At least 20% of the Amazon microbasins are heavily impacted by activities or infrastructure that take place around them, such as hydroelectric plants — the main pressure agent —, mining and illegal mining, roads and agriculture.
This is the conclusion of a new index, the IIAA (Impact Index on the Waters of the Amazon), created by Ambiental Media, with the support of the Serrapilheira Institute and the participation of researchers.
The index is part of the Aquazônia project, launched this Thursday (5th).
The IIAA ranges from 0, which means very low impact, to more than 5, for extreme impact rating.
Data from hydroelectricity, mineral exploration, waterways, agriculture and livestock, forest degradation, river crossings with roads, urban areas and climate change were analyzed in 11,216 watersheds in the Legal Amazon.
Of these, 2,299 have an impact considered high by the IIAA.
The top five most impacted areas —and, therefore, with the highest numbers in the index— have hydroelectric basins. They are: Madeira, which has the Canaã hydroelectric plant, in Rondônia; Tapajós, with the Braço Norte hydroelectric plant, in Mato Grosso; the Xingu, region of the Belo Monte hydroelectric plant, in Pará; Tapajós, with the Paranorte hydroelectric plant, in Mato Grosso; and Madeira, again, with the Jamari hydroelectric plant, in Rondônia, once again.
Filtering by watersheds with high, very high or extreme impacts, about 50% —which represents 1,146— are in areas affected by hydroelectric plants. Interestingly, 478 (21%) of these microbasins with high degrees of impacts suffer, at the same time, from the presence of mining (or illegal mining).
According to the survey, the Putumayo-Içá river basin is the tributary water body of the Amazon river that suffers the most from mining, with an impact on 63% of the route.
The index also points out the situation in conservation units and indigenous lands. In the former, about 23% (or 77) have a high impact rate — ten are in Rondônia. In the case of indigenous protected areas, 14% (53) have high, very high or extreme impact rates.
In the Amazon, a biome in which agriculture is known as a vector of deforestation and fires, logically the activity would also have considerable impacts in some regions.
According to project data, the Curuá-una, Guamá and Pacajá basins (all tributary to the Amazon River) are in areas totally impacted by agribusiness.
The Tocantins and Xingu river basins are not far behind: 98% of their area is impacted by this economic activity.
It is worth noting that, despite the participation of researchers, the index is not intended to be scientific. Thiago Medaglia, founder of Ambiental Media and coordinator of the project, says that it is a science-based initiative, but still a journalistic work.
Medaglia says that the idea for the project came about when she realized that, when talking about the Amazon, the focus is almost always and exclusively on the forest.
“When we talk about deforestation, we have shocking scenes of the forest being deforested or we can measure it via satellite”, says the creator of Aquazônia. “But when we talk about water it is more difficult for this to be, in any way, measured and perceived.”
Hence the idea of an index that could convey a perception of what is happening with the Amazon waters.
Looking at the waters of this biome and others is relevant, especially in a context of climate change. Data from MapBiomas Water, point to a country that dries up. Brazil lost, from 1991 to 2020, about 15.7% of the water surface it had, the equivalent of 3.1 million hectares. The Pantanal had a reduction of 74% of the water surface, and the Amazon, of about 13%.
But, returning to the IIAA, in order to create an index, certain weights are assigned to the different elements that compose it. The hydroelectric plants had the greatest weight, thus explaining why the most impacted areas are, in general, close to these structures.
According to Cecília Gontijo Leal, a scientific consultant at Aquazônia and a researcher at USP, this is no accident. “A hydroelectric plant is a completely drastic change in a watercourse,” she says. “We had no doubt. The consensus is that dams and dams are the most drastic things that can happen on a river.”
While the impact of this form of power generation is not necessarily surprising, some surprises have emerged. Gontijo Leal points out that, by the index, it is possible to see that, when there are hydroelectric plants, other impact factors add up, increasing the weight of this structure in the equation.
“One impact can potentiate the effects of another and, in biological systems, everything is very interconnected”, says the researcher.
Gontijo Leal and Medaglia question the individual licensing of hydroelectric plants, without an integrated assessment with other of these structures and considering cumulative effects. “Licensing one by one is very easy”, says the scientist.
According to the coordinator of Aquazônia, it is necessary to be careful with the maxim that hydroelectric plants are always positive solutions. “It’s not that you can’t build a plant, but it’s building with strategy, which needs to encompass not only energy production, but also ecosystem services and the natural processes of rivers. There are several studies that show that impact studies should be better and they can be better. There are metrics for that.”
Although the aquatic map of impacts in the Amazon is already well colored, the project data is not yet complete. But this is due to the lack of reliable and quality information for points such as fishing and pesticide contamination.
One of the goals of the initiative is to help bring to the public debate the need for more data on the health of the rivers of the Amazon and the scientific and legislative gaps related to the subject, says Medaglia.
“These are important data that we would need to include, but they don’t exist. The index must be underestimating what happens”, says Gontijo Leal.
The USP researcher makes yet another reservation. The IIAA only addresses the distribution of threats. In other words, a qualitative analysis of the waters of the Amazon basins or the possible impacts on local biodiversity, for example, was not carried out.
THE Sheet sent inquiries to the Ministries of the Environment, Mines and Energy, Infrastructure, Ana (National Water Agency) and ANM (National Mining Agency).
Only Ana responded until the publication of this report. The agency states that it has not yet become aware of the index and that, in the “process of issuing grants for the right to use water resources for Union waters (interstate and transboundary), Ana considers environmental constraints from Ibama or the respective competent environmental agency. “.
