This article deals with ‘Plains.’ This is part of our series on ‘Geography’ which is important pillar of GS-1 syllabus . For more articles , you can click here
- Plain is an extensive tract of flat and or a gently undulating terrain without prominent hills or depressions.
- They are formed both by internal forces of the Earth and by external processes of aggradation and degradation.
- They range in size from very small to a very large areas.
- The great centres of population of the world are on plains. Development of means of communications and transportation facilities is easier in the plains. Hence, these are best known areas for human habitation.
Types of Plains
Plains are best classified according to their origin
1 . Diastrophic Plains
- Plains formed on regions that were once submerged under ocean or sea.
- Example : Great plains of U.S.A which extend till Canada were formed due to upliftment submerged landmasses under epicontinental seas and were uplifted at the end of Cretaceous period to due tectonic movements . They have deposits of horizontal thick beds of Marine sediments
- Undulating surface of low relief, interspersed with occasional residual hills and claimed to have been formed due to erosion by rivers and rain.
- Example include East Central Africa
3. Flood Plains
- Flood Plain is that part of river valley adjacent to the channel, over which a river flows in times of floods.
- Floodplain is composed of Alluvium
- Examples : Indo-Gangetic plain and the plains of Mississippi, Amazon, Nile, Hwang-Ho, Yangtze Ob, , Lena, Volga rivers
4. Delta Plains
- As rivers draw near seas to disappear in them, their flow goes dead slow. It necessities the waters to deposit all types of materials being carried by it. Such depositions are made in triangular shape which resembles to Greek word ‘Delta’.
- These plains are the most fertile plains of the world.
- Examples : Sundarbans of Ganga and Brahmaputra, Deltas of Nile and Mississippi etc.
5. Aeolian Plains
- Aeolian plains are plains formed by either erosive or depositional action of winds
- Sahara and Thar
- Plains formed by filling of lakes in Kashmir and Manitoba (Canada)
- Lava plains of Idaho (U.S.A.)
- Plains of Mecca & Medina
Importance of Plains
- Plains are the ‘cradles of civilizations’ and the ‘food baskets’ of the world with 80% of population living in plains, i.e., Prairies (U.S.A), Steppes, Pustaz (Europe), Veld (South Africa), Great Indo-Gangetic Plains of India, Downs (Australia), Canterbury plains of New Zealand
- Undulating and fertile land of plains is beneficial for conducting agricultural activities and irrigation
- Developing means of transport like building roads, lying railways, preparing air strips etc. is easy in plains.
- Industry and other commercial activities are more easy to be carried out in plains.