South America: Intense water deficits to persist in Amapá & Roraima

26 October 2017

The Big Picture
Water deficits of varying intensity are forecast across much of Brazil for the 12-month period ending June 2018, with large pockets of exceptional deficits in Amapá, western Amazonas, southern Pará, northern Mato Grosso, and Tocantins.

Deficits reaching exceptional severity are also forecast for northwest and southern Venezuela, French Guiana, and in a north/south line through Bolivia beginning at Cochabamba.

Surpluses are expected in Buenos Aires and La Pampa Provinces, Argentina, and in southern Patagonia. Surpluses of generally lesser intensity are forecast for central Colombia, eastern Bolivia, and southern Uruguay.

Impacts
Low water levels in many of Brazil's hydropower reservoirs, upon which the country depends for two-thirds of its electricity production, have prompted energy regulator, ANEEL, to raise prices in October by 17 percent over September. Recent rainfall near the Paraguay border has assured that some of the power shortages can be met by the Itaipu hydroelectric project, whose production set a world record last year.

Though the current drought has helped fuel fires in the Amazon, experts are looking beyond drought to help explain what might make 2017 a record-breaking fire year, pointing to forest degradation and changing climate. Brazil's National Institute of Space Research (INPE) reports that 208,278 fires were detected by October 5 - setting a path that could exceed the 2004 record - with more fires in September than in any month in the 20 years the agency has kept records. The state of Pará alone reported a six-fold increase in fires over last year, and in the state of Tocantins fires have killed over 1,000 cattle and destroyed 70 percent of Araguaia National Park.

Forest degradation is one of the reasons cited in new research suggesting that the world's tropical forests like the Amazon, long regarded as net carbon sinks, may now emit more carbon than they sequester.

Brazilian health researchers have concluded that particulate matter smaller than 10 microns, commonly released by agricultural fires used to clear sugarcane and other biomass, can reach lung alveoli, promoting DNA damage and cell death.

Drought near Cochabamba, Bolivia has affected 20,000 hectares (49,421 acres) of agricultural crops, primarily maize, along with potatoes, vegetables, and fruit.

Flooding in Argentina continues to impact farming, especially in Buenos Aires and La Pampa Provinces. By the end of September satellite imagery indicated 9 million hectares flooded (22 million acres). CRA, the country's agricultural union, reports that 285,000 hectares (704,250 acres) of wheat have been lost, and that at least 200,000 calves will be lost due to water-related respiratory diseases. Though the region's wheat losses are not expected to negatively impact national production levels overall due to increases elsewhere, the affected regions are those that generate more foreign exchange, a financial arena where regional losses will be reflected.

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

Noticeable at a glance in the map progression is the significant retreat of exceptional deficits – shown in dark red – in the October through June forecasts. However, from October through December exceptional deficits remain in the forecast for northernmost Brazil, particularly Amapá, from French Guiana into Suriname, and in Venezuela’s southern extreme. Deficits ranging from severe to exceptional are forecast in an arc from north of Lake Titicaca in southern Peru through La Paz and Cochabamba, Bolivia and south across the border into northern Argentina; and, in Tierra del Fuego. Widespread, primarily moderate deficits are predicted in much of eastern Brazil, but may be more severe along the coast of the State of São Paulo. Moderate deficits are also forecast for southern Peru.

Surpluses are forecast in: Trinidad and Tobago; central Colombia; Piura, Peru and rivers in northeast Peru; northern Bolivia; eastern Argentina including Buenos Aires Province; Uruguay; and surrounding O’Higgins (San Martín) Lake in Patagonia. Surpluses may be especially intense in Piura, Peru; Santa Cruz de la Sierra, Bolivia; and O’Higgins Lake, Patagonia.

In the January through March map the emergence of widespread surpluses of moderate to severe intensity is evident in the northern Amazon Basin into southern Venezuela and Suriname. Surpluses are expected to retreat in northeastern Peru; Rio Grande do Sul, Brazil; the Iberá Wetlands of northeastern Argentina; and Uruguay. Surpluses will persist, though diminish somewhat, in northern Bolivia; Buenos Aires Province, Argentina; and O’Higgins Lake region, Patagonia. Moderate surpluses are expected to emerge during this period in western Mato Grosso, Brazil and across the border into Paraguay. Deficits in eastern Brazil will diminish considerably, becoming mild; some moderate deficits will continue to emerge in Peru and western Ecuador. Deficits of greater severity are forecast for eastern Roraima, Brazil into southern Guyana, and surrounding the Guárico Reservoir in northern Venezuela.

The forecast for the final months is similar to the January through March forecast.

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

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.