Branco River | |
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![]() The Branco River is a tributary of the Rio Negro (highlighted on map) | |
Native name | Rio Branco (Portuguese) |
Location | |
Country | ![]() |
Physical characteristics | |
Source | |
• location | confluence of Takutu and Uraricoera, Roraima, Brazil |
• coordinates | 3°1′28.5276″N60°29′14.8596″W / 3.024591000°N 60.487461000°W |
• elevation | 64 m (210 ft) |
2nd source | |
• location | Uraricoera, Parima Mountains |
• coordinates | 3°41′42.2484″N64°12′36.018″W / 3.695069000°N 64.21000500°W |
• elevation | 1,240 m (4,070 ft) |
3rd source | |
• location | Takutu, Guiana Shield |
• coordinates | 1°47′48.6492″N60°1′38.2656″W / 1.796847000°N 60.027296000°W |
• elevation | 306 m (1,004 ft) |
Mouth | |
• location | Rio Negro, Roraima, Brazil |
• coordinates | 1°23′38″S61°50′46″W / 1.39389°S 61.84611°W |
• elevation | 12 m (39 ft) |
Length | 560 km (350 mi) [2] to 775 km (482 mi) [3] |
Basin size | 192,392.66 km2 (74,283.22 sq mi) [4] |
Discharge | |
• location | Confluence of Rio Negro, Roraima |
• average | (Period:1967-2010)5,400 m3/s (190,000 cu ft/s) [4] (Period: 1980-2006)5,300 m3/s (190,000 cu ft/s) [5] (Period: 1998-2022)6,469 m3/s (228,500 cu ft/s) [6] |
• minimum | 278 m3/s (9,800 cu ft/s) [6] |
• maximum | 28,697 m3/s (1,013,400 cu ft/s) [6] |
Discharge | |
• location | Caracaraí (400 km upstream of mouth; Basin size: 124,980 km2 (48,260 sq mi) |
• average | (Period: 1997/01/01-2015/12/31) 3,170.343 m3/s (111,959.6 cu ft/s) [7] (Period: 1998-2022)3,615.65 m3/s (127,685 cu ft/s) [4] |
• minimum | 178 m3/s (6,300 cu ft/s) (1998/03/24) [4] |
• maximum | 15,735 m3/s (555,700 cu ft/s) (1976/07/10) [4] |
Discharge | |
• location | Boa Vista (Basin size: 97,200 km2 (37,500 sq mi) |
• average | (Period: 1967-2010)2,436.76 m3/s (86,053 cu ft/s) [4] (Period: 1998-2022)3,129.97 m3/s (110,534 cu ft/s) [4] |
Basin features | |
Tributaries | |
• left | Takutu, Anauá, Itapará |
• right | Uraricoera, Mucajai, Ajarani, Univini, Catrimani, Xeruini |
The Branco River (Portuguese : Rio Branco; Engl: White River) is the principal affluent of the Rio Negro from the north.
The river drains the Guayanan Highlands moist forests ecoregion. [8] It is enriched by many streams from the Tepui highlands which separate Venezuela and Guyana from Brazil. Its two upper main tributaries are the Uraricoera and the Takutu. [9] The latter almost links its sources with those of the Essequibo; during floods headwaters of the Branco and those of the Essequibo are connected, allowing a level of exchange in the aquatic fauna (such as fish) between the two systems. [10]
The Branco flows nearly south, and finds its way into the Negro through several channels and a chain of lagoons similar to those of the latter river. It is 350 miles (560 km) long, up to its Uraricoera confluence. It has numerous islands, and, 235 miles (378 km) above its mouth, it is broken by a bad series of rapids.
Average, minimum and maximum discharge of the Branco River at near mouth. Period from 1998 to 2022. [6]
Year | Discharge (m3/s) | Year | Discharge (m3/s) | ||||
---|---|---|---|---|---|---|---|
Min | Mean | Max | Min | Mean | Max | ||
1998 | 5,664 | 16,435 | 2011 | 454 | 5,008 | 16,815 | |
1999 | 1,792 | 9,538 | 22,576 | 2012 | 2,135 | 8,381 | 17,944 |
2000 | 2,506 | 9,725 | 28,697 | 2013 | 1,377 | 6,493 | 13,229 |
2001 | 788 | 6,551 | 17,791 | 2014 | 1,117 | 6,384 | 15,489 |
2002 | 1,271 | 5,219 | 18,760 | 2015 | 772 | 3,983 | 10,416 |
2003 | 640 | 4,375 | 13,320 | 2016 | 435 | 4,316 | 11,677 |
2004 | 756 | 4,244 | 11,959 | 2017 | 2,258 | 7,437 | 16,449 |
2005 | 729 | 7,868 | 19,893 | 2018 | 777 | 6,653 | 17,912 |
2006 | 2,457 | 9,899 | 22,644 | 2019 | 625 | 5,205 | 15,859 |
2007 | 845 | 7,271 | 15,118 | 2020 | 1,567 | 7,216 | 16,564 |
2008 | 2,739 | 7,630 | 17,280 | 2021 | 1,712 | 8,828 | 23,180 |
2009 | 486 | 4,318 | 10,735 | 2022 | 1,810 | 9,087 | 23,631 |
2010 | 278 | 2,754 | 8,040 | 278 | 6,469 | 28,697 |
As suggested by its name, the Branco (literally "white" in Portuguese) has whitish water that may appear almost milky due to the inorganic sediments it carries. [11] It is traditionally considered a whitewater river, [12] [13] although the major seasonal fluctuations in its physico-chemical characteristics makes a classification difficult and some consider it clearwater. [14] [15] Especially the river's upper parts at the headwaters are clear and flow through rocky country, leading to the suggestion that sediments mainly originate from the lower parts. [11] Furthermore, its chemistry and color may contradict each other compared to the traditional Amazonian river classifications. [14] The Branco River has pH 6–7 and low levels of dissolved organic carbon. [15]
Alfred Russel Wallace mentioned the coloration in "On the Rio Negro", a paper read at the 13 June 1853 meeting of the Royal Geographical Society, in which he said: "[The Rio Branco] is white to a remarkable degree, its waters being actually milky in appearance". Alexander von Humboldt attributed the color to the presence of silicates in the water, principally mica and talc. [16] There is a visible contrast with the waters of the Rio Negro at the confluence of the two rivers. The Rio Negro is a blackwater river with dark tea-colored acidic water (pH 3.5–4.5) that contains high levels of dissolved organic carbon. [15]
Until approximately 20,000 years ago the headwaters of the Branco River flowed not into the Amazon, but via the Takutu Graben in the Rupununi area of Guyana towards the Caribbean. [17] Currently in the rainy season much of the Rupununi area floods, with water draining both to the Amazon (via the Branco River) and the Essequibo River. [10]
{{cite book}}
: CS1 maint: location missing publisher (link)The Madeira River is a major waterway in South America. It is estimated to be 1,450 km (900 mi) in length, while the Madeira-Mamoré is estimated near 3,250 km (2,020 mi) or 3,380 km (2,100 mi) in length depending on the measuring party and their methods. The Madeira is the biggest tributary of the Amazon, accounting for about 15% of the water in the basin. A map from Emanuel Bowen in 1747, held by the David Rumsey Map Collection, refers to the Madeira by the pre-colonial, indigenous name Cuyari.
The River of Cuyari, called by the Portuguese Madeira or the Wood River, is formed by two great rivers, which join near its mouth. It was by this River, that the Nation of Topinambes passed into the River Amazon.
The Rio Negro, or Guainía as it is known in its upper part, is the largest left tributary of the Amazon River, the largest blackwater river in the world, and one of the world's ten largest rivers by average discharge.
Roraima is one of the 26 states of Brazil. Located in the country's North Region, it is the northernmost and most geographically and logistically isolated state in Brazil. It is bordered by the state of Pará to the southeast, Amazonas to the south and west, Venezuela to the north and northwest, and Guyana to the east.
The Amazon basin is the part of South America drained by the Amazon River and its tributaries. The Amazon drainage basin covers an area of about 7,000,000 km2 (2,700,000 sq mi), or about 35.5 percent of the South American continent. It is located in the countries of Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, Suriname, and Venezuela, as well as the territory of French Guiana.
The Essequibo River is the largest river in Guyana, and the largest river between the Orinoco and Amazon. Rising in the Acarai Mountains near the Brazil–Guyana border, the Essequibo flows to the north for 1,014 km (630 mi) through forest and savanna into the Atlantic Ocean. It has a total drainage basin of 156,828 km2 (60,552 sq mi) and an average discharge of 5,650 m3/s (200,000 cu ft/s).
A blackwater river is a type of river with a slow-moving channel flowing through forested swamps or wetlands. Most major blackwater rivers are in the Amazon Basin and the Southern United States. The term is used in fluvial studies, geology, geography, ecology, and biology. Not all dark rivers are blackwater in that technical sense. Some rivers in temperate regions, which drain or flow through areas of dark black loam, are simply black due to the color of the soil; these rivers are black mud rivers. There are also black mud estuaries.
The Rupununi is a region in the south-west of Guyana, bordering the Brazilian Amazon. The Rupununi river, also known by the local indigenous peoples as Raponani, flows through the Rupununi region. The name Rupununi originates from the word rapon in the Makushi language, in which it means the black-bellied whistling duck found along the river.
Upper Takutu-Upper Esequibo is a region of Guyana. It borders the region of Potaro-Siparuni to the north, the region of East Berbice-Corentyne to the east and Brazil to the south and west. It contains the town of Lethem, and the villages of Aishalton, Nappi and Surama. It is also the largest region of Guyana.
The Takutu River is a river in the Upper Takutu-Upper Essequibo Region of Guyana and Roraima in Brazil. It forms part of the boundary between the two countries. The confluence of the Takutu and Uraricoera Rivers forms the Branco River. The Takutu River's sources almost link with those of the Essequibo River; in the rainy season, flooding links the Takutu to the Rupununi River, a tributary of the Essequibo.
Dadanawa Ranch is located on the Rupununi River in the Rupununi savannah in the Upper Takutu-Upper Essequibo Region of Guyana. It is the largest and one of the most isolated cattle ranches in Guyana.
Lake Parime or Lake Parima is a legendary lake located in South America. It was reputedly the location of the fabled city of El Dorado, also known as Manoa, much sought-after by European explorers. Repeated attempts to find the lake failed to confirm its existence, and it was dismissed as a myth along with the city. The search for Lake Parime led explorers to map the rivers and other features of southern Venezuela, northern Brazil, and southwestern Guyana before the lake's existence was definitively disproved in the early 19th century. Some explorers proposed that the seasonal flooding of the Rupununi savannah may have been misidentified as a lake. Recent geological investigations suggest that a lake may have existed in northern Brazil, but that it dried up some time in the 18th century. Both Manoa and Parime are believed to mean "big lake".
Rhinodoras armbrusteri is a species of thorny catfish known from the Takutu River and Ireng Rivers that drains into the upper Rio Branco in Guyana and Roraima State, Brazil; it is also known from the Rupununi River in the Essequibo River basin in southwestern Guyana. This species grows to a length of 9.62 centimetres (3.79 in) SL.
The Kwitaro River is a tributary of the Rupununi River in Guyana.
The Amazon biome contains the Amazon rainforest, an area of tropical rainforest, and other ecoregions that cover most of the Amazon basin and some adjacent areas to the north and east. The biome contains blackwater and whitewater flooded forest, lowland and montane terra firma forest, bamboo and palm forest, savanna, sandy heath and alpine tundra. Some areas of the biome are threatened by deforestation for timber and to make way for pasture or soybean plantations.
A whitewater river is classified based on its chemistry, sediments and water colour. Whitewater rivers have high levels of suspended sediments, giving the water a pH that is near-neutral, a high electric conductivity and a pale muddy, café au lait-like colour. Whitewater rivers are of great ecological importance and are important to local fisheries. The major seasonal Amazonian floodplains known as várzea receive their water from them.
The Caquetá moist forests (NT0107) is an ecoregion of tropical moist broad leaf forest to the east of the Andes in the east of Colombia, with a small section in Brazil, in the Amazon biome. The forests are in the transition between the Guiana and Amazon regions, and have highly diverse flora and fauna. They are relatively intact, although they are mostly unprotected and are threatened with deforestation to create cattle pastures.
Guyana occurs within the northern part of the Guiana Shield. The Guiana Shield forms the northern part of the Amazonian Craton, the core of the South American continent.
St. Ignatius is an Amerindian village in the Upper Takutu-Upper Essequibo region of Guyana, near the regional capital Lethem and the border of Brazil. It was originally a mission founded by Jesuit priests to serve the Amerindians in the Rupununi savannah.
Nappi is an indigenous village of Macushi Amerindians in the Upper Takutu-Upper Essequibo Region of Guyana. It is located in the Rupununi savannah along the Nappi and Maipaima creeks on the edge of the Kanuku Mountains.