Orinoco

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Coordinates: 8°37′N 62°15′W / 8.617°N 62.25°W / 8.617; -62.25
Orinoco
Río Orinoco
River
Deltaorinoco.jpg
Panorama of the Orinoco River
Countries Venezuela, Colombia
District South America
Source
 - location Cerro Delgado-Chalbaud, Parima Mountains, Venezuela & Brazil
 - elevation 1,047 m (3,435 ft)
 - coordinates 02°19′05″N 63°21′42″W / 2.31806°N 63.36167°W / 2.31806; -63.36167
Mouth Delta Amacuro
 - location Atlantic Ocean, Venezuela
 - elevation m (0 ft)
 - coordinates 8°37′N 62°15′W / 8.617°N 62.25°W / 8.617; -62.25 [1]
Length 2,140 km (1,330 mi)
Basin 880,000 km² (339,770 sq mi)
Discharge
 - average 33,000 /s (1,165,384 cu ft/s)
A map of Orinoco's watershed by the Venezuelan government (in Spanish)
A map of Orinoco's watershed by the Venezuelan government (in Spanish)

The Orinoco is a river in northern South America. It is one of the longest rivers in South America, at 2,140 km (1,330 mi). Its drainage basin, sometimes called the Orinoquia, covers 880,000 square kilometres (340,000 sq mi), with 76.3% of it in Venezuela and the rest in Colombia. The Orinoco and its tributaries are the major transportation system for eastern and interior Venezuela and the llanos of Colombia.

The Orinoco Basin is also ecologically important. It is the only habitat of the Orinoco crocodile. This is one of the rarest reptiles in the world, with fewer than 250 living in the wild. It is also home to Amazon river dolphins.

History[change | edit source]

The mouth of the Orinoco was recorded by Christopher Columbus on 1 August 1498. Its source, however, was first explored by non-native people in 1951, 453 years later. It was explored by a team of Venezuelan and French people. The delta, and tributaries in the eastern llanos such as the Apure and Meta, were explored in the 16th century. They were explored by German expeditions under Ambrosius Ehinger and his successors. Alexander von Humboldt explored the basin in 1800. He reported on the river dolphins, and wrote extensively about the plants and animals he found.[2]

Geography[change | edit source]

The course of the Orinoco forms a wide arc that surrounds the Guiana Shield. The source of the river is at Cerro Delgado-Chalbaud, in the Parima Mountains. This is on the border between Venezuela and Brazil, at 1,047 m (3,435 ft) high (02°19′05″N 63°21′42″W / 2.31806°N 63.36167°W / 2.31806; -63.36167). The river can be divided into four stretches:

  • Upper Orinoco — 242 kilometres (150 mi) long, from its headwaters to the rapids Raudales de Guaharibos. This section flows through mountainous landscape in a northwesterly direction.
  • Middle Orinoco — 750 kilometres (470 mi) long. The first part of this section has a general westward direction. It flows down to the confluence with the Atabapo and Guaviare rivers at San Fernando de Atabapo. The river then flows northward along the Venezuelan–Colombian border. On both sides of the river are the mountains of the Guiana Shield. The section ends at the Atures rapids, near the confluence with the Meta at Puerto Carreño.
  • Lower Orinoco — 959 kilometres (596 mi) long, with a wide alluvial plain. It flows in a northeast direction, from Atures rapids down to Piacoa in front of Barrancas.
  • Delta Amacuro — 200 kilometres (120 mi) long. It forms a large delta that empties into the Gulf of Paría and the Atlantic Ocean.

At its mouth, the Orinoco forms a wide delta that branches off into hundreds of rivers and waterways. They flow through 41,000 km2 (16,000 sq mi) of swampy forests. At its widest, this delta is about 22,500 km2 (8,700 sq mi) large and 370 kilometres (230 mi) at its widest. In the rainy season, the Orinoco can swell to a breadth of 22 kilometres (14 mi) and a depth of 100 metres (330 ft).

Off the coast of the delta is Trinidad and Tobago, which is separated from the mainland by the Columbus Channel.

Major rivers in the Orinoco Basin[change | edit source]

Most of the important rivers in Venezuela are tributaries of the Orinoco. The largest tributaries are the Caroní, which joins it at Puerto Ordaz. The river is actually connected to the Amazon River through the Casiquiare canal. This is a distributary of the Orinoco, flowing into the Rio Negro and then the Amazon. This connection forms a natural canal between Orinoco and Amazon.

  • Apure: 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.
  • 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 (Guiana Highlands) southwest into the Orinoco.
  • Vichada: from Colombia east into the Orinoco.

Economics[change | edit source]

Bridge over the Orinoco at Ciudad Bolívar, Venezuela

Boats can travel on the river for most of its length. Ocean ships can travel as far as Ciudad Bolívar, 435 km (270 mi) upstream. River steamers carry cargo as far as Puerto Ayacucho.

There is a rich iron ore deposit in the Orinoco delta. It was found in 1926, south of the town of San Felix on a mountain named El Florero. Mining there began after World War II. At the start in the early 1950s, about 10,000 tons of soil with ore in it was being mined each day.[3]

There are also tar sands in the Orinoco Belt, which may be a source of future oil production.[4]

Notes[change | edit source]

  1. Orinoco River at GEOnet Names Server
  2. Gerard Helferich (2004). Humboldt's cosmos: Alexander von Humboldt and the Latin American journey that changed the way we see the world. New York: Gotham Books. ISBN 1-59240-052-3.
  3. Harry Chapin Plummer (July 1949), "Venezuela's Magnetic Mountain", Popular Mechanics, 92, Hearst Magazines, p. 142, ISSN 0032-4558, http://books.google.com/books?id=GtkDAAAAMBAJ&pg=PA142
  4. Forero, Juan (1 June 2006) "For Venezuela, A Treasure In Oil Sludge" New York Times Vol. 155 Issue 53597, pC1-C6

References[change | edit source]

Other websites[change | edit source]