Plain
Overview
 
In geography
Geography
Geography is the science that studies the lands, features, inhabitants, and phenomena of Earth. A literal translation would be "to describe or write about the Earth". The first person to use the word "geography" was Eratosthenes...

, a plain is land
Landscape
Landscape comprises the visible features of an area of land, including the physical elements of landforms such as mountains, hills, water bodies such as rivers, lakes, ponds and the sea, living elements of land cover including indigenous vegetation, human elements including different forms of...

 with relatively low relief, that is flat or gently rolling. Prairie
Prairie
Prairies are considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and grasses, herbs, and shrubs, rather than trees, as the dominant vegetation type...

s and steppe
Steppe
In physical geography, steppe is an ecoregion, in the montane grasslands and shrublands and temperate grasslands, savannas, and shrublands biomes, characterized by grassland plains without trees apart from those near rivers and lakes...

s are types of plains, and the archetype
Archetype
An archetype is a universally understood symbol or term or pattern of behavior, a prototype upon which others are copied, patterned, or emulated...

 for a plain is often thought of as a grassland
Grassland
Grasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...

, but plains in their natural state may also be covered in shrubland
Shrubland
Shrubland, scrubland, scrub or brush is a plant community characterized by vegetation dominated by shrubs, often also including grasses, herbs, and geophytes. Shrubland may either occur naturally or be the result of human activity...

s, woodland
Woodland
Ecologically, a woodland is a low-density forest forming open habitats with plenty of sunlight and limited shade. Woodlands may support an understory of shrubs and herbaceous plants including grasses. Woodland may form a transition to shrubland under drier conditions or during early stages of...

 and forest
Forest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...

, or vegetation may be absent in the case of sandy or stony plains in hot deserts. Types of flatlands for which the term is not generally used include those covered entirely and permanently by swamp
Swamp
A swamp is a wetland with some flooding of large areas of land by shallow bodies of water. A swamp generally has a large number of hammocks, or dry-land protrusions, covered by aquatic vegetation, or vegetation that tolerates periodical inundation. The two main types of swamp are "true" or swamp...

s, marsh
Marsh
In geography, a marsh, or morass, is a type of wetland that is subject to frequent or continuous flood. Typically the water is shallow and features grasses, rushes, reeds, typhas, sedges, other herbaceous plants, and moss....

es, playa
Dry lake
Dry lakes are ephemeral lakebeds, or a remnant of an endorheic lake. Such flats consist of fine-grained sediments infused with alkali salts. Dry lakes are also referred to as alkali flats, sabkhas, playas or mud flats...

s, or ice sheet
Ice sheet
An ice sheet is a mass of glacier ice that covers surrounding terrain and is greater than 50,000 km² , thus also known as continental glacier...

s.

Plains occur as lowland
Lowland
In physical geography, a lowland is any broad expanse of land with a general low level. The term is thus applied to the landward portion of the upward slope from oceanic depths to continental highlands, to a region of depression in the interior of a mountainous region, to a plain of denudation, or...

s and at the bottoms of valley
Valley
In geology, a valley or dale is a depression with predominant extent in one direction. A very deep river valley may be called a canyon or gorge.The terms U-shaped and V-shaped are descriptive terms of geography to characterize the form of valleys...

s but also on plateau
Plateau
In geology and earth science, a plateau , also called a high plain or tableland, is an area of highland, usually consisting of relatively flat terrain. A highly eroded plateau is called a dissected plateau...

s at high elevation
Elevation
The elevation of a geographic location is its height above a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational surface ....

s.
Encyclopedia
In geography
Geography
Geography is the science that studies the lands, features, inhabitants, and phenomena of Earth. A literal translation would be "to describe or write about the Earth". The first person to use the word "geography" was Eratosthenes...

, a plain is land
Landscape
Landscape comprises the visible features of an area of land, including the physical elements of landforms such as mountains, hills, water bodies such as rivers, lakes, ponds and the sea, living elements of land cover including indigenous vegetation, human elements including different forms of...

 with relatively low relief, that is flat or gently rolling. Prairie
Prairie
Prairies are considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and grasses, herbs, and shrubs, rather than trees, as the dominant vegetation type...

s and steppe
Steppe
In physical geography, steppe is an ecoregion, in the montane grasslands and shrublands and temperate grasslands, savannas, and shrublands biomes, characterized by grassland plains without trees apart from those near rivers and lakes...

s are types of plains, and the archetype
Archetype
An archetype is a universally understood symbol or term or pattern of behavior, a prototype upon which others are copied, patterned, or emulated...

 for a plain is often thought of as a grassland
Grassland
Grasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...

, but plains in their natural state may also be covered in shrubland
Shrubland
Shrubland, scrubland, scrub or brush is a plant community characterized by vegetation dominated by shrubs, often also including grasses, herbs, and geophytes. Shrubland may either occur naturally or be the result of human activity...

s, woodland
Woodland
Ecologically, a woodland is a low-density forest forming open habitats with plenty of sunlight and limited shade. Woodlands may support an understory of shrubs and herbaceous plants including grasses. Woodland may form a transition to shrubland under drier conditions or during early stages of...

 and forest
Forest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...

, or vegetation may be absent in the case of sandy or stony plains in hot deserts. Types of flatlands for which the term is not generally used include those covered entirely and permanently by swamp
Swamp
A swamp is a wetland with some flooding of large areas of land by shallow bodies of water. A swamp generally has a large number of hammocks, or dry-land protrusions, covered by aquatic vegetation, or vegetation that tolerates periodical inundation. The two main types of swamp are "true" or swamp...

s, marsh
Marsh
In geography, a marsh, or morass, is a type of wetland that is subject to frequent or continuous flood. Typically the water is shallow and features grasses, rushes, reeds, typhas, sedges, other herbaceous plants, and moss....

es, playa
Dry lake
Dry lakes are ephemeral lakebeds, or a remnant of an endorheic lake. Such flats consist of fine-grained sediments infused with alkali salts. Dry lakes are also referred to as alkali flats, sabkhas, playas or mud flats...

s, or ice sheet
Ice sheet
An ice sheet is a mass of glacier ice that covers surrounding terrain and is greater than 50,000 km² , thus also known as continental glacier...

s.

Plains occur as lowland
Lowland
In physical geography, a lowland is any broad expanse of land with a general low level. The term is thus applied to the landward portion of the upward slope from oceanic depths to continental highlands, to a region of depression in the interior of a mountainous region, to a plain of denudation, or...

s and at the bottoms of valley
Valley
In geology, a valley or dale is a depression with predominant extent in one direction. A very deep river valley may be called a canyon or gorge.The terms U-shaped and V-shaped are descriptive terms of geography to characterize the form of valleys...

s but also on plateau
Plateau
In geology and earth science, a plateau , also called a high plain or tableland, is an area of highland, usually consisting of relatively flat terrain. A highly eroded plateau is called a dissected plateau...

s at high elevation
Elevation
The elevation of a geographic location is its height above a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational surface ....

s. 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 cliffs. Where a geological region contains more than one plain, they may be connected by a pass (sometime termed a gap). Plains may have been formed from flowing lava
Lava
Lava refers both to molten rock expelled by a volcano during an eruption and the resulting rock after solidification and cooling. This molten rock is formed in the interior of some planets, including Earth, and some of their satellites. When first erupted from a volcanic vent, lava is a liquid at...

, deposited by water, ice or wind, or formed by erosion
Erosion
Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...

 by these agents from hills and mountains.

Plains in many areas are important for agriculture
Agriculture
Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...

, because where the soils were deposited as sediment
Sediment
Sediment is naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particle itself....

s 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
Livestock
Livestock refers to one or more domesticated animals raised in an agricultural setting to produce commodities such as food, fiber and labor. The term "livestock" as used in this article does not include poultry or farmed fish; however the inclusion of these, especially poultry, within the meaning...

.

Types of terrestrial plains

  • Coastal plain
    Coastal plain
    A coastal plain is an area of flat, low-lying land adjacent to a seacoast and separated from the interior by other features. One of the world's longest coastal plains is located in eastern South America. The southwestern coastal plain of North America is notable for its species diversity...

    , an area of low-lying land adjacent to a sea; the term is used especially where they contrast with hills, mountains or plateau further inland.
  • Alluvial plains are formed by rivers, and may be one of these overlapping types:
    • Flood plain, adjacent to a stream, river, lake or wetland that experiences occasional or periodic flooding.
    • Alluvial plain
      Alluvial plain
      An alluvial plain is a relatively flat landform created by the deposition of sediment over a long period of time by one or more rivers coming from highland regions, from which alluvial soil forms...

      , formed over a long period of time by a river
      River
      A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

       depositing sediment on its floodplain or bed which becomes alluvial soil. The difference between a floodplain and an alluvial plain is that the floodplain represents the area experiencing flooding fairly regularly in the present or recently, whereas an alluvial plain includes areas where the floodplain is now and used to be, or areas which only experience flooding a few times a century.
    • Scroll plain
      Scroll plain
      A scroll plain occurs where a river meanders across an area with a very low gradient, usually with a fairly continuous discharge. In addition to meanders, scroll plains are also characterised by many oxbow lakes.-New Zealand:...

      , a plain through which a river meander
      Meander
      A meander in general is a bend in a sinuous watercourse. A meander is formed when the moving water in a stream erodes the outer banks and widens its valley. A stream of any volume may assume a meandering course, alternately eroding sediments from the outside of a bend and depositing them on the...

      s with a very low gradient.
  • Lacustrine plain
    Lacustrine plain
    Some lakes get filled up by the sediments brought down by the rivers and turn into plains in the course of time. Such plains are called lacustrine plains...

    , a plain that originally formed in a lacustrine environment, that is, as the bed of a lake
    Lake
    A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...

    .
  • Lava plain
    Lava plain
    A lava plain, also called a lava field or lava bed, is a large expanse of nearly flat-lying lava flows. Such features are generally composed of highly-fluid basalt lava, and can extend for tens or even hundreds of miles across the underlying terrain...

    , formed by sheets of flowing lava
    Lava
    Lava refers both to molten rock expelled by a volcano during an eruption and the resulting rock after solidification and cooling. This molten rock is formed in the interior of some planets, including Earth, and some of their satellites. When first erupted from a volcanic vent, lava is a liquid at...

    .
  • Glacial plains are formed by the movement of glaciers under the force of gravity:
    • Till plain
      Till plain
      A till plain is an extensive flat plain of glacial till that forms when a sheet of ice becomes detached from the main body of a glacier and melts in place depositing the sediments it carried. A till plain with irregular topography is referred to as a ground moraine.-See also:*Glacial till plains...

      , a plain of glacial till that forms when a sheet of ice
      Ice
      Ice is water frozen into the solid state. Usually ice is the phase known as ice Ih, which is the most abundant of the varying solid phases on the Earth's surface. It can appear transparent or opaque bluish-white color, depending on the presence of impurities or air inclusions...

       becomes detached from the main body of a glacier
      Glacier
      A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...

       and melts in place depositing the sediment
      Sediment
      Sediment is naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particle itself....

      s it carries. Till plains are composed of unsorted material (till) of all sizes.
    • Sandur
      Sandur
      A sandur is a glacial outwash plain formed of sediments deposited by meltwater at the terminus of a glacier.- Formation :Sandar are found in glaciated areas, such as Svalbard, Kerguelen Islands, and Iceland...

       (plural sandar), a glacial out-wash plain formed of sediments deposited by melt-water at the terminus of a glacier. Sandar consist mainly of stratified (layered and sorted) gravel and sand

Other types

The term may also be used for flat areas of the ocean
Ocean
An ocean is a major body of saline water, and a principal component of the hydrosphere. Approximately 71% of the Earth's surface is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas.More than half of this area is over 3,000...

 floor or for flat areas on moons and planets.
  • Abyssal plain
    Abyssal plain
    An abyssal plain is an underwater plain on the deep ocean floor, usually found at depths between 3000 and 6000 metres. Lying generally between the foot of a continental rise and a mid-ocean ridge, abyssal plains cover more than 50% of the Earth’s surface. They are among the flattest, smoothest...

    , a flat or very gently sloping area of the deep ocean basin floor.

See also

  • Field
    Field (agriculture)
    In agriculture, the word field refers generally to an area of land enclosed or otherwise and used for agricultural purposes such as:* Cultivating crops* Usage as a paddock or, generally, an enclosure of livestock...

  • Flooded grasslands and savannas
    Flooded grasslands and savannas
    Flooded grasslands and savannas is a terrestrial biome. Its component ecoregions are generally located at subtropical and tropical latitudes, which are flooded seasonally or year-round...

  • Flood-meadow
    Flood-meadow
    A flood-meadow is an area of grassland or pasture beside a river, subject to seasonal flooding. Flood-meadows are distinct from water-meadows in that the latter are artificially created and maintained, with flooding controlled on a seasonal and even daily basis.- Examples :* Angel & Greyhound...

  • Grassland
    Grassland
    Grasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...

  • Machair
  • Meadow
    Meadow
    A meadow is a field vegetated primarily by grass and other non-woody plants . The term is from Old English mædwe. In agriculture a meadow is grassland which is not grazed by domestic livestock but rather allowed to grow unchecked in order to make hay...

  • Pasture
    Pasture
    Pasture is land used for grazing. Pasture lands in the narrow sense are enclosed tracts of farmland, grazed by domesticated livestock, such as horses, cattle, sheep or swine. The vegetation of tended pasture, forage, consists mainly of grasses, with an interspersion of legumes and other forbs...

  • Plateau
    Plateau
    In geology and earth science, a plateau , also called a high plain or tableland, is an area of highland, usually consisting of relatively flat terrain. A highly eroded plateau is called a dissected plateau...

  • Prairie
    Prairie
    Prairies are considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and grasses, herbs, and shrubs, rather than trees, as the dominant vegetation type...

  • Rangeland
    Rangeland
    Rangelands are vast natural landscapes in the form of grasslands, shrublands, woodlands, wetlands, and deserts. Types of rangelands include tallgrass and shortgrass prairies, desert grasslands and shrublands, woodlands, savannas, chaparrals, steppes, and tundras...

  • Savanna
    Savanna
    A savanna, or savannah, is a grassland ecosystem characterized by the trees being sufficiently small or widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of C4 grasses.Some...

  • Steppe
    Steppe
    In physical geography, steppe is an ecoregion, in the montane grasslands and shrublands and temperate grasslands, savannas, and shrublands biomes, characterized by grassland plains without trees apart from those near rivers and lakes...

  • Water-meadow
    Water-meadow
    A water-meadow is an area of grassland subject to controlled irrigation to increase agricultural productivity. Water-meadows were mainly used in Europe from the 16th to the early 20th centuries...

  • Wet meadow
    Wet meadow
    A wet meadow is a semi-wetland meadow which is saturated with water throughout much of the year. Wet meadows may occur because of poor drainage or the receipt of large amounts of water from rain or melted snow. They may also occur in riparian zones....

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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