The strongest La Niña weather cycle in 35 years has reduced rainfall by up to 46% in some areas of Chile. The dry season began last March and is expected to continue through May.
The drought affects the Coquimbo, Valparaíso, O’Higgins, Maule, and Metropolitan regions covering central Chile. In the capital city of Santiago, rainfall is 17% below average rainfall levels.
La Niña is the name given to a specific set of ocean conditions that dramatically affect the weather patterns in Pacific Rim countries. It is caused when cooler water moves closer to the South American coast than is usual. High pressure forms over the coast, preventing weather systems from moving on the continent and lowering the possibility of rainfall.
The surface temperature of the South American coast has dropped 1.1 degrees Celsius, nearly 2 degrees Fahrenheit. This marks the biggest drop since 1975, when the temperature fell 1.2 degrees Celsius.
The result has been a fall in the water levels of different reservoirs that feed hydroelectric generators. The La Paloma reservoir in the Coquimbo Region, for example, currently has reserves 74% below its capacity.
“The drought caught us with already very low reservoir reserves, so the effect has been more pronounced,” said Fernando Santibañez, professor of climatology at Universidad de Chile.
The lack of rainfall is expected to affect energy production, as Chile produces about one half of its energy though hydroelectric power. In 2002, hydroelectric power accounted for 70% of total energy production. On Feb. 3 Energy Minister Laurence Golborne said Chile was facing a complicated energy situation due to drought.
Predictions for this year suggest only 41% of energy demand will be met by hydroelectric plants. This will create an increased reliance on fossil fuels to meet the gap in demand and much greater contamination levels and CO2 emissions. In response to possible energy deficits, the government is considering implementation of a rationing system for energy consumption.
“Things are tight, but with some measure of support we’re confident that can we can develop something between now and six months, so the problem can be overcome without rationing,” said Eduardo Ricke, chief operating officer of the CDE-SIC, which coordinates the operation of electrical system.
Ricke admitted that one option being discussed was a limit on industrial electricity usage in the north – where the nation’s mining industry is concentrated - to develop a surplus to help meet demand further south.
Luis Mayol, president of the National Agriculture Society (SNA), suggested the country seriously consider building more water reservoirs and dams. Farmers in Norte Cote are pruning back their fruit trees so that they will recover for next year, limiting production this year.
La Niña has likewise affected other Pacific Rim countries. The weather cycle was responsible for last year’s favourable monsoon conditions in India, and the floods and storms that hit Queensland, Australia, recently.
La Niña is the counterpart of El Niño in the Southern Oscillation Climate Cycle. Worldwide, El Niño has a more far-reaching effect on weather. A strong El Niño weather pattern, such as that which caused heavy rain in Peru and Ecuador is often preceded by La Niña.
By Mark Briggs – Santiago Times