Brazil: Cerrado can lose 34% of its water by 2050

The Cerrado biome could lose 33.9% of its river flows by 2050, if the pace of farming and cattle raising continues at current levels. In view of this situation, authorities and specialists must dedicate the same attention to the biome as they do to the Amazon, since one cannot exist without the other.

The warning was given by the founder and executive director of the Cerrados Institute, Yuri Botelho Salmona, on Wednesday (Mar. 22), when World Water Day—instituted by the United Nations (UN)—was celebrated. Salmona explained that this is the largest study ever carried out on the Cerrado rivers.

Salmona measured the effect of land appropriation for monocultures and pastures during research supported by the Institute for Society, Population, and Nature (ISPN).

Watersheds

A total of 81 Cerrado watersheds were analyzed in the period between 1985 and 2022. According to the survey, the decrease in their flow was verified in 88% of them due to the increase in agriculture and cattle raising. The survey indicates that the cultivation of soy, corn, and cotton, as well as livestock farming, have influenced the hydrological cycle.

The study also shows that changes in the use of soil provoke the reduction of water in 56% of the cases. The rest (44%) is associated with climate change.

“When I talk about land use change, I am actually talking about deforestation and what you put on top after you deforest,” said Saloma in an interview with Agência Brasil. According to the researcher, the west of Bahia is one of the places where the scenario has worsened the most.

As for climatic consequences, the researcher explains that “what is increasing is the solar radiation. It is getting hotter, and you have greater water evaporation, and that is where climate change is acting, very clearly, in a generalized way, in the Cerrado.” He said that in some regions in the states of Maranhão, Piauí, and Bahia, changes are clearer.

Rains

Another factor that has undergone changes is the rainfall pattern. As Salmona emphasized, what is observed is not necessarily a lower level of rainfall.

“We have seen that places, where it is raining less, are not the rule, but the exception. What is happening a lot is the decrease in the rainy periods. The same volume of water that used to fall in four or five months is now falling in two or three months. Thus, you have a lower capacity to filter this water into a deep soil and make it available in a dry period,” he commented.

According to the researcher, approximately 80% to 90% of the water in the rivers of this biome originates from groundwater.