South America: Water surpluses forecast to persist in Uruguay, NE Argentina

28 February 2019

The 12-month forecast through October 2019 indicates water deficits ranging from moderate to exceptional in much of Brazil, its northern neighbors, and Peru and Chile. Areas of intense deficit include southeastern Venezuela, French Guiana, large pockets in the Amazon Basin and in eastern Brazil, along many rivers in Brazil, and along the Pacific Coast from Peru through northern Chile.

Surpluses are forecast in parts of the continent’s mid-section, and anomalies will be extreme to exceptional in central Paraguay. Moderate to severe surpluses will extend from eastern Paraguay into northeastern Argentina, Uruguay, and Rio Grande do Sul, Brazil. Surpluses are also forecast for northwestern Bolivia; Neuquén Province, Argentina; Patagonia surrounding O’Higgins/San Martín Lake; and northeastern Pará, Brazil.

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

The forecast through April indicates that deficits in the Amazon Basin will shrink, with nearly normal conditions returning to Pará and northern Amazonas, Brazil. Exceptional deficits will persist, however, in Acre and in eastern Amazonas. Deficits of varying intensity are forecast for many other parts of the country, including intense deficits in the states of Maranhão, eastern Goiás, Minas Gerais, and São Paulo and along many rivers. In southern Brazil, severe surpluses are forecast in Rio Grande do Sul.

Across the northern arc of the continent primarily moderate to severe deficits are forecast from Colombia through Suriname with some pockets of exceptional deficit in southeastern Venezuela and eastern Suriname. Exceptional deficits are expected in French Guiana. Deficits are forecast for Peru, Chile, Tierra del Fuego, and along many rivers in southern Argentina. Deficits will be exceptional in the Atacama Desert and around the Gulf of Corcovado in Chile, and extreme around Santiago. Moderate to severe surpluses are forecast for central Paraguay, northeastern Argentina, and Uruguay, and conditions be extreme in Corrientes, Argentina.

Deficits are forecast to generally downgrade from May through July. Mild to moderate deficits are forecast for Brazil, with some more intense pockets in Maranhão and in the southeast. Nearly normal conditions will return to eastern Venezuela and neighboring Guyana, and relatively mild deficits are forecast for Suriname and French Guiana. Moderate deficits are expected in Colombia, but deficits will be more intense in the south. Deficits will also intensify in a long path along the Pacific from Peru through northern Chile. Surpluses will increase in Paraguay and northeastern Argentina, shrink somewhat in Uruguay, and downgrade in Rio Grande do Sul, Brazil.

In the final quarter – August through October – deficits will intensify over the northern half of the continent, with pockets of exceptional deficit in northeastern Brazil and severe deficits on the Amazon. Surpluses will retreat from southern Brazil and Uruguay and will shrink in Paraguay and northeastern Argentina.

(It should be noted that forecast skill declines with longer lead times.)

A strong storm system battered Rio de Janeiro early this month, causing floods and mudslides and killing at least six people. The storm followed Rio’s hottest January in nearly 100 years.

A heavy rainstorm flooded parts of Argentina and Paraguay in mid-January with up to 100mm (3.9 inches) of rain in under an hour. Thousands of families from Corrientes and Resistencia on the Parana River in northeastern Argentina evacuated their homes, seeking emergency shelters. High winds accompanying the rain tore down trees and power lines, prompting electrocution warnings from local authorities.

Crippled agricultural production from Argentina’s recent drought, combined with high interest rates and 50 percent depreciation of the peso, made a hard year by all accounts for Argentina, the third-largest economy in Latin America. High interest rates have compounded the woes of farmers, forcing them to increase slaughter rates in recent months to keep up with loan payments. Experts say the country’s herd could be reduced by 500,000 head.

Some farmers in northeastern Brazil are taking to cultivating cactus for dairy cattle feed, substituting the drought-tolerant and native plant in place of thirsty grains like corn.

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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Many analyses reported in ISciences-authored blog posts are based on data generated by the ISciences Water Security Indicator Model (WSIM). Other sources, if used, are referenced in footnotes accompanying individual posts. WSIM is a validated capability that produces monthly reports on current and forecast global freshwater surpluses and deficits with lead times of 1-9 months at 0.5°x0.5° resolution. This capability has been in continuous operation since April 2011 and has proven to provide reliable forecasts of emerging water security concerns in that time-frame. WSIM has the ability to assess the impacts of water anomalies on people, agriculture, and electricity generation. Detailed data, customized visualizations, and reports are available for purchase.

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