Thanks to its privileged geographical situation – located on the South American coast closest to Europe – Rio Grande do Norte has always had a unique strategic importance. As the 16th century Portuguese said, “it is the closest land that exists in Brazil”.
According to health-beauty-guides.com, the state of Rio Grande do Norte, in the Northeast region, occupies an area of 53,307 km2, mostly included in the so-called Polígono das Secas . It is limited to the north and east with the Atlantic Ocean, to the south with Paraíba to the west with Ceará. The capital is Natal.
Geology and relief
About 83% of the state’s territory is below 300m and 60% below 200m. Two relief units make up the morphological picture: lowland and plateau. The plateau, the northern tip of Borborema, penetrates the state from the south, moving far away from the eastern coast, unlike what occurs in the states of Paraíba and Pernambuco. It has a grayish back and lower than in the state of Paraíba (only north of Currais Novos reaches the plateau at an altitude of 800m), tortuous and not very steep edge.
The lowlands surround the plateau on the east, north and west sides. They comprise the sandstone boards, arranged along the eastern and northern coastlines; the strip of low crystalline terrains located to the east of Borborema; the large tabular surface in the Apodi plateau (200m altitude), located in the northeast of the state and cut by the valleys of the Apodi and Piranhas rivers; and finally the crystalline peneplane, with its large extensions of wavy relief, from which sparse crystals and isolated peaks emerge. Another form of relief characteristic of the lowlands is the alluvial plain that develops along the main rivers, especially Piranhas and Apodi.
In the southwestern portion of the state there are some isolated massifs with an altitude of about 600m, among which the mountains of São Miguel, Martins and Luís Gomes stand out. It is called the mountain region of Rio Grande do Norte.
Three types of climate occur in the state: the tropical humid, with autumn-winter rains (As ‘of the Köppen system), the warm semi-arid (BSh) and the tropical semi-humid (Aw’), with autumn rains. . The humid tropical climate occurs in the eastern coastal lowlands. It registers an average temperature of 24 ° C and a rainfall of 1,000 mm, which decreases rapidly from the coast to the interior, reaching 600 mm just fifty kilometers from the coast.
The warm semi-arid climate dominates practically the rest of the state, including the northern coast, giving way to a very dry coast. Average temperatures reach 26o C inland and rainfall, below 600mm, is subject to great irregularity, with the autumn rainy season not occurring in some years. The semi-humid tropical occurs only in the far west. It also records average high temperatures and autumn rains more abundant than in the semi-arid area (more than 600mm per year), especially in the mountainous region, to the southwest.
The wide coastal plain of Rio Grande do Norte is the only coastal region in Brazil with a semi-arid climate. There, reduced rainfall, dry and constant winds and high temperatures make the state the largest Brazilian salt producer, with 77 to 85% of national production, depending on the year.
The hydrographic network comprises rivers that flow towards the eastern coast and rivers that flow towards the northern coast. The latter are the most extensive in the state, such as Apodi and Piranhas or Açu. The great basin of this includes the western portion of Paraíba.
All rivers in Rio Grande do Norte have an intermittent regime: they register great floods in the rainy season and disappear during the dry season. Inland, numerous dams were built, giving rise to dams such as Cruzeta, Gargalheiras and Itãs. At the mouth of the rivers on the eastern coast, there are numerous lagoons, which also occur in the floodplains of the Piranhas and Apodi rivers.
Three vegetation formations cover the territory of Rio Grande do Sul: the tropical forest, the wild and the caatinga. The tropical forest is found only in a small area located to the southeast, where it forms the northern end of the coastal forest that gives its name to the northeastern forest zone.
The wild, with a less exuberant forest than the previous one, presents a type of transition vegetation to the semi-arid climate of the sertão, with mixed composition, with species from the tropical forest and the caatinga. It dominates the entire eastern portion of Rio Grande do Norte, the only state in which this vegetation reaches the coast.
The caatinga covers the central and western portions of the state. It is the type of vegetation that occupies the largest area, with approximately ninety percent of the state’s surface. In the coastal border, the characteristic mangrove vegetation is observed.
The most populated strip is that of the eastern coastal lowlands, especially in the microregion of Natal, the most humid region in the state. In the other regions, the densities are greatly reduced, in the following decreasing order, by region: rough, southwestern mountain microregion, saline, Borborema, Seridó, Serra Verde, Açu and Apodi, coast of São Bento do Norte and sertão de Angicos.
The entire state territory is part of the area of influence of the city of Recife PE. The economic action of the Pernambuco metropolis takes place in the state through two regional capitals, Natal and Campina Grande PB. The first serves the entire eastern and northern portion of the state, while the second serves only the southwest portion. Among the most important cities in Rio Grande do Norte, in addition to the capital, Mossoró, Parnamirim, Ceará-Mirim, São Gonçalo do Amarante, Caicó, Açu and Currais Novos stand out.