South America: Water deficits will downgrade overall

21 September 2020

THE BIG PICTURE
The 12-month forecast through May 2021 indicates nearly normal water conditions in roughly half of the continent’s extent though deficits of varying intensity are expected in nearly every nation.

Pockets of deficit are forecast across the northern arc and will be exceptional in Colombia’s southwestern and southeastern corners, a broad band across northern Venezuela, and French Guiana’s southern half leading into Suriname. Deficits of lesser intensity are expected in Ecuador, northern Columbia, Guyana, and Suriname, and some surpluses are forecast for central Colombia.

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Deficits of varying intensity will dominate Brazil’s vast central bulk from Amapá in the north through Mato Grosso do Sul in the south and will extend east to the Atlantic Coast through the state of São Paulo. Exceptional anomalies will be especially widespread in Mato Grosso and are also expected in Pará. Deficits will be moderate to extreme in São Paulo State. The western state of Acre will also see intense deficits, particularly in the region of the Juruá River and across the border into neighboring Peru. Some pockets of surplus are expected in Brazil’s eastern tip in Rio Grande do Norte and Bahia.

In Peru, moderate to severe deficits are forecast for many regions. And in Bolivia, surpluses are expected in the center of the country with deficits along the Brazilian border and in the south where anomalies will be intense.

In the southern portion of the continent, deficits are forecast throughout much of Chile reaching across the northern border into Argentina. Anomalies will be severe in Santiago and exceptional in pockets along Chile’s northeastern border. The forecast for Argentina includes pockets of surplus in the west in the provinces of La Rioja, Mendoza, and Río Negro. Deficits are expected in the Gran Chaco area of northeastern Argentina and in the continent’s southernmost regions.

FORECAST BREAKDOWN
The 3-month maps (below) for the same 12-month period show the evolving conditions in greater detail.

The forecast through November indicates that deficits will shrink and downgrade significantly. While intense deficits remain in the forecast for pockets across the northern arc of the continent in Ecuador, northwestern Venezuela, and from Guyana through French Guiana, deficits in Brazil will downgrade, becoming mild to moderate overall. Deficits will be moderate along the Amazon River and in eastern Amazonas, Pará, Mato Grosso do Sul, and São Paulo State; moderate to severe in western Amazonas and Acre; and exceptional in Amapá. Exceptional deficits will emerge in Brazil’s easternmost states, though surpluses will persist in other parts of the region. Surpluses will shrink and downgrade in central Colombia, and moderate surpluses will emerge in the Orinoco Delta of northeastern Venezuela.

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Deficits will continue to be widespread in Peru - primarily moderate to severe with intense deficits retreating - and moderate surpluses will persist in a pocket of southern Peru. Surpluses in central Bolivia will intensify with exceptional anomalies expected, while moderate to mild deficits are forecast elsewhere in the nation. Exceptional deficits along the Paraguay River through its namesake will downgrade with mild to moderate anomalies forecast on the river and in eastern Paraguay. Deficits of varying intensity are forecast for most of Chile, but deficits in Argentina will shrink and downgrade, leaving primarily moderate deficits in the northeast and in northern Buenos Aires Province. Surpluses will persist in the northwest but will shrink in the Pampas.

From December 2020 through February 2021, nearly normal conditions are forecast for most of the continent. Intense deficits will persist in northwestern Venezuela, southern Guyana, and pockets from Bolivia’s southern tip into the northern border of Chile and Argentina. Some moderate deficits are forecast for central Peru and deficits will shrink and downgrade in Chile. Pockets of surplus will persist in Brazil’s eastern tip and moderate surpluses will emerge in northern Pará.

In the final quarter – March through May 2021 – normal conditions will continue in most regions, with some deficits in northern Venezuela and from Bolivia’s southern tip into the northern border of Chile and Argentina. Surpluses will nearly disappear in Brazil’s eastern tip, but mild anomalies will emerge in central Brazil and some moderate pockets are forecast elsewhere, including Ecuador and Bolivia.

Please note that WSIM forecast skill declines with longer lead times.

IMPACTS
Brazil’s Pantanal region, or “swamp,” has been burning for weeks. The wetland area in Mato Grosso do Sul and Mato Grosso is experiencing its worst fires in 15 years after a disappointing rainy season and subsequent drought. Fires in the Pantanal are especially difficult to extinguish since they often smolder beneath the surface. It’s estimated that 10 percent of the 150,000 square kilometer region has burned.

Minais Gerais, Brazil’s main coffee producing area, has received just 33 percent of its normal precipitation in southern districts over the last two months, leading analysts to predict crop losses.

Brazil’s history is pocked by periods of devastating drought, including the droughts of 1915 and 1932 during which mass migrations from rural areas produced the stain of “poverty corrals,” concentration camps set up in the state of Ceará to control rural to urban migration.

The U.N. has issued a rebuke to the Chilean government asserting that the government is favoring economic development, specifically avocado and hydroelectric production, over the humanitarian obligation to provide water for human consumption.

Water scarcity in Chile is affecting mining operations. Antafogasta, the Chilean-based copper company, says it will spend an additional $150 million to adapt a $500 million desalination plant for one of its mines.

In its mid-September crop report, the Buenos Aires Grain Exchange says that wheat yields in northern Argentina are expected to be halved by drought in the region.

NOTE ON ADMINISTRATIVE BOUNDARIES
There are numerous regions around the world where country borders are contested. ISciences depicts country boundaries on these maps solely to provide some geographic context. The boundaries are nominal, not legal, descriptions of each entity. The use of these boundaries does not imply any judgement on the legal status of any territory, or any endorsement or acceptance of disputed boundaries on the part of ISciences or our data providers.

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