Western Ghats are higher and continuous; Eastern are low and discontinuous.
Do this: Remember W is Wall.
Usually costs: 1 mark.
Mistake: Placing deltas on the western coast
East-flowing rivers forgotten.
Wrong working
The west coast has large deltas.
Right working
West coast has no deltas; east coast has the four deltas.
Do this: Learn four deltas of the east.
Usually costs: 1 mark.
Mistake: Calling Lakshadweep volcanic
Mixing with Barren Island.
Wrong working
Lakshadweep is volcanic.
Right working
Lakshadweep is entirely coral; Barren Island (Andaman) is the active volcano.
Do this: Coral for Lakshadweep.
Usually costs: 1 mark.

Exam tips

Use two columns for west and east coasts and for Andaman and Lakshadweep.
Quote heights exactly: Anaimudi 2,695 m, Dodabetta 2,637 m.
Mark the coastal divisions (Konkan, Malabar, Coromandel, Northern Circars) on a map.

Practice questions on The Peninsular Plateau, the Indian Desert, the Coastal Plains and the Islands of India

Write each answer on paper first. Open the hint only if you are stuck, and the answer only when you have finished.

Q1 · 1 mark · MCQBoard level
The highest peak of the Peninsular plateau is:
(A) Dodabetta
(B) Anaimudi
(C) Mahendragiri
(D) Saddle Peak
Hint
Anaimalai.
Answer
(B)
Q2 · 2 marks · Very short answerBoard level
Which channel separates the Andaman from the Nicobar islands, and which separates Amini and Cannanore islands? (2 marks)
Hint
Degree channels.
Answer
The Ten Degree Channel separates the Andaman and Nicobar groups; the Eleven Degree Channel separates Amini (north) from Cannanore (south) in Lakshadweep. The Nine Degree Channel separates Minicoy from the main Lakshadweep group.
Q3 · 3 marks · Short answerHarder board level
Describe the features of the Central Highlands. (3 marks)
Hint
Aravali, Satpura.
Answer
The Central Highlands are bounded on the west by the Aravali, with the Satpura forming the northern boundary of the Deccan. Elevation is 700 to 1,000 m sloping north and north-east, and they have metamorphic rocks such as marble, slate and gneiss. The Rajmahal hills form the eastern extension.
Q4 · 3 marks · Short answerHarder board level
Give three features of the Indian Desert. (3 marks)
Hint
Rainfall, dunes, fossils.
Answer
It lies north-west of the Aravali; rainfall is below 150 mm a year; it has longitudinal dunes and barchans, mushroom rocks and oases mostly in the south; it was under the sea in the Mesozoic era, shown by wood fossils at Aakal and marine deposits near Brahmsar.
Q5 · 4 marks · Short answerHOTS / competency
The east coast has well-developed deltas but fewer ports than the west coast. Explain both facts and name two deltas. (4 marks)
Hint
Emergent coast, wide shelf.
Answer
The eastern plain is emergent and broader, and rivers flowing east build deltas such as those of the Mahanadi and Godavari. The continental shelf extends up to 500 km into the sea, so natural harbours are fewer. The western plain is submerged and offers natural conditions for ports.

Test your recall

Answer in your head or on paper first, then open the card. Pulling an answer out of memory makes it stick far better than re-reading.

1.Highest peak of the peninsula?Show answer
Anaimudi, 2,695 m.
2.Where do the two Ghats meet?Show answer
At the Nilgiri hills.
3.Which coast has kayals?Show answer
The Malabar coast.
4.How many islands in Lakshadweep group?Show answer
About 36.

The Peninsular Plateau, the Indian Desert, the Coastal Plains and the Islands of India: frequently asked questions

What is a quartzite dyke?

A wall-like rock structure in the plateau that serves as a natural water storage site.

Why is the western plain narrow?

It is a submerged coast, narrow in the middle and broader in north and south.

What is Minicoy?

The largest island of the Lakshadweep group, 453 sq km.