Rondônia, Brazil Overview

In 1956, by an act of the National Congress, the former territory of Guaporé was named Rondônia in honor of the great explorer of the region, Marshal Cândido Mariano da Silva Rondon, who at the beginning of the 20th century extended the lines of the telegraph to the western border from the country.

The state of Rondônia is located in the northern region of Brazil. With a surface of 238,513km2, it is limited to the south with Bolivia, to the east with the state of Mato Grosso, to the west with Acre, and to the north with the Amazon. The capital is Porto Velho.

Physical geography


About 66% of the territory’s surface is between 100 and 300m of altitude; thirty percent, between 300 and 800m; and four percent, below 100m. Three units make up the morphological picture: the crystalline plateau, the chapadão and the alluvial plain.

The crystalline plateau occupies most of the state. Its undulating terrain, carved in crystalline rocks, constitutes an extension, to the northwest, of the northern slope of the central Brazilian plateau. The chapadão, which rises above the crystalline plateau, has a tabular topography cut in sedimentary terrains and reaches the highest altimetric levels of Rondônia.

With an elongated shape, it crosses the state from southeast to northwest, with the name, at the northwest end, of the Serra or Chapada dos Parecis and Serra dos Pacaás Novos. The floodplain forms a narrow strip of flat land, subject to flooding, which develops along the course of the Guaporé River.

Climate and hydrography

In Rondônia, the humid tropical climate with little dry season predominates (Am de Köppen). The rainfall ranges from 1,900mm in the south to 2,500mm in the north. The temperature remains high throughout the year, with annual averages over 26 ° C.

All rivers in the state belong to the Madeira River basin, a tributary of the Amazon. The chapadão forms the watershed between the rivers that flow directly to Madeira, located in the eastern part of the state, and those in the western region, which flow to Mamoré and Guaporé.


About seventy percent of Rondônia’s surface is covered by the Amazon rainforest. The remaining thirty percent correspond to cerrados and cerradões that line the tabulate surface of the chapadão. However, deforestation, which accelerated in the mid-1980s, for the exploitation of ores is of concern.


In 1950, the then territory of Guaporé had an extremely rarefied population, no more than just over 37,000 inhabitants. Forty years later, in the early 1990s, the state of Rondônia had already surpassed the mark of 1,100,000 inhabitants.

In the 1980s, intense immigration increased the population of Rondônia by about twenty percent a year, an unprecedented rate in the country’s history and which caused serious problems for the state government, unable to supply health care needs so quickly. , education and energy supply. In some regions of Rondônia, in the mid-1980s, semi-slave labor regimes were found to exist. Rapid and disorderly growth has further aggravated land conflicts between Indians, squatters and gold miners.

In addition to the capital, Porto Velho, on the banks of the Madeira River, the cities of Ariquemes, Ji-Paraná, Pimenta Bueno, Guajará-Mirim, on the banks of Guaporé, and some new municipalities, such as Jaru, Ouro Preto do Oeste and Rolim de Moura.



Agricultural and pastoral products started to gain importance in the economy of Rondônia after the opening of the Cuiabá-Porto Velho highway (BR-364) in 1961. In 1994, the state assumed a leadership role in the North as an agricultural pole capable of compete on an equal footing with the southern states. It has become one of the largest Brazilian cocoa producers and the fifth largest coffee producer in the country. The crops of corn, beans, cotton, soy, rice, cassava and bananas were also developed. In the same year, Rondônia had the tenth bovine herd in the country.


In 1986, a group of loggers discovered in the middle of the jungle a mine of cassiterite (tin ore), later named Bom Futuro. Three years later, 10 percent of the world’s ore production was extracted from Bom Futuro, which was equivalent to 37% of Brazilian production.

Despite this, in the early 1990s, the plant and mineral extraction industry – in the past the main economic activity in the state – lost its importance in the economy of Rondônia as a whole. In addition to cassiterite, the basic products of the region are gold, diamond, rubber, Brazil nuts, poaia, leather and fish.

The timber industry developed due to the opening of the BR-364, taking advantage of the return of trucks. Rondônia’s forests are extraordinarily rich, mainly in mahogany, vinhático and cherry. Responsible for creating a large number of jobs – in cutting down trees and preparing boards, logs, rafters, posts and sleepers – the timber industry is also a matter of concern for ecologists, in view of the devastations it has caused. According to analyzes of photographs taken by satellites in the early 1990s, thirty percent of Rondônia’s forests had already been destroyed. To solve the problem, the government demarcated reserves in the forest and created incentives for reforestation. The state’s lumber companies also started to produce plywood and laminates and not only sell raw wood.

There are three important areas of environmental preservation in the state: the Pacaás Novos National Park, with an area of ​​6,764,000 hectares; the Jaru and Guaporé Biological Reserves (947,000 ha); and the Rondônia National Forest (300,000 ha).


The state is included in the Polonoroeste development program, which also includes northwestern Mato Grosso. One of its initial basic projects was the construction of the Samuel hydroelectric plant, designed to ensure the supply of electricity to the entire state, affected, for more than a decade, by constant energy rationing. The hydroelectric plant, designed to generate around 217MW, through five turbines, was expected to start operating in the second half of the 1990s.


Built the BR-364, with 1,450km of extension, the state of Rondônia started to have a terrestrial and direct connection with Cuiabá and São Paulo. Inaugurated in 1984, the highway freed the state from the old dependence on the river connection with Manaus and Belém. Thus, the economy of Manaus and Belém had to face competition from São Paulo, which began to expand its area of ​​influence in the south of the Amazon. . Other highways of the National Integration Plan also serve the state: BR-319, which connects Guajará-Mirim-Abunã-Porto Velho-Humaitá AM; and BR-236, which links Abunã to Rio Branco AC.

When the state was created, the colonization projects developed by the National Institute of Colonization and Agrarian Reform (INCRA) covered a total of 36,518 registered families, who were awaiting the distribution of the respective plots of land. The influx of immigrants at that time was estimated at 1,000 families per month. The health conditions of the population were still deficient; mainly due to immigration, Rondônia has the highest incidence of malaria in the Amazon.

Rondônia, Brazil Overview