A ravine is a

landform A landform is a natural or anthropogenic land feature on the solid surface of the Earth or other planetary body. Landforms together make up a given terrain, and their arrangement in the landscape is known as topography. Landforms include hills, ...

that is narrower than a

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 ...

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 stream ...

bank erosion. Ravines are typically classified as larger in scale than gullies, although smaller than valleys. Ravines may also be called a cleuch, dell, ghout ( Nevis), 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. Whittow defines it as a "Scottish term for a deep valley in the Highlands" that is "narrower ...

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 ...

, kloof ( South Africa), and chine ( Isle of Wight) A ravine is generally a

fluvial In geography and geology, fluvial processes are associated with rivers and streams and the deposits and landforms created by them. When the stream or rivers are associated with glaciers, ice sheets, or ice caps, the term glaciofluvial or fluviog ...

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

Definition

According to

Merriam-Webster Merriam-Webster, Inc. is an American company that publishes reference books and is especially known for its dictionaries. It is the oldest dictionary publisher in the United States. In 1831, George and Charles Merriam founded the company as ...

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

gully 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 ...

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 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 of waterways. The formation of ravine lands can be sped up by deforestation and overgrazing. 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, m ...

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

Examples

Hawaii

The shield volcanoes 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, 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, Spain * Barranco del Infierno, Spain * Gravina Ravine, Italy * Moola Chotok, Pakistan * Ravenna Park, United States * Rauðfeldsgjá, Iceland *

Stuðlagil Stuðlagil (; also transliterated as ''Studlagil'') is a ravine in in the municipality of Múlaþing, in the Eastern Region of Iceland. It is known for its columnar basalt rock formations and the blue-green water that runs through it. It became ...

, Iceland * Taishaku Valley, Japan * Toronto ravine system, Canada

References

Citations

Bibliography

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External links

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