Brazil – January 23rd, 2013
This image of the Amazon Rainforest, in Brazil, also shows the confluence of the Branco River (right) and Negro River (left), near the border of the states of Amazonas and Roraima. The Rio Branco (meaning White River) is the principal affluent of the Rio Negro (meaning Black River) from the north.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.
The Rio Negro, in turn, is the largest left tributary of the Amazon and the largest blackwater river in the world. It flows into the Rio Solimões to form the Amazon River South of Manaus, Brazil. Rio Negro is navigable for 700 kilometres (430 mi) from its mouth in 1 metre of water in the dry season, but it has many sandbanks and minor difficulties. In the wet season, it floods the country far and wide, sometimes to a width of 30 kilometres (19 mi), for long distances, and for 650 kilometres (400 mi) upstream. During this time, from April until October, it is a succession of lagoons, full of long islands and intricate channels.