
Amazon / Travel & Tours – The Amazon River Basin is located in the central part of the
Amazon Rainforest biome,
representing the largest drainage basin on Earth.
It covers 7 million square kilometers in
Brazil (3,8),
Peru, Colombia, Ecuador, Venezuela and Bolivia and provides about 1 / 5 of the World's fresh water demand.
This basin is limited to the north by the shield of
Guianas and to the south by the shield of
Guaporé
(see
geology).
It is entirely covered by dense tropical rainforest (see
vegetation)
In accordance to the color of its waters, the rivers of the Amazon basin are classified as:
Rios de Águas Claras
The "clear water rivers" descend from the plateau of
Guaporé in northern direction (
Xingu,
Tapajós,
Tocantins and
Araguaia)
and are relatively poor in sediments.
Rios de Águas Brancas
The "white water rivers" have their springs in the Andes (
Solimões,
Purus,
Madeira) and carry soils which are relatively rich
in sediments and nutrients. These sediments are deposited along the shore of the rivers, forming the so-called
várzeas
(see
ecosystems).
Rios de Águas Pretas
The "black water rivers" descend from the
Guianas Plateau in southern direction (
Negro,
Branco) and are poor in sediments.