Road network spreads “arteries of destruction” across 41% of the Brazilian Amazon

Road network spreads “arteries of destruction” across 41% of the Brazilian Amazon

• Innovative study, made using satellite data and an artificial intelligence algorithm, shows how the proliferation of unofficial roads in the Amazon is driving widespread deforestation.

• One of these roads is about to cross the Xingu Socio-environmental Corridor, with a serious risk of helping to push the Amazon beyond an irreversible point.

• Unprotected public land accounts for 25% of all stretches of illegal roads, and experts say creating more protected areas could contain the spread, as well as slow deforestation and land grabbing.

• Officially approved roads, such as the Transamazônica Highway, also need better planning to minimize their impact and prevent the growth of illegal offshoots, experts say.

The Americas have a long history of occupation based on the destruction of nature and the violent massacre of native peoples, all in the name of a particular vision of “progress”. The Brazilian military dictatorship, which lasted from 1964 to 1985, took on this ideology to the point of having a specific motto – “integrate not to surrender” – in its nationalist project for the Amazon Forest. This mentality is still alive in the systemic and uncontrolled proliferation of unofficial roads in the Amazon, and the scale of the destruction is becoming increasingly clear.

A study by the NGO Imazon identified 3.46 million kilometers of roads in the Legal Amazon. The researchers estimated that at least 86% of the length of these roads are unofficial, and they were "built by loggers, miners and unauthorized settlements from existing official roads". The extensive road network also means that 41% of the Amazon Forest is already crossed or within 10 km of a road.

While two-thirds (in length) of the roads identified in the study are situated on private properties and settlements, the other third are on public lands where unofficial roads have multiplied, mainly in areas without special government protection. In these public areas, roads cover 854,000 km, representing a quarter of the total in the Amazon.

According to Imazon, the roads located in these areas indicate criminal activities, such as illegal logging, mining and land grabbing. The study also shows that 5% of these roads are within Conservation Units and 3% are in Indigenous Lands, covering a total of 280,000 km within these supposedly protected areas.

“They are arteries of destruction,” study co-author Carlos Souza Jr., a research associate at Imazon who coordinates the institute's program for monitoring the Amazon, told Mongabay. “The roads are opened to extract wood, and the branches spread out from the main line, where the trucks and heavy machinery are.” He added that degradation is followed by occupation of these areas, in a pattern that has become well known in the Amazon.

According to Souza, previous studies estimated the length of official roads in the Brazilian Amazon at around 80,000 km, including federal, state and municipal roads, as well as roads located in official settlements, all of which form part of the planned infrastructure.

But the official numbers are much lower. The National Department of Transport Infrastructure (DNIT) told Mongabay via email that it recognizes 23,264 km of paved and unpaved roads in the Legal Amazon. This is a small fraction of the more than 3 million kilometers of roads, mostly undocumented, that Imazon has identified in the region.

“Roads created without planning by municipalities, states and the Federal Government do not appear on official maps”, said Souza, “but end up being incorporated into the municipal network, requiring public money for their maintenance”.

The Imazon study, published in July in the journal Remote Sensing , used 2020 images from the Sentinel-2 satellite, made available by the European Space Agency. The researchers applied an artificial intelligence algorithm created by Imazon to analyze the images.

In previous efforts to identify roads from large amounts of satellite imagery, researchers spent months analyzing these images. This time, Imazon's algorithm reduced the analysis time to just seven hours, allowing researchers to focus on the data. Studies using previous methods already indicated that the advance of unofficial roads contributed to deforestation in the Amazon, but this research will allow scientists to recreate a historical series with data from previous years, using the new algorithm for the entire Amazon region.

Souza said that mapping and monitoring the length of roads is crucial to identifying threats to the forest, its people and traditional communities. Previous studies have already shown that 95% of deforestation occurs within 5.5 km of a road; and 85% of fires each year within 5 km. Considering only the official road network, deforestation would be at least 50 km from the nearest road, and fires 30 km away.

“This proves that mapping clandestine roads improves models for predicting deforestation and fire risk, and can be used as a tool to prevent forest destruction,” said Souza. “Monitoring usually looks for deforestation after the forest has already been cleared. If this monitoring is focused on the roads, the potential to avoid deforestation is enormous.”

Souza and the Imazon team are also building a network to deploy their tool in tropical forests around the world, with the aim of mapping the footprint of roads in other areas under pressure, such as the Congo Basin and Indonesia. The deforestation prediction tool PrevisIA is already using the new database. According to the latest Imazon analysis, 75% of deforestation occurred within 4 km of PrevisIA forecasts.

Both in extension and density (ratio between occupied area and extension), unofficial roads in the Amazon are concentrated in the states of Mato Grosso, Pará, Tocantins, Maranhão and Rondônia. The data show that the area known as the Arch of Deforestation, on the southeast edge of the biome, continues to be the most targeted, but also point to an increase in southern Amazonas, as well as western Pará and the region known as Terra do Meio, in the central part of the state.

Souza said that although most roads in private areas without public access are very well maintained, regulatory bodies such as DNIT must work with environmental protection agencies to restrict traffic on these roads.

imminent threat

An example of an illegal road that represents a danger to one of the most extensive contiguous forests in the Amazon was detected by Rede Xingu+, a group of conservationist NGOs. The organization spotted an unofficial 42.8 km long road in two important conservation areas: the Terra do Meio Ecological Station and the Iriri State Forest. The road threatens to divide the Xingu Socio-environmental Corridor , a strip of 28 million hectares of native forest that is home to 21 Indigenous Lands and nine Conservation Units.

According to the Instituto Socioambiental (ISA), the illegal road starts at a pole of deforestation within the Triunfo do Xingu Environmental Protection Area. Leaving there, he is about to complete the connection between the municipalities of Novo Progresso and São Félix do Xingu, center of illegal trade in wood and gold. With only 10 km of forest to be crossed in Iriri, the road could soon reach the Curuá River, inside the State Forest, completing the connection and cutting the Xingu corridor, thus drastically increasing the vulnerability of its forests.

“The threat is imminent”, said Thaise Rodrigues, ISA's geoprocessing analyst, “and so far we are not aware of any legal action to stop it”. The Xingu+ Network identified the road for the first time in January of this year. Its progress was interrupted for a few months when it reached a mine inside the Terra do Meio Ecological Station. As of May of this year, the works were resumed and reached the Iriri State Forest . In July and August, monitoring showed 575 hectares of deforestation around this road.

“When a large mass of forest is disrupted, it becomes vulnerable. Roads cause fragmentation, which intensifies deforestation,” said Rodrigues. ISA has criticized both the state of Pará and the Federal Government for their inaction, as both are responsible for protected areas within the Xingu corridor. The illegal road increases what is known as the “edge effect”, where areas of forest exposed to clearings, such as roads, become more vulnerable to threats. And the deforestation caused by these threats brings the Amazon closer to an “ irreversible point ”, from which the tropical forest loses its capacity for self-regeneration and turns into a dry savannah.

According to the ISA, the Xingu corridor contains around 16 billion tons of carbon dioxide, and its mass of exuberant vegetation is responsible for generating the “flying rivers” of water vapor that bring rain to the rest of the continent. The division of forest strips with roads also causes loss of connectivity, which has a direct impact on the migration of aquatic and terrestrial wildlife, while accelerating land desertification. The ISA points to another serious risk: the opening of the rainforest brings humans closer to the 3,000 known species of coronavirus that bats in the Amazon are carriers of, further increasing the likelihood of another global pandemic.

Close to the Iriri State Forest, the Baú Indigenous Land is already under strong pressure from mining and the deforestation front that is advancing from the municipality of Novo Progresso.

“The greater the network of roads around and within the protected areas”, said Rodrigues, “the greater the access for the consolidation of these illegal activities”.

She added that unprotected public areas are even more susceptible to land grabbing. “The delimitation of protected areas would help, but the public authorities need to show an interest in protecting these areas and the communities that live in them.”

Souza, from Imazon, said that the creation of protected areas is the quickest way to contain the expansion of these roads, as land grabbers have little chance of obtaining legal title to the land designated as protected.

“Deforestation is an expensive business,” he said, “and nobody is going to spend money if they don't have a chance to own this land in the future.” This even applies to areas where roads have already been opened, as they would be less attractive to speculators.

Official roads also pose risks

Experts say Brazil must also rethink government road building. One example is the BR-230, a project conceived during the military dictatorship that became a problem child for successive administrations. The road, known as the Transamazônica, began construction in 1969 and was inaugurated in 1972, although it was not completed. Today it extends over 4,000 km into the Amazon, starting from the northeast coast of Brazil, with long stretches still unpaved and completely impassable during the rainy season. The combination of cost, logistics and the inherent difficulty of building a colossal infrastructure in the middle of the forest means that it is still incomplete, 50 years after its inauguration.

In addition to the Transamazônica, there is the BR-163, which connects Cuiabá, in Mato Grosso, to Santarém, in northern Pará, and the BR-319 , from Manaus, in Amazonas, to Porto Velho, in Rondônia. The expectation is that both will cross the Brazilian Amazon in different directions. Experts say that despite being officially approved projects, the poor planning behind them increases the risks to the region's environment.

A 2020 study evaluated 75 road projects in the Amazon, including Brazil, Bolivia, Colombia, Ecuador and Peru, on a total of 12,000 km of planned roads, and showed that if built in the next 20 years, the roads would cause deforestation of 2.4 million hectares of forest. In addition to environmental damage, 45% of the projects would also generate economic losses. Canceling these unfeasible projects would save $7.6 billion and save 1.1 million hectares of forests, the study showed.

The research also sustains that the judicious choice of a smaller number of projects could provide 77% of the economic benefits with only 10% of the socio-environmental damages.

“Any project will cause environmental damage to some degree,” study co-author Thaís Vilela, senior economist at the Washington-based Conservation Strategy Fund, told Mongabay. “But there is a subset of projects that have a positive financial return with less environmental and social impacts.”

The research considered variables such as initial cost of the project, deforestation, ecological relevance of the area, access to schools and health centers, and non-compliance with environmental regulations.

“Many times, those who make the decisions only consider the financial costs and benefits of the project”, said Vilela, “and there are political demands that often do not follow the economic logic”.

The research shows that the economic perspectives of a project stop being positive and become negative when the potential environmental and social impacts are taken into account. To pave 2,234 km of the Transamazon Highway, for example, 561,000 hectares of forest would be destroyed. In terms of impact on biodiversity, water, carbon storage and integrity of protected areas, BR-163, BR-230 and BR-319 would cause the most significant damage to the environment, according to the study. Paving 496 km of BR-163 alone would generate 400 million tons of carbon dioxide emissions by 2030.

As dire as those numbers sound, the true extent of the damage would be even greater because of the unofficial roads that would sprout from these major highways, the study authors said. According to them, the construction and improvement of these primary roads “may lead to the construction of secondary, tertiary and even illegal roads in the region, promoting additional impacts”.

“The unofficial roads usually come from the official ones,” said Souza, from Imazon. He blamed poor quality environmental impact assessments for allowing this proliferation, adding that major official roads also harm protected areas and indigenous territories.

“There are areas where roads should not be built, as the environmental and social damage would be greater than the potential benefits,” said Vilela. “Ideally, the definition of these variables would involve all individuals directly affected by the project.”