Brazil gains water surface in 2022, but tends to drought – 02/15/2023 – Environment

Brazil had a 10% gain in water surface in 2022, compared to the previous year, the lowest in the historical series. Despite the positive news, the trend is for the country to continue getting drier.

According to data from the Mapbiomas Água study released this Wednesday (15), almost 17,000 km² of water were recovered in the national territory last year, the equivalent of eleven cities in São Paulo.

In total, the country surpassed the mark of 182,000 km² of water surface, which had not happened since 1999.

Juliano Schirmbeck, technical coordinator of MapBiomas Água, explains that the monitoring of the water surface is different from that done with deforestation, for example. “Water resources are cyclical, with variations throughout the year. This is a natural characteristic of the phenomenon”, he says.

“We had a breather in 2022, but if you look from 2013 to here, we had the ten years with the most loss of water surface in the historical series”, he highlights.

Mapping began in 1985. Since 2010, in seven years, a drop in the water surface has been recorded, reaching the lowest level in 2021, with 165,000 km².

According to the researcher, the improvement observed last year is due to a change in the rainfall regime, with above-average rainfall, mainly in the Midwest region and in the caatinga, and also in the Amazon.

All biomes gained water in 2022 —except the pampa, which recorded a 1.7% drop compared to the average and had the driest year in history.

“[Na dinâmica do] pampa does not have a dry season. Historically, it rains every year. However, in the last three years there have been critical situations in the precipitation regime, with important losses in the harvest”, says Schirmbeck.

In part, this is due to La Niña, a phenomenon that causes less rain in the south of the country and which has lasted for three years. The lack of rain has a direct impact on crops, which have suffered losses due to weather conditions. However, the relationship between agribusiness and the change in Brazilian hydrology does not stop there.

Especially in the Midwest, rainfall depends on the so-called flying rivers that come from the Amazon. This large volume of water vapor is produced by the forest and is what guarantees agricultural productivity in the region. Thus, the destruction of the forest, which is often associated with agribusiness, has a direct impact on the climate.

“With regard to agribusiness, there is pressure on water resources associated with deforestation and the lack of conservation of permanent preservation areas, which are those strips that need to be preserved on the banks of rivers. At the same time, the agro is harmed by these factors”, emphasizes the researcher.

“In a large part of the Brazilian territory there is no longer a harvest and second crop like 30 years ago because the rainy season ended up being shortened. Today, a large part of the second season is based on irrigation [artificial]”, it says.

The exposure of rivers, with the removal of vegetation, also causes more water to evaporate. In addition, deforestation also impairs water containment. When it rains heavily and quickly in an area covered by crops, the earth cannot contain that volume and it goes away. In places with native vegetation, however, this water is contained and better absorbed by the soil.

Climate change also impacts the amount of water in the country, as extreme events such as prolonged droughts and concentrated rainfall in short periods of time become more frequent.

The 2022 data also brought good news in relation to the Pantanal, which had an increase in water surface for the first time since 2018. This improvement, however, is not enough to reverse three decades of constant reduction in water from the greatest floodplain in the world. The area occupied today by water in the biome is 60% smaller than the average of the historical series.

One of the consequences of the prolonged drought in the Pantanal is the fires that, especially in 2020, hit the biome hard.

The two states of the Pantanal, Mato Grosso and Mato Grosso do Sul, go against the grain of most of the country, with a reduction of 48% and 23%, respectively, in the water surface. In addition to these, Paraíba also recorded a drop of 12%.

_{The Planeta em Transe project is supported by the Open Society Foundations.}