Plain
In geography, a plain is a flat, sweeping landmass that generally does not change much in elevation. Plains occur as lowlands along valleys or on the doorsteps of mountains, as coastal plains, and as plateaus or uplands.
In a valley, a plain is enclosed on two sides, but in other cases a plain may be delineated by a complete or partial ring of hills, by mountains, or by cliffs. Where a geological region contains more than one plain, they may be connected by a pass. Coastal plains would mostly rise from sea level until they run into elevated features such as mountains or plateaus.
Plains are one of the major landforms on earth, where they are present on all continents, and would cover more than one-third of the world's land area. Plains may have been formed from flowing lava, deposited by water, ice, wind, or formed by erosion by these agents from hills and mountains. Plains would generally be under the grassland, steppe, savannah or tundra biomes. In a few instances, deserts and rainforests can also be plains.
Plains in many areas are important for agriculture because where the soils were deposited as sediments they may be deep and fertile, and the flatness facilitates mechanization of crop production; or because they support grasslands which provide good grazing for livestock.
Types of plain
Depositional plains
The types of depositional plains include:- Abyssal plains, flat or very gently sloping areas of the deep ocean basin.
- Planitia, the Latin word for plain, is used in the naming of plains on extraterrestrial objects, such as Hellas Planitia on Mars or Sedna Planitia on Venus.
- Alluvial plains, which are formed by rivers and which may be one of these overlapping types:
- * Alluvial plains, formed over a long period of time by a river depositing sediment on their flood plains or beds, which become alluvial soil. The difference between a flood plain and an alluvial plain is: a flood plain represents areas experiencing flooding fairly regularly in the present or recently, whereas an alluvial plain includes areas where a flood plain is now and used to be, or areas which only experience flooding a few times a century.
- * Flood plain, adjacent to a lake, river, stream, or wetland that experiences occasional or periodic flooding.
- * Scroll plain, a plain through which a river meanders with a very low gradient.
- Glacial plains, formed by the movement of glaciers under the force of gravity:
- * Outwash plain, a glacial out-wash plain formed of sediments deposited by melt-water at the terminus of a glacier. Sandar consist mainly of stratified gravel and sand.
- * Till plains, plain of glacial till that form when a sheet of ice becomes detached from the main body of a glacier and melts in place depositing the sediments it carries. Till plains are composed of unsorted material of all sizes.
- Lacustrine plains, plains that originally formed in a lacustrine environment, that is, as the bed of a lake.
- Lava plains, formed by sheets of flowing lava.
Erosional plains
Structural plains
Structural plains are relatively undisturbed horizontal surfaces of the Earth. They are structurally depressed areas of the world that make up some of the most extensive natural lowlands on the Earth's surface.dominates the eastern horizon of the Maniototo Plain
, on the North American Great Plains
Notable examples
Americas
Caribbean and South America
- Altiplano
- Altiplano Cundiboyacense
- Caroni Plain
- Chilean Central Valley
- *
- * Los Llanos
- Gran Chaco
- Los Llanos
- * Venezuelan Llanos
- Pampas
- Coastal plains of Chile
North America
- Atlantic coastal plain
- Carrizo Plain
- Great Plains
- Gulf Coastal Plain
- Interior Plains
- Lake Superior Lowland
- Laramie Plains
- Mississippi Alluvial Plain
- Oxnard Plain
- Snake River Plain
Asia
Eastern Asia
- Chianan Plain
- Depsang Plains
- Kantō Plain
- Kedu Plain
- Kewu Plain
- Mallig Plains
- Nōbi Plain
- North China Plain
- Osaka Plain
- Pingtung Plain
- Sarobetsu plain
- West Siberian Plain
- Yilan Plain
South Asia
- Bhuikhel
- Depsang Plains
- Dooars
- Eastern coastal plains
- Indo-Gangetic Plains
- More plains
- North Bengal plains
- Punjab Plains
- Terai
- Utkal Plains
- Western coastal plains
Western Asia
- Al-Ghab Plain
- Aleppo plateau
- Ararat plain
- Israeli coastal plain
- Khuzestan Plain
- Mugan plain
- Nineveh Plains
- Shiraki Plain
Europe
Central Europe
- Limagne
- North German Plain
- Ochsenfeld
- Pannonian Basin
- Parndorf Plain
- Westphalian Lowland
Eastern Europe
- Bărăgan Plain
- Danubian Plain
- Dnieper Lowland
- East European Plain
- European Plain
- Great Hungarian Plain
- Kosovo field
- Little Hungarian Plain
- Pannonian Steppe
- Polesian Lowland
- Upper Thracian Plain
- Wallachian Plain
Northern Europe
- Cheshire Plain
- Hardangervidda
- Kaffiøyra
- Muddus plains
- North European Plain
- North Northumberland Coastal Plain
- North Somerset Levels
- Salisbury Plain
- Solway Plain
- Somerset Levels
- South Coast Plain
- South Småland peneplain
- Stora Alvaret
- Strandflat
- Sub-Cambrian peneplain
- * Central Swedish lowland
- * Ostrobothnian Plain
- The Fylde
Southern Europe
- Agro Nocerino Sarnese
- Campidano
- Lelantine Plain
- Mesaoria
- Messara Plain
- Nurra
- Po Valley
- Rieti Valley
- Tavoliere delle Puglie
Oceania