Eric Schill
Professor Kelly
Geography in History
4 November 2008
Rio Negro River
The Rio Negro River is one the major tributaries of the Amazon River; it’s strategic location, and unique characteristics make it one of the most interesting rivers in the world.
The Amazon River is the largest river in South America, and the largest
drainage system in the world in terms of volume of its flow as well as the area
of its basin. The Amazon River is estimated to account for 1/5 of the world’s
river flow. The Amazon River is estimated to have a total length of 4000 miles
measured from the headwaters of the Ucayali-Apurímac river
system in Peru. The Amazon is still slightly smaller than the great Nile River,
but has a length equivalent to the distance from New York City to Rome (Amazon
1).
The Amazon River has a series of major
river systems in both Peru and Ecuador; it also includes other rivers such as
the Morona, Pastaza, Chambira, Tigre, Nanay, and the Napo.
The most
distant source of the Amazon River is a glacial stream located 18,000 ft up in
the Peruvian Andes Mountains. The Union of the Ucayali,
and the Maranon Rivers form the great Amazon River. The River systems and flood
plains in Brazil, Peru, Ecuador, Colombia, and Venezuela, whose waters drain
into the native called Solimoes (Amazon) River is known as the “Upper Amazon”
(Lathrap 24). The Amazon River runs through mostly Brazil and Peru, but
branches off in Venezuela, Colombia, Ecuador, and Bolivia (Amazon 1).
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The Amazon basin is the largest Lowland in
Latin America containing an area of nearly 2.7 million square miles. The basin
is twice as large as the world’s other great basin known as the Congo River
system. Nearly 2/3 of the river’s main stream, as well as the largest part of its
basin is located in Brazil. The flood-stage discharge
at the river's mouth is four times that of the Congo and more than 10 times the
amount carried by the Mississippi River. The immense volume of fresh water that
flows into the ocean water dilutes the waters saltiness for more than 100 miles
from shore. The extensive amounts of low-lands which border the river are
subject to annual flooding each year. During the rainy season the average depth
of the river is 131 ft, and can reach a width of 25 miles wide. The river
begins to rise in November, and increases in volume until early June. However,
the Negro branch of the Amazon does not have its rainy season until February or
March, and then is full by June, and begins to fall with the Amazon (Amazon 1).
Nearly 2/3 of the entire Amazon basin
consists of tropical rainforest. The rainforest grades into dry forest and
savanna to the North and South, and to the West turns
into montane forest in the Andes. More than 1/3 of all species in the world
live in the Amazon Rainforest. The Amazon River has more 3000 species of fish.
It contains species such as the Boto (river dolphin), and the notoriously
dangerous Piranha. The Basin is home to the Bull Shark, and the largest snake
in the world, the Anaconda (Lathrap 48). The Amazon Rainforest represents half
of the world’s remaining rainforest, and constitutes for the single largest
reserve of biological resources. Due to human activities in the basin,
deforestation has increased dramatically especially south of the river, and on
the outwash of the Andes. Significant mineral discoveries in the region have
brought an influx of settlers, corporations, and researchers into the region
(Amazon 1).
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The mouth of the Amazon River is 210 miles
wide, and is measured from Cabo do Norte to Punto Patijoca. The beautiful
island Marajo is located at the mouth of the river, and is the largest island
to be completely surrounded by fresh water in the world. The main river of the
Amazon is between 1 and 6 miles wide, and is navigable for large ocean steamers
to Manaus, which is about 930 miles up river from the mouth. Smaller vessels
weighing less than 3000 tons can reach as far as Loreto, Peru, which is about
2,240 miles, from the sea. Small river boats are able to go 485 miles higher,
which takes them to Achual Point. Beyond that the river is not navigable, and
smaller boats can make it just above Achual Point (Czaya 131-133).
The Rio Negro is located in northwestern
Brazil and eastern Colombia. The river begins as the Rio Guainia in
southwestern Colombia. The river flows northeasterly before turning to the
south where it forms part of the boundary between Colombia and Venezuela. The
Negro then changes directions once again and flows southeasterly through what
is known as the Amazonas state (Brazil). The river then joins the Amazon River
11 miles below Manaus, which is the major upriver town of the Amazon River. The
black waters of the Rio Negro join the light brown waters of the Amazon River
at the Encontro das Agaus, which means the meeting of the waters. In actuality
the two rivers flow side by side for several miles before the waters actually
merge.
The river is
filled with many islands, and has many secondary channels as well (Penn 170).
The river is navigable for about 450 miles
in its dry season, and is a total of 1,400 miles long. One of the main
tributaries of the Negro River is the Branco River. Boaters encounter many sand
banks and other minor difficulties while navigating the river. During the wet
season the river can flood up to 20 miles wide and 400 miles up. During this
time the river becomes a succuession of
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lagoons full of islands and
channels, which reach as far as Santa Isabel do Rio Negro. The foothills of the
great Andes Mountains are located just before the Vaupes River. At this point
of the river the Negro becomes very narrow, and is filled with very large
rocks, of which it flows into giant cataracts, rapids, and whirlpools. Despite
some of these very large and often dangerous parts of the river, Canoes and
motorboats are able to ascend past Sao Gabriel da cachoeira to the Andes
Mountains (Penn 170).
The name Rio Negro means “Black River”,
but its waters are not exactly black. The true color of the water is similar
too a cup of really strong tea, which has a very dark brown color. The color of
the river comes from the tannin-rich mulch of the rainforest floor. When it
rains or floods, all of the soils and vegetation from the floor of the
rainforest are washed out and flow into the river, which gives it such a
distinct color. The dark color also comes from humic acid, which is a result of
the incomplete breakdown of phenol containing vegetation from sandy clearings
(Penn 171).
The Negro River is connected with the
Orinoco basin via the Casiquiare waterway, which was first explored by
Alexander von Humboldt. The river was first named by the Spanish explorer
Francisco de Orellana, who first discovered it in 1541. By the middle of the 17th
century Jesuits had settled along the banks of the river. The Jesuits lived
amongst the Manau, Aruak, and Taruma Indians. After the year 1700, as with
mostly all settlements in the new world, slavery began to develop along the
river. It was during this time that the Indian population started to diminish
due slavery and contact with infectious European diseases. It was in this very
area where scientific explorers first began investigating the river. Scientists
such as Alexander von
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Humboldt,
Alfred Russel Wallace, Henry Walter Bates, and Richard Spruce all investigated
the area. Wallace investigated the biography of the Negro River, while Bates
studied the main-stem Amazon River. Wallace discovered that the surrounding
rainforest of the river had a rich diversity of species. Wallace’s later
discovery in Malay archipelago, led him to a theory of
organic evolution that he proposed independent of Charles Darwin’s theory (Penn
171).
The Rio Negro River along with other black
water rivers is said to be a “hunger river.” However, the Negro River is the
exact apposite of what is believed; it happens to support a large fishing
industry, and has numerous turtle beaches. The Fisheries sector along the
Amazon and Negro
Rivers generates an estimated 389 million dollars a year, and employs and
estimated 168,315 people. The major share of employment is generated by
subsistence, and commercial fishing activity, while most of the income is
generated in the processing industry. There is an estimated 7,500 fishing boats
located on the Amazon River, which concludes that a substantial part of the
Amazon area relies on fishing for survival. In other areas along the Negro
River mining and forestry are major parts of the economy. As stated above the
majority of the economy is based on fishing. This is proven by looking beyond
the river bank, and into the villages and cites that rest by the river. Most of
the cities consist of Restaurants, which sell fish as their main course, fish
processing plants, gas stations that are responsible for re-fueling the
vessels, boat factories, and fishing supply companies. All of these areas of
the economy have a heavy reliance on the fishing industry, without it many
people would be out of jobs, and would be unable to feed their families
(Almeida 2-8).
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The Negro River is one of the most
important tributaries of the Amazon River, not only is it thriving with wildlife,
but it is home to one of the world’s largest fresh water fishing industries in
South America.
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Works Cited
Almeida, O.
“The Commercial Fishing Sector In the Regional Economy of the Brazilian
Amazon.” London:
Imperial College Press, 2003.
“Amazon River.” Encyclopedia Britannica. 2008. Encyclopedia
Britannica Online. 2 Nov. 2008
<http://0-search.eb.com.alicat.adelphi.edu:80/eb/article-9109565>.
Czaya, Eberhard.
Rivers of the World. New York: Van Nostrand
Reinhold Company Inc,
1981.
Lathrap,
Donald. The Upper Amazon. New York: Praeger
Publishers Inc, 1971.
Penn, James. Rivers
of The World: A Social, Geographical, and
Environmental Sourcebook.
California: ABC Clio Inc, 2001.
Maps:
“Joining of the Rivers.” Online map/still. NASA. 2 November 2008.
http://www.nasa.gov/multimedia/imagegallery/image_feature_577.html
“Rio Negro River.” Online map/still. MSN Encarta. 2
November 2008.
http://encarta.msn.com/map_701516012/Negro_R%C3%ADo_
(Colombia_Venezuela_Brazil).html
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Maps:
Joining of Rio Negro and The Amazon Rivers:
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Rio Negro River:
