South America: Large pockets of exceptional water deficits in Brazil

22 May 2017

The Big Picture
Water deficits are forecast for much of the northern half of South America through January 2018, as seen in the 12-month map (below). Exceptional deficits are expected in large pockets and along major rivers in Brazil; and in northern Chile, the Gulf of Corcovado, and Tierra del Fuego.

Surpluses are forecast for Piura, western Loreto, and Huánuco, Peru; and Buenos Aires Province and La Pampa Province in Argentina.

Impacts
The price of the eponymous Brazil nut has soared by 61 percent in Europe. Drought in the Amazon reduced the harvest by a third and triggered high unemployment in Brazilian communities dependent on nut processing facilities.

In Chile it's the almond harvest that's suffering, with one producer estimating a 15 to 25 percent decrease in volume. Significant contributing factors were drought in May, June, and July of last year - winter months which are the normal rainy season - followed by extreme heat in the summer months, resulting in fewer flowers and an increase in soil salinity that damaged trees. Experts say industry recovery could take years; existing orchards will need several years of normal rainfall and new orchards take seven years to produce marketable harvests.

Drought continues to curtail Brazil's hydroelectric power generation and a "red flag" tariff instituted in April by ANEEL, the country's electrical power regulator, will be extended through May adding R$3 (US$0.93) for every 100 kilowatt-hours (kWh) consumed.

The State of Minas Gerais in Brazil is facing a fourth consecutive year of drought prompting officials in the municipality of Montes Claros - a city of 398,000 - to propose a 100-km (62-mile) pipeline drawing water from the São Francisco River. The plan is one of several to alleviate rationing in the city due to low water volume on the River Juramento. A 48-km connector to the Pacuí River is currently being built at a cost of R $140 million (US$43 million), along with 30 emergency wells.

The federal government of Argentina has approved a declaration of emergency for eleven provinces affected by flooding including Buenos Aires, La Pampa, and Chubut, enabling economic and financial assistance. Crop damage in La Pampa is estimated to be ARS$2 billion (Argentinian Nuevo peso; US$130 million), and 130,000 hectares (321,239 acres) are flooded in the north according to the province's production minister.

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

The forecast map for May through July shows water conditions similar to the prior three months. Similarities include widespread deficits in Brazil, including large pockets of exceptional deficits in Acre, Rondônia, Pará, Tocantins, Mato Grosso, Goiás, Minas Gerais, and São Paulo. Deficits are also expected along many rivers including the São Francisco, Tocantins, the Amazon and its tributaries.

In Venezuela deficits are forecast to recede in the north, but exceptional deficits in the south will increase. Formerly moderate deficits along the border of Peru and Colombia are forecast to increase in both extent and severity, reaching exceptional intensity in Peru’s northernmost point. Deficits will recede somewhat in Bolivia, persisting in the northeast (Huacaraje Municipality), in central Bolivia (near Cochabamba), and in a pocket of southern Bolivia.

Moderate to extreme deficits will continue to emerge in southern Uruguay, and severe to exceptional deficits will persist in northern Chile, near the Gulf of Corcovado, and in Tierra del Fuego.

Also in the next three months, surpluses are forecast to emerge in Bolivia east of Lake Titicaca, and severe surpluses in eastern Paraguay will increase in extent. Severe to exceptional surpluses are expected to persist in the following regions of Argentina: Buenos Aires Province, particularly along the Salado River and in western reaches of the province; La Pampa Province; and, Neuquén Province.

From August through October the extent of deficits in Brazil will remain much the same as forecast for May through July. However, water conditions for northern nations are expected to change as moderate to extreme deficits continue to emerge in greater extent in French Guiana, Suriname, Guyana, Venezuela, Colombia, and Ecuador. Deficits reaching greater severity will continue to emerge in northern Chile. Many aforementioned surpluses in South America are expected to diminish during this period.

The forecast for the latter months – November through January – indicates near-normal conditions across Brazil’s mid-section but the persistence of deficits elsewhere in northern South America.

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