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Among experts, one expression has become increasingly common: the Cerrado is the biome of sacrifice. While all eyes are on the preservation of the Amazon, predatory agribusiness is expanding its borders, exploiting Brazilians' lack of understanding that this is where the water that supplies much of the country comes from. Eight of Brazil's twelve hydrographic regions have their sources in the biome.

In the special story “Cerrado - the sacred link to Brazil's waters”, Ambiental investigates more than 50 years of data to understand how much of the biome has already been sacrificed and what the impacts of human actions are on the waters. Under scientific coordination, journalists and data analysts spent more than a year researching, interviewing and using the best available data on river flow, rainfall, evapotranspiration and land use and occupation. The aim is to enable a broad and non-specialized audience to understand the importance of the Cerrado for Brazil's waters, which basins are most impacted and by which predatory human actions, its connection with other Brazilian biomes, its role as a water regulator and the ways to halt its destruction.

Exploitation of the Cerrado began in the 19th century, when the vegetation, considered worthless, began to be replaced by extensive cattle ranching, started by soldiers returning from the Paraguayan War. Later, the biome came to be seen as “the breadbasket of the world”. With many tax benefits, agribusiness, which doesn't produce food but commodities, claim to sustain the country's Gross Domestic Product (GDP). But at what price? Water has clearly not been included in this calculation. States that are big water producers, like Bahia, Mato Grosso and Mato Grosso do Sul don't even charge for its use.

The exploitation of water is already generating conflicts, such as the episode that became known as the Water War in 2017, in the municipality of Correntina, in the west of Bahia, when communities of family farmers ran out of water. A similar scenario can already be seen in the Jequitinhonha Valley region of Minas Gerais. Experts predict increasingly frequent conflicts. We need to understand and accept the reality of the climate crisis and its consequences.

In 2023, for the first time since the beginning of the MapBiomas Alert series, the area deforested in the Cerrado surpassed the figures for the Amazon. Today, science already knows that the vegetation of the most biodiverse savannah on the planet, with its deep roots, is very valuable and guarantees the supply of gigantic aquifers - such as the Urucuia, Guarani and Bambuí - and the flow of rivers such as the São Francisco and Paraná.

The researchers emphasize that climate change is amplifying the impacts in an inconsequential cycle: irrigation and deforestation for the production of agricultural commodities generate ever more intense droughts which, in turn, affect water, energy and food security, as well as agricultural production itself. It's a death spiral in motion.

In the project “Cerrado - the sacred link between Brazil's waters”, Ambiental is proposing a debate, based on science, about the connection between the biomes and how the destruction of one affects all the others. It is urgent to understand, once and for all, that to sacrifice the Cerrado is to destroy our water and, with it, any viable alternative for the near future.

Ambiental is dedicated to investigative journalism based on science and data. We dive into the best available science on the most relevant topics to bring you the data and evidence that make a difference in people's lives. We believe journalism is a tool for alerting and raising awareness about the climate emergency, as well as for defending Brazilian biomes and their forms of life, including human life.

Ambiental's unique vision has become a signature recognized by major awards. Among our outstanding reports is Aquazônia, through which we created the Amazon Water Impact Index (IIAA), a report that was awarded six prizes in journalism and voted the best data visualization in Brazil (Cláudio Weber Abramo Award) and Latin America, as well as one of the best in the world (by Wan-Ifra, the World Association of News Publishers).

Due to its proximity to science, Ambiental's work also serves as a source of information for other journalists and news outlets, having been replicated by some of the main press outlets in Brazil and the world, including The Guardian, Folha de São Paulo, Estadão, O Globo, Valor, National Geographic Brasil, BBC Brasil, Mongabay International and others.

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1. Objective

The project “Cerrado - the sacred link between Brazil's waters” outlined the conditions of the biome's main river basins over the last few decades and made this content comprehensible to a wide audience through maps, data visualization and stories.

2. Data

Data from six river basins in their predominant portions of the Cerrado were analyzed:

• Araguaia
• Paraná
• Parnaíba
• São Francisco
• Taquari
• Tocantins

Area of Analysis:
The portions of the main basins predominantly within the Cerrado biome were selected. This delimitation seeks to provide analysis and answers on the status of the Cerrado in the context of the main rivers, given the natural non-uniformity between the boundaries of biomes and river basins, since some of them include smaller portions of other biomes. The aim was to keep significant parts of the Cerrado in the analysis, as is the case with the São Francisco basin.

Databases included:

• National Water and Sanitation Agency (ANA) - data made available between 1970 and 2021 through a Technical Cooperation Agreement between the Ministry of the Environment and the Cerrados Institute, with no financial transaction. The agency shared and processed data on hydrological and climatological variables, their return being able to communicate the data in an accessible way. The work was carried out in partnership with Ambiental Media. The results shared were:
  • Potential evapotranspiration: the total amount of moisture that could be transferred from the soil and vegetation to the atmosphere due to evaporation;
  • Pluviometry: amount of rainfall in a given place and over a specific period of time;
  • Flow: volume of water flowing through a river in a given time, measured in cubic meters per second (m³/s).
• MapBiomas (collection 8)
  • Land use and occupation between 1985 and 2022: native vegetation, deforested areas, soybean cultivation, water bodies and other land uses.

3. Development stages

1. Definition of the river basins
The project's scientific coordinator Yuri Salmona - a geographer and PhD in Forestry Sciences from the University of Brasilia (UnB) - selected the six basins that would be part of the project. Based on this decision, the ANA team created files with the boundaries of each of the basins. Salmona also selected the points in each basin from which the data should be generated. The sites chosen are on the border of the biome or in an upstream stretch (upstream, towards the source), so that the portion analyzed is mostly or entirely within the Cerrado biome.

2. Data collection and flow, rainfall and potential evapotranspiration
The main data used in the project was the flow rate, generated locally by fluviometers and measured in cubic meters per second. Following a scientific methodology and validated statistical principles, ANA transposed the data to the point on the river indicated by Salmona. This transposition was necessary to understand the contribution of the Cerrado portions to these basins. The data is monthly and shows how the biome's rivers are losing water.

In order to put this reduction into context, the team began to look at the main variables related to flow, including rainfall. Data from rainfall stations was also provided by ANA and made it possible to estimate how much it rained per month in each of the six river basins analyzed. All of them experienced some reduction in rainfall.

To put this into context, we used the potential evapotranspiration data provided by ANA. This variable is directly related to climate change and shows how much water a standard land cover is estimated to return to the atmosphere due to solar radiation. There was also an increase in all the basins analyzed.

3. Collecting land use and land cover data
The same watershed boundaries generated by ANA were used to extract land use and land cover data from the MapBiomas – collaborative network of co-creators formed by NGOs, universities and technology companies, that maps land use and cover in Brazil.

Each of the many types of land use provided by MapBiomas were grouped into one of the following classes: native vegetation, deforested areas, deforested areas for soybean plantations, bodies of water and other land uses.

The aim of the selected databases was to analyze the links in the hydrological cycle: both the water that evaporates and the water that falls with the rain. Land cover, on the other hand, shows the different forms of occupation in the basin, which have a bearing on river flow. The data showed how the biome is losing water and how this reduction in water availability is related to increased deforestation and climate change.

4. Generating exploratory graphs
Exploratory graphs were then generated to show the changes in each of these variables, which allowed the team to understand how much of the flow changed and how it was changed. To do this, various statistical tests and exploratory analyses were carried out to see if there was a trend. A number of graphical representations were generated, which made it possible to observe changes in the pattern.

5. Before and after analysis of basin conditions
To analyze the impacts on the biome's waters, the average rainfall, potential evapotranspiration, and flow rates for two different periods were considered: from 1970 to 1979 and from 2012 to 2021. In the case of flow, the Q90 (minimum safe flow) was taken into account, as it should be used to guide the definition of limits for the sustainable use of water resources.

For land use and occupation, we used annual data for the entire historical series: from 1985 to 2022.

4. Main bibliographical references

Databases:
National Water Agency (ANA) and MapBiomas Project

Scientific articles:
Salmona et al. (2023). A Worrying Future for River Flows in the Brazilian Cerrado Provoked by Land Use and Climate Changes. Sustainability, 15. https://www.mdpi.com/2071-1050/15/5/4251
ANA, 2024. Impact of Climate Change on Water Resources in Brazil / National Water and Sanitation Agency. https://metadados.snirh.gov.br/geonetwork/srv/api/records/31604c98-5bbe-4dc9-845d-998815607b33/attachments/Mudancas_Climaticas_25012024.pdf

To the Climate and Land Use Alliance (CLUA) for their financial support and assistance throughout the development process, especially Cecília Viana, consultant and advisor to Iniciativa Brasil. The Serrapilheira Institute, which has believed in and supported the work of Ambiental Media for years, especially Natasha Felizi and Raika Moisés.

We would also like to thank Diálogo Brasil for their consultancy and support in publicizing the platform in major media outlets, as well as in local media and on social networks.

We would also like to thank the Cerrados Institute and its executive director, Yuri Salmona, the scientific coordinator of this project, as well as Mercedes Bustamante for recommending Salmona and for believing in our work.

To the National Water and Sanitation Agency (ANA) for processing and sharing an extensive database on the basins, through a Technical Cooperation Agreement signed between the Ministry of the Environment and the Cerrados Institute, which did not involve a financial transaction. In return, the institute undertook to communicate the data in an accessible way. The work was carried out in partnership with Ambiental Media.

To the researchers from the MapBiomas Project, who produced the data on which the analysis of land use and occupation was based. To all the scientists who collaborated with interviews and shared the results of their research.