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A valley is an elongated low area often running between
hills A hill is a landform that extends above the surrounding terrain. It often has a distinct summit. Terminology The distinction between a hill and a mountain is unclear and largely subjective, but a hill is universally considered to be not as ...
or
mountains A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher th ...
, which will typically contain a
river A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of wate ...
or
stream A stream is a continuous body of water, body of surface water Current (stream), flowing within the stream bed, bed and bank (geography), banks of a channel (geography), channel. Depending on its location or certain characteristics, a stream ...
running from one end to the other. Most valleys are formed by
erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distin ...
of the land surface by rivers or streams over a very long period. Some valleys are formed through erosion by
glacial ice A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its Ablation#Glaciology, ablation over many years, often Century, centuries. It acquires dis ...
. These glaciers may remain present in valleys in high mountains or polar areas. At lower latitudes and altitudes, these glacially formed valleys may have been created or enlarged during
ice age An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gree ...
s but now are ice-free and occupied by streams or rivers. In
desert A desert is a barren area of landscape where little precipitation occurs and, consequently, living conditions are hostile for plant and animal life. The lack of vegetation exposes the unprotected surface of the ground to denudation. About on ...
areas, valleys may be entirely dry or carry a watercourse only rarely. In areas of limestone bedrock,
dry valley A dry valley may develop on many kinds of permeable rock, such as limestone and chalk, or sandy terrains that do not regularly sustain surface water flow. Such valleys do not hold surface water because it sinks into the permeable bedrock. There ...
s may also result from drainage now taking place
underground Underground most commonly refers to: * Subterranea (geography), the regions beneath the surface of the Earth Underground may also refer to: Places * The Underground (Boston), a music club in the Allston neighborhood of Boston * The Underground (S ...
rather than at the surface.
Rift valley A rift valley is a linear shaped lowland between several highlands or mountain ranges created by the action of a geologic rift. Rifts are formed as a result of the pulling apart of the lithosphere due to extensional tectonics. The linear dep ...
s arise principally from earth movements, rather than erosion. Many different types of valleys are described by geographers, using terms that may be global in use or else applied only locally.


Formation of valleys

Valleys may arise through several different processes. Most commonly, they arise from
erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distin ...
over long periods by moving water and are known as river valleys. Typically small valleys containing streams feed into larger valleys which in turn feed into larger valleys again, eventually reaching the ocean or perhaps an internal drainage basin. In polar areas and at high altitudes, valleys may be eroded by
glacier A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its Ablation#Glaciology, ablation over many years, often Century, centuries. It acquires dis ...
s; these typically have a U-shaped profile in cross-section, in contrast to river valleys, which tend to have a V-shaped profile. Other valleys may arise principally through tectonic processes such as
rifting In geology, a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics. Typical rift features are a central linear downfaulted depression, called a graben, or more commonly a half-graben ...
. All three processes can contribute to the development of a valley over geological time. The flat (or relatively flat) portion of a valley between its sides is referred to as the valley floor. The valley floor is typically formed by river sediments and may have fluvial terraces.


River valleys

The development of a river valley is affected by the character of the bedrock over which the river or stream flows, the elevational difference between its top and bottom, and indeed the climate. Typically the flow will increase downstream and the gradient will decrease. In the upper valley, the stream will most effectively erode its bed through
corrasion Corrasion is a geomorphological term for the process of mechanical erosion of the earth's surface caused when materials are transported across it by running water, waves, glaciers, wind or gravitational movement downslope. An example is the wear ...
to produce a steep-sided V-shaped valley. The presence of more resistant rock bands, of geological faults,
fractures Fracture is the separation of an object or material into two or more pieces under the action of stress. The fracture of a solid usually occurs due to the development of certain displacement discontinuity surfaces within the solid. If a displa ...
, and folds may determine the course of the stream and result in a twisting course with
interlocking spur An interlocking spur, also known as an overlapping spur, is one of any number of projecting ridges that extend alternately from the opposite sides of the wall of a young, V-shaped valley down which a river with a winding course flows. Each of t ...
s. In the middle valley, as numerous streams have coalesced, the valley is typically wider, the flow slower and both erosion and deposition may take place. More lateral erosion takes place in the middle section of a river's course, as strong currents on the outside of its curve erode the bank. Conversely, deposition may take place on the inside of curves where the current is much slacker, the process leading to the river assuming a
meander A meander is one of a series of regular sinuous curves in the channel of a river or other watercourse. It is produced as a watercourse erodes the sediments of an outer, concave bank ( cut bank) and deposits sediments on an inner, convex bank ...
ing character. In the lower valley, gradients are lowest, meanders may be much broader and a broader
floodplain A floodplain or flood plain or bottomlands is an area of land adjacent to a river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudi ...
may result. Deposition dominates over erosion. A typical river basin or drainage basin will incorporate each of these different types of valleys. Some sections of a stream or river valleys may have vertically incised their course to such an extent that the valley they occupy is best described as a
gorge A canyon (from ; archaic British English spelling: ''cañon''), or gorge, is a deep cleft between escarpments or cliffs resulting from weathering and the erosion, erosive activity of a river over geologic time scales. Rivers have a natural tenden ...
,
ravine A ravine is a landform that is narrower than a canyon and is often the product of streambank erosion.canyon A canyon (from ; archaic British English spelling: ''cañon''), or gorge, is a deep cleft between escarpments or cliffs resulting from weathering and the erosion, erosive activity of a river over geologic time scales. Rivers have a natural tenden ...
. Rapid down-cutting may result from localized uplift of the land surface or rejuvenation of the watercourse as a result for example of a reduction in the base level to which the river is eroded, e.g. lowered global sea level during an
ice age An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gree ...
. Such
rejuvenation Rejuvenation is a medical discipline focused on the practical reversal of the aging process. Rejuvenation is distinct from life extension. Life extension strategies often study the causes of aging and try to oppose those causes in order to slow ...
may also result in the production of
river terrace Fluvial terraces are elongated terraces that flank the sides of floodplains and fluvial valleys all over the world. They consist of a relatively level strip of land, called a "tread", separated from either an adjacent floodplain, other fluvial te ...
s.


Glacial valleys

There are various forms of valleys associated with glaciation. True glacial valleys are those that have been cut by a glacier which may or may not still occupy the valley at the present day. Such valleys may also be known as glacial troughs. They typically have a U-shaped cross-section and are characteristic landforms of mountain areas where glaciation has occurred or continues to take place. The uppermost part of a glacial valley frequently consists of one or more 'armchair-shaped' hollows, or '
cirques A (; from the Latin word ') is an amphitheatre-like valley formed by glacial erosion. Alternative names for this landform are corrie (from Scottish Gaelic , meaning a pot or cauldron) and (; ). A cirque may also be a similarly shaped landform ...
', excavated by the rotational movement downslope of a cirque glacier. During glacial periods, for example, the
Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...
ice ages An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gree ...
, it is in these locations that glaciers initially form and then, as the ice age proceeds extend downhill through valleys that have previously been shaped by water rather than ice. Abrasion the movement of ice and particularly by rock material embedded within it causes the widening and deepening of the valley to produce the characteristic U or trough shape with relatively steep, even vertical sides and a relatively flat bottom.
Interlocking spur An interlocking spur, also known as an overlapping spur, is one of any number of projecting ridges that extend alternately from the opposite sides of the wall of a young, V-shaped valley down which a river with a winding course flows. Each of t ...
s associated with the development of river valleys are preferentially eroded to produce
truncated spur A truncated spur is a spur, which is a ridge that descends towards a valley floor or coastline from a higher elevation, that ends in an inverted-V face and was produced by the erosional truncation of the spur by the action of either streams, wa ...
s, typical of glaciated mountain landscapes. The upper end of the trough below the ice-contributing cirques may be a trough-end.
Valley step A valley step (german: Talstufe or ''Talschwelle'') is a prominent change in the longitudinal slope of a valley, mainly in trough valleys formed by glaciers. Typically, a valley formed by glaciers has a series of basins with intervening steps f ...
s (or 'rock steps') can result from differing erosion rates due to both the nature of the bedrock (hardness and jointing for example) and the power of the moving ice. In places, a rock basin may be excavated which may later be filled with water to form a
ribbon lake A ribbon lake is a long and deep, finger-shaped lake, usually found in a glacial trough. As such, a ribbon lake is one of a number of glacial landscapes, including arêtes, corries, rock lips, rock basins and terminal moraines. Such a lake's fo ...
or else by sediments. Such features are found in coastal areas as
fjord In physical geography, a fjord or fiord () is a long, narrow inlet with steep sides or cliffs, created by a glacier. Fjords exist on the coasts of Alaska, Antarctica, British Columbia, Chile, Denmark, Germany, Greenland, the Faroe Islands, Ice ...
s. The shape of the valley which results from all of these influences may only become visible upon the recession of the glacier that forms it. A river or stream may remain in the valley; if it is smaller than one would expect given the size of its valley, it can be considered an example of a
misfit stream A misfit stream is a river that is either too large or too small to have eroded the valley or cave passage in which it flows. This term is also used for a stream or river with meanders that obviously are not proportional in size to the meanders ...
. Other interesting glacially carved valleys include: *
Yosemite Valley Yosemite Valley ( ; ''Yosemite'', Miwok for "killer") is a U-shaped valley, glacial valley in Yosemite National Park in the western Sierra Nevada (U.S.), Sierra Nevada mountains of Central California. The valley is about long and deep, surroun ...
(United States) *
Side valley Side valleys and tributary valleys are valleys whose brooks or rivers flow into greater ones. Upstream, the valleys can be classified in an increasing order which is equivalent to the usual orographic order: the tributaries are ordered from th ...
s of the Austrian river
Salzach The Salzach (Austrian: saltsax ) is a river in Austria and Germany. It is in length and is a right tributary of the Inn, which eventually joins the Danube. Its drainage basin of comprises large parts of the Northern Limestone and Central E ...
for their parallel directions and hanging mouths. * That of the St. Mary River in Glacier National Park in
Montana Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columbi ...
, United States.


Tunnel

A tunnel valley is a large, long, U-shaped valley originally cut under the glacial ice near the margin of continental ice sheets such as that now covering Antarctica and formerly covering portions of all continents during past glacial ages. Such valleys can be up to long, wide, and deep (its depth may vary along its length). Tunnel valleys were formed by subglacial
water erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distin ...
. They once served as subglacial drainage pathways carrying large volumes of meltwater. Their cross-sections exhibit steep-sided flanks similar to fjord walls, and their flat bottoms are typical of subglacial glacial erosion.


Meltwater

In northern Central Europe, the Scandinavian ice sheet during the various ice ages advanced slightly uphill against the lie of the land. As a result, its meltwaters flowed parallel to the ice margin to reach the North Sea basin, forming huge, flat valleys known as
Urstromtäler An ''urstromtal'' (plural: ''Urstromtäler'') is a type of broad glacial valley, for example, in northern Central Europe, that appeared during the ice ages, or individual glacial periods of an ice age, at the edge of the Scandinavian ice sheet and ...
. Unlike the other forms of glacial valleys, these were formed by glacial meltwaters.


Transition forms and shoulders

Depending on the
topography Topography is the study of the forms and features of land surfaces. The topography of an area may refer to the land forms and features themselves, or a description or depiction in maps. Topography is a field of geoscience and planetary sci ...
, the
rock type In geology, rock (or stone) is any naturally occurring solid mass or aggregate of minerals or mineraloid matter. It is categorized by the minerals included, its chemical composition, and the way in which it is formed. Rocks form the Earth's ...
s, and the
climate Climate is the long-term weather pattern in an area, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteorologic ...
, a variety of transitional forms between V-, U- and plain valleys can form. The floor or bottom of these valleys can be broad or narrow, but all valleys have a shoulder. The broader a mountain valley, the lower its shoulders are located in most cases. An important exception is canyons where the shoulder almost is near the top of the valley's slope. In the Alps – e.g. the Tyrolean
Inn Inns are generally establishments or buildings where travelers can seek lodging, and usually, food and drink. Inns are typically located in the country or along a highway; before the advent of motorized transportation they also provided accommo ...
valley – the shoulders are quite low (100–200 meters above the bottom). Many villages are located here (esp. on the sunny side) because the climate is very mild: even in winter when the valley's floor is filled with fog, these villages are in
sunshine Sunlight is a portion of the electromagnetic radiation given off by the Sun, in particular infrared, visible, and ultraviolet light. On Earth, sunlight is scattered and filtered through Earth's atmosphere, and is obvious as daylight when th ...
. In some stress-tectonic regions of the
Rockies The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in great-circle distance, straight-line distance from the northernmost part of western Can ...
or the Alps (e.g.
Salzburg Salzburg (, ; literally "Salt-Castle"; bar, Soizbuag, label=Bavarian language, Austro-Bavarian) is the List of cities and towns in Austria, fourth-largest city in Austria. In 2020, it had a population of 156,872. The town is on the site of the ...
), the
side valley Side valleys and tributary valleys are valleys whose brooks or rivers flow into greater ones. Upstream, the valleys can be classified in an increasing order which is equivalent to the usual orographic order: the tributaries are ordered from th ...
s are parallel to each other, and are
hanging Hanging is the suspension of a person by a noose or ligature around the neck.Oxford English Dictionary, 2nd ed. Hanging as method of execution is unknown, as method of suicide from 1325. The ''Oxford English Dictionary'' states that hanging i ...
. Smaller streams flow into rivers as deep canyons or
waterfall A waterfall is a point in a river or stream where water flows over a vertical drop or a series of steep drops. Waterfalls also occur where meltwater drops over the edge of a tabular iceberg or ice shelf. Waterfalls can be formed in several wa ...
s.


Hanging tributary

A hanging valley is a
tributary A tributary, or affluent, is a stream or river that flows into a larger stream or main stem (or parent) river or a lake. A tributary does not flow directly into a sea or ocean. Tributaries and the main stem river drain the surrounding drainage ...
valley that is higher than the main valley. They are most commonly associated with U-shaped valleys, where a tributary glacier flows into a glacier of larger volume. The main glacier erodes a deep U-shaped valley with nearly vertical sides, while the tributary glacier, with a smaller volume of ice, makes a shallower U-shaped valley. Since the surfaces of the glaciers were originally at the same
elevation The elevation of a geographic location is its height above or below a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational surface (see Geodetic datum § Vert ...
, the shallower valley appears to be 'hanging' above the main valley. Often, waterfalls form at or near the outlet of the upper valley. Hanging valleys also occur in
fjord In physical geography, a fjord or fiord () is a long, narrow inlet with steep sides or cliffs, created by a glacier. Fjords exist on the coasts of Alaska, Antarctica, British Columbia, Chile, Denmark, Germany, Greenland, the Faroe Islands, Ice ...
systems underwater. The branches of
Sognefjord The Sognefjord or Sognefjorden (, en, Sogn Fjord), nicknamed the King of the Fjords ( no, Fjordenes konge), is the largest and deepest fjord in Norway. Located in Vestland county in Western Norway, it stretches inland from the ocean to the smal ...
are much shallower than the main fjord. The mouth of Fjærlandsfjord is about 400 meters deep while the main fjord nearby is 1200 meters deep. The mouth of Ikjefjord is only 50 meters deep while the main fjord is around 1300 meters at the same point. Glaciated terrain is not the only site of hanging streams and valleys. Hanging valleys are also simply the product of varying rates of erosion of the main valley and the tributary valleys. The varying rates of erosion are associated with the composition of the adjacent rocks in the different valley locations. The tributary valleys are eroded and deepened by glaciers or erosion at a slower rate than that of the main valley floor; thus the difference in the two valleys' depth increases over time. The tributary valley, composed of more resistant rock, then hangs over the main valley.


Trough-shaped

Trough-shaped valleys also form in regions of heavy topographic
denudation Denudation is the geological processes in which moving water, ice, wind, and waves erode the Earth's surface, leading to a reduction in elevation and in relief of landforms and landscapes. Although the terms erosion and denudation are used interch ...
. By contrast with glacial U-shaped valleys, there is less downward and sideways erosion. The severe downslope denudation results in gently sloping valley sides; their transition to the actual valley bottom is unclear. Trough-shaped valleys occur mainly in
periglacial Periglaciation (adjective: "periglacial", also referring to places at the edges of glacial areas) describes geomorphic processes that result from seasonal thawing of snow in areas of permafrost, the runoff from which refreezes in ice wedges and ot ...
regions and in
tropical The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...
regions of variable wetness. Both climates are dominated by heavy denudation.


Box

Box valleys have wide, relatively level floors and steep sides. They are common in periglacial areas and occur in mid-latitudes, but also occur in tropical and arid regions.


Rift

Rift valleys, such as the
Albertine Rift The Albertine Rift is the western branch of the East African Rift, covering parts of Uganda, the Democratic Republic of the Congo (DRC), Rwanda, Burundi and Tanzania. It extends from the northern end of Lake Albert to the southern end of Lake Tan ...
and
Gregory Rift The Gregory Rift is the eastern branch of the East African Rift fracture system. The rift is being caused by the separation of the Somali plate from the Nubian plate, driven by a thermal plume. Although the term is sometimes used in the narrow s ...
are formed by the expansion of the
Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...
's crust due to
tectonic Tectonics (; ) are the processes that control the structure and properties of the Earth's crust and its evolution through time. These include the processes of mountain building, the growth and behavior of the strong, old cores of continents k ...
activity beneath the Earth's surface.


Terms for valleys

There are many terms used for different sorts of valleys. They include: *
Cove A cove is a small type of bay or coastal inlet. Coves usually have narrow, restricted entrances, are often circular or oval, and are often situated within a larger bay. Small, narrow, sheltered bays, inlets, creeks, or recesses in a coast are o ...
: A small valley, closed at one or both ends, in the central or southern
Appalachian Mountains The Appalachian Mountains, often called the Appalachians, (french: Appalaches), are a system of mountains in eastern to northeastern North America. The Appalachians first formed roughly 480 million years ago during the Ordovician Period. They ...
which sometimes results from the erosion of a geologic window. *
Dell Dell is an American based technology company. It develops, sells, repairs, and supports computers and related products and services. Dell is owned by its parent company, Dell Technologies. Dell sells personal computers (PCs), servers, data ...
: A small, secluded, and often wooded valley. *
Dry valley A dry valley may develop on many kinds of permeable rock, such as limestone and chalk, or sandy terrains that do not regularly sustain surface water flow. Such valleys do not hold surface water because it sinks into the permeable bedrock. There ...
: A valley not created by sustained surface water flow. * Erosional Valley: A valley formed by
erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distin ...
. * Hollow: A term used regionally for a small valley surrounded by mountains or
ridge A ridge or a mountain ridge is a geographical feature consisting of a chain of mountains or hills that form a continuous elevated crest for an extended distance. The sides of the ridge slope away from the narrow top on either side. The line ...
s. In
Ireland Ireland ( ; ga, Éire ; Ulster Scots dialect, Ulster-Scots: ) is an island in the Atlantic Ocean, North Atlantic Ocean, in Northwestern Europe, north-western Europe. It is separated from Great Britain to its east by the North Channel (Grea ...
,
New England New England is a region comprising six states in the Northeastern United States: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. It is bordered by the state of New York to the west and by the Canadian provinces ...
,
Appalachia Appalachia () is a cultural region in the Eastern United States that stretches from the Southern Tier of New York State to northern Alabama and Georgia. While the Appalachian Mountains stretch from Belle Isle in Newfoundland and Labrador, Ca ...
, and the
Ozarks The Ozarks, also known as the Ozark Mountains, Ozark Highlands or Ozark Plateau, is a physiographic region in the U.S. states of Missouri, Arkansas, Oklahoma and the extreme southeastern corner of Kansas. The Ozarks cover a significant port ...
of
Arkansas Arkansas ( ) is a landlocked state in the South Central United States. It is bordered by Missouri to the north, Tennessee and Mississippi to the east, Louisiana to the south, and Texas and Oklahoma to the west. Its name is from the Osage ...
and
Missouri Missouri is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it is bordered by eight states (tied for the most with Tennessee ...
, a hollow is a small valley or dry
stream bed A stream bed or streambed is the bottom of a stream or river (bathymetry) or the physical confine of the normal water flow (Channel (geography), channel). The lateral confines or channel margins are known as the stream Bank (geography), banks ...
. *
Longitudinal valley A longitudinal valley is an elongated valley found between two almost-parallel mountain chains in geologically young fold mountains, such as the Alps, Carpathians, Andes, or the highlands of Central Asia. They are often occupied and shaped by a ...
: An elongated valley found between two nearly-parallel mountain chains. *
Steephead Valley A steephead valley, steephead or blind valley is a deep, narrow, flat bottomed valley with an abrupt ending. Such closed valleys may arise in limestone or karst landscapes, where a layer of permeable rock lies above an impermeable substract such ...
: A deep, narrow, flat-bottomed valley with an abrupt ending. *
Strike Valley Strike may refer to: People * Strike (surname) Physical confrontation or removal *Strike (attack), attack with an inanimate object or a part of the human body intended to cause harm *Airstrike, military strike by air forces on either a suspected ...
: A valley typically developed parallel to a
cuesta A cuesta (from Spanish ''cuesta'' "slope") is a hill or ridge with a gentle slope on one side, and a steep slope on the other. In geology the term is more specifically applied to a ridge where a harder sedimentary rock overlies a softer layer ...
from more readily eroded strata. *
Structural Valley A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Material structures include man-made objects such as buildings and machines and natural objects such as ...
: A valley formed by geologic events such as drop faults or the rise of highlands. Similar geographical features such as
gullies A gully is a landform created by running water, mass movement, or commonly a combination of both eroding sharply into soil or other relatively erodible material, typically on a hillside or in river floodplains or terraces. Gullies resemble lar ...
,
chine A chine () is a steep-sided coastal gorge where a river flows to the sea through, typically, soft eroding cliffs of sandstone or clays. The word is still in use in central Southern England—notably in East Devon, Dorset, Hampshire and the Isl ...
s, and
kloof Kloof is a leafy upper-class town, that includes a smaller area called Everton, located approximately 26 km north-west of Durban in KwaZulu-Natal, South Africa. Once an independent municipality, it now forms part of greater Durban area ...
s, are not usually referred to as valleys.


British regional terms for valleys

The terms corrie,
glen A glen is a valley, typically one that is long and bounded by gently sloped concave sides, unlike a ravine, which is deep and bounded by steep slopes. Whittow defines it as a "Scottish term for a deep valley in the Highlands" that is "narrower ...
, and
strath A strath is a large valley, typically a river valley that is wide and shallow (as opposed to a glen, which is typically narrower and deep). Word and etymology An anglicisation of the Gaelic word ''srath'', it is one of many that have been ab ...
are all
Anglicisation Anglicisation is the process by which a place or person becomes influenced by English culture or British culture, or a process of cultural and/or linguistic change in which something non-English becomes English. It can also refer to the influen ...
s of
Gaelic Gaelic is an adjective that means "pertaining to the Gaels". As a noun it refers to the group of languages spoken by the Gaels, or to any one of the languages individually. Gaelic languages are spoken in Ireland, Scotland, the Isle of Man, and Ca ...
terms and are commonly encountered in place-names in
Scotland Scotland (, ) is a country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to the ...
and other areas where Gaelic was once widespread. Strath signifies a wide valley between hills, the floor of which is either level or slopes gently. A glen is a river valley which is steeper and narrower than a strath. A corrie is a basin-shaped hollow in a mountain. Each of these terms also occurs in parts of the world formerly colonized by Britain. ''Corrie'' is used more widely by geographers as a synonym for (glacial) ''
cirque A (; from the Latin word ') is an amphitheatre-like valley formed by glacial erosion. Alternative names for this landform are corrie (from Scottish Gaelic , meaning a pot or cauldron) and (; ). A cirque may also be a similarly shaped landform ...
'', as is the word '' cwm'' borrowed from
Welsh Welsh may refer to: Related to Wales * Welsh, referring or related to Wales * Welsh language, a Brittonic Celtic language spoken in Wales * Welsh people People * Welsh (surname) * Sometimes used as a synonym for the ancient Britons (Celtic peop ...
. The word dale occurs widely in place names in the north of England and, to a lesser extent, in southern Scotland. As a generic name for a type of valley, the term typically refers to a wide valley, though there are many much smaller stream valleys within the
Yorkshire Dales The Yorkshire Dales is an upland area of the Pennines in the Historic counties of England, historic county of Yorkshire, England, most of it in the Yorkshire Dales National Park created in 1954. The Dales comprise river valleys and the hills ri ...
which are named "(specific name) Dale".
Clough Clough ( ; ) is a village and townland in County Down, Northern Ireland. It sits about 3 miles from Dundrum, County Down, Dundrum on the A2 road (Northern Ireland), A2 between Newcastle, County Down, Newcastle and Belfast. The A2 road (Northern ...
is a word in common use in northern England for a narrow valley with steep sides. ''
Gill A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are ...
'' is used to describe a ravine containing a mountain stream in
Cumbria Cumbria ( ) is a ceremonial and non-metropolitan county in North West England, bordering Scotland. The county and Cumbria County Council, its local government, came into existence in 1974 after the passage of the Local Government Act 1972. Cumb ...
and the
Pennines The Pennines (), also known as the Pennine Chain or Pennine Hills, are a range of uplands running between three regions of Northern England: North West England on the west, North East England and Yorkshire and the Humber on the east. Commo ...
. The term
combe A combe (; also spelled coombe or coomb and, in place names, comb) can refer either to a steep, narrow valley, or to a small valley or large hollow on the side of a hill; in any case, it is often understood simply to mean a small valley through wh ...
(also encountered as ''coombe'') is widespread in southern England and describes a short valley set into a hillside. Other terms for small valleys such as hope, dean, slade, slac''k'' and bottom are commonly encountered in place-names in various parts of England but are no longer in general use as synonyms for ''valley''. The term vale is used in England and Wales to describe a wide river valley, usually with a particularly wide
flood plain A floodplain or flood plain or bottomlands is an area of land adjacent to a river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudi ...
or flat valley bottom. In Southern England, vales commonly occur between the outcrops of different relatively erosion-resistant rock formations, where less resistant rock, often
claystone Mudrocks are a class of fine-grained siliciclastic sedimentary rocks. The varying types of mudrocks include siltstone, claystone, mudstone, slate, and shale. Most of the particles of which the stone is composed are less than and are too sm ...
has been eroded. An example is the
Vale of White Horse The Vale of White Horse is a local government district of Oxfordshire in England. It was historically a north-west projection of Berkshire. The area is commonly referred to as the 'Vale of ''the'' White Horse'. It is crossed by the Ridgeway Nat ...
in Oxfordshire.


Human settlement

Some of the first human complex societies originated in river valleys, such as that of the
Nile The Nile, , Bohairic , lg, Kiira , Nobiin language, Nobiin: Áman Dawū is a major north-flowing river in northeastern Africa. It flows into the Mediterranean Sea. The Nile is the longest river in Africa and has historically been considered ...
, Tigris-Euphrates,
Indus The Indus ( ) is a transboundary river of Asia and a trans-Himalayan river of South and Central Asia. The river rises in mountain springs northeast of Mount Kailash in Western Tibet, flows northwest through the disputed region of Kashmir, ...
,
Ganges The Ganges ( ) (in India: Ganga ( ); in Bangladesh: Padma ( )). "The Ganges Basin, known in India as the Ganga and in Bangladesh as the Padma, is an international river to which India, Bangladesh, Nepal and China are the riparian states." is ...
,
Yangtze The Yangtze or Yangzi ( or ; ) is the longest river in Asia, the third-longest in the world, and the longest in the world to flow entirely within one country. It rises at Jari Hill in the Tanggula Mountains (Tibetan Plateau) and flows ...
,
Yellow River The Yellow River or Huang He (Chinese: , Standard Beijing Mandarin, Mandarin: ''Huáng hé'' ) is the second-longest river in China, after the Yangtze River, and the List of rivers by length, sixth-longest river system in the world at th ...
,
Mississippi Mississippi () is a state in the Southeastern region of the United States, bordered to the north by Tennessee; to the east by Alabama; to the south by the Gulf of Mexico; to the southwest by Louisiana; and to the northwest by Arkansas. Miss ...
, and arguably the
Amazon Amazon most often refers to: * Amazons, a tribe of female warriors in Greek mythology * Amazon rainforest, a rainforest covering most of the Amazon basin * Amazon River, in South America * Amazon (company), an American multinational technology c ...
. In
prehistory Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of ...
, the rivers were used as a source of
fresh water Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include ...
and food (fish and game), as well as a place to wash and a sewer. The proximity of water moderated
temperature Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measured with a thermometer. Thermometers are calibrated in various temperature scales that historically have relied o ...
extremes and provided a source for
irrigation Irrigation (also referred to as watering) is the practice of applying controlled amounts of water to land to help grow Crop, crops, Landscape plant, landscape plants, and Lawn, lawns. Irrigation has been a key aspect of agriculture for over 5,00 ...
, stimulating the development of
agriculture Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people to ...
. Most of the first civilizations developed from these river valley communities. Siting of settlements within valleys is influenced by many factors, including the need to avoid flooding and the location of river crossing points.


Notable examples


Africa

*
Albertine Rift The Albertine Rift is the western branch of the East African Rift, covering parts of Uganda, the Democratic Republic of the Congo (DRC), Rwanda, Burundi and Tanzania. It extends from the northern end of Lake Albert to the southern end of Lake Tan ...
*
East African Rift The East African Rift (EAR) or East African Rift System (EARS) is an active continental rift zone in East Africa. The EAR began developing around the onset of the Miocene, 22–25 million years ago. In the past it was considered to be part of a ...
*
Ethiopian Rift Valley The Great Rift Valley of Ethiopia, (or Main Ethiopian Rift or Ethiopian Rift Valley) is a branch of the East African Rift that runs through Ethiopia in a southwest direction from the Afar Triple Junction. In the past, it was seen as part of a "G ...
*
Great Rift Valley The Great Rift Valley is a series of contiguous geographic trenches, approximately in total length, that runs from Lebanon in Asia to Mozambique in Southeast Africa. While the name continues in some usages, it is rarely used in geology as it i ...
*
Nile Valley The Nile, , Bohairic , lg, Kiira , Nobiin: Áman Dawū is a major north-flowing river in northeastern Africa. It flows into the Mediterranean Sea. The Nile is the longest river in Africa and has historically been considered the longest rive ...
(Egypt/Sudan/Ethiopia/Uganda) * Nugaal Valley (Somalia) * Umba Valley (Tanzania) * Valley of the Kings (Egypt)


Asia

*List of valleys in India *List of valleys in Pakistan * Beqaa Valley (Lebanon) * Emin Valley (Kazakhstan) * Ihlara, Turkey * Inner Terai Valleys of Nepal, Dang Valley (Western Nepal) * Jordan Rift Valley (Jordan - Israel) * Jordan Valley (Middle East), Jordan Valley * Kathmandu Valley, Kathmandu (Nepal) * Mahaweli (Sri Lanka) * Panjshir Valley (Afghanistan) * Valleys of China **Baligou Valley **Emin Valley **Heizhu Valley **Insukati Valley **Jiuzhaigou Valley **Mutou Valley


Oceania

* Barossa Valley (Australia) * Bulolo Valley (Papua New Guinea) * Capertee Valley (Australia) * Hunter Region (Australia) * Hutt Valley (New Zealand) * Macarthur, New South Wales (Australia) * Markham Valley (Papua New Guinea) * Cagayan Valley (Philippines) * Strath Taieri (New Zealand)


Europe

* Dalen, Telemark (Telemark, Norway) * Bergensdalen (Vestland, Norway) * Danube Valley (Eastern Europe) * Glen Coe (Scotland, United Kingdom) * Great Glen (Scotland, United Kingdom) * Gudbrandsdalen (Oppland, Norway) * Hallingdalen (Buskerud, Norway) * Heddal (Telemark, Norway) * Iron Gate (Danube), Iron Gate (Romania/Serbia) * Lauterbrunnen Valley (Bern, Switzerland) * Loire Valley with its famous castles (France) * Midt-Telemark (Telemark, Norway) * Nant Ffrancon (Wales, United Kingdom) * Numedalen (Buskerud, Norway) * Østerdalen (Hedmark, Norway) * Po Valley, (Italy) * Rhone Valley from the Matterhorn to Grenoble and Lyon (France) * Romsdalen (Møre Og Romsdal, Norway) * Setesdal (Agder, Norway) * South Wales Valleys (Wales, United Kingdom) * Upper Rhine Valley or Upper Rhine Plain, an old graben system. (France and Germany) * Vestfjorddalen (Norway)


North America

* Caguas, Puerto Rico, Caguas (Puerto Rico) * Central Valley (California), Central Valley (California) * Coachella Valley (California) * Cumberland Valley (Maryland/Pennsylvania) * Death Valley (California) * Fraser Canyon (British Columbia) * Fraser Valley (British Columbia) * Grand Canyon (Arizona, United States) * Hell's Gate, British Columbia, Hell's Gate (British Columbia) * Hudson Valley (New York) * Imperial Valley (California) * Las Vegas Valley (Nevada) * Missouri River Valley (Missouri) * Monument Valley (Arizona, Utah) * Napa Valley AVA, Napa Valley (California) * Okanagan Valley (British Columbia) * Ottawa Valley (Ontario/Quebec) * Palo Duro Canyon (Texas) * Phoenix, Arizona, Valley of the Sun (Arizona) * Rio Grande Valley (Texas), Rio Grande Valley (Texas) * Saint Lawrence River, Saint Lawrence Valley (Ontario/Quebec/New York) * Salt Lake Valley (Utah) * San Fernando Valley (California) * Shenandoah Valley (Virginia/West Virginia) * Sonoma Valley (California) * Toluca Valley (Mexico) * Valley of the Gods (Utah) * Valley of Mexico (Mexico) * Willamette Valley (Oregon) *
Yosemite Valley Yosemite Valley ( ; ''Yosemite'', Miwok for "killer") is a U-shaped valley, glacial valley in Yosemite National Park in the western Sierra Nevada (U.S.), Sierra Nevada mountains of Central California. The valley is about long and deep, surroun ...
(California)


South America

* Aburra Valley (Colombia) * Calchaquí Valleys (Argentina) * Paraíba Valley (Brazil) * Cauca River, Cauca Valley (Colombia) * Ischigualasto ''Valley of the Moon'' (Argentina)


Antarctica

*West Antarctic Rift System


Extraterrestrial valleys

Numerous elongate depressions have been identified on the surface of Mars, Venus, the Moon, and other Solar System, planets and their satellites and are known as vallis (planetary geology), valles (singular: 'vallis'). Deeper valleys with steeper sides (akin to canyons) on certain of these bodies are known as chasmata (singular: 'chasma'). Long narrow depressions are referred to as Fossa (planetary nomenclature), fossae (singular: 'fossa'). These are the Latin terms for 'valley, 'gorge' and 'ditch' respectively. The German term 'rille' or Latin term 'rima' (signifying 'cleft') is used for certain other elongate depressions on the Moon. See also: *List of valleys on Mars, *List of chasmata on Mars, *List of valleys on the Moon, *List of largest rifts, canyons and valleys in the Solar System


See also

* * * *


References


External links


NPS.gov
University of Wisconsin
UWSP.edu
Glossary of Alpine Glacial Landforms * , SAR interferometry (analysis of valley forms in Fig.2 and 6)
Valleys.com
Valleys of the World
Valley definitions
YourDictionary


Extraterrestrial valleys



Vallis Alpes, bisecting the Lunar Alps
Valles Marineris and Ophir Chasma
bilingual website (English language, English and German language, German) {{Authority control Valleys, Erosion landforms Fluvial landforms Slope landforms Bodies of water