South America: Water deficits in Central & SE Brazil

22 July 2022

THE BIG PICTURE
The 12-month forecast through March 2023 indicates widespread water deficits in Brazil’s Central West region through the Southeast with intense pockets in Mato Grosso, Tocantins, and Goiás. In the north, deficits are expected throughout the state of Amapá and exceptional anomalies through much of neighboring French Guiana. Some pockets of deficit are forecast in Brazil’s northeast in Piauí and Ceará, and pockets of surplus in the small states of the far east and in central Bahia.

Across the northern arc of the continent, exceptional deficits are forecast from Merida, Venezuela east to the Guárico River, downgrading as they continue through much of the Orinoco River’s northern watershed. The Orinoco Delta, however, will experience surpluses that will lead south to Guyana. Surpluses are also forecast in much of central Colombia and a pocket northeast of Quito, Ecuador.

In Peru, deficits will be widespread from the Lower Marañón River in the north through central Peru with exceptional deficits in the middle reaches of the Ucayali River Watershed. From there, deficits will gradually downgrade as they radiate outward and will reach across the border into Brazil. A few pockets of surplus are expected in Peru including near Trujillo on the north coast and east of Huancayo in the central Peruvian Andes. Central Bolivia will see surpluses while deficits are expected in the east and south.

Widespread exceptional deficits are forecast in Chile from La Serena through Valparaiso and Santiago to the Gulf of Corcovado. In Argentina, deficits are forecast in pockets of the Chaco region, slipping across the border into Paraguay, and will be widespread in the eastern Pampas with exceptional anomalies approaching Buenos Aires. Exceptional surpluses are forecast in coastal Chubut Province and exceptional deficits in Patagonia on the Chico River and in Tierra del Fuego.

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

The forecast through September indicates deficits in many regions of Brazil other than the northwest, far east, and south. Deficits will be widespread and will include intense deficits in Amapá, Tocantins, and Mato Grosso. Surpluses are forecast in Brazil’s eastern tip, a pocket in south-central Bahia, and pockets in the northwestern Amazon Basin. Surpluses are expected in Colombia; from the Orinoco Delta into Guyana; and in a pocket near Quito, Ecuador. Deficits will be exceptional in Merida, Venezuela, moderating as they reach Caracas. Intense deficits are also forecast for French Guyana. Widespread severe to exceptional deficits are forecast for central Peru and moderate deficits in pockets of the north and south, though anomalies will be intense near Arequipa. Surpluses are expected near Huancayo.

In Bolivia, surpluses are forecast in the Altiplano and deficits in many other regions, intense in the far south. Deficits will be widespread in Chile, exceptional in central and southern areas. Deficits are predicted for the Pilcomayo and Bermejo Rivers in northern Argentina, and in the eastern Pampas where anomalies will be exceptional approaching Buenos Aires. Surpluses are forecast in the nation’s northwest, a pocket in the central Pampas, and in coastal Chubut. Patagonia will see deficits of varying intensity, exceptional in Tierra del Fuego.

From October through December, anomalies will shrink considerably, leaving near-normal conditions in many regions. However, deficits are forecast from northern Pará and Amapá (Brazil) into French Guiana, near Caracas, in south-central Colombia, on the Jururá River in western Acre (Brazil), in Bolivia’s southern tip, and in Chile, the eastern Pampas, and Patagonia. Areas of surplus include the Orinoco Delta, Brazil’s easternmost tip, and pockets in Bolivia.

In the final quarter – January through March 2023 – deficits are expected in Chile, Bolivia’s southern tip, Tierra del Fuego, and pockets in central Peru and near Caracas. Areas of surplus include central and eastern Bolivia, Brazil’s eastern tip, and coastal Chubut.

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

IMPACTS
A leading agricultural insurer estimates that drought in southeastern Brazil will cost over $200 million. Soybean producers are projecting 90 percent crop loss. In Paraguay, May 2022 soybean exports were just half that of May 2021 and experts expect further decline due to poor weather conditions including drought at the beginning of the year.

Excessive rainfall triggered flooding in Brazil’s small northeastern states. Nearly four inches of rainfall (97.6 mm) was recorded in Alagoas over 24 hours in early July—prompting evacuation of over 39,000 people. In the state of Rio Grande do Norte, 160 mm (6.3 inches) fell in just one day in Ponte Negra, Natal, damaging many roads and homes.

Drought, in conjunction with a pipeline leak, lowered copper production through the first half of the year for Chile’s main producer by 26 percent compared to last year.

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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