The Amazon River in South America is the second longestriver in the world and is by far the largest by waterflow with an average discharge greater than the next seven largest rivers combined(not including Madeira and Rio Negro, which are tributaries of the Amazon). The Amazon, which has the largest drainage basin in the world, about 7,050,000 square kilometres (2,720,000 sq mi), accounts for approximately one-fifth of the world’s total river flow. In fact, the river becomes biggest in the world even just entering Brazil, at only 1/5 of its final discharge into the Atlantic.
The width of the Amazon is between 1.6 and 10 kilometres (1.0 and 6.2 mi) at low stage but expands during the wet season to 48 kilometres (30 mi) or more. The river enters the Atlantic Ocean in a broad estuary about 240 kilometres (150 mi) wide. The mouth of themain stem is 80 kilometres (50 mi). Because of its vast dimensions, it is sometimes called The River Sea. The first bridge in the Amazon river system (over the Rio Negro) opened on 10 October 2010 near Manaus, Brazil.
The Amazon river has a series of major river systems in Colombia, Ecuador and Peru, some of which flow into the Marañón and Ucayali, others directly into the Amazon proper. Among others, these include the following rivers: Putumayo, Caquetá, Vaupés, Guainía, Morona, Pastaza, Nucuray, Urituyacu,Chambira, Tigre, Nanay, Napo, and Huallaga.
More than one-third of all known species in the world live in the Amazon Rainforest, a giant tropical forest and river basin with an area that stretches more than 5,400,000 square kilometres (2,100,000 sq mi). It is the richest tropical forest in the world in terms of biodiversity. There are over 2,100 species of fish currently recognized in the Amazon Basin, with more being discovered every year.
The Amazon River in South America is an amazing and important river for the planet and therefore, you need to know about it. Here are the eight most important things you need to know about the Amazon River:
1. The Amazon River carries more water than any other river in the world. In fact, the Amazon River is responsible for about one-fifth (twenty percent) of the fresh water that flows into the world’s oceans.
2. The Amazon River is the second longest river in the world (the Nile River in Africa is the longest) and is about 4,000 miles (6400 km) long. (In July 2007 a group of scientists reportedly determined that the Amazon River might just be the longest river in the world, taking that title from the Nile River. It will take further studies to substantiate the claim and for the Amazon River to be recognized as the longest.)
3. The Amazon River has the largest watershed (area of land that flows into the river) and more tributaries (streams that flow into it) than any other river in the world. The Amazon River has more than 200 tributaries.
4. Streams that begin in the Andes Mountains are the starting sources for the Amazon River.
5. Most of the runoff of Brazil flows into the Amazon River along with runoff from four other countries: Peru, Bolivia, Colombia, and Ecuador.
6. Due to the vast amount of water as well as sediment that are deposited where the Amazon River meets the Atlantic Ocean, the color and salinity of the Atlantic Ocean are modified for nearly 200 miles (320 km) from the delta.
7. For much of its path, the Amazon River can be as much as one to six miles wide! During flood seasons, the Amazon River can be much, much wider; some report it is more than 20 miles wide (32 km) in certain places.
8. The Amazon River taken different routes since it began to carry water. Some scientists have determined that the Amazon River even flowed west at one time or more, into the Pacific Ocean.
Sources :
http://geography.about.com/od/specificplacesofinterest/a/amazonriver8.htm