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Orinoco

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For other uses, see Orinoco (disambiguation).

Template:Infobox river

The Orinoco (es) is one of the longest rivers in South America at Template:Cvt. Its drainage basin, sometimes known as the Orinoquia, covers approximately Template:Cvt, with 65% of it in Venezuela and 35% in Colombia. It is the fourth largest river in the world by discharge volume of water (Template:Cvt at delta) due to the high precipitation throughout its catchment area (2,300 millimetres per are or 0.084 in/sq ft).

The river and its tributaries are the major transportation system for eastern and interior Venezuela and the Llanos plain of Colombia. The Guaviare River is the main tributary. The environment and wildlife in the Orinoco's basin are extremely diverse.

Etymology

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The river's name is derived from the Warao term for "a place to paddle", derived from the terms güiri (paddle) and noko (place) i.e. a navigable place.[1][2]

History

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The mouth of the Orinoco River at the Atlantic Ocean was documented by Christopher Columbus on 1 August 1498, during his third voyage.[3] The Orinoco as well as its tributaries in the eastern Llanos, such as the Apure and Meta, were explored in the 16th century by German expeditions under Ambrosius Ehinger 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 sailed down the Casanare to the Meta, and then down the Orinoco 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, the Englishman Sir Walter Raleigh sailed down the river, reaching the savanna country.

From April to May 1800, the Prussian-born Alexander von Humboldt 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.[4] He reported on the pink river dolphins and later published extensively on the river's flora and fauna.[5]

Template:Wideimage

The source of the Orinoco River, located at Cerro Delgado–Chalbaud (2º19’05” N, 63º21’42” W), at Template:Cvt above sea level, was discovered in 1951 by a French-Venezuelan expedition that explored the upper Orinoco course to the Sierra Parima near the border with Brazil, headed by Venezuelan army officer Frank Risquez Iribarren.[6][7]

In 1968, an expedition from The Geographical Journal set off from Manaus, Brazil aboard a SR.N6 hovercraft to follow the Rio Negro 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 through perilous rapids of Maipures and Atures. The Orinoco was then traversed down to its mouths in the Gulf of Paria and then to the Port of Spain. The primary purpose of the expedition was filming for the BBC 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 the British invention.

The first bridge across the Orinoco River, the Angostura Bridge at Ciudad Bolívar, Venezuela, was completed in 1967.[8] The first powerline crossing of the Orinoco River was completed in 1981 for an 800 kV TL single span of Template:Cvt using two towers Template:Cvt tall.[9] In 1992, an overhead power line crossing for two 400 kV-circuits was completed west of Morocure (between Ciudad Bolívar and Ciudad Guayana). It had three towers, and the two spans measured Template:Cvt and Template:Cvt, respectively.[9][10][11][12] In 2006, the Orinoquia Bridge was completed near Ciudad Guayana.[citation needed]

Geography

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The course forms a wide ellipsoidal arc, surrounding the Guiana Shield; it is divided in four stretches of unequal length that very roughly correspond to the longitudinal zonation of a typical large river:

File:Deltaorinoco.jpg
Orinoco in Mariusa National Park (Delta Amacuro)
File:Ciudad guyana.jpg
Orinoco at its confluence with the Caroní River (lower left)[13]
File:Orinoco-Landschaft.JPG
Rapids of the Orinoco, near Puerto Ayacucho airport, Venezuela
File:Orinoco 33. 2005.jpg
Orinoco in Amazonas State, Venezuela
File:Orinoco4.jpg
Orinoco in Amazonas State, Venezuela

At its mouth, the Orinoco River forms a wide delta that branches off into hundreds of rivers and waterways that flow through Template:Cvt of swampy forests. In the rainy season, the Orinoco River can swell to a breadth of Template:Cvt and a depth of Template:Cvt. The stream gradient of the entire river is 0.05% (Template:Cvt over Template:Cvt). Downstream of Raudales de Guaharibos the gradient is 0.01% (Template:Cvt[14] over Template:Cvt), which is also the gradient from Ciudad Bolivar to the ocean (Template:Cvt over Template:Cvt).

Encompassing the states of Anzoategui-Guarico and Monagas states, the Interior Range forms the northern boundary and the Guayana Shield the southern boundary.[15]: 155  Maturin forms the eastern subbasin and Guarico forms the western subbasin.[15]: 156  The El Furrial oil field was discovered in 1978, producing from late Oligocene shallow marine sandstones in an overthrusted foreland basin.[15]: 155 

Tributaries

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Most of the important Venezuelan rivers are tributaries of the Orinoco, the largest being the Caroní, which joins it at Puerto Ordaz, close to the Llovizna Falls. The Guaviare River, with a flow of 8,200 cubic meters, is the main tributary.[16]

A peculiarity of the 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 River, thus forming a distributary and 'natural canal' between the Orinoco and the Amazon.

See also: Casiquiare canal-Orinoco River hydrographic divide

Discharge

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Ciudad Guayana

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Period: 1995–2024[17][18]
Year Average discharge (m3/s)
2024
33,007
2023
36,380
2022
42,663
2021
42,786
2020
31,551
2019
34,620
2018
40,870
2017
39,057
2016
39,841
2015
33,747
2014
36,018
2013
36,484
2012
44,049
2011
40,189
2010
40,101
2009
30,919
2008
38,444
2007
40,936
2006
42,628
2005
37,972
2004
42,409
2003
41,235
2002
40,373
2001
30,510
2000
37,390
1999
39,080
1998
36,844
1997
33,094
1996
38,620
1995
32,853
Monthly average discharge (m3/s, period 1996 to 1998)[18]
Month 1996 1997 1998 1943–1998
January 17,627 24,386 10,919 16,661
February 14,486 17,144 7,583 10,108
March 15,334 15,767 8,906 7,702
April 12,514 12,615 12,411 10,609
May 23,670 25,152 32,751 26,317
June 45,781 43,142 49,062 45,179
July 61,177 55,597 63,659 58,412
August 67,639 61,275 67,756 64,975
September 65,933 53,825 66,416 63,244
October 57,912 38,742 54,189 53,201
November 45,267 28,372 38,345 40,805
December 36,094 21,116 30,130 29,229
Mean 38,620 33,094 36,844 35,537

Ciudad Bolívar

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Minimum and maximum discharge (m3/s, period 2000 to 2023)[19][17]
Year Min Mean Max Year Min Mean Max
2000 4,799 33,415 67,667 2012 7,805 38,685 77,909
2001 3,438 25,695 59,527 2013 5,581 32,041 65,850
2002 3,868 34,002 74,367 2014 4,364 31,632 71,214
2003 3,287 34,728 74,367 2015 5,725 29,476 71,136
2004 4,071 35,717 74,208 2016 3,514 35,474 78,398
2005 5,439 31,980 64,800 2017 7,520 34,302 77,315
2006 6,521 35,901 77,422 2018 4,693 36,467 82,611
2007 3,949 34,477 71,527 2019 4,846 32,017 72,203
2008 4,754 32,378 70,536 2020 4,570 28,915 63,638
2009 7,419 26,041 59,671 2021 7,279 39,378 74,873
2010 3,067 35,286 75,807 2022 6,463 39,094 75,912
2011 6,368 37,957 74,367 2023 8,377 32,523 68,742
Monthly average discharge (m3/s, period 2018 to 2023)[19]
Month 2018 2019 2020 2021 2022 2023 1926–2023
January 11,009 8,955 13,667 19,108 11,067 14,528 11,637
February 7,593 6,414 7,142 9,554 6,463 9,412 6,840
March 4,693 4,846 4,570 7,279 10,187 8,377 5,521
April 6,862 5,634 5,080 16,378 13,860 10,036 7,347
May 27,262 17,343 11,688 33,363 28,156 19,290 20,295
June 46,541 36,447 29,204 63,086 50,344 41,963 39,205
July 73,295 57,240 42,542 68,208 68,499 59,398 57,550
August 82,611 72,203 57,742 74,873 75,912 68,742 69,207
September 70,591 69,859 63,638 68,441 73,589 67,129 66,502
October 50,838 48,298 50,060 53,294 54,020 52,622 51,206
November 34,852 34,644 36,926 36,518 45,509 23,332 35,752
December 21,457 22,317 24,718 22,437 31,527 15,450 22,974
Mean 36,467 32,017 28,915 39,378 39,094 32,523 32,836
Average discharge (m3/s, complete series from 1926 to 2023)[20][21][17]
Year m3/s Year m3/s Year m3/s
1926 23,376 1959 30,333 1992 28,571
1927 37,476 1960 31,818 1993 35,204
1928 32,838 1961 27,830 1994 35,110
1929 32,653 1962 32,930 1995 29,360
1930 30,610 1963 32,560 1996 35,992
1931 33,766 1964 27,736 1997 28,757
1932 33,302 1965 27,643 1998 35,000
1933 32,792 1966 29,220 1999 34,925
1934 34,137 1967 34,323 2000 33,415
1935 31,168 1968 32,280 2001 25,695
1936 31,260 1969 32,606 2002 34,002
1937 29,962 1970 34,600 2003 34,728
1938 37,383 1971 33,673 2004 35,717
1939 28,292 1972 36,177 2005 31,980
1940 25,232 1973 27,597 2006 35,901
1941 28,200 1974 26,344 2007 34,477
1942 31,540 1975 29,313 2008 32,378
1943 38,403 1976 37,290 2009 26,041
1944 34,878 1977 30,705 2010 35,286
1945 33,395 1978 32,514 2011 37,957
1946 36,363 1979 32,885 2012 38,685
1947 30,426 1980 35,018 2013 32,041
1948 31,818 1981 38,080 2014 31,632
1949 32,745 1982 36,224 2015 29,476
1950 32,096 1983 36,130 2016 35,474
1951 38,220 1984 31,493 2017 34,302
1952 33,858 1985 30,380 2018 36,467
1953 36,177 1986 35,040 2019 32,017
1954 38,310 1987 34,090 2020 28,915
1955 31,076 1988 30,472 2021 39,378
1956 36,734 1989 29,638 2022 39,094
1957 29,128 1990 33,442 2023 32,523
1958 28,108 1991 31,770 2024

Ecology

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The environment and wildlife in the Orinoco's basin are extremely diverse.[22][23][24][25][26] The boto and the giant otter inhabit the river system.[27] 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.[28]

More than 1,000 fish species have been recorded in the river basin, and about 15% are endemic.[29] By far the largest orders are Characiformes and Siluriformes, which together account for more than 80% of the fresh water species.[30] Some of the more famous are the black spot piranha and the cardinal tetra.[31] Because the Casiquiare canal includes both blackwater and clear- to whitewater sections, only relatively adaptable species are able to pass through it between the two river systems, such as the cardinal tetra.[32]

Economic activity

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The river is navigable for most of its length, and dredging enables ocean ships to go as far as Ciudad Bolívar, at the confluence of the Caroní River, Template:Cvt upstream. River steamers carry cargo as far as Puerto Ayacucho and the Atures Rapids.

In 1926, a Venezuelan mining inspector found one of the richest iron ore 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, by a conglomerate of Venezuelan firms and US steel companies. In the early 1950s, about 10,000 tons of ore-bearing soil was mined per day.[33]

The river deposits contain extensive tar sands in the Orinoco oil belt, which may be a source of future oil production.[34]

File:Vista RioCaroni DesdeOrinoco.jpg
Union of the Orinoco with the Caroní River

Recreation and sports

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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 has conducted a swim race in the 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 in April. Worldwide, this swim meet has grown in importance, and it has a large number of competitors.[35][36]

In culture

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The Irish singer and songwriter Enya wrote and sang the song "Orinoco Flow", which she released in 1988 to popular acclaim in Europe and North America.[37] Jules Verne's novel "Superbe Orénoque" has the river as its central theme.

See also

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Notes

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  1. ↑ "Orinoco River". Encyclopaedia Britannica. Retrieved 11 April 2020.
  2. ↑ "Orinoco". Diccionario Etimológico Español en Línea. Retrieved 11 April 2020.
  3. ↑ Morison, Samuel Eliot (1991). Admiral of the Ocean Sea: A Life of Christopher Columbus. Boston: Little, Brown. p. 547. ISBN 9780316584784.
  4. ↑ Daum, Andreas W. (2024). Alexander von Humboldt: A Concise Biography. Trans. Robert Savage. Princeton, N.J.: Princeton University Press. pp. 68‒70. ISBN 978-0-691-24736-6.
  5. ↑ Helferich, Gerard (2004) Humboldt's Cosmos: Alexander von Humboldt and the Latin American Journey that Changed the Way We See the World, Gotham Books, New York; ISBN 1-59240-052-3.
  6. ↑ Alberto Contramaestre Torres. Expedición a las fuentes del Orinoco. Caracas, 1954.
  7. ↑ Pablo J. Anduce. Shailili-Ko. Descubrimiento de las fuentes del Orinoco. Caracas: Talleres Gráficos Ilustraciones S.A., 1960.
  8. ↑ Scott, R. (2001). In the Wake of Tacoma: Suspension Bridges and the Quest for Aerodynamic Stability. American Society of Civil Engineers. p. 184. ISBN 9780784470732. Retrieved 13 April 2015.
  9. ↑ 9.0 9.1 "Experience". SAE Power Lines. Archived from the original on 2 August 2015. Retrieved 13 October 2015.
  10. ↑ "Critical Path" (PDF). PEI. June 2005. pp. 105–111, page 107. Archived from the original (PDF) on 23 September 2006.
  11. ↑ "Pylons of the Orinoco High-Voltage Crossing". International Database for Civil and Structural Engineering. Archived from the original on 4 March 2016. Retrieved 13 October 2015.
  12. ↑ "Orinoco Powerline Crossing". Skyscraper Source Media Inc. Archived from the original on 5 March 2016.
  13. ↑ "Ciudad Guayana, Venezuela : Image of the Day". earthobservatory.nasa.gov. 2006-01-23. Retrieved 2009-10-31.
  14. ↑ "Raudal de Guaharibos rapids, Estado Amazonas, Venezuela". ve.geoview.info. Retrieved 2021-07-21.
  15. ↑ 15.0 15.1 15.2 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, ISBN 0891813330
  16. ↑ "Las aguas del Orinoco". FAO. Retrieved 18 March 2026.
  17. ↑ 17.0 17.1 17.2 "The Flood Observatory".
  18. ↑ 18.0 18.1 NATURAL CONDITIONS OF THE ORINOCO RIVER DELTA (PDF).
  19. ↑ 19.0 19.1 "Actualidad Hidrometeorológica".
  20. ↑ José L., López; José R., Córdova; Bartolo, Castellanos; Santiago, Yépez; Alain, Laraque. "THE EXTRAORDINARY FLOOD OF THE ORINOCO RIVER IN 2018" (PDF).
  21. ↑ "Actualidad Hidrometeorológica".
  22. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named XXI. PECES DEL FONDO DEL RÍO ORINOCO Y AFLUENTES PRINCIPALES (COLOMBIA-VENEZUELA): diversidad y aspectos bioecológicos
  23. ↑ Supplement of Lehmann, Fanny; Vishwakarma, Bramha Dutt; Bamber, Jonathan (2021). "How well are we able to close the water budget at the global scale?" (PDF). Hydrology and Earth System Sciences. 26: 35–54. doi:10.5194/hess-26-35-2022. Archived (PDF) from the original on 4 January 2022. Retrieved 21 February 2022.
  24. ↑ "Orinoco River Basin, South America–WWF".
  25. ↑ "Publications-EcoHealth Report Cards".
  26. ↑ "Orinoquia, Orinoquía". Diccionario panhispánico de dudas. Royal Spanish Academy. 2005. Retrieved 2023-01-07.
  27. ↑ WWF: Orinoco River Basin, South America. Retrieved 24 May 2014
  28. ↑ Thorbjarnarson, John B.; Hernández, Gustavo (1993). "Reproductive ecology of the Orinoco crocodile (Crocodylus intermedius) in Venezuela. I. Nesting ecology and egg and clutch relationships". Journal of Herpetology. 27 (4): 363–370. doi:10.2307/1564821. JSTOR 1564821.
  29. ↑ Reis, R. E.; Albert, J. S.; Di Dario, F.; Mincarone, M. M.; Petry, P.; Rocha, L. A. (2016). "Fish biodiversity and conservation in South America". Journal of Fish Biology. 89 (1): 12–47. Bibcode:2016JFBio..89...12R. doi:10.1111/jfb.13016. PMID 27312713.
  30. ↑ Hales, J., and P. Petry: Orinoco Llanos. Orinoco Delta & Coastal Drainages. Retrieved 24 May 2014.
  31. ↑ "Paracheirodon axelrodi, Cardinal Tetra". Seriously Fish. Retrieved 24 May 2014.
  32. ↑ Staeck, W.; Schindler, I. (2015). "Description of a new Heros species (Teleostei, Cichlidae) from the Rio Orinoco drainage and notes on Heros severus Heckel, 1840" (PDF). Bulletin of Fish Biology. 15 (1–2): 121–136. Archived (PDF) from the original on 2022-10-09.[permanent dead link]
  33. ↑ "Venezuela's Magnetic Mountain" Popular Mechanics, July 1949
  34. ↑ Forero, Juan (1 June 2006). "For Venezuela, A Treasure In Oil Sludge". The New York Times. 155 (53597). pp. C1–C6. Archived from the original on 20 December 2016.
  35. ↑ "Antecedentes y Sumario Paso a Nado Internacional de Los Rios Orinoco/Caroni" Paso Nado Internacional de Los Rios Orinoco y Caroní" [Antecedents and Summary of the International Swim Meet of the Orinoco and Caroni Rivers] (in Spanish). Archived from the original on 17 December 2007.
  36. ↑ "26 edición Paso a Nado de Ríos Orinoco y Caroní 2016". Roberto Muñoz Natación Venezuela. Archived from the original on 9 November 2016.
  37. ↑ Moore, Rick (2020-11-18). "Behind the Song: "Orinoco Flow (Sail Away)" by Enya". American Songwriter. Retrieved 2023-12-27.

References

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  • 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 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, ISSN 0886-9308 /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.
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Template:Orinoco Tributaries

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