Theory:

Second-order landforms
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Examples of second order Landforms
  1. Mountains
  2. Plateaus
  3. Plains
1. Mountains
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  • Mountains are landforms that are 600 meters above its surroundings.
  • Made of steep slopes
  • They are found as individual or in groups.
  • Mountain ranges extends for a large area continuously (hundreds or thousands of kilometer).
Important!
Peak: The highest point of a mountain.
  Examples:
  
Mountain Range
Continent
HimalayaAsia
Rocky MountainsNorth America
AndesSouth America
 
The longest mountain range in the world: The Andes (7,000 km)
The highest peak in the world: Mt. Everest (8,848 m)
  • December 11 is noted as the International Mountain Day.
  • Hill Stations in Tamil Nadu: Udhagamandalam, Kodaikanal, Kolli hills, Yercaud and Yelagiri.
2. Plateaus
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Plateaus: the elevated portions of the Earth that have flat surfaces sorrounded by steep slopes.
  • Elevation of plateaus: few hundred meters or several thousand meters
  • The highest plateau in the world: Tibetan Plateau
  • Tibetan plateau is also called as the ‘Roof of the world’.
  • The flat-topped part of the plateau is called Tableland.
  • The plateaus are generally mineral-rich in nature.
  • The Chotanagpur Plateau is one of plateaus in India, i.e. rich in minerals.
  • Mining is one of the major activities of the people living here.
  • The Deccan Plateau is an example of volcanic plateau, i.e. volcanic origin.
Plateaus in Tamil Nadu: Dharmapuri Plateau, Coimbatore Plateau and Madurai Plateau
3. Plains
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  • Flat and relatively low-lying lands.
  • Usually less than \(200\) meters above sea level.
  • Maybe they are rolling or undulating sometimes.
  • Most plains are formed byrivers and their tributaries and distributaries.
  • Due to fertile soil deposited by rivers, they are extensively used for agriculture.
  • Most suitable topography for human inhabitation, therefore highly populated.
  • The plains have been the cradle of civilisations from the earliest times.
For example:
  
Civilisation
River
Country
Indus
Indus
India
Nile valley
Nile
Egypt
Mesopotamian
Tigris–Euphrates
West Asia
Important plains in Tamil Nadu: Cauvery and Vaigai.
Important!
Indo-Gangetic plain is one of the largest plains in the world.
Coastal plains: Low lying lands adjacent to oceans and seas
Third-order landforms
  • These landforms are formed as a result of erosional and depositional activities of rivers, glaciers, winds, and waves on mountains, plateaus, and plains.
  • Example: Valleys, beaches and sand dunes
Valley
Beach
Sand dunes
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  • The process of removal of surface material from the Earth's crust is known as erosion.
  • The transportation and deposition of eroded materials on the low lying areas is known as deposition.