A ravine is a

landform A landform is a land feature on the solid surface of the Earth or other planetary body. They may be natural or may be anthropogenic (caused or influenced by human activity). Landforms together make up a given terrain, and their arrangement ...

that is narrower than a

canyon A canyon (; archaic British English spelling: ''cañon''), gorge or chasm, is a deep cleft between escarpments or cliffs resulting from weathering and the erosive activity of a river over geologic time scales. Rivers have a natural tendency t ...

and is often the product of

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 strea ...

bank

erosion Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...

. Ravines are typically classified as larger in scale than

gullies A gully is a landform created by running water, mass movement, or both, which erodes soil to a sharp angle, typically on a hillside or in river floodplains or terraces. Gullies resemble large ditches or small valleys, but are metres to t ...

, although smaller than

valley A valley is an elongated low area often running between hills or mountains and typically containing a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers or streams over ...

s. Ravines may also be called a cleuch, dell, ghout (

Nevis Nevis ( ) is an island in the Caribbean Sea that forms part of the inner arc of the Leeward Islands chain of the West Indies. Nevis and the neighbouring island of Saint Kitts constitute the Saint Kitts and Nevis, Federation of Saint Kitts ...

), gill or ghyll,

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. The word is Goidelic in origin: ''gleann'' in Irish and Scottish Gaelic, ''glion'' in Manx. ...

gorge A canyon (; archaic British English spelling: ''cañon''), gorge or chasm, 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 tend ...

, kloof (

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

), and

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 Is ...

(

Isle of Wight The Isle of Wight (Help:IPA/English, /waɪt/ Help:Pronunciation respelling key, ''WYTE'') is an island off the south coast of England which, together with its surrounding uninhabited islets and Skerry, skerries, is also a ceremonial county. T ...

) A ravine is generally a

fluvial A river is a natural stream of fresh water that flows on land or inside caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of its course if it ru ...

slope landform of relatively steep (cross-sectional) sides, on the order of twenty to seventy percent in

gradient In vector calculus, the gradient of a scalar-valued differentiable function f of several variables is the vector field (or vector-valued function) \nabla f whose value at a point p gives the direction and the rate of fastest increase. The g ...

. Ravines may or may not have active streams flowing along the downslope channel which originally formed them; moreover, often they are characterized by intermittent streams, since their geographic scale may not be sufficiently large to support a

perennial stream A stream is a continuous body of surface water flowing within the bed and banks of a channel. Depending on its location or certain characteristics, a stream may be referred to by a variety of local or regional names. Long, large stream ...

Definition

According to

Merriam-Webster Merriam-Webster, Incorporated is an list of companies of the United States by state, American company that publishes reference work, reference books and is mostly known for Webster's Dictionary, its dictionaries. It is the oldest dictionary pub ...

, a ravine is "a small, narrow, steep-sided valley that is larger than a

gully A gully is a landform A landform is a land feature on the solid surface of the Earth or other planetary body. They may be natural or may be anthropogenic (caused or influenced by human activity). Landforms together make up a given ter ...

and smaller than a

and that is usually worn by running water". Some societies and languages do not differentiate between a gully and ravine; in others, there is a distinction, particularly when concerning environmental management.

Formation

Gullies are often found in hilly or mountainous regions, where

water runoff Runoff is the flow of water across the earth, and is a major component in the hydrological cycle. Runoff that flows over land before reaching a watercourse is referred to as ''surface runoff'' or ''overland flow''. Once in a watercourse, runoff is ...

is guided downhill by steep slopes and over time erodes the landscape. A ravine is the final step in gully erosion, formed when a

has eroded so severely it forms a deep cut in the earth. A gully can be classified as a ravine after it reaches a large depth, typically in excess of .

Environmental impact

Ravine erosion contributes heavily to land loss globally and particularly threatens agricultural lands. Additionally, soil loss contributes to pollution, flooding, and

sedimentation Sedimentation is the deposition of sediments. It takes place when particles in suspension settle out of the fluid in which they are entrained and come to rest against a barrier. This is due to their motion through the fluid in response to th ...

of waterways. The formation of ravine lands can be sped up by

deforestation Deforestation or forest clearance is the removal and destruction of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. Ab ...

and

overgrazing Overgrazing occurs when plants are exposed to intensive grazing for extended periods of time, or without sufficient recovery periods. It can be caused by either livestock in poorly managed agricultural applications, game reserves, or nature ...

. In Indian

badlands Badlands are a type of dry terrain where softer sedimentary rocks and clay-rich soils have been extensively eroded."Badlands" in '' Chambers's Encyclopædia''. London: George Newnes, 1961, Vol. 2, p. 47. They are characterized by steep slopes, ...

, soil erosion is estimated to exceed a rate of annually.

Examples

Hawaii

The

shield volcanoes A shield volcano is a type of volcano named for its low profile, resembling a shield lying on the ground. It is formed by the eruption of highly fluid (low viscosity) lava, which travels farther and forms thinner flows than the more viscous lava ...

of Hawaii have significant impact on the distribution of ravines across the islands, specifically Mauna Loa and Mauna Kea, the former of which is one the most active shield volcanoes on Earth. Both of these volcanoes show V-shaped ravines on their flanks, solely where they have been mantled by Pahala ash. Being the older of the two, Mauna Kea displays more pronounced dissection of these ravines. Rainfall and infiltration capacity are critical to valley initiation on the Hawaiian volcanoes. Once these valleys are initiated, their streams incise to form V-shaped ravines. Eventually, they become sufficiently deep ravine systems and expose groundwater activity. The deepest of these incisions are U-shaped, theatre-headed valleys.

Notable ravines

Babi Yar Babi Yar () or Babyn Yar () is a ravine in the Ukraine, Ukrainian capital Kyiv and a site of massacres carried out by Nazi Germany's forces during Eastern Front (World War II), its campaign against the Soviet Union in World War II. The first and ...

, Ukraine *

Bam Bam Amphitheaters The Bam Bam Amphitheaters are large erosional ravines found in Wonga-Wongue Presidential Reserve in western Gabon. Although they are referred to as "cirques," they are unrelated to the glacial cirques of high latitudes and mountains. In Gabon, the ...

, Gabon *

Barranco de Badajoz The Barranco de Badajoz or Chamoco is a ravine on the island of Tenerife (Canary Islands, Spain), in the province of Santa Cruz de Tenerife, part of the municipality of Güímar in the southeast of the island.

, Spain *

Barranco del Infierno ''Barranco'' (), which is Spanish for "ravine", may refer to: Places * Barranco, Belize, a village in Toledo District, Belize * Barranco, Spain, a village south of Jijona, Alicante, Spain *Barranco District, Peru *Barranco de Loba, Colombia Perso ...

, Spain * Gravina Ravine, Italy *

Moola Chotok Moola Chotok (Urdu:) is a hidden ravine located in the middle of the Khuzdar District in the southern province of Balochistan, Pakistan, Balochistan, Pakistan. It is situated approximately north-east of Khuzdar at an elevation of . Surrounded ...

, Pakistan *

Ravenna Park Ravenna Park and Cowen Park comprise a single contiguous recreation and green space between the Ravenna and University District neighborhoods of Seattle, Washington in the United States. These public parks encompass the ravine with a maximum dep ...

, United States *

Rauðfeldsgjá Rauðfeldsgjá (, ) is a ravine in Snæfellsnes in Iceland. Name The ravine is mentioned in the Icelandic saga, ''Bárðar saga Snæfellsáss ''Bárðar saga Snæfellsáss'' (14th c. Middle Icelandic: ; Modern Icelandic: ) or ''Bárðar saga ...

, Iceland *

Stuðlagil Stuðlagil Canyon (; also transliterated as ''Studlagil'') is a basalt column canyon located in the Jökuldalur valley in East Iceland. Known for its towering hexagonal basalt formations and vivid turquoise river, the canyon gained international ...

, Iceland * Taishaku Valley, Japan *

Toronto ravine system The Toronto ravine system is a distinctive feature of the city's geography, consisting of a network of deep ravines, which forms a large urban forest that runs through most of Toronto. The ravine system is the largest in any city in the world, ...

, Canada

References

Citations

Bibliography

* ** **

External links

* * Erosion landforms Fluvial landforms Slope landforms Oronyms {{erosion-stub