Orinoco
   HOME

TheInfoList



OR:

The Orinoco () is one of the longest
river A river is a natural stream of fresh water that flows on land or inside Subterranean river, 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 ...
s in
South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...
at . Its
drainage basin A drainage basin is an area of land in which all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, ...
, sometimes known as the Orinoquia, covers approximately 1 million km2, with 65% of it in
Venezuela Venezuela, officially the Bolivarian Republic of Venezuela, is a country on the northern coast of South America, consisting of a continental landmass and many Federal Dependencies of Venezuela, islands and islets in the Caribbean Sea. It com ...
and 35% in
Colombia Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...
. It is the fourth largest river in the world by discharge volume of water (39,000 m3/s at
delta Delta commonly refers to: * Delta (letter) (Δ or δ), the fourth letter of the Greek alphabet * D (NATO phonetic alphabet: "Delta"), the fourth letter in the Latin alphabet * River delta, at a river mouth * Delta Air Lines, a major US carrier ...
) due to the high precipitation throughout its catchment area (ca 2,300 mm/a). The Orinoco River and its tributaries are the major transportation system for eastern and interior Venezuela and the
Llanos The Llanos ( Spanish ''Los Llanos'', "The Plains"; ) is a vast tropical grassland plain situated to the east of the Andes in Colombia and Venezuela, in northwestern South America. It is an ecoregion of the tropical and subtropical grasslands, ...
of Colombia. The environment and wildlife in the Orinoco's basin are extremely diverse.


Etymology

The river's name is derived from the Warao term for "a place to paddle", itself derived from the terms ''güiri'' (paddle) and ''noko'' (place) i.e. a navigable place.


History

The mouth of the Orinoco River at the
Atlantic Ocean The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...
was documented by
Christopher Columbus Christopher Columbus (; between 25 August and 31 October 1451 – 20 May 1506) was an Italians, Italian explorer and navigator from the Republic of Genoa who completed Voyages of Christopher Columbus, four Spanish-based voyages across the At ...
on 1 August 1498, during his third voyage. Its source at the Cerro Delgado–Chalbaud, in the Parima range, was not explored until 453 years later, in 1951. The source, near the Venezuelan–
Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...
ian border, at above sea level (), was explored in 1951 by a joint French-Venezuelan expedition. The Orinoco, as well as its tributaries in the eastern
llanos The Llanos ( Spanish ''Los Llanos'', "The Plains"; ) is a vast tropical grassland plain situated to the east of the Andes in Colombia and Venezuela, in northwestern South America. It is an ecoregion of the tropical and subtropical grasslands, ...
such as the
Apure Apure State (, ) is one of the 23 States of Venezuela, states of Venezuela. Its territory formed part of the provinces of Mérida (state), Mérida, Maracaibo, and Barinas (state), Barinas, in accordance with successive territorial ordinations ...
and Meta, were explored in the 16th century by German expeditions under
Ambrosius Ehinger Ambrosius Ehinger, also (Ambrosio Alfínger in Spanish) Dalfinger, Thalfinger, (ca. 1500 in Thalfingen near Ulm – 31 May 1533 near Chinácota in modern-day Colombia) was a German conquistador and the first governor of the Welser conces ...
and his successors. In 1531, starting at the principal outlet in the delta, the Boca de Navios, Diego de Ordaz sailed up the river to the Meta.
Antonio de Berrio Antonio de Berrío (1527–1597) was a Spanish soldier, governor and explorer in Colonial America. Biography Antonio de Berrío was born in Segovia. He began his military career at the age of 14 in the service of the king Carlos I. The young ...
sailed down the Casanare to the Meta, and then down the Orinoco River and back to Coro. In 1595, after capturing de Berrio to obtain information while conducting an expedition to find the fabled city of
El Dorado El Dorado () is a mythical city of gold supposedly located somewhere in South America. The king of this city was said to be so rich that he would cover himself from head to foot in gold dust – either daily or on certain ceremonial occasions ...
, the Englishman
Sir Walter Raleigh Sir Walter Raleigh (; – 29 October 1618) was an English statesman, soldier, writer and explorer. One of the most notable figures of the Elizabethan era, he played a leading part in English colonisation of North America, suppressed rebellio ...
sailed down the river, reaching the savanna country. From April to May 1800, the Prussian-born
Alexander von Humboldt Friedrich Wilhelm Heinrich Alexander von Humboldt (14 September 1769 – 6 May 1859) was a German polymath, geographer, natural history, naturalist, List of explorers, explorer, and proponent of Romanticism, Romantic philosophy and Romanticism ...
and his companion, Aime Bonpland, explored stretches of the Orinoco, supported by indigenous helpers and guided by his interest to prove that South America's waterways formed an interconnected system from the Andes to the Amazon. He reported on the pink river dolphins and later published extensively on the river's flora and fauna. The sources of the Orinoco River, located at Cerro
Carlos Delgado Chalbaud Carlos Román Delgado Gómez (20 January 1909 – 13 November 1950) was a Venezuelan military officer who served as president of Venezuela from 1948 to 1950 as leader of a Military dictatorship, military junta. In 1945, he was one of the high- ...
(2º19’05” N, 63º21’42” W), were discovered in 1951 by the French-Venezuelan expedition that went back and explored the Upper Orinoco course to the Sierra Parima near the border with Brazil, headed by Venezuelan army officer Frank Risquez Iribarren. The first bridge across the Orinoco River, the Angostura Bridge at
Ciudad Bolívar Ciudad Bolívar (; Spanish for "Bolivar City"), formerly known as Angostura and St. Thomas de Guyana, is the capital of Venezuela's southeastern Bolívar, Venezuela, Bolívar State. It lies at the spot where the Orinoco River narrows to about ...
, Venezuela, was completed in 1967. In 1968, an expedition was set off by
The Geographical Journal ''The Geographical Journal'' is a quarterly peer-reviewed academic journal of the Royal Geographical Society (with the Institute of British Geographers). It publishes papers covering research on all aspects of geography. It also publishes shorter ...
and
Hovercraft A hovercraft (: hovercraft), also known as an air-cushion vehicle or ACV, is an amphibious craft capable of travelling over land, water, mud, ice, and various other surfaces. Hovercraft use blowers to produce a large volume of air below the ...
from
Manaus Manaus () is the List of capitals of subdivisions of Brazil, capital and largest city of the States of Brazil, Brazilian state of Amazonas (Brazilian state), Amazonas. It is the List of largest cities in Brazil, seventh-largest city in Brazil, w ...
(
Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...
) to Port of Spain (Trinidad). Aboard a SR.N6 hovercraft, the expedition members followed the Negro river upstream to where it is joined by the Casiquiare canal, on the border between Colombia and Venezuela. After following the Casiquiare to the Orinoco River they hovered thru perilous rapids of the rivers Maipures and Atures. The Orinoco was then traversed down to its mouths in the Gulf of Paria and then to Port of Spain. The primary purpose of the expedition was filming for the
BBC The British Broadcasting Corporation (BBC) is a British public service broadcaster headquartered at Broadcasting House in London, England. Originally established in 1922 as the British Broadcasting Company, it evolved into its current sta ...
series '' The World About Us'' episode "The Last Great Journey on Earth from Amazon to Orinoco by Hovercraft", which aired in 1970, and demonstrated the abilities of a hovercraft, thereby promoting sales of this British invention. The first powerline crossing of the Orinoco River was completed in 1981 for an 800kVTL single span of using two towers tall. In 1992, an overhead power line crossing for two 400kV-circuits was completed just west of Morocure (between the cities of
Ciudad Bolívar Ciudad Bolívar (; Spanish for "Bolivar City"), formerly known as Angostura and St. Thomas de Guyana, is the capital of Venezuela's southeastern Bolívar, Venezuela, Bolívar State. It lies at the spot where the Orinoco River narrows to about ...
and
Ciudad Guayana Ciudad Guayana () (English: Guayana City) is a city in Bolívar State (Venezuela), Bolívar State, Venezuela. It stretches 40 kilometers along the south bank of the Orinoco, Orinoco river, at the point where it is joined by its main tributary ...
), north of the confluence of Routes1 and 19. It had three towers, and the two spans measured and , respectively. In 2006, a second bridge, known as the Orinoquia Bridge, was completed near
Ciudad Guayana Ciudad Guayana () (English: Guayana City) is a city in Bolívar State (Venezuela), Bolívar State, Venezuela. It stretches 40 kilometers along the south bank of the Orinoco, Orinoco river, at the point where it is joined by its main tributary ...
, Venezuela.


Geography

The course of the Orinoco forms a wide ellipsoidal arc, surrounding the
Guiana Shield The Guiana Shield (; ; ; ) is one of the three cratons of the South American Plate. It is a 1.7 billion-year-old Precambrian geological formation in northeast South America that forms a portion of the northern coast. The higher elevations on ...
; it is divided in four stretches of unequal length that very roughly correspond to the longitudinal zonation of a typical large river: * Upper Orinoco – long, from its headwaters to the Raudales de Guaharibos rapids, flows through mountainous landscape in a northwesterly direction * Middle Orinoco – long, divided into two sectors, the first of which ca. long has a general westward direction down to the confluence with the Atabapo and Guaviare rivers at San Fernando de Atabapo; the second flows northward, for about , along the Venezuelan–Colombian border, flanked on both sides by the westernmost granitic upwellings of the Guiana Shield which impede the development of a flood plain, to the Atures rapids near the confluence with the
Meta River The Meta River is a major left tributary of the Orinoco River in eastern Colombia and southern Venezuela, South America. The Meta originates in the Cordillera Oriental (Colombia), Eastern Ranges of the Andes and flows through the Meta Department ...
at Puerto Carreño *Lower Orinoco – long with a well-developed alluvial plain, flows in a northeast direction, from Atures rapids down to Piacoa in front of Barrancas * Delta Amacuro – long that empties into the Gulf of Paría and the Atlantic Ocean, a very large
delta Delta commonly refers to: * Delta (letter) (Δ or δ), the fourth letter of the Greek alphabet * D (NATO phonetic alphabet: "Delta"), the fourth letter in the Latin alphabet * River delta, at a river mouth * Delta Air Lines, a major US carrier ...
, some and at its widest. At its mouth, the Orinoco River forms a wide delta that branches off into hundreds of rivers and waterways that flow through of swampy forests. In the rainy season, the Orinoco River can swell to a breadth of and a depth of . Most of the important Venezuelan rivers are tributaries of the Orinoco River, the largest being the Caroní, which joins it at Puerto Ordaz, close to the Llovizna Falls. A peculiarity of the Orinoco river system is the Casiquiare canal, which starts as an arm of the Orinoco, and finds its way to the Rio Negro, a tributary of the
Amazon Amazon most often refers to: * Amazon River, in South America * Amazon rainforest, a rainforest covering most of the Amazon basin * Amazon (company), an American multinational technology company * Amazons, a tribe of female warriors in Greek myth ...
, thus forming a 'natural canal' between Orinoco and Amazon. The
stream gradient Stream gradient (or stream slope) is the grade (or slope) of a stream. It is measured by the ratio of drop in elevation and horizontal distance. It is a dimensionless quantity, usually expressed in units of meters per kilometer (m/km) or feet pe ...
of the entire river is 0.05% (1,047 m over 2,250 km). Downstream of Raudales de Guaharibos the gradient is 0.01% (183/1,964), which is also the gradient from Ciudad Bolivar to the ocean (54/435).


Major rivers in the Orinoco Basin

*
Apure Apure State (, ) is one of the 23 States of Venezuela, states of Venezuela. Its territory formed part of the provinces of Mérida (state), Mérida, Maracaibo, and Barinas (state), Barinas, in accordance with successive territorial ordinations ...
: from Venezuela through the east into the Orinoco * Arauca: from Colombia to Venezuela east into the Orinoco * Atabapo: from the Guiana Highlands of Venezuela north into the Orinoco * Caroní: from the Guiana Highlands of Venezuela north into the Orinoco * Casiquiare canal: in SE Venezuela, a
distributary A distributary, or a distributary channel is a stream channel that branches off and flows a main stream channel. It is the opposite of a ''tributary'', a stream that flows another stream or river. Distributaries are a result of river bifurc ...
from the Orinoco flowing west to the Negro River, a major affluent to the Amazon * Caura: from eastern Venezuela (Guiana Highlands) north into the Orinoco * Guaviare: from Colombia east into the Orinoco * Inírida: from Colombia southeast into the Guaviare. * Meta: from Colombia, border with Venezuela east into the Orinoco * Ventuari: from eastern Venezuela (the Guiana Highlands) southwest into the Orinoco * Vichada: from Colombia east into the Orinoco


Discharge


Ciudad Guayana Ciudad Guayana () (English: Guayana City) is a city in Bolívar State (Venezuela), Bolívar State, Venezuela. It stretches 40 kilometers along the south bank of the Orinoco, Orinoco river, at the point where it is joined by its main tributary ...


Ciudad Bolívar Ciudad Bolívar (; Spanish for "Bolivar City"), formerly known as Angostura and St. Thomas de Guyana, is the capital of Venezuela's southeastern Bolívar, Venezuela, Bolívar State. It lies at the spot where the Orinoco River narrows to about ...


Ecology

The boto and the
giant otter The giant otter or giant river otter (''Pteronura brasiliensis'') is a South American carnivorous mammal. It is the longest member of the weasel family, Mustelidae, a globally successful group of predators, reaching up to . Atypical of mustel ...
inhabit the Orinoco River system.WWF:
Orinoco River Basin, South America.
' Retrieved 24 May 2014
The Orinoco crocodile is one of the rarest reptiles in the world. Its range in the wild is restricted to the middle and lower Orinoco River Basin. More than 1000 fish species have been recorded in the river basin and about 15% are
endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...
. Among the fish in the river are species found in
brackish Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuari ...
or salt water in the Orinoco
estuary An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime enviro ...
, but also many restricted to fresh water. By far the largest orders are Characiformes and Siluriformes, which together account for more than 80% of the fresh water species.Hales, J., and P. Petry:
Orinoco Llanos
'. Orinoco Delta & Coastal Drainages. Retrieved 24 May 2014.
Some of the more famous are the black spot piranha and the cardinal tetra. The latter species, which is important in the aquarium industry, is also found in the Rio Negro, revealing the connection between this river and the Orinoco through the Casiquiare canal. Because the Casiquiare includes both blackwater and clear- to
whitewater Whitewater forms in the context of rapids, in particular, when a river's Stream gradient, gradient changes enough to generate so much turbulence that air is trapped within the water. This forms an unstable current that foam, froths, making t ...
sections, only relatively adaptable species are able to pass through it between the two river systems.


Economic activity

The river is navigable for most of its length, and
dredging Dredging is the excavation of material from a water environment. Possible reasons for dredging include improving existing water features; reshaping land and water features to alter drainage, navigability, and commercial use; constructing d ...
enables ocean ships to go as far as
Ciudad Bolívar Ciudad Bolívar (; Spanish for "Bolivar City"), formerly known as Angostura and St. Thomas de Guyana, is the capital of Venezuela's southeastern Bolívar, Venezuela, Bolívar State. It lies at the spot where the Orinoco River narrows to about ...
, at the confluence of the
Caroní River The Caroní River is the second most important river of Venezuela, the second in flow, and one of the longest, from the Kukenan tepui through to its confluence with the Orinoco River. The name "Caroní" is applied starting from the confluenc ...
, upstream. River steamers carry cargo as far as Puerto Ayacucho and the Atures Rapids.


El Florero iron mine

In 1926, a Venezuelan mining inspector found one of the richest
iron ore Iron ores are rocks and minerals from which metallic iron can be economically extracted. The ores are usually rich in iron oxides and vary in color from dark grey, bright yellow, or deep purple to rusty red. The iron is usually found in the f ...
deposits near the Orinoco delta, south of the city of San Felix on a mountain named ''El Florero''. Full-scale mining of the ore deposits began after
World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...
, by a conglomerate of Venezuelan firms and US steel companies. At the start in the early 1950s, about 10,000 tons of ore-bearing soil was mined per day.


Tar sands

The Orinoco River deposits also contain extensive tar sands in the Orinoco oil belt, which may be a source of future oil production.


Eastern Venezuelan basin

Encompassing the states of Anzoategui- Guarico and
Monagas Monagas State (, ) is one of the 23 states of Venezuela. Monagas State covers a total surface area of and, as of the 2011 census, had a population of 905,443. Monagas State is surrounded by Sucre State in the north, Anzoátegui State in the ...
states, the Interior Range forms the northern boundary and the Guayana Shield the southern boundary.Prieto, R., Valdes, G., 1992, El Furrial Oil Field, In Giant Oil and Gas Fields of the Decade, 1978–1988, AAPG Memoir 54, Halbouty, M.T., editor, Tulsa: American Association of Petroleum Geologists, Maturin forms the eastern subbasin and Guarico forms the western subbasin. The El Furrial oil field was discovered in 1978, producing from late
Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...
shallow marine
sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...
s in an overthrusted
foreland basin A foreland basin is a structural basin that develops adjacent and parallel to a mountain belt. Foreland basins form because the immense mass created by crustal thickening associated with the evolution of a mountain belt causes the lithospher ...
.


Recreation and sports

Since 1973, the Civil Association Nuestros Rios son Navegables organize the Internacional Rally ''Nuestros Rios son Navegables'', a motonautical round trip of over 1,200 kilometers through the Orinoco, Meta and Apure Rivers. Starting out from Ciudad Bolívar or San Fernando de Apure, is the longest fluvial rally in the world with the participation of worldwide competitors, more than 30 support boats, logistics teams, thousands of tourists and fans travel. The boats had an average speed of 120 miles per hour. Since 1988, the local government of
Ciudad Guayana Ciudad Guayana () (English: Guayana City) is a city in Bolívar State (Venezuela), Bolívar State, Venezuela. It stretches 40 kilometers along the south bank of the Orinoco, Orinoco river, at the point where it is joined by its main tributary ...
has conducted a swim race in the rivers Orinoco and Caroní, with up to 1,000 competitors. Since 1991, the ''Paso a Nado Internacional de los Rios Orinoco–Caroní'' has been celebrated every year, on a Sunday close to 19 April. Worldwide, this swim-meet has grown in importance, and it has a large number of competitors. The 26th meet was held in 2016.


In culture

The Irish singer and songwriter Enya wrote and sang the song " Orinoco Flow", which she released in 1988. Jules Verne's novel Superbe Orénoque has the river as its central theme. One of the characters in the children's novels and television series
The Wombles ''The Wombles'' are fictional pointy-nosed, furry creatures created by Elisabeth Beresford and originally appearing in a series of children's novels from 1968. They live in burrows, where they aim to help the environment by collecting and recycl ...
is named Orinoco.


See also

* Adaheli, the Sun in the
mythology Myth is a genre of folklore consisting primarily of narratives that play a fundamental role in a society. For scholars, this is very different from the vernacular usage of the term "myth" that refers to a belief that is not true. Instead, the ...
of the Orinoco region * '' Fishes of the Orinoco in the Wild'' (2020) book * " Orinoco Flow" – the song uses the Orinoco and its environs as a theme for its lyrics


Notes


References

* Stark, James H. 1897. ''Stark's Guide-Book and History of Trinidad including Tobago, Granada, and St. Vincent; also a trip up the Orinoco and a description of the great Venezuelan Pitch Lake''. Boston, James H. Stark, publisher; London, Sampson Low, Marston & Company. (This book has an excellent description of a trip up the Orinoco as far as
Ciudad Bolívar Ciudad Bolívar (; Spanish for "Bolivar City"), formerly known as Angostura and St. Thomas de Guyana, is the capital of Venezuela's southeastern Bolívar, Venezuela, Bolívar State. It lies at the spot where the Orinoco River narrows to about ...
and a detailed description of the Venezuelan Pitch Lake situated on the western side of the Gulf of Paria opposite.) * MacKee, E.D., Nordin, C.F. and D. Perez-Hernandez (1998). "The Waters and Sediments of the Rio Orinoco and its major Tributaries, Venezuela and Colombia." United States Geological Survey water-supply paper, /A-B. Washington: United States Government Printing Office. * Rawlins, C.B. (1999). ''The Orinoco River''. New York: Franklin Watts. * Triana, S. Pérez
Down the Orinoco in a Canoe
* Weibezahn, F.H., Haymara, A. and M.W. Lewis (1990). ''The Orinoco River as an ecosystem''. Caracas: Universidad Simon Bolivar.


External links

* * (Transcription of book from 1902)
"Rios de Integracion ". Geurgescu, Paul. CAF. 2017
{{Authority control Border rivers Colombia–Venezuela border Dredged rivers and waterways International rivers of South America Orinoco basin Rivers of Colombia Rivers of Venezuela Rivers of Amazonas (Venezuelan state)