Earth's Movement: Landforms
Landforms - Landforms are features on the Earth's surface that make up the terrain, such as mountains, valleys, plains or plateau.
Types of Landforms/topography
- Riverine (formed due to the action of river water)
- Karst (formed due to the action of underground water)
- Desert/Arid landform (formed due to the action of wind)
- Marine (formed due to the action of coastal water)
- Glacial (formed due to the action of glacier)
Riverine Landforms
- Agent - River water
- Process involved - Abrasion, Attrition, Corrosion, Cavitation, Hydraulic action
- Erosional Landforms
1. V-Shaped Valley - formed at youth stage
3. Canyon - (formed between youth and mature stage) It's a deep narrow valley with steep side.
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| Great Canyon of Colorado |
Difference between Canyon and Gorge
Gorge
- Formed at youth phase of the river
- Have very narrow valley
- Bit smaller but deeper
- Formed due to vertical erosion
Canyon
- Formed between youth and mature phase of the river
- Comparatively wider
- Comparatively larger, all across its length
- Formed due to both vertical as well as lateral erosion
4. Rapids
5. Cataract - It is like a small waterfall
6. Waterfall
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| Victoria falls |
7. Plunge pool (formed at the base of waterfall)
8. Pot holes (circular depressions along river basin)
9. River Captures (when river changes its course) - When river changes its way and drains into another river due to depositional, resulting in substantial decrease in water flow in original river, it is called river capture.
10. Meander (snake like river course)
Note - Meander causes both erosional as well as depositional features.
On one side of the river - Lateral erosion 🠞 River cliff
On other side of the river - Deposition 🠞 Slip off slope
- Depositional features
1. Slip off slope (it occurs on the inside convex bank of the meandering river)
2. Flood plain (a flat area of land next to river or a stream)
3. Levee (natural embankment along the bank of river due to deposition of sediments)
4. Ox-bow lakes - It's a U-shaped lake formed when a wide meander of river is cut off creating a free standing body of water.
5. Alluvial fan - When river enters from the youth stage to mature stage. It's slope reduced resulting in decrease in velocity. So, it could bot carry all the sediments. Thus, depositing the sediments at the transition zone leading to the formation of Alluvial fan.
6. Delta - Formed at the mouth of the sea due to deposition of sediments. Here, the sediments are very fine.
7. Estuary - formed at the mouth of sea by the river having less sediments
Difference between Estuary and Delta
Estuary -
- Amount of sediment is low & water flow is high 🠞 less sediment deposition (forming estuary)
- Amount of water is high
Delta -
- Amount of sediment is high & water flow is low 🠞 huge sediment deposition (forming delta)
- Amount of sediments is high
Cross-section of river from source to the mouth
Upper Course (Youth Phase) - Mountains
Steep slope 🠞 High energy 🠞 High velocity 🠞 flows straight 🠞 very high degree of erosion (mostly vertical erosion) with almost no deposition.
Middle Course (Mature Stage) - when river just enters the plains
Some slope 🠞 moderate energy 🠞 velocity reduced 🠞 river started to meander 🠞 Erosion (Lateral as well as Vertical) and Deposition
Old Stage - Plains
Almost no slope 🠞 Energy reduced 🠞 Velocity 🠞 Meandering increase 🠞 almost no vertical erosion with high degree of deposition
Previous Article - Exogenic Movements
Next Article - Other Landforms
Notes on other subjects
Optional Notes
Note - This is my Vision IAS Notes (Vision IAS Class Notes) and Ashutosh Pandey Sir's Public Administration Class notes. I've also added some of the information on my own.
Hope! It will help you to achieve your dream of getting selected in Civil Services Examination 👍
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