Costa Verde (Green Brazilian Coast) near Paraty

A report commissioned last year by the Ministry of the Environment warns that the Brazilian coast is at risk due to erosion. The study estimates that about 60 percent of Brazilian seaside (which is 7,500 kilometers long) is affected by erosion and the accumulation of sediments. In 2003, when the first version of the investigation was published, the percentage stood at 40 percent.

The North and Northeast regions are the most affected, the report informs, with 60 and 65 percent of the coast in these regions being at risk. In Bahia state, for example, 20 percent of the areas by the sea have been affected; in Sergipe, 38 percent. One of the problems in these states is that the beaches have a lower slope, making it easier for the sea to advance. Also, tides are more intense there than in other regions of Brazil, drought has drained the rivers, and less sand has ended up on the shores.

The numbers are lower in the South and Southeast, at just 15 percent. But in some specific areas, such as Rio de Janeiro, they reach as high as 38 percent. The coastlines have not receded, although the landscape underwent changes due to the erosion process.

The study also highlights that the decay is not only provoked by natural causes. Removing sand from the banks of rivers for use in construction has, in turn, reduced the quantity of sediment sent to the Brazilian coast. For example, the city of Cabeço, by the São Francisco River, was destroyed by erosion in 1998.

According to Dieter Muehe, a geographer at the Federal University of Rio de Janeiro (UFRJ) and the coordinator of the study, the document serves as a warning. Erosion happens all over the planet, he explains, although there is a “dynamic balance” that has been countering the effects of global climate change. But this could rapidly change, Mr. Muehe says. Any interference, especially man-made, can lead to a deficit of sediments on beaches and, in consequence, the erosion of the coastline, including the encroachment of the sea over land.

Measures necessary to avoid possible tragedies

The present situation is not yet alarming, he believes. Except for localized problems, the coastline is “still reasonably stable.”  According to him, they are closely monitoring the erosion process to see if they can identify the turning point, at which large-scale erosion processes become more visible.

To avoid tragedies, it is necessary to control populated areas along the Brazilian coast. Mr. Muehe suggests that “retreat areas” be created to keep problems at bay. These areas would serve the purpose of “absorbing” the erosion and protecting citizens. There is, however, strong pushback from the population and authorities. A federal government initiative already tried to address the issue, to little success. Named Projeto Orla (Project Waterfront), the policy was created by the Ministries of the Environment and Planning. It determines that, in coastal cities, buildings must be built at least 50 meters from the beach.

Dieter Muehe hopes the report will help bring awareness not only to scientists and policymakers, but also to those who live in exposed areas. He wants the knowledge on the issue to “be incorporated into all levels of education so that the citizens can have a sense of the risks associated with living close to the sea.”

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BY Diogo Rodriguez

Rodriguez is a social scientist and journalist based in São Paulo.