The hydrography of Brazil is very wide and has a series of diversified watersheds, of which the Amazon Basin, the Paraná Basin, the Tocantins-Araguaia, Uruguay and San Francisco. In them are rivers of great importance, such as Amazonas, Paraná, Tocantins and São Francisco.
Most of these rivers are fed by rainwater, characterizing them as rainwater rivers. In the highlands, these rivers act as relief transformers because they carry sediments from plateau areas and deposit elements in lowland areas.
It is located in the northern region of the country. It is considered the second longest river in the world, with 6,992 km long, and runs 3,165 km through the Brazilian territory. It is a plain river, with a smooth and progressive drop of only 82 meters, which provides excellent sailing conditions.