![Salto del Angel-Canaima-Venezuela08](https://upload.wikimedia.org/wikipedia/commons/3/3c/Salto_del_Angel-Canaima-Venezuela08.JPG)
A waterfall is a point in 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 ...
where water flows over a vertical drop or a series of steep drops. Waterfalls also occur where
meltwater
Meltwater is water released by the melting of snow or ice, including glacial ice, tabular icebergs and ice shelves over oceans. Meltwater is often found in the ablation zone of glaciers, where the rate of snow cover is reducing. Meltwater can be ...
drops over the edge of a tabular
iceberg
An iceberg is a piece of freshwater ice more than 15 m long that has broken off a glacier or an ice shelf and is floating freely in open (salt) water. Smaller chunks of floating glacially-derived ice are called "growlers" or "bergy bits". The ...
or
ice shelf.
Waterfalls can be formed in several ways, but the most common method of formation is that a river courses over a top layer of resistant
bedrock
In geology, bedrock is solid Rock (geology), rock that lies under loose material (regolith) within the crust (geology), crust of Earth or another terrestrial planet.
Definition
Bedrock is the solid rock that underlies looser surface mater ...
before falling on to softer rock, which
erodes faster, leading to an increasingly high fall. Waterfalls have been studied for their impact on species living in and around them.
Humans have had a distinct relationship with waterfalls for years, travelling to see them, exploring and naming them. They can present formidable barriers to navigation along rivers. Waterfalls are religious sites in many cultures. Since the 18th century they have received increased attention as tourist destinations, sources of
hydropower
Hydropower (from el, ὕδωρ, "water"), also known as water power, is the use of falling or fast-running water to Electricity generation, produce electricity or to power machines. This is achieved by energy transformation, converting the Pot ...
, andparticularly since the mid-20th centuryas subjects of research.
Definition and terminology
A waterfall is generally defined as a point in a river where water flows over a steep drop that is close to or directly vertical. In 2000 Mabin specified that "The horizontal distance between the positions of the lip and
plunge pool should be no more than c 25% of the waterfall height." There are various types and methods to classify waterfalls. Some scholars have included
rapids
Rapids are sections of a river where the river bed has a relatively steep gradient, causing an increase in water velocity and turbulence.
Rapids are hydrological features between a ''run'' (a smoothly flowing part of a stream) and a ''cascade''. ...
as a subsection.
What actually constitutes a waterfall continues to be debated.
Waterfalls are sometimes interchangeably referred to as "cascades" and "cataracts", though some sources specify a cataract as being a larger and more powerful waterfall and a cascade as being smaller. A plunge pool is a type of
stream pool formed at the bottom of a waterfall.
Formation
Waterfalls are commonly formed in the upper course of a river where lakes flow into valleys in steep mountains.
A river sometimes flows over a large step in the rocks that may have been formed by a
fault line. Waterfalls can occur along the edge of a
glacial trough
U-shaped valleys, also called trough valleys or glacial troughs, are formed by the process of glaciation. They are characteristic of mountain glaciation in particular. They have a characteristic U shape in cross-section, with steep, straight s ...
, where a stream or river flowing into a
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 ...
continues to flow into a valley after the glacier has receded or melted. The large waterfalls in
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 ...
are examples of this phenomenon, which is referred to as a
hanging valley. Another reason hanging valleys may form is where two rivers join and one is flowing faster than the other.
When warm and cold water meet by a gorge in the ocean, large underwater waterfalls can form as the cold water rushes to the bottom.
Caprock model
The caprock model of waterfall formation states that the river courses over resistant
bedrock
In geology, bedrock is solid Rock (geology), rock that lies under loose material (regolith) within the crust (geology), crust of Earth or another terrestrial planet.
Definition
Bedrock is the solid rock that underlies looser surface mater ...
, erosion happens slowly and is dominated by impacts of water-borne sediment on the rock, while downstream the erosion occurs more rapidly.
As the watercourse increases its velocity at the edge of the waterfall, it may pluck material from the riverbed, if the bed is fractured or otherwise more erodible. Hydraulic jets and hydraulic jumps at the toe of a falls can generate large forces to erode the bed, especially when forces are amplified by water-borne sediment. Horseshoe-shaped falls focus the erosion to a central point, also enhancing riverbed change below a waterfalls.
A process known as "potholing" involves local erosion of a potentially deep hole in bedrock due to turbulent
whirlpools spinning stones around on the bed, drilling it out. Sand and stones carried by the watercourse therefore increase erosion capacity.
This causes the waterfall to carve deeper into the bed and to recede upstream. Often over time, the waterfall will recede back to form a canyon or gorge downstream as it recedes upstream, and it will carve deeper into the ridge above it.
The rate of retreat for a waterfall can be as high as one-and-a-half metres per year.
Often, the rock
stratum
In geology and related fields, a stratum ( : strata) is a layer of rock or sediment characterized by certain lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by visible surfaces known as ei ...
just below the more resistant shelf will be of a softer type, meaning that undercutting due to splashback will occur here to form a shallow cave-like formation known as a
rock shelter
A rock shelter (also rockhouse, crepuscular cave, bluff shelter, or abri) is a shallow cave-like opening at the base of a bluff or cliff. In contrast to solutional caves (karst), which are often many miles long, rock shelters are almost alway ...
under and behind the waterfall. Eventually, the
outcropping, more resistant cap rock will collapse under pressure to add blocks of rock to the base of the waterfall. These blocks of rock are then broken down into smaller boulders by
attrition
Attrition may refer to
*Attrition warfare, the military strategy of wearing down the enemy by continual losses in personnel and material
**War of Attrition, fought between Egypt and Israel from 1968 to 1970
**War of attrition (game), a model of agg ...
as they collide with each other, and they also erode the base of the waterfall by
abrasion, creating a deep
plunge pool in the gorge downstream.
Streams can become wider and shallower just above waterfalls due to flowing over the rock shelf, and there is usually a deep area just below the waterfall because of the
kinetic energy
In physics, the kinetic energy of an object is the energy that it possesses due to its motion.
It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its accele ...
of the water hitting the bottom. However, a study of waterfalls systematics reported that waterfalls can be wider or narrower above or below a falls, so almost anything is possible given the right geological and hydrological setting.
Waterfalls normally form in a rocky area due to erosion. After a long period of being fully formed, the water falling off the ledge will retreat, causing a horizontal pit parallel to the waterfall wall. Eventually, as the pit grows deeper, the waterfall collapses to be replaced by a steeply sloping stretch of river bed.
In addition to gradual processes such as erosion, earth movement caused by
earthquake
An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, from ...
s or
landslide
Landslides, also known as landslips, are several forms of mass wasting that may include a wide range of ground movements, such as rockfalls, deep-seated grade (slope), slope failures, mudflows, and debris flows. Landslides occur in a variety of ...
s or
volcano
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.
On Earth, volcanoes are most often found where tectonic plates are ...
es can lead to the formation of waterfalls.
Ecology
![Iceland Dettifoss 1972-4](https://upload.wikimedia.org/wikipedia/commons/0/06/Iceland_Dettifoss_1972-4.jpg)
Waterfalls are an important factor in determining the distribution of
lotic
River ecosystems are flowing waters that drain the landscape, and include the Biotic component, biotic (living) interactions amongst plants, animals and micro-organisms, as well as abiotic (nonliving) physical and chemical interactions of its man ...
organisms such as fish and aquatic invertebrates, as they may restrict dispersal along streams. The presence or absence of certain species can have cascading ecological effects, and thus cause differences in trophic regimes above and below waterfalls. Certain aquatic insects also specialize in the environment of the waterfall itself. A 2012 study of the
Agbokim Waterfalls
Agbokim waterfalls are situated in the Etung local government area of Cross River State in the South-South (Niger delta) region of Nigeria, very close to its border with Cameroon. The waterfalls are about from Ikom and from Calabar.
See also ...
, has suggested that they hold biodiversity to a much higher extent than previously thought.
Waterfalls also affect terrestrial species. They create a small microclimate in their immediate vicinity characterized by cooler temperatures and higher humidity than the surrounding region, which may support diverse communities of
moss
Mosses are small, non-vascular flowerless plants in the taxonomic division Bryophyta (, ) '' sensu stricto''. Bryophyta (''sensu lato'', Schimp. 1879) may also refer to the parent group bryophytes, which comprise liverworts, mosses, and hor ...
es and
liverworts
The Marchantiophyta () are a division of non-vascular land plants commonly referred to as hepatics or liverworts. Like mosses and hornworts, they have a gametophyte-dominant life cycle, in which cells of the plant carry only a single set of ge ...
. Species of these plants may have disjunct populations at waterfall zones far from their core range.
Waterfalls provide nesting cover for several species of bird, such as the
black swift
The American black swift, or more simply black swift (''Cypseloides niger''), is a species of bird that is found from northern British Columbia in Canada through the United States and Mexico to Costa Rica and Brazil. They are also found in the Ca ...
and
white-throated dipper. These species preferentially nest in the space behind the falling water, which is thought to be a strategy to avoid predation.
Types
![An ephemeral waterfall](https://upload.wikimedia.org/wikipedia/commons/d/da/An_ephemeral_waterfall.jpg)
Some waterfalls are also distinct in that they do not flow continuously. Ephemeral waterfalls only flow after a rain or a significant snowmelt. Waterfalls can also be found
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 ...
and in oceans.
Humans and waterfalls
Research
The geographer
Andrew Goudie wrote in 2020 that waterfalls have received "surprisingly limited research."
Alexander von Humboldt
Friedrich Wilhelm Heinrich Alexander von Humboldt (14 September 17696 May 1859) was a German polymath, geographer, naturalist, explorer, and proponent of Romantic philosophy and science. He was the younger brother of the Prussian minister, p ...
wrote about them in the 1820s. There is no name for the specific field of researching waterfalls, and in the published literature been described as "scattered", though it is popular to describe studying waterfalls as "waterfallology". An early paper written on waterfalls was published in 1884 by
William Morris Davis, a geologist known as the "father of American geography". In the 1930s
Edward Rashleigh
Edward is an English given name. It is derived from the Anglo-Saxon name ''Ēadweard'', composed of the elements '' ēad'' "wealth, fortune; prosperous" and '' weard'' "guardian, protector”.
History
The name Edward was very popular in Anglo-Sax ...
published a pioneering work on waterfalls.
In 1942
Oscar von Engeln
Oscar, OSCAR, or The Oscar may refer to:
People
* Oscar (given name), an Irish- and English-language name also used in other languages; the article includes the names Oskar, Oskari, Oszkár, Óscar, and other forms.
* Oscar (Irish mythology), ...
wrote of the lack of research on waterfalls:
As late as 1985 a scholar felt that "waterfalls remain a very much neglected aspect of river studies". Studies of waterfalls increased dramatically in the second half of the 20th century. Numerous waterfall guidebooks exist, and the World Waterfall Database is a website cataloging thousands of waterfalls.
Exploration and naming
Many explorers have visited waterfalls. European explorers recorded waterfalls they came across. In 1493,
Christopher Columbus
Christopher Columbus
* lij, Cristoffa C(or)ombo
* es, link=no, Cristóbal Colón
* pt, Cristóvão Colombo
* ca, Cristòfor (or )
* la, Christophorus Columbus. (; born between 25 August and 31 October 1451, died 20 May 1506) was a ...
noted
Carbet Falls
Carbet Falls (french: Les chutes du Carbet) is a series of waterfalls on the Carbet River in Guadeloupe, an overseas department of France located in the Leeward Islands of the eastern Caribbean region. Its three cascades are set amid the tropical ...
in
Guadeloupe
Guadeloupe (; ; gcf, label=Antillean Creole, Gwadloup, ) is an archipelago and overseas department and region of France in the Caribbean. It consists of six inhabited islands—Basse-Terre, Grande-Terre, Marie-Galante, La Désirade, and the ...
, which was likely the first waterfall Europeans recorded seeing in the Americas. In the late 1600s,
Louis Hennepin
Father Louis Hennepin, O.F.M. baptized Antoine, (; 12 May 1626 – 5 December 1704) was a Belgian Roman Catholic priest and missionary of the Franciscan Recollet order (French: ''Récollets'') and an explorer of the interior of North Ameri ...
visited North America, providing early descriptions of
Niagara Falls
Niagara Falls () is a group of three waterfalls at the southern end of Niagara Gorge, spanning the border between the province of Ontario in Canada and the state of New York in the United States. The largest of the three is Horseshoe Falls, ...
and the
Saint Anthony Falls. The geographer Brian J. Hudson argues that it was uncommon to specifically name waterfalls until the 1700s. The trend of Europeans specifically naming falls was in tandem with increased scientific focus on nature, the rise of
Romanticism
Romanticism (also known as the Romantic movement or Romantic era) was an artistic, literary, musical, and intellectual movement that originated in Europe towards the end of the 18th century, and in most areas was at its peak in the approximate ...
, and increased importance of hydropower with the
Industrial Revolution
The Industrial Revolution was the transition to new manufacturing processes in Great Britain, continental Europe, and the United States, that occurred during the period from around 1760 to about 1820–1840. This transition included going f ...
. European explorers often ignored the names native peoples had given the falls in favor of a "European" name; for instance, David Livingstone named
Victoria Falls
Victoria Falls ( Lozi: ''Mosi-oa-Tunya'', "The Smoke That Thunders"; Tonga: ''Shungu Namutitima'', "Boiling Water") is a waterfall on the Zambezi River in southern Africa, which provides habitat for several unique species of plants and animal ...
after
Queen Victoria
Victoria (Alexandrina Victoria; 24 May 1819 – 22 January 1901) was Queen of the United Kingdom of Great Britain and Ireland from 20 June 1837 until Death and state funeral of Queen Victoria, her death in 1901. Her reign of 63 years and 21 ...
, though it was already known as Mosi-oa-Tunya. Many waterfalls have descriptive names which can come from the river they are on, places they are near, their features, or events that happened near them.
Some countries that were colonized by European nations have taken steps to return names to waterfalls previously renamed by European explorers.
Exploration of waterfalls continues; the
Gocta Cataracts
Gocta ( es, Catarata del Gocta) is a perennial waterfall with two drops located in Peru's province of Bongara in Amazonas, approximately to the northeast of Lima. It flows into the Cocahuayco River. Although the waterfall had been well known ...
were first announced to the world in 2006.
Waterfalls can pose major barriers to travel. Canals are sometimes built as a method to go around them, other times
things must be physically carried around or
a railway built.
In 1885, the geographer
George Chisholm wrote that, "The most signal example of the effect of waterfalls and rapids in retarding the development of civilisation is undoubtedly presented by the continent of Africa, the 'darkness' of which is almost entirely due to this cause."
Development and tourism
Waterfalls are often visited by people simply to see them. Hudson theorizes that they make good tourism sites because they are generally considered beautiful and are relatively uncommon.
Activities at waterfalls can include bathing, swimming, photography,
rafting,
canyoning,
abseiling,
rock climbing
Rock climbing is a sport in which participants climb up, across, or down natural rock formations. The goal is to reach the summit of a formation or the endpoint of a usually pre-defined route without falling. Rock climbing is a physically and ...
, and
ice climbing. Waterfalls can also be sites for generating hydroelectric power and can hold good fishing opportunities. Wealthy people were known to visit areas with features such as waterfalls at least as early as in
Ancient Rome
In modern historiography, ancient Rome refers to Roman civilisation from the founding of the city of Rome in the 8th century BC to the collapse of the Western Roman Empire in the 5th century AD. It encompasses the Roman Kingdom (753–509 B ...
and
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
. However, many waterfalls were essentially inaccessible due to the treacherous terrain surrounding them until improvements began to be made such as paths to the falls, becoming common across the United Kingdom and America in the 1800s and continuing through the 1900s and into the 21st century. Remote waterfalls are now often visited by air travel.
Human development has also threatened many waterfalls. For instance, the
Guaíra Falls
Guairá Falls ( es, Saltos del Guairá, pt, Salto das Sete Quedas do Guaíra) were a series of immense waterfalls on the Paraná River along the border between Paraguay and Brazil. The falls ceased to exist in 1982 when they were inundated by the ...
, once one of the most powerful waterfalls in the world, were submerged in 1982 by a human-made dam, as were the
Ripon Falls Ripon Falls at the northern end of Lake Victoria in Uganda was formerly considered the source of the river Nile. In 1862–3 John Hanning Speke was the first European to follow the course of the Nile downstream after discovering the falls that his i ...
in 1952. Conversely, other waterfalls have seen significantly lower water levels as a result of diversion for
hydroelectricity
Hydroelectricity, or hydroelectric power, is Electricity generation, electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other Renewabl ...
, such as the
Tyssestrengene
Tyssestrengene are waterfalls east of the village of Tyssedal in Ullensvang Municipality, in Vestland county, Norway. The waterfalls are fed by the Tysso River before flowing down into the lake Ringedalsvatnet. The Trolltunga cliff is located n ...
in Norway. Development of the areas around falls as tourist attractions has also destroyed the natural scene around many of them.
Waterfalls are included on thirty-eight
World Heritage Site
A World Heritage Site is a landmark or area with legal protection by an international convention administered by the United Nations Educational, Scientific and Cultural Organization (UNESCO). World Heritage Sites are designated by UNESCO for h ...
s and many others are protected by governments.
In culture
![Taki-gyo 8118084](https://upload.wikimedia.org/wikipedia/commons/6/69/Taki-gyo_8118084.jpg)
Waterfalls play a role in many cultures, as religious sites and subjects of art and music.
Many artists have painted waterfalls and they are referenced in many songs, such as those of the
in
Papua New Guinea
Papua New Guinea (abbreviated PNG; , ; tpi, Papua Niugini; ho, Papua Niu Gini), officially the Independent State of Papua New Guinea ( tpi, Independen Stet bilong Papua Niugini; ho, Independen Stet bilong Papua Niu Gini), is a country i ...
.
Michael Harner titled his study of the
Jivaroan peoples
The Jivaroan peoples are the indigenous peoples in the headwaters of the Marañon River and its tributaries, in northern Peru and eastern Ecuador. The tribes speak the Chicham languages.
Their traditional way of life relies on gardening, and ...
of Ecuador ''The Jivaro: People of the Sacred Waterfalls.'' Artists such as those of the
Hudson River School and
J. M. W. Turner
Joseph Mallord William Turner (23 April 177519 December 1851), known in his time as William Turner, was an English Romantic painter, printmaker and watercolourist. He is known for his expressive colouring, imaginative landscapes and turbulen ...
and
John Sell Cotman
John Sell Cotman (16 May 1782 – 24 July 1842) was an English marine and landscape painter, etcher, illustrator, author and a leading member of the Norwich School of painters.
Born in Norwich, the son of a silk merchant and lace dealer, Cot ...
painted particularly notable pictures of waterfalls in the 19th century.
One of the versions of the
Shinto
Shinto () is a religion from Japan. Classified as an East Asian religion by scholars of religion, its practitioners often regard it as Japan's indigenous religion and as a nature religion. Scholars sometimes call its practitioners ''Shintois ...
purification ceremony of
misogi
is a Japanese Shinto practice of ritual purification by washing the entire body. Misogi is related to another Shinto purification ritual called ''Harae'' – thus both being collectively referred to as .
Background
Every year, many people ...
involves standing underneath a waterfall in ritual clothing.
In Japan the
Nachi Falls
in Nachikatsuura, Wakayama Prefecture, Japan, is one of the best-known waterfalls in Japan. With a drop of 133 meters (and 13 meters wide), it is the country's tallest water fall with single uninterrupted drop; however, the tallest waterfalls ...
are a site of pilgrimage, as are falls near
Tirupati
Tirupati () is a city in the Indian state of Andhra Pradesh. It is the administrative headquarters of the Tirupati district. The city is home to the important Hindu shrine of Tirumala Venkateswara Temple and other historic temples and is refe ...
, India, and the
Saut-d'Eau
Saut-d'Eau ( ht, Sodo) is a commune in the Mirebalais Arrondissement, in the Centre department of Haiti. It has 34,885 inhabitants.
Its name is French for 'waterfall', named after a large waterfall called 'Le Saut'. It is said that this water ...
, Haiti. The
Otavalos use Piguchi waterfall as part of the Churru ritual which serves as a coming of age ceremony.
Many waterfalls in Africa were places of worship for the native peoples and got their names from gods in the local religion.
List
260px, in Armenia">Shaki Waterfall in Armenia ">Armenia.html" ;"title="Shaki Waterfall in Armenia">Shaki Waterfall in Armenia
There are thousands of waterfalls in the world, though no exact number has been calculated. The World Waterfall Database lists 7,827 as of 2013, but this is likely incomplete; as noted by Hudson, over 90% of their listings are in North America. Many guidebooks to local waterfalls have been published. There is also no agreement how to measure the height of a waterfall, or even what constitutes one. Angel Falls in Venezuela is the List of waterfalls by height, tallest waterfall in the world, the Khone Phapheng Falls in Laos are the widest,
and the Inga Falls on the Congo River are the biggest
List of waterfalls by flow rate, by flow rate, while the
Dry Falls in
Washington
Washington commonly refers to:
* Washington (state), United States
* Washington, D.C., the capital of the United States
** A metonym for the federal government of the United States
** Washington metropolitan area, the metropolitan area centered on ...
are the largest confirmed waterfalls ever. The highest known subterranean waterfall is in
Vrtoglavica Cave
Vrtiglavica, also Vrtoglavica (both from Slovene ''vrtoglavica'' 'vertigo'), is a karst shaft on the Kanin Plateau, part of the Kanin Mountains, Western Julian Alps, on the Slovene side of the border between Slovenia and Italy
Italy ( ...
in
Slovenia
Slovenia ( ; sl, Slovenija ), officially the Republic of Slovenia (Slovene: , abbr.: ''RS''), is a country in Central Europe. It is bordered by Italy to the west, Austria to the north, Hungary to the northeast, Croatia to the southeast, an ...
. The largest known oceanic waterfall is the
Denmark Strait cataract.
Artificial waterfall
An artificial waterfall is a water feature or fountain which imitates a natural waterfall.
Artificial waterfalls have long been featured in traditional Japanese gardens, where they can serve to highlight a scene or to provide focus. The classic ...
s are
water feature
In landscape architecture and garden design, a water feature is one or more items from a range of fountains, jeux d'eau, pools, ponds, rills, artificial waterfalls, and streams. Before the 18th century they were usually powered by gravity, tho ...
s or
fountains that imitate a natural waterfall.
[Susan C. Anderson (Editor), Bruce Tabb (Editor), ''Water, Leisure and Culture: European Historical Perspectives'', Berg Publishers, 2002, , page 122] The
Cascata delle Marmore
The Cascata delle Marmore () or Marmore Falls is a man-made waterfall created by the ancient Romans. Its total height is 165 m (541 feet), making it the tallest man-made waterfall in the world.
It is located 7.7 km from Terni, a prov ...
is the tallest artificially built waterfall at .
References
Bibliography
*
*
External links
{{Authority control
Fluvial landforms