Class 11 Geography Chapter 6 – Landforms and Their Evolution Notes
These Landforms and Their Evolution Class 11 Notes explain how different geomorphic agents like running water, groundwater, glaciers, waves and wind shape the Earth’s surface through erosion and deposition. The chapter discusses erosional and depositional landforms along with stages of landscape evolution. (NCERT Pages 47–62)
These notes are highly useful for UPSC, SSC, Railways, State PSC, CUET, CBSE Board Exams and other competitive examinations because geomorphology, landforms and geomorphic processes are frequently asked in Geography and Environment sections. Exact NCERT page references are included throughout the notes for revision and exam preparation. (NCERT Pages 47–62)
Table of Contents
- Chapter Overview
- Landforms and Landscape Evolution
- Running Water
- Evolution of River Valleys
- Erosional River Landforms
- Depositional River Landforms
- Meanders
- Karst Topography
- Glaciers
- Coastal Landforms
- Wind Action and Desert Landforms
- Important Topics
- Geographical Concepts
- Important Questions
- FAQs
- Quick Revision Summary
Chapter Overview
This chapter explains the formation and evolution of landforms through geomorphic processes. It discusses the role of running water, groundwater, glaciers, waves and wind in shaping the Earth’s surface. The chapter also explains various erosional and depositional landforms formed by these agents. (NCERT Pages 47–62)
Major Topics Covered
- Meaning of landforms
- Landscape evolution
- Running water landforms
- Erosional and depositional landforms
- Groundwater and karst topography
- Glacial landforms
- Coastal landforms
- Wind erosion and deposition
- Desert landforms
- Sand dunes
Meaning of Landforms and Landscape Evolution (NCERT Page 47)
Landforms
- Small to medium tracts of Earth’s surface are called landforms.
- Several related landforms together form a landscape.
- Landforms are created by geomorphic processes and agents.
- Landforms continuously change due to erosion and deposition.
Landscape Evolution
- Landforms pass through stages:
- Youth
- Mature
- Old age
- Climatic changes and tectonic movements modify landforms.
Running Water as a Geomorphic Agent (NCERT Pages 47–48)
Running Water
- Most important geomorphic agent in humid regions.
- Causes:
- Erosion
- Transportation
- Deposition
Components of Running Water
| Component | Description |
|---|---|
| Overland Flow | Water flowing as sheet |
| Linear Flow | Streams and rivers |
Evolution of River Valleys (NCERT Pages 48–49)
Valley Development
- Sheet erosion
- Formation of rills
- Development of gullies
- Formation of valleys
River Landscape Stages
| Stage | Features |
|---|---|
| Youth | V-shaped valleys, waterfalls |
| Mature | Wider valleys, meanders |
| Old | Floodplains, oxbow lakes |
Erosional Landforms by Running Water (NCERT Pages 48–49)
Types of Valleys
| Valley Type | Features |
|---|---|
| V-shaped Valley | Narrow and deep |
| Gorge | Deep valley with steep sides |
| Canyon | Deep valley with step-like sides |
Potholes and Plunge Pools
- Circular depressions formed on rocky river beds.
- Created due to abrasion by pebbles and boulders.
- Deep holes at waterfall bases are called plunge pools.
Incised or Entrenched Meanders
- Deep meanders cut into hard rocks.
- Formed due to vertical erosion.
River Terraces
- Old floodplain or valley floor surfaces.
- Indicate former river levels.
Depositional Landforms by Running Water (NCERT Pages 49–51)
Alluvial Fans
- Cone-shaped deposits at foothills.
- Formed when streams enter plains.
Deltas
- Deposits formed where rivers meet sea.
- Deposits are well stratified.
- Distributaries increase with delta growth.
- Fine sediments carried into sea.
Floodplains
- Flat depositional surfaces beside rivers.
- Formed by river deposition during floods.
Associated Features
| Feature | Description |
|---|---|
| Natural Levees | Raised river banks |
| Point Bars | Deposits along meanders |
| Oxbow Lakes | Cut-off meander loops |
Meanders (NCERT Page 51)
- Loop-like river channel patterns.
- Form due to lateral erosion.
Features
- Concave bank → erosion
- Convex bank → deposition
- Deep meanders may form oxbow lakes.
Groundwater and Karst Topography (NCERT Pages 51–54)
Karst Topography
- Formed mainly in limestone and dolomite regions.
- Dominated by:
- Solution
- Deposition
Erosional Karst Landforms
- Sinkholes and dolines
- Lapies
- Caves
Depositional Karst Landforms
| Feature | Description |
|---|---|
| Stalactites | Hang from cave roof |
| Stalagmites | Rise from cave floor |
| Pillars | Form when stalactites and stalagmites join |
Glaciers (NCERT Pages 54–57)
Types of Glaciers
| Type | Description |
|---|---|
| Continental Glacier | Large ice sheet |
| Valley Glacier | Glacier flowing in valleys |
Glacial Erosional Landforms
- Cirques
- Horns
- Arêtes
- U-shaped valleys
- Fjords
Glacial Depositional Landforms
| Type | Description |
|---|---|
| Terminal Moraine | At glacier end |
| Lateral Moraine | Along glacier sides |
| Medial Moraine | Centre of glacier |
| Ground Moraine | Spread over valley floor |
Waves and Currents (NCERT Pages 57–59)
Coastal Processes
- Waves are major coastal geomorphic agents.
- Cause:
- Erosion
- Transportation
- Deposition
Types of Coasts
| Coast Type | Characteristics |
|---|---|
| High Rocky Coast | Erosional landforms dominate |
| Low Sedimentary Coast | Depositional landforms dominate |
Coastal Erosional Landforms
- Sea cliffs
- Wave-cut terraces
- Sea caves
- Sea stacks
Coastal Depositional Landforms
- Beaches
- Coastal dunes
- Bars
- Spits
Wind as a Geomorphic Agent (NCERT Pages 59–61)
Wind Action
- Deflation
- Abrasion
- Impact
Desert Erosional Landforms
- Pediments
- Pediplains
- Playas
- Deflation hollows
- Mushroom rocks
Sand Dunes
| Type | Features |
|---|---|
| Barchans | Crescent-shaped dunes |
| Parabolic Dunes | Vegetation-covered dunes |
| Seif | One-winged dunes |
| Longitudinal Dunes | Long ridges |
| Transverse Dunes | Perpendicular to wind |
Important Topics
| Important Topic | NCERT Page |
|---|---|
| Landscape evolution | 47 |
| Running water erosion | 47–49 |
| Valleys and canyons | 48 |
| Karst topography | 52 |
| Glacial landforms | 54–57 |
| Sand dunes | 60–61 |
Important Geographical Concepts and Terms
| Concept | Explanation | NCERT Page |
|---|---|---|
| Peneplain | Nearly level plain formed by erosion | 48 |
| Gorge | Deep narrow valley | 48 |
| Canyon | Step-sided deep valley | 48 |
| Meander | Loop-like river bend | 51 |
| Karst Topography | Limestone landscape | 52 |
| Cirque | Basin-like glacial hollow | 54 |
| Barchan | Crescent-shaped dune | 61 |
Important Questions
Very Short Answer Questions
- What is a landform? (NCERT Page 47)
- What is a peneplain? (NCERT Page 48)
- Define canyon. (NCERT Page 48)
- What are meanders? (NCERT Page 51)
- What is karst topography? (NCERT Page 52)
- Define stalactites. (NCERT Page 53)
- What is a cirque? (NCERT Page 54)
- What are moraines? (NCERT Page 55)
- What is a fjord? (NCERT Page 55)
- What are barchans? (NCERT Page 61)
Short Answer Questions
- Explain the stages of landscape evolution. (NCERT Pages 47–48)
- Differentiate between gorge and canyon. (NCERT Page 48)
- Explain formation of floodplains. (NCERT Pages 50–51)
- Describe karst topography. (NCERT Pages 52–53)
- Explain formation of stalactites and stalagmites. (NCERT Page 53)
- Describe glacial valleys. (NCERT Page 55)
- Explain coastal depositional landforms. (NCERT Pages 58–59)
- Describe wind action in deserts. (NCERT Pages 59–60)
Long Answer Questions
- Explain the role of running water in shaping landforms. (NCERT Pages 47–51)
- Describe erosional and depositional landforms formed by groundwater. (NCERT Pages 52–53)
- Explain glacial erosional and depositional landforms. (NCERT Pages 54–57)
- Describe coastal landforms formed by waves and currents. (NCERT Pages 57–59)
- Explain erosional and depositional landforms formed by wind. (NCERT Pages 59–61)
FAQs
1. What are geomorphic agents?
Agents like rivers, glaciers, waves and wind that shape Earth’s surface are geomorphic agents. (NCERT Page 47)
2. What is a meander?
A loop-like river bend formed due to lateral erosion is called a meander. (NCERT Page 51)
3. What is karst topography?
Karst topography is limestone landscape formed by groundwater action. (NCERT Page 52)
4. What are moraines?
Moraines are deposits left behind by glaciers. (NCERT Pages 55–56)
5. Which coast of India is depositional in nature?
The east coast of India is depositional in nature. (NCERT Page 58)
Quick Revision Summary
- Landforms evolve through erosion and deposition.
- Running water creates valleys and floodplains.
- Canyons have step-like sides.
- Meanders form due to lateral erosion.
- Karst topography develops in limestone areas.
- Stalactites hang from cave roofs.
- Glaciers create U-shaped valleys.
- Moraines are glacial deposits.
- Waves form cliffs and beaches.
- Wind action includes deflation and abrasion.
- Pediplains are low-relief desert plains.
- Barchans are crescent-shaped dunes.