The region covered by fresh water in the interior of Brazil occupies 55,457 km2, which is equivalent to 1.66% of the planet’s surface. The country’s humid climate provides a large hydrographic network formed by rivers of great volume of water, all of which flow into the sea. With the exception of the headwaters of the Amazon River, which receive water from melting snow and glaciers, the origin of the waters of Brazilian rivers is found in the rains. Most rivers are perennial, that is, they do not become extinct in the dry season. Only in the northeastern hinterland, a semi-arid region, there are temporary rivers.
The basins of the Brazilian rivers are formed from three major divides: the Brazilian plateau, the Guianas plateau and the Andes mountain range. According to the form of relief that they cross, the hydrographic basins can be divided into two types: the plateaus, which allow hydroelectric use, and the plain, weak current, used for navigation. There are four main Brazilian hydrographic basins: Amazon, Silver or Platinum; São Francisco and Tocantins.
Amazon Basin – It has the largest water surface in the world (3,889,489.6 km2). The Amazon River, with 6,515 km in length, has more than seven thousand tributaries, being the second in the planet in length and the first in water flow (100 thousand m3 per second). It is born on the plateau of La Raya, in Peru, under the name of Vilcanota, and along its route it also receives the names of Ucaiali, Urubanda and Marañon. In Brazilian territory, it first receives the name of Solimões, so that, from the confluence with the Negro river, near the city of Manaus, capital of the state of Amazonas, it becomes known as the Amazon river. Although it is a lowland basin, with 23,000 navigable km, the Amazon basin also has great hydroelectric potential.
La Plata Basin – It spreads over an area of 1,393,115.6 km 2 and is formed by the Paraná, Paraguay and Uruguay rivers, which are born in Brazil and will later form the La Plata River on the border between Argentina and Uruguay. The Paraná River has the largest hydroelectric potential in the country, which led to the construction of the Itaipu plant on the border with Paraguay. The Uruguay River also has hydroelectric potential in its course. The Paraguay River, which flows through the Pantanal plain, is widely used for navigation.
São Francisco Basin – It occupies an area of 645,876.6 km 2 and its main river, the São Francisco, is the only source of water in the semi-arid region of Northeast Brazil. With reasonable hydroelectric potential, it has an important plant in the state of Bahia, called Paulo Afonso. Despite being a Planalto river, it has 2,000 navigable km between the cities of Pirapora in the state of Minas Gerais and Juazeiro in the state of Bahia.
Tocantins-Araguaia Basin – It is the largest basin in Brazilian territory, with 808,150.1 km 2 . Its main river is Tocantins, which rises in the state of Goiás and flows into the mouth of the Amazon River, in the state of Pará. Taking advantage of its hydroelectric potential, it is home to the Tucuruí plant, located in the state of Pará.
There are five groups of islands far from the coast in Brazilian territory, which present stunning scenery and very rich fauna: Penedos de São Pedro and São Paulo, Atol das Rocas, Fernando de Noronha, Abrolhos, Trindade and Martim Vaz.
Penedos de São Pedro and São Paulo – Located about 900 km northeast of the state of Rio Grande do Norte, they form rocks in the shape of a half moon, covered with guano (sea bird feces) and surrounded by dangerous reefs.
Atol das Rocas – It is a small island formed by corals, difficult to access due to the large number of reefs, located 240 km northeast of the state of Rio Grande do Norte. On this island, in 1979, the country’s first biological reserve was created.
Fernando de Noronha – Archipelago of 18.4 km2, formed by 19 islands is located 345 km east of the state of Rio Grande do Norte. In 1988, it was transformed into a National Marine Park and annexed to the state of Pernambuco.
Abrolhos – It is located 80 km from the south coast of the state of Bahia, in an area where there is an intense movement of maritime navigation. The archipelago is formed by five coral islets and has a lighthouse built in 1861, in addition to a population of about 15 people.
Trindade and Martim Vaz – Located 1,100 km off the coast in the city of Vitória, capital of the state of Espírito Santo, in the Southeast region, these islands have belonged to Brazil since 1897 and, being located in the anticyclone area of the South Atlantic, they are used as the base of the Brazilian navy and meteorological station.
The richness and diversity of Brazilian natural resources and their geographical accidents have been the object of study and observation by scientists, academics, governmental bodies linked to the environment, both in Brazil and abroad, or simply people interested in getting to know better. nature and enjoy what it has to offer. There is a great effort on the part of the Brazilian government to preserve and publicize this potential for natural wealth and ecological diversity found in its territory, which provides different options both for interests related to economic investment, and for the enjoyment from the tourist and ecological point of view.