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34-610: The Amazon / Solimões river just above the confluence of the Solimões and Rio Negro is already by far the largest river in the world, even though its two largest tributaries (the Negro and the Madeira River ) have not yet contributed to the flow volume. The Solimões portion of the Amazon River lies entirely in the state of Amazonas , Brazil, and some portion of the state is often referred to as

68-637: A 365 km (227 mi) loop around the unnavigable section to Guajará-Mirim on the Mamoré River, but is not functional, limiting shipping from the Atlantic at Porto Velho. Today, it is also one of the Amazon basin 's most active waterways, and helps export close to four million tons of grains, which are loaded onto barges in Porto Velho , where both Cargill and Amaggi have loading facilities, and then shipped down

102-552: A confluence of tributaries can be a true river source, though both often provide the starting point for the portion of a river carrying a single name. For example, National Geographic and virtually every other geographic authority and atlas define the source of the Nile River not as Lake Victoria 's outlet where the name "Nile" first appears, which would reduce the Nile's length by over 900 km (560 mi) (dropping it to fourth or fifth on

136-656: A river's "length may be considered to be the distance from the mouth to the most distant headwater source (irrespective of stream name), or from the mouth to the headwaters of the stream commonly known as the source stream". As an example of the second definition above, the USGS at times considers the Missouri River as a tributary of the Mississippi River . But it also follows the first definition above (along with virtually all other geographic authorities and publications) in using

170-496: A subspecies of the Amazon river dolphin or a separate species, is restricted to the upper Madeira River system. It has been estimated that there are more than 900 fish species in the Madeira River Basin, making it one of the freshwater systems in the world with the highest species richness . The river is the fifth title of the 1993/1999 Philip Glass album Aguas da Amazonia . In July 2007, plans have been approved by

204-592: Is Ilha Tupinambaranas , an extensive marshy region formed by the Madeira's distributaries. The Madeira river rises more than 15 m (50 ft) during the rainy season , and ocean vessels may ascend it to the Falls of San Antonio, near Porto Velho , Brazil, 1,070 km (660 mi) above its mouth; but in the dry months, from June to November, it is only navigable for the same distance for craft drawing about 2 meters (7 ft) of water. The Madeira-Mamoré Railroad runs in

238-530: 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

272-426: Is considered a linear geographic feature, with only one mouth and one source. For an example, the Mississippi River and Missouri River sources are officially defined as follows: The verb "rise" can be used to express the general region of a river's source, and is often qualified with an adverbial expression of place. For example: The word "source", when applied to lakes rather than rivers or streams, refers to

306-415: Is considered one of the river's sources , as it is the place where surface runoffs from rainwater , meltwater and/or spring water begin accumulating into a more substantial and consistent flow that becomes a first-order tributary of that river. The tributary with the longest course downstream of the headwaters is regarded as the main stem . The United States Geological Survey (USGS) states that

340-569: The Churn — although not without contention. When not listing river lengths, however, alternative definitions may be used. The Missouri River's source is named by some USGS and other federal and state agency sources, following Lewis and Clark 's naming convention, as the confluence of the Madison and Jefferson rivers, rather than the source of its longest tributary (the Jefferson). This contradicts

374-715: 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 mean inter-annual precipitations on the great basins vary from 75 to 300 cm (2.5–9.8 ft),

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408-616: The Itonamas or San Miguel , the Mamoré , Beni , and Madre de Dios or Mayutata , all of which are reinforced by numerous secondary but powerful affluents. The climate of the upper catchment area varies from humid in the western edge with the origin of the river's main stem by volume (Río Madre de Dios, Río Beni) to semi arid in the southernmost part with the Andine headwaters of the main stem by length ( Río Caine , Río Rocha , Río Grande , Mamoré). All of

442-560: The Smithsonian Institution , is also used by the National Geographic Society when pinpointing the source of rivers such as the Amazon or Nile . A definition given by the state of Montana agrees, stating that a river source is never a confluence but is "in a location that is the farthest, along water miles, from where that river ends." Under this definition, neither a lake (excepting lakes with no inflows) nor

476-528: The "Solimões region". The ecoregion of the Solimões River drainage basin is entirely tropical rainforest . An Amazonian aboriginal nation called Soriman was corrupted in Portuguese to Solimão and Soliemoens , from which the name of this section of the river and the region it drains is derived. Use of the name Solimões for the upper Amazon is mostly confined to Brazilian speakers of Portuguese ;

510-746: The Brazilian Government to construct two hydroelectric dams on the Madeira River, the Santo Antônio Dam near Porto Velho and the Jirau Dam about 100 km upstream. Both the Jirau and Santo Antonio dams are run-of-the-river projects that do not impound a large reservoir. Both dams also feature some environmental re-mediation efforts (such as fish ladders). As a consequence, it has been suggested that there has not been strong environmental opposition to

544-676: The Madeira to the ports of Itacoatiara , near the mouth of the Madeira, just upstream on the left bank of the Amazon, or further down the Amazon, to the port of Santarem , at the mouth of the Tapajos River. From these two ports, Panamax -type ships then export the grains - mainly soy and corn - to Europe and Asia. The Madeira waterway is also used to take fuel from the REMAN refinery ( Petrobras ) in Manaus , state capital of Amazonas , to Porto Velho , from where

578-400: The combined Missouri—lower Mississippi length figure in lists of lengths of rivers around the world. Most rivers have numerous tributaries and change names often; it is customary to regard the longest tributary or stem as the source, regardless of what name that watercourse may carry on local maps and in local usage. This most commonly identified definition of a river source specifically uses

612-517: The discharge of the Congo River . On the further course towards the Amazon, the mean discharge of the Madeira increases up to 31,200 m /s (1,100,000 cu ft/s). Between Guajará-Mirim and the falls of Teotônio, the Madeira receives the drainage of the north-eastern slopes of the Andes from Santa Cruz de la Sierra to Cuzco , the whole of the south-western slope of Brazilian Mato Grosso and

646-436: The entire upper Madeira basin receiving 170.5 cm (5.6 ft). The greatest extremes of rainfall are between 49 and 700 cm (1.6–23 ft). Even just below the confluence that forms it, the Madeira is one of the largest rivers by discharge of the world, with a mean inter-annual discharge of 18,000 cubic metres per second (640,000 cu ft/s), i.e., 568 km (136 cu mi) per year, approximately half

680-530: The implementation of the Madeira river complex. Yet, if the fish ladders fail, "several valuable migratory fish species could suffer near-extinction as a result of the Madeira dams." There are also concerns with deforestation and pressure on conservation areas and indigenous peoples' territories. The Worldwatch institute has also criticized the fast-track approval process for "kindler, gentler dams with smaller reservoirs, designed to lessen social and environmental impacts", claiming that no project should "fast-track

714-644: The impounded reservoir and the downstream river. If the project is completed, "more than 4,000 km [2,500 mi] of waterways upstream from the dams in Brazil, Bolivia, and Peru would become navigable." As typical of Amazonian rivers with the primary headwaters in the Andes, the Madeira River is turbid because of high sediment levels and it is whitewater , but some of its tributaries are clearwater (e.g., Aripuanã and Ji-Paraná ) or blackwater (e.g., Manicoré ). The Bolivian river dolphin , variously considered

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748-467: The latter tributary the flow of river changes to north-eastward direction, inland of Rondônia state of Brazil. The section of the river from the border to Porto Velho has notable drop of bed and was not navigable. Before 2012 the falls of Teotônio and of San Antônio existed here, they had higher flow rate and bigger level drop than more famous Boyoma Falls in Africa. Currently these rapids are submerged by

782-497: The licensing of new dams in Amazonia and allow projects to circumvent Brazil's tough environmental laws". Indigenous languages of the upper Madeira River basin (in Brazil, Bolivia, and Peru): Note : † = extinct language Headwaters The headwater of a river or stream is the point on each of its tributaries upstream from its mouth / estuary into a lake / sea or its confluence with another river. Each headwater

816-558: The list of world's rivers), but instead use the source of the largest river flowing into the lake, the Kagera River . Likewise, the source of the Amazon River has been determined this way, even though the river changes names numerous times along its course. However, the source of the Thames in England is traditionally reckoned according to the named river Thames rather than its longer tributary,

850-598: The melting of glacial ice . Headwater areas are the upstream areas of a watershed , as opposed to the outflow or discharge of a watershed. The river source is often but not always on or quite near the edge of the watershed, or watershed divide. For example, the source of the Colorado River is at the Continental Divide separating the Atlantic Ocean and Pacific Ocean watersheds of North America . A river

884-636: The most common definition, which is, according to a US Army Corps of Engineers official on a USGS site, that "[geographers] generally follow the longest tributary to identify the source of rivers and streams." In the case of the Missouri River, this would have the source be well upstream from Lewis and Clark's confluence, "following the Jefferson River to the Beaverhead River to Red Rock River , then Red Rock Creek to Hell Roaring Creek ." Sometimes

918-496: The most distant point (along watercourses from the river mouth ) in the drainage basin from which water runs year-around ( perennially ), or, alternatively, as the furthest point from which water could possibly flow ephemerally . The latter definition includes sometimes-dry channels and removes any possible definitions that would have the river source "move around" from month to month depending on precipitation or ground water levels. This definition, from geographer Andrew Johnston of

952-546: The northern slope of the Chiquitos sierras. In total, this catchment area, which is slightly more than the combined area of all headwaters, is 850,000 km (330,000 sq mi), almost equal in size to France and Spain combined. The waters flow into the Madeira from many large rivers, the principal of which, (from east to west), are the Guaporé or Iténez , the Baures and Blanco ,

986-464: The reservoir of Santo Antônio Dam . Below Porto Velho the Madeira meanders north-eastward through the Rondônia and Amazonas states of north west Brazil to its junction with the Amazon . The 283,117 hectares (2,800 km ; 1,100 sq mi) Rio Madeira Sustainable Development Reserve , created in 2006, extends along the north bank of the river opposite the town of Novo Aripuanã . At its mouth

1020-545: The rest of the country are concerned, to bring in part of its raw materials, and export its produce to the major consumer centres of São Paulo and Rio de Janeiro . In 2012, the cargo amounted to 287,835 tons (both directions). The total tonnage shipped in 2012 on the Madeira accounted to 5,076,014. Two large dams (see below) are under construction as part of the IIRSA regional integration project. The dam projects include large ship-locks capable of moving oceangoing vessels between

1054-489: The rest of the world refers to both the upper and lower portions of the river as the Amazon . 04°38′09″S 70°15′57″W  /  4.63583°S 70.26583°W  / -4.63583; -70.26583 This article related to a river in the Brazilian state of Amazonas is a stub . You can help Misplaced Pages by expanding it . Madeira River The Madeira River (Portuguese: Rio Madeira [maˈdejɾɐ] )

Solimões River - Misplaced Pages Continue

1088-501: The source of the most remote tributary may be in an area that is more marsh -like, in which the "uppermost" or most remote section of the marsh would be the true source. For example, the source of the River Tees is marshland . The furthest stream is also often called the head stream. Headwaters are often small streams with cool waters because of shade and recently melted ice or snow. They may also be glacial headwaters, waters formed by

1122-450: The states of Acre , Rondônia and parts of Mato Grosso are supplied mainly with gasoline (petrol) refined in Manaus . Cargo barges also use the Madeira on the route between Manaus and Porto Velho, which is 1,225 km (760 mi) along the Rio Negro , Amazon and Madeira, connecting Manaus' industrial district with the rest of Brazil, as Manaus is land-locked as far as logistics with

1156-491: The upper branches of the river Madeira find their way to the falls across the open, almost level Mojos and Beni plains, 90,000 km (35,000 sq mi) of which are yearly flooded to an average depth of about one meter (3 ft) for a period of from three to four months. From its source in the confluence of Madre de Dios and Mamoré rivers and downstream to Abuna River the Madeira flows northward forming border between Bolivia and Brazil . Below its confluence with

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