Source: The Earth: Our Habitat – Class VI Geography, Pages 39–46 Class: VI | Subject: Social Science – Geography
The surface of the earth is not the same everywhere. The earth has an infinite variety of landforms. Some parts of the lithosphere may be rugged and some flat.
| Process | What it Does | Agents |
|---|
| Internal process | Leads to upliftment and sinking of the earth's surface | Forces within the earth |
| External process | Continuous wearing down and rebuilding of the land surface | Running water, ice, wind |
Key Terms:
| Term | Meaning |
|---|
| Erosion | The wearing away of the earth's surface |
| Deposition | The process by which eroded material is dropped and builds up the land surface |
🔑 Broadly, landforms are grouped by elevation and slope into three types: mountains, plateaus and plains.
Section 2. Mountains ⛰️
2.1 What Is a Mountain?
A mountain is any natural elevation of the earth surface. It has a small summit (top), a broad base, and is considerably higher than the surrounding area. Some mountains are even higher than the clouds; climate becomes colder as you go higher.
⚠️ A hill rises higher than the surrounding area. A steep hill with an elevation of more than 600 metres is generally called a mountain.
| Feature | Detail |
|---|
| Glaciers | Permanently frozen rivers of ice found in some mountains |
| Undersea mountains | Some mountains are under the sea and cannot be seen |
| Settlement & Farming | Harsh climate → less people; steep slopes → less farming land |
2.2 Types of Mountains
Mountains may be arranged in a line known as a range. Many mountain systems consist of a series of parallel ranges extending over hundreds of kilometres.
There Are Three Types of Mountains:
| Type | Key Features | Examples |
|---|
| Fold Mountains | Young ones have rugged relief and high conical peaks; old ones have rounded features and low elevation (worn down by erosion) | Young: Himalayas (Asia), Alps (Europe); Old: Aravali (India), Appalachians (North America), Ural (Russia) |
| Block Mountains | Formed when large areas are broken and displaced vertically; uplifted blocks = horsts; lowered blocks = graben | Rhine valley and Vosges mountain in Europe |
| Volcanic Mountains | Formed due to volcanic activity | Mt. Kilimanjaro (Africa), Mt. Fujiyama (Japan) |
2.3 Uses of Mountains
| Use | Detail |
|---|
| Water & energy | Rivers sourced from glaciers; water used for irrigation and hydro-electricity generation |
| Cultivation | River valleys and terraces are ideal for growing crops |
| Forests | Rich flora and fauna; forests provide fuel, fodder, shelter, gum, raisins, etc. |
| Tourism & sports | Scenic beauty attracts tourists; paragliding, hang gliding, river rafting and skiing are popular |
Section 3. Plateaus 🏔️
3.1 What Is a Plateau?
A plateau is an elevated flat land. It is a flat-topped table land standing above the surrounding area.
| Feature | Detail |
|---|
| Sides | May have one or more sides with steep slopes |
| Height | Varies from a few hundred metres to several thousand metres |
Examples of Plateaus:
| Plateau | Location | Special Feature |
|---|
| Deccan Plateau | India | One of the oldest plateaus |
| East African Plateau | Kenya, Tanzania and Uganda | – |
| Western Plateau | Australia | – |
| Tibet Plateau | Asia | Highest plateau in the world; 4,000 to 6,000 metres above mean sea level |
3.2 Uses of Plateaus
| Use | Detail |
|---|
| Mining | Rich in mineral deposits – African plateau (gold, diamonds); Chhotanagpur plateau – India (iron, coal, manganese) |
| Waterfalls | Rivers fall from great heights – Hundru falls (river Subarnarekha, Chhotanagpur); Jog falls (Karnataka) |
| Farming & Tourism | Lava plateaus have fertile black soil; many plateaus have scenic spots for tourists |
Section 4. Plains 🌾
4.1 What Is a Plain?
Plains are large stretches of flat land. They are generally not more than 200 metres above mean sea level.
- Some plains are extremely level; others may be slightly rolling and undulating
- Most plains are formed by rivers and their tributaries
Step 1: Rivers flow down the slopes of mountains and erode them ↓ Step 2: Rivers carry forward the eroded material (stones, sand and silt) ↓ Step 3: Rivers deposit their load along their courses and in their valleys ↓ Result: Plains are formed from these deposits
4.3 Uses and Examples of Plains
| Use | Detail |
|---|
| Farming | Very fertile; highly productive for cultivation |
| Settlement & Transport | Flat land easy for building houses and transport networks |
| Population | Most thickly-populated regions of the world |
🔑 Largest river plains in Asia: Ganga and Brahmaputra (India), Yangtze (China). Some of the largest plains are also found in North America.
🔑 In India, the Indo-Gangetic plains are the most densely populated regions of the country.
- Life is difficult in mountainous areas; plains provide much better conditions for farming, housing and transport
- Natural calamities – earthquakes, volcanic eruptions, storms, floods – cause widespread destruction and huge loss of life and property
- Creative awareness about such events can help lower the risks
Common Confusions ⚠️
| Confusion | Clarification |
|---|
| Mountain vs Hill | A hill rises above surrounding area; a hill with elevation over 600 metres is generally called a mountain. Mountains are considerably higher with small summits and broad bases. |
| Mountain vs Plateau | A mountain has a peak (small summit, broad base). A plateau is flat-topped table land – elevated but with a flat surface, not a peak. |
| Erosion vs Deposition | Erosion = wearing away and removing material. Deposition = dropping and building up that eroded material elsewhere. They are opposites carried out by the same agents (water, ice, wind). |
| Horst vs Graben | In Block Mountains: the uplifted (raised) block is a horst; the lowered (sunken) block is a graben. |
Memory Aids 💡
| What to Remember | Mnemonic / Trick |
|---|
| Three types of mountains | 💡 "F-B-V" → Fold, Block, Volcanic – like three flavours of mountains: Folded paper, Broken blocks, Vomiting lava |
| Horst = raised, Graben = lowered | 💡 Think: Horst = High up. Graben = Goes down (into a grave). |
| Plains are formed by rivers | 💡 Rivers Rob mountains (erosion) and Redecorate valleys (deposition) – plains are their gift to humans. |
| Tibet = highest plateau | 💡 Tibet = Tallest table in the world (4,000–6,000 m above sea level). |
Exam Corner 🎯
Directly from The Earth: Our Habitat, Chapter 6 Exercises (Page 46):
Q1.Answer the Following Questions Briefly:
| Question | Topic Tested | Reference |
|---|
| (a) What are the major landforms? | Three types – mountains, plateaus, plains | p.40 |
| (b) What is the difference between a mountain and a plateau? | Comparison of features | p.40, p.42 |
| (c) What are the different types of mountains? | Fold, Block, Volcanic with examples | p.41 |
| (d) How are mountains useful to man? | Uses of mountains | p.41–42 |
| (e) How are plains formed? | Formation process – rivers, erosion, deposition | p.43 |
| (f) Why are the river plains thickly populated? | Fertile soil, easy transport, flat land | p.43 |
| (g) Why are mountains thinly populated? | Harsh climate, steep slopes, less farming land | p.40 |
Q2.Tick the Correct Answers:
| Question | Correct Answer | Reference |
|---|
| (a) Mountains differ from hills in terms of | (i) elevation | p.39 |
| (b) Glaciers are found in | (i) the mountains | p.40 |
| (c) The Deccan Plateau is located in | (iii) India | p.42 |
| (d) The river Yangtze flows in | (iii) China | p.43 |
| (e) An important mountain range of Europe is | (ii) the Alps | p.41 |
Q3.Fill in the Blanks:
| Blank | Answer | Reference |
|---|
| 1. A ________ is an unbroken flat or a low-level land | Plain | p.43 |
| 2. The Himalayas and Alps are examples of ________ mountains | Fold | p.41 |
| 3. ________ areas are rich in mineral deposits | Plateau | p.42 |
| 4. The ________ is a line of mountains | Range | p.41 |
| 5. The ________ areas are most productive for farming | Plain | p.43 |
Abbreviation Legend
| Abbreviation | Full Form |
|---|
| m | metres |
| MSL | Mean Sea Level |
| Fig. | Figure |
