Orinoco

{{short description|River in Venezuela and Colombia}} {{Other uses}} {{Infobox river | name = Orinoco River | native_name = | native_name_lang = | name_other = Río Orinoco | name_etymology = Warao for "a place to paddle"  | image = Orinoco Bridge.jpg | image_size = | image_caption = Orinoquia Bridge near Ciudad Guayana, Venezuela | map = Orinoco drainage basin map (plain)-es.svg | map_size = | map_caption = The Orinoco drainage basin | pushpin_map = Venezuela | pushpin_map_size = | pushpin_map_caption = Mouth location in Venezuela | mapframe = yes | mapframe-zoom = 4  | subdivision_type1 = Countries | subdivision_name1 = {{hlist|Colombia|Venezuela}} | subdivision_type2 = | subdivision_name2 = | subdivision_type3 = Region | subdivision_name3 = South America | subdivision_type4 = | subdivision_name4 = | subdivision_type5 = | subdivision_name5 =  | length = {{cvt|2,140|km}}<ref name="XXI. PECES DEL FONDO DEL RÍO ORINOCO Y AFLUENTES PRINCIPALES (COLOMBIA-VENEZUELA): diversidad y aspectos bioecológicos">{{cite book |url=https://www.researchgate.net/publication/370581100 |title=XXI. PECES DEL FONDO DEL RÍO ORINOCO Y AFLUENTES PRINCIPALES (COLOMBIA-VENEZUELA): diversidad y aspectos bioecológicos |last1=Carlos Andrés |first1=Lasso Alcalá |last2=Mónica Andrea |first2=Morales Betancourt |isbn=978-958-5183-65-0 |doi=10.21068/eh9789585183629 |year=2022}}</ref><ref name="Orinoco River Basin, South America">{{cite web|url=https://files.worldwildlife.org/wwfcmsprod/files/Publication/file/5o1b74cnbo_English_Version_Orinoco_River_Report_Card_3_High_Res.pdf|title=Orinoco River Basin, South America|year=2016}}</ref> | basin_size ={{cvt|1,014,797|km2}}<ref name="XXI. PECES DEL FONDO DEL RÍO ORINOCO Y AFLUENTES PRINCIPALES (COLOMBIA-VENEZUELA): diversidad y aspectos bioecológicos"/> | width_min = | width_avg = | width_max = | depth_min = | depth_avg = | depth_max = {{cvt|100|m}}

| source1 = Hydrological source (main stem) | source1_location = Cerro Delgado-Chalbaud, Parima Mountains, Venezuela | source1_coordinates= {{coord|2|19|05|N|63|21|42|W|display=inline}} | source1_elevation = {{cvt|1,047|m}}

| source2 = Geographical source (Orinoco–Guaviare–Guayabero–Papamene–Sorrento: 3,010 km) | source2_location = Cordillera Oriental, Colombia | source2_coordinates= {{coord|3|31|36.5952|N|74|28|27.3684|W|}} | source2_elevation = {{cvt|3,080|m}}

| mouth = Delta Amacuro | mouth_location = Atlantic Ocean, Venezuela | mouth_coordinates = {{coord|8|37|N|62|15|W|display=inline,title}}<ref>{{GEOnet2|32FA87C3E20B3774E0440003BA962ED3|Orinoco River}}</ref> | mouth_elevation = {{cvt|0|m}}

| discharge1_location= Orinoco Delta | discharge1_avg = (Period: 1983–2020) {{cvt|39,000|m3/s}}<ref name="XXI. PECES DEL FONDO DEL RÍO ORINOCO Y AFLUENTES PRINCIPALES (COLOMBIA-VENEZUELA): diversidad y aspectos bioecológicos"/> | discharge1_min = {{cvt|8,000|m3/s}}<ref name="XXI. PECES DEL FONDO DEL RÍO ORINOCO Y AFLUENTES PRINCIPALES (COLOMBIA-VENEZUELA): diversidad y aspectos bioecológicos"/> | discharge1_max = {{cvt|85,000|m3/s}}<ref name="XXI. PECES DEL FONDO DEL RÍO ORINOCO Y AFLUENTES PRINCIPALES (COLOMBIA-VENEZUELA): diversidad y aspectos bioecológicos"/>

| discharge2_location= Ciudad Guayana | discharge2_avg = (Period: 1926–2011) {{cvt|37,740|m3/s}}<ref name="La geografía del agua">{{cite web |url=https://bibliofep.fundacionempresaspolar.org/media/1378189/agua_ti_cap03.pdf |title=La geografía del agua |last1=José Rafael |first1=Córdova |last2=Marcelo González |first2=Sanabria}}</ref>

|discharge3_location= Ciudad Bolívar |discharge3_avg = (Period: 1926–2011) {{cvt|32,760|m3/s}}<ref name="La geografía del agua"/>

|discharge5_location= Puerto Ayacucho |discharge5_avg = (Period: 1926–2011) {{cvt|16,182|m3/s}}<ref name="La geografía del agua"/>

|discharge4_location=Puerto Carreño |discharge4_avg = (Period: 1971–2000) {{cvt|18,363.7|m3/s}}<ref name="Orinoco">{{cite web |url=https://www.riversnetwork.org/V1/index.php/component/content/?view=article&id=67&catid=10&Itemid=179 |title=Orinoco}}</ref>

| progression = Atlantic Ocean | river_system = Orinoco River | tributaries_left = Casiquiare, Guaviare, Vichada, Tomo, Cinaruco, Capanaparo, Meta, Arauca, Apure, Guárico | tributaries_right = Mavaca, Sipapo, Ocamo, Ventuari, Suapure, Parguaza, Caura, Cuchivero, Aro, Caroní

| custom_label = | custom_data = | extra = }}

The '''Orinoco''' ({{IPA|es|oɾiˈnoko}}) is one of the longest rivers in South America at {{cvt|2,140|km}}. Its drainage basin, sometimes known as the '''Orinoquia''', covers approximately {{cvt|1000000|km2}}, with 65% of it in Venezuela and 35% in Colombia. It is the fourth largest river in the world by discharge volume of water ({{cvt|39,000|m3/s|disp=or}} at delta) due to the high precipitation throughout its catchment area ({{convert|2,300|mm/a|lk=in|abbr=out|disp=or}}).

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 == The river's name is derived from the Warao term for "a place to paddle", derived from the terms {{lang|wba|güiri}} (paddle) and {{lang|wba|noko}} (place) i.e. a navigable place.<ref>{{cite web |title=Orinoco River |url=https://www.britannica.com/place/Orinoco-River |website=Encyclopaedia Britannica |access-date=11 April 2020}}</ref><ref>{{cite web |title=Orinoco |url=http://etimologias.dechile.net/?Orinoco |website=Diccionario Etimológico Español en Línea |access-date=11 April 2020}}</ref>

== History == {{More citations needed|section|date=December 2022}}

The mouth of the Orinoco River at the Atlantic Ocean was documented by Christopher Columbus on 1 August 1498, during his third voyage.<ref>{{cite book |last=Morison |first=Samuel Eliot |year=1991 |title=Admiral of the Ocean Sea: A Life of Christopher Columbus |location=Boston |publisher=Little, Brown |isbn=9780316584784 |pages=547}}</ref> 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.<ref>{{cite book | last=Daum | first=Andreas W.|author-link=Andreas Daum | year=2024 | title=Alexander von Humboldt: A Concise Biography | location=Trans. Robert Savage. Princeton, N.J. | publisher=Princeton University Press |pages=68‒70 | isbn=978-0-691-24736-6 }}</ref> He reported on the pink river dolphins and later published extensively on the river's flora and fauna.<ref>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}}.</ref>

{{wideimage|Map of Lower Orinoco pub. 1897.jpg|300px|Map of the Lower Orinoco, 1897}}

The source of the Orinoco River, located at Cerro Delgado–Chalbaud (2º19’05” N, 63º21’42” W), at {{cvt|1047|m}} 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.<ref>Alberto Contramaestre Torres. Expedición a las fuentes del Orinoco. Caracas, 1954.</ref><ref>Pablo J. Anduce. ''Shailili-Ko. Descubrimiento de las fuentes del Orinoco''. Caracas: Talleres Gráficos Ilustraciones S.A., 1960.</ref>

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.<ref>{{cite book|title=In the Wake of Tacoma: Suspension Bridges and the Quest for Aerodynamic Stability|author=Scott, R.|date=2001|publisher=American Society of Civil Engineers|isbn=9780784470732|url=https://books.google.com/books?id=dLOR_CjeiBMC|page=184|access-date=13 April 2015}}</ref> The first powerline crossing of the Orinoco River was completed in 1981 for an 800{{nbsp}}kV{{nbsp}}TL single span of {{cvt|1200|m}} using two towers {{cvt|110|m}} tall.<ref name="SAE-Power">{{Cite web |title=Experience |publisher=SAE Power Lines |url=http://www.saepowerlines.com/eng/esperienze.htm |access-date=13 October 2015 |archive-date=2 August 2015 |archive-url=https://web.archive.org/web/20150802012558/http://www.saepowerlines.com/eng/esperienze.htm |url-status=dead }}</ref> In 1992, an overhead power line crossing for two 400{{nbsp}}kV-circuits was completed west of Morocure (between Ciudad Bolívar and Ciudad Guayana). It had three towers, and the two spans measured {{cvt|2161|m}} and {{cvt|2537|m}}, respectively.<ref name="SAE-Power" /><ref>{{Cite magazine|title=Critical Path |date=June 2005 |magazine=PEI |pages=105–111, page 107 |url=http://www.pbpower.net/inprint/articles/critical/critical.pdf |archive-url=https://web.archive.org/web/20060923215840/http://www.pbpower.net/inprint/articles/critical/critical.pdf |archive-date=23 September 2006 |url-status=dead}}</ref><ref>{{Cite web |title=Pylons of the Orinoco High-Voltage Crossing |work=International Database for Civil and Structural Engineering |url=http://structurae.net/structures/pylons-of-the-orinoco-high-voltage-crossing |archive-url=https://web.archive.org/web/20160304200554/http://structurae.net/structures/pylons-of-the-orinoco-high-voltage-crossing |archive-date=4 March 2016 |url-status=dead |access-date=13 October 2015 }}</ref><ref>{{Cite web |title=Orinoco Powerline Crossing |publisher=Skyscraper Source Media Inc. |url=http://skyscraperpage.com/cities/?buildingID=58412 |archive-url=https://web.archive.org/web/20160305034956/http://skyscraperpage.com/cities/?buildingID=58412 |archive-date=5 March 2016 |url-status=live }}</ref> In 2006, the Orinoquia Bridge was completed near Ciudad Guayana.{{citation needed|date=February 2016}}

== Geography ==

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: * Upper Orinoco – {{cvt|286|km}} long, from its headwaters to the Raudales de Guaharibos rapids, flows through mountainous landscape in a northwesterly direction * Middle Orinoco – {{cvt|805|km}} long, divided into two sectors, the first of which ca. {{cvt|515|km}} 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 {{cvt|290|km}}, along the Colombia–Venezuela 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 at Puerto Carreño *Lower Orinoco – {{cvt|959|km}} long with a well-developed alluvial plain, flows in a northeast direction, from Atures rapids down to Piacoa at Barrancas * Delta Amacuro – {{cvt|200|km}} long that empties into the Gulf of Paría and the Atlantic Ocean, a very large delta, some {{cvt|22500|km2}} and {{cvt|370|km}} at its widest.

thumb|right|Orinoco in Mariusa National Park (Delta Amacuro) [[File:Ciudad guyana.jpg|thumb|right|Orinoco at its confluence with the Caroní River (lower left)<ref>{{cite web | url=http://earthobservatory.nasa.gov/IOTD/view.php?id=6215 | title=Ciudad Guayana, Venezuela : Image of the Day | publisher=earthobservatory.nasa.gov | access-date=2009-10-31 | date=2006-01-23 }}</ref>]] right|thumb|Rapids of the Orinoco, near Puerto Ayacucho airport, Venezuela [[File:Orinoco 33. 2005.jpg|right|thumb|Orinoco in Amazonas State, Venezuela]] right|thumb|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 {{cvt|41,000|km2}} of swampy forests. In the rainy season, the Orinoco River can swell to a breadth of {{cvt|22|km}} and a depth of {{cvt|100|m}}. The stream gradient of the entire river is 0.05% ({{cvt|1,047|m|disp=sqbr}} over {{cvt|2,250|km|disp=sqbr}}). Downstream of Raudales de Guaharibos the gradient is 0.01% ({{cvt|183|m|disp=sqbr}}<ref name="gv">{{Cite web |title=Raudal de Guaharibos rapids, Estado Amazonas, Venezuela |url=https://ve.geoview.info/raudal_de_guaharibos,3640388 |access-date=2021-07-21 |website=ve.geoview.info}}</ref> over {{cvt|1,964|km|disp=sqbr}}), which is also the gradient from Ciudad Bolivar to the ocean ({{cvt|54|m|disp=sqbr}} over {{cvt|435|km|disp=sqbr}}).

Encompassing the states of Anzoategui-Guarico and Monagas states, the Interior Range forms the northern boundary and the Guayana Shield the southern boundary.<ref name="Prieto">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}}</ref>{{rp|155}} Maturin forms the eastern subbasin and Guarico forms the western subbasin.<ref name="Prieto" />{{rp|156}} The El Furrial oil field was discovered in 1978, producing from late Oligocene shallow marine sandstones in an overthrusted foreland basin.<ref name="Prieto" />{{rp|155}}

=== Tributaries === 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.<ref name="Guaviare river">{{cite web |title=Las aguas del Orinoco |url=https://www.fao.org/4/ad770b/AD770B03.htm |website=FAO |access-date=18 March 2026}}</ref>

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}} * Apure * Arauca * Atabapo * Caroní * Casiquiare canal * Caura * Guaviare * Inírida * Meta * Ventuari * Vichada ==Discharge== ===Ciudad Guayana=== {{Bar chart | title = Period: 1995–2024<ref name="The Flood Observatory">{{cite web |url=https://floodobservatory.colorado.edu/SiteDisplays/141.htm |title=The Flood Observatory}}</ref><ref name="NATURAL CONDITIONS OF THE ORINOCO RIVER DELTA">{{cite book |url=https://openjicareport.jica.go.jp/pdf/11603503_11.PDF |title=NATURAL CONDITIONS OF THE ORINOCO RIVER DELTA}}</ref> | label_type = Year | data_type = Average discharge (m3/s) | bar_width = 13 | width_units = em | data_max = 44,050 | label1=2024 | data1=33,007 | label2=2023 | data2=36,380 | label3=2022 | data3=42,663 | label4=2021 | data4=42,786 | label5=2020 | data5=31,551 | label6=2019 | data6=34,620 | label7=2018 | data7=40,870 | label8=2017 | data8=39,057 | label9=2016 | data9=39,841 | label10=2015 | data10=33,747 | label11=2014 | data11=36,018 | label12=2013 | data12=36,484 | label13=2012 | data13=44,049 | label14=2011 | data14=40,189 | label15=2010 | data15=40,101 | label16=2009 | data16=30,919 | label17=2008 | data17=38,444 | label18=2007 | data18=40,936 | label19=2006 | data19=42,628 | label20=2005 | data20=37,972 | label21=2004 | data21=42,409 | label22=2003 | data22=41,235 | label23=2002 | data23=40,373 | label24=2001 | data24=30,510 | label25=2000 | data25=37,390 | label26=1999 | data26=39,080 | label27=1998 | data27=36,844 | label28=1997 | data28=33,094 | label29=1996 | data29=38,620 | label30=1995 | data30=32,853 }} {| class="wikitable mw-collapsible" style="text-align:center;" |+ Monthly average discharge (m3/s, period 1996 to 1998)<ref name="NATURAL CONDITIONS OF THE ORINOCO RIVER DELTA">{{cite book |url=https://openjicareport.jica.go.jp/pdf/11603503_11.PDF |title=NATURAL CONDITIONS OF THE ORINOCO RIVER DELTA}}</ref> |- !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=== {| class="wikitable mw-collapsible" style="text-align:center;" |+ Minimum and maximum discharge (m3/s, period 2000 to 2023)<ref name="Actualidad Hidrometeorológica">{{cite web |url=https://hidromet-ucv.org.ve/category/actualidad-meteorolog/ |title=Actualidad Hidrometeorológica}}</ref><ref name="The Flood Observatory"/> |- ! 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 |} {| class="wikitable mw-collapsible" style="text-align:center;" |+ Monthly average discharge (m3/s, period 2018 to 2023)<ref name="Actualidad Hidrometeorológica">{{cite web |url=https://hidromet-ucv.org.ve/category/actualidad-meteorolog/ |title=Actualidad Hidrometeorológica}}</ref> |- ! 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'' |- | colspan="8" | |- |''Mean'' |''36,467'' |''32,017'' |''28,915'' |''39,378'' |''39,094'' |''32,523'' |''32,836'' |} {| class="wikitable mw-collapsible" style="text-align:center;" |+ Average discharge (m3/s, complete series from 1926 to 2023)<ref name="THE EXTRAORDINARY FLOOD OF THE ORINOCO RIVER IN 2018">{{cite web |last1=José L. |first1=López |last2=José R. |first2=Córdova |last3=Bartolo |first3=Castellanos |last4=Santiago |first4=Yépez |last5=Alain |first5=Laraque |title=THE EXTRAORDINARY FLOOD OF THE ORINOCO RIVER IN 2018 |url=https://hybam.obs-mip.fr/wp-content/uploads/2019/09/6_Lopez.pdf}}</ref><ref name="Actualidad Hidrometeorológica2">{{cite web |title=Actualidad Hidrometeorológica |url=https://hidromet-ucv.org.ve/category/actualidad-meteorolog/}}</ref><ref name="The Flood Observatory"/> |- !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 == The environment and wildlife in the Orinoco's basin are extremely diverse.<ref name="XXI. PECES DEL FONDO DEL RÍO ORINOCO Y AFLUENTES PRINCIPALES (COLOMBIA-VENEZUELA): diversidad y aspectos bioecológicos" /><ref>Supplement of {{cite journal |url=https://hess.copernicus.org/articles/26/35/2022/hess-26-35-2022-supplement.pdf |year=2021 |access-date=21 February 2022 |archive-date=4 January 2022 |archive-url=https://web.archive.org/web/20220104103919/https://hess.copernicus.org/articles/26/35/2022/hess-26-35-2022-supplement.pdf |url-status=live |doi=10.5194/hess-26-35-2022 |title=How well are we able to close the water budget at the global scale? |last1=Lehmann |first1=Fanny |last2=Vishwakarma |first2=Bramha Dutt |last3=Bamber |first3=Jonathan |journal=Hydrology and Earth System Sciences |volume=26 |pages=35–54 |doi-access=free }}</ref><ref name="Orinoco River Basin, South America–WWF">{{cite web |url=https://wwf.panda.org/discover/knowledge_hub/where_we_work/orinoco_river_basin |title=Orinoco River Basin, South America–WWF}}</ref><ref name="Publications-EcoHealth Report Cards">{{cite web|url=https://ecoreportcard.org/report-cards/orinoco-river/publications/|title=Publications-EcoHealth Report Cards}}</ref><ref>{{cite encyclopedia |title=Orinoquia, Orinoquía |encyclopedia=Diccionario panhispánico de dudas |year=2005 |publisher=Royal Spanish Academy |url=https://www.rae.es/dpd/Orinoquia |access-date=2023-01-07}}</ref> The boto and the giant otter inhabit the river system.<ref name=WWF>WWF: ''[http://wwf.panda.org/what_we_do/where_we_work/orinoco_river_basin/ Orinoco River Basin, South America.]'' Retrieved 24 May 2014</ref> 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.<ref>{{Cite journal|last1=Thorbjarnarson |first1=John B. |last2=Hernández |first2=Gustavo |year=1993 |title=Reproductive ecology of the Orinoco crocodile (''Crocodylus intermedius'') in Venezuela. I. Nesting ecology and egg and clutch relationships |journal=Journal of Herpetology |volume=27 |issue=4 |pages=363–370 |doi=10.2307/1564821 |jstor=1564821}}</ref>

More than 1,000 fish species have been recorded in the river basin, and about 15% are endemic.<ref name=Reis2016>{{Cite journal |doi = 10.1111/jfb.13016|pmid = 27312713|title = Fish biodiversity and conservation in South America|journal = Journal of Fish Biology|volume = 89|issue = 1|pages = 12–47|year = 2016|last1 = Reis|first1 = R. E.|last2 = Albert|first2 = J. S.|last3 = Di Dario|first3 = F.|last4 = Mincarone|first4 = M. M.|last5 = Petry|first5 = P.|last6 = Rocha|first6 = L. A.|url = https://zenodo.org/record/896303|doi-access = free| bibcode=2016JFBio..89...12R }}</ref> By far the largest orders are Characiformes and Siluriformes, which together account for more than 80% of the fresh water species.<ref name=FEW>Hales, J., and P. Petry: ''[http://www.feow.org/ecoregions/details/307 Orinoco Llanos]''. Orinoco Delta & Coastal Drainages. Retrieved 24 May 2014.</ref> Some of the more famous are the black spot piranha and the cardinal tetra.<ref>{{cite web|website=Seriously Fish|url=http://www.seriouslyfish.com/species/paracheirodon-axelrodi/|title=Paracheirodon axelrodi, Cardinal Tetra.|access-date=24 May 2014}}</ref> 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.<ref name=Staeck2015>{{cite journal|last1=Staeck|first1=W.|last2=Schindler|first2=I.|title=Description of a new Heros species (Teleostei, Cichlidae) from the Rio Orinoco drainage and notes on Heros severus Heckel, 1840|year=2015|journal=Bulletin of Fish Biology|volume=15|issue=1–2|pages=121–136|url=http://www.ichthyologie.de/images/stories/gfi/publikationen/Bulletin_of_Fish_Biology/Volume_15/BoFB_Vol15_121_136_Staeck_and_Schindler.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.ichthyologie.de/images/stories/gfi/publikationen/Bulletin_of_Fish_Biology/Volume_15/BoFB_Vol15_121_136_Staeck_and_Schindler.pdf |archive-date=2022-10-09 |url-status=live}}{{Dead link|date=April 2020 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

== Economic activity == 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, {{cvt|435|km}} 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.<ref>[https://books.google.com/books?id=GtkDAAAAMBAJ&dq=popular+mechanics+July+1932+airplane&pg=PA142 "Venezuela's Magnetic Mountain"] ''Popular Mechanics'', July 1949</ref>

The river deposits contain extensive tar sands in the Orinoco oil belt, which may be a source of future oil production.<ref>{{Cite news |last=Forero |first=Juan |date=1 June 2006 |title=For Venezuela, A Treasure In Oil Sludge |newspaper=The New York Times |volume=155 |issue=53597 |pages=C1–C6 |url=https://www.nytimes.com/2006/06/01/business/worldbusiness/01oil.html |archive-url=https://web.archive.org/web/20161220134004/http://www.nytimes.com/2006/06/01/business/worldbusiness/01oil.html |archive-date=20 December 2016 |url-status=live |df=dmy }}</ref>[[File:Vista RioCaroni DesdeOrinoco.jpg|thumbnail|Union of the Orinoco with the Caroní River]] == 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 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.<ref>{{Cite web|title=Antecedentes y Sumario Paso a Nado Internacional de Los Rios Orinoco/Caroni" ''Paso Nado Internacional de Los Rios Orinoco y Caroní'' |language=es |trans-title=Antecedents and Summary of the ''International Swim Meet of the Orinoco and Caroni Rivers'' |url=http://www.almacaronidireccion.com/imdecaroni/static.php?page=static070130-092723 |archive-url=https://web.archive.org/web/20071217065719/http://www.almacaronidireccion.com/imdecaroni/static.php?page=static070130-092723 |archive-date=17 December 2007 |url-status=dead |df=dmy}}</ref><ref>{{Cite web|title=26 edición Paso a Nado de Ríos Orinoco y Caroní 2016 |publisher=Roberto Muñoz Natación Venezuela |url=http://1968.com.ve/26-edicion-paso-a-nado-de-rios-orinoco-y-caroni-2016/ |archive-url=https://web.archive.org/web/20161109162140/http://1968.com.ve/26-edicion-paso-a-nado-de-rios-orinoco-y-caroni-2016/ |archive-date=9 November 2016 |url-status=dead |df=dmy }}</ref>

== In culture == 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.<ref>{{Cite web |last=Moore |first=Rick |date=2020-11-18 |title=Behind the Song: "Orinoco Flow (Sail Away)" by Enya |url=https://americansongwriter.com/sail-away-by-enya-behind-the-song/ |access-date=2023-12-27 |website=American Songwriter |language=en-US}}</ref> Jules Verne's novel "Superbe Orénoque" has the river as its central theme.

== See also == * Adaheli, the Sun in the mythology of the Orinoco region

== Notes == {{Reflist|30em}}

== 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 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. [http://www.gutenberg.org/files/50506/50506-h/50506-h.htm 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 == {{commons category|Orinoco River}} *{{cite EB1911 |wstitle=Orinoco |volume=20 |pages=275–276 |first=George Earl |last=Church |short=1}} *{{Gutenberg|no=50506|name=Down the Orinoco in a Canoe}} (Transcription of book from 1902) *[https://scioteca.caf.com/bitstream/handle/123456789/495/el_camino_de_los_r_os_w_2013.pdf?sequence=1&isAllowed=y "Rios de Integracion ". Geurgescu, Paul. CAF. 2017]

Category:Border rivers Category:Colombia–Venezuela border Category:Dredged rivers and waterways Category:International rivers of South America Category:Orinoco basin Category:Rivers of Colombia Category:Rivers of Venezuela Category:Rivers of Amazonas (Venezuelan state)