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Orinoco

geography Maturity 7-9 Next article →

The Orinoco is one of the longest and most significant river systems in South America. It serves as a vital lifeline for the regions it touches. Most of its vast drainage basin, known as the Orinoquia, lies within Venezuela. About 35% of this area is located in Colombia. The river is a massive force of nature. It is the fourth largest river in the world by discharge volume. This high volume is caused by heavy precipitation throughout its catchment area.

Orinoco4
Orinoco4

The river's course follows a wide, ellipsoidal arc. This path wraps around the Guiana Shield. Geographers divide the river into four distinct stretches. The Upper Orinoco begins at its headwaters. It flows through a mountainous landscape in a northwesterly direction. Next is the Middle Orinoco, which is a long section divided into two sectors. The first part flows west toward the confluence with the Atabapo and Guaviare rivers. The second part flows north along the border of Colombia and Venezuela. This section is flanked by granitic upwellings from the Guiana Shield.

Orinoco-Landschaft
Orinoco-Landschaft

Following the Middle Orinoco is the Lower Orinoco. This stretch features a well-developed alluvial plain. It flows northeast toward the river's end. The final stage is the Delta Amacuro. This is a very large delta that empties into the Gulf of Paria and the Atlantic Ocean. The delta branches into hundreds of waterways. These paths flow through thick, swampy forests.

Deltaorinoco
Deltaorinoco

History shows how much humans have sought to understand this river. Christopher Columbus documented the mouth of the Orinoco in 1498. During the 16th century, German expeditions explored the tributaries in the eastern Llanos. In 1531, Diego de Ordaz sailed from the delta up to the Meta River. The Englishman Sir Walter Raleigh also sailed the river in 1595. He was searching for the fabled city of El Dorado. In the 1800s, Alexander von Humboldt explored the river. He wanted to prove that South American waterways formed an interconnected system. He also studied the local flora and fauna.

Orinoco 33. 2005
Orinoco 33. 2005

Finding the true source of the river took much longer. A French-Venezuelan expedition discovered the source in 1951. It is located at Cerro Delgado–Chalbaud near the border with Brazil. The river system also features a unique natural phenomenon. The Casiquiare canal acts as a natural link between river systems. It starts as an arm of the Orinoco. It then flows into the Rio Negro, which is a tributary of the Amazon River. This allows certain adaptable species, like the cardinal tetra, to travel between the two systems.

Ciudad guyana
Ciudad guyana

The Orinoco supports incredible biological diversity. There are more than 1,000 recorded fish species in the basin. About 15% of these species are endemic, meaning they are found nowhere else. The largest groups are the Characiformes and Siluriformes. Notable animals include the pink river dolphin and the giant otter. The Orinoco crocodile is also found here, though it is one of the rarest reptiles in the world.

Vista RioCaroni DesdeOrinoco
Vista RioCaroni DesdeOrinoco

Human activity is also tied to the river's resources. The river is navigable for most of its length. This makes it a major transportation system for eastern Venezuela and the Colombian Llanos. Large ships can reach Ciudad Bolívar by using dredging. In 1926, rich iron ore deposits were found near the delta. Mining began in full scale after World War II. There are also tar sands in the Orinoco oil belt. Additionally, the river is used for sport. The Internacional Rally Nuestros Rios son Navegables is a motonautical race. It covers over 1,200 kilometers and attracts thousands of fans.

Orinoco-Landschaft
Orinoco-Landschaft
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🖼️ Images & Media (7)
File:Map of Lower Orinoco pub. 1897.jpg
Map of Lower Orinoco pub. 1897.jpg
File:Deltaorinoco.jpg
Deltaorinoco.jpg
File:Ciudad guyana.jpg
Ciudad guyana.jpg
File:Orinoco-Landschaft.JPG
Orinoco-Landschaft.JPG
File:Orinoco 33. 2005.jpg
Orinoco 33. 2005.jpg
File:Orinoco4.jpg
Orinoco4.jpg
File:Vista RioCaroni DesdeOrinoco.jpg
Vista RioCaroni DesdeOrinoco.jpg
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