People on a flooded street in southeastern Brazil
Photo: dpa / Eugenio Savio
Weeks of continuous rain and three dam failures have flooded large areas in central and eastern Brazil. Floods and landslides have already claimed at least 50 lives. More than 133,000 people lost their homes in the states of Maranhão, Tocantins, Piauí, Bahia, Pará, Goiás, Minas Gerais, Espírito Santo, Rio de Janeiro and São Paulo. Bahia is currently the hardest hit state. At least 24 people lost their lives here and around 100,000 people had to leave their homes.
Mass media and state politicians blame the unusually heavy rains for this time of year and global climate change for the events. But this is only half the truth. The flood catastrophe is also homemade. In fact, years of deforestation of the cerrado savannas of the central Brazilian high plateau and the high plains of the Northeast, and their conversion into vast tracts of monoculture agriculture, particularly soybean plantations, have severely disrupted the region’s water balance.
In Brazil, the Cerrado is known as »Berça das águas«, the birthplace of water. It supplies eight of the country’s twelve major watersheds and major rivers such as the Xingu, Rio Tocantins and Rio São Francisco. But more than 50 percent of the originally around two million square kilometers of Cerrado savannah have already been cleared. Between August 2020 and July 2021 alone, another 8531 square kilometers were sacrificed to agribusiness, according to the latest figures from the INPE space research institute, which is responsible for forest monitoring via satellite.
Researchers from the environmental research institute IPAM analyzed the largest deforestation in the agricultural region of Matopiba, consisting of the states of Maranhão, Tocantins, Piauí and Bahia. According to official agricultural statistics, the area under soybean cultivation in Matopiba has multiplied from around 600,000 hectares in 1995 to around 8 million hectares today. And these are the states that have been hit the hardest by the recent floods.
The extremely species-rich Cerrado ecosystem consists largely of plants with a complex root system that extends up to 20 meters deep. They are adapted to the extreme alternation of heavy rainfall in the rainy season and a long-lasting dry phase. Only a third of the trees and shrubs are visible on the surface. Two thirds of these plants are underground and can thus hold large amounts of rainwater and balance the water balance. This is not the case with the monocultures that are spreading in the region, such as soya or corn with their surface roots. Their water storage capacity is significantly lower.
When it rains, most of the water, enriched with topsoil and pesticides, goes straight into the rivers. A study published in 2014 by the University of São Paulo already showed a fivefold increase in surface runoff due to monocultures or artificial cattle pastures in the Cerrado region. In the phases without soil cover, i.e. following the harvest and until following sowing, the surface runoff is even up to 20 times higher than on non-deforested cerrado areas. The result is increasing flooding and silting up of reservoirs. Added to this is the increasing soil sealing due to ongoing road construction for the transport of the soybean harvest to the export ports and the cities that are expanding due to rural exodus – and the catastrophe is perfect.
“If we add the effects of global climate change to the progress of soybean cultivation in areas of high ecological value, we see that the catastrophic situations in Bahia, Tocantins and Piauí are not natural at all,” comments Brazilian geographer Marcos A. Pędłowski of the Center for Humanities from the National University of Norte Fluminense on his blog. “What we are witnessing today is a particularly drastic combination of extreme weather events and the consolidation of a predatory agricultural model that pushes the poorest to peripheral areas where there is typically no urban infrastructure.”
Pędłowski criticizes the fact that the connection between the soybean harvest and the tidal waves in the cities is being concealed by the major Brazilian media. “These are just offering the reader or TV viewer a catastrophe narrative that only mentions the issue of climate change, and only vaguely mentions it.”