请输入您要查询的百科知识:

 

词条 Branco River
释义

  1. Basin

  2. Water chemistry

  3. River capture

  4. Citations

     Notes  References 
{{about|the river in Roraima, Brazil|other rivers with the same name|}}{{Infobox river
| name = Branco River
| name_native = Rio Branco
| name_native_lang =
| name_other =
| name_etymology =
| image = Rio Branco sul.JPG
| image_size = 300
| image_caption = Branco River in Boa Vista city, Roraima state, Brazil. The Macuxi Bridge, {{convert|1.2|km|mi|abbr=on}} long,[1] can be seen in the background.
| map = Negroamazonrivermap.png
| map_size = 300
| map_caption = The Branco River is a tributary of the Rio Negro (highlighted on map)
| pushpin_map =
| pushpin_map_size = 300
| pushpin_map_caption=
| subdivision_type1 = Country
| subdivision_name1 = Brazil
| subdivision_type2 =
| subdivision_name2 =
| subdivision_type3 =
| subdivision_name3 =
| subdivision_type4 =
| subdivision_name4 =
| subdivision_type5 =
| subdivision_name5 =
| length = {{convert|560|km|mi|abbr=on}}[2]
| width_min =
| width_avg =
| width_max =
| depth_min =
| depth_avg =
| depth_max =
| discharge1_location=
| discharge1_min =
| discharge1_avg = {{convert|5400|m3/s|cuft/s|abbr=on}}
| discharge1_max =
| source1 =
| source1_location = confluence of Takutu and Uraricoera Rivers, Roraima, Brazil
| source1_coordinates=
| source1_elevation =
| mouth =
| mouth_location = Rio Negro, Roraima, Brazil
| mouth_coordinates = {{coord|1|23|38|S|61|50|46|W|display=inline,title}}
| mouth_elevation =
| progression =
| river_system =
| basin_size =
| tributaries_left =
| tributaries_right =
| custom_label =
| custom_data =
| extra =
}}

The Branco River ({{lang-pt|Rio Branco}}; Engl: White River) is the principal affluent of the Rio Negro from the north.

Basin

The river drains the Guayanan Highlands moist forests ecoregion.[3]

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.[4] 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.[5]

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 {{convert|350|mi|km}} long, up to its Uraricoera confluence. It has numerous islands, and, {{convert|235|mi|km}} above its mouth, it is broken by a bad series of rapids.

Water chemistry

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.[6] It is traditionally considered a whitewater river,[7][8] although the major seasonal fluctuations in its physico-chemical characteristics makes a classification difficult and some consider it clearwater.[9][10] 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.[6] Furthermore, its chemistry and color may contradict each other compared to the traditional Amazonian river classifications.[9] The Branco River has pH 6–7 and low levels of dissolved organic carbon.[10]

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.[11] 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.[10]

River capture

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.[12] 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.[5]

Citations

Notes

1. ^UOL. Turismo em Boa Vista. Access on Feb 17 2012.
2. ^{{cite book |last1=Ziesler |first1=R. |last2=Ardizzone |first2=G.D. |title=The Inland waters of Latin America |year=1979 |url=http://www.fao.org/docrep/008/ad770b/AD770B05.htm |publisher=Food and Agriculture Organization of the United Nations |isbn=92-5-000780-9 |chapter=Amazon River System |archiveurl=https://web.archive.org/web/20141108152358/http://www.fao.org/docrep/008/ad770b/AD770B05.htm |archivedate=8 November 2014 |deadurl=no}}
3. ^{{citation |title=South America: Southern Venezuela, northern Brazil, western Guyana, and eastern Colombia (NT0124)|publisher=WWF: World Wildlife Fund |last=Sears |first=Robin |url=http://www.worldwildlife.org/ecoregions/nt0124|accessdate=2017-04-01}}
4. ^{{cite web|title=Map of the Branco or Parimé River and of the Caratirimani Uararicapará Majari, Tacutú and Mahú Rivers|url=http://www.wdl.org/en/item/816|publisher=World Digital Library|accessdate=27 April 2013}}
5. ^{{cite book| editors=Quinn, J.A.; and S.L. Woodward | year=2015 | title=Earth's Landscape: An Encyclopedia of the World's Geographic Features | volume=1 | page=142 | isbn=978-1-61069-445-2 }}
6. ^The Alfred Russel Wallace page: On the Rio Negro. Retrieved 10 October 2017.
7. ^{{cite journal | authors=Venticinque; Forsberg; Barthem; Petry; Hess; Mercado; Cañas; Montoya; Durigan; and Goulding | year=2016 | title=An explicit GIS-based river basin framework for aquatic ecosystem conservation in the Amazon | journal=Earth Syst. Sci. Data | volume=8 | pages=651-661 | doi=10.5194/essd-8-651-2016 }}
8. ^{{cite book| editor1=Val, A.L.|editor2=V.M.F. de Almeida-Val|editor3=D.J. Randall | year=2013 | title=Fish Physiology: The Physiology of Tropical Fishes | page=27 | isbn=978-0-12350-445-6 }}
9. ^{{cite web | authors=Ríos-Villamizar, E.A.; M.T.F. Piedade; J.G. da Costa; J.M. Adeney; and J. Junk | year=2013 | title=Chemistry of different Amazonian water types for river classification: A preliminary review | url= https://www.researchgate.net/publication/271427552_Chemistry_of_different_Amazonian_water_types_for_river_classification_A_preliminary_review }}
10. ^{{cite journal | authors=de Souza kodra, A.; M.N. Fernandes; and W.L. Paxiúba Duncan | year=2014 | title=Effect of clearwater on osmoregulation of cururu ray, Potamotrygon sp. (Chondrichthes; Potamotrogonidae), an endemic species from blackwater river | journal=Scientia Amazonia | volume=3 | issue=1 | pages=15-24 }}
11. ^[https://ebooks.adelaide.edu.au/h/humboldt/alexander/travels/chapter25.html Alexander von Humboldt, Personal Narrative of Travels to the Equinoctial Regions of America During the Years 1799-1804, (chapter 25). Henry G. Bohn, London, 1853.]
12. ^{{Cite book|url=http://urlib.net/8JMKD3MGP3W34P/3LSDRJB|title=Evolução quaternária do Rio Branco - norte da Amazônia - com base em dados orbitais e geológicos.|last=Cremon|first=É. H.|publisher=|year=2016|isbn=|publication-place=Tese (Doutorado em Sensoriamento Remoto) - Instituto Nacional de Pesquisas Espaciais (INPE), São José dos Campos|pages=}}

References

  • Encyclopædia Britannica Online.com: "Branco River" . retrieved 19 September 2009.
{{Commons category|position=left|Rivers of Roraima}}{{-}}

4 : Rivers of Roraima|Tributaries of the Rio Negro (Amazon)|Boa Vista, Roraima|Guayana Highlands

随便看

 

开放百科全书收录14589846条英语、德语、日语等多语种百科知识,基本涵盖了大多数领域的百科知识,是一部内容自由、开放的电子版国际百科全书。

 

Copyright © 2023 OENC.NET All Rights Reserved
京ICP备2021023879号 更新时间:2024/9/28 9:33:55