The National Meteorological Institute (IMN) reported that more than 50% of Costa Rica’s territory presents some degree of drought.Furthermore, based on historical records, it is unprecedented that the Pacific and Caribbean slopes present drought at the same time.
According to Luis Alvarado, from the IMN Climatology unit, there are two factors that are influencing this situation:El Niño Phenomenon and the Atlantic Ocean Overheating Phenomenon
“On the one hand there is El Niño, and in particular its atmospheric component, which has maintained a marginal coupling with the oceanic component, which is the most strengthened,” indicated the meteorologist.
Overheating of the Atlantic Ocean
“And second, due to the counteracting effect of the overheating of the Atlantic Ocean, whose influence may be overshadowing, spatially and temporally, the typical impacts of El Niño,” explained the expert.The above is because usually, under this phenomenon in Costa Rica, for example, the Caribbean and the Northern Zone present a surplus of rain.
“The simplest definition of meteorological drought is a sustained and prolonged rainfall deficit,” commented the IMN.Since May 2023, it has been present in the Pacific but in the Caribbean, it is the strongest since historical records have been recorded, it began in 2020.
According to IMN data, in percentage terms, the Caribbean region has the highest shortages in 2023. They vary from 32% in the Southern Caribbean and 44% in the Northern Caribbean.
Likewise, for the city of Limón, there is a history since 1941 and the current drought has the highest lack of rain, compared to others of the same duration, between 3 and 4 years, the data reflects:The percentage deficit for 2020-2023 is currently at 23%. It exceeds the 19% of the 1966-1969 period and 15% of the 2011-2013 period.
“Therefore, it is the strongest drought in 82 years,” the meteorologist emphasized.This drought also shows a very uneven pattern between the coast and the mountains, since the rainfall deficits are percentage-wise higher at low altitudes,” highlighted the IMN.
Such is the case of Turrialba, where the percentage deficit from January to August 2023 reaches 20%. That is, almost half of what the city of Limón registers with 37%. “Added to the above is the thermal condition, where this year is shaping up to be among the hottest in history, not only nationally, but globally,” the experts say.
Another region in Costa Rica that stands out for the significant decrease in rainfall is Liberia. “In Liberia, a decrease in rainfall was observed in the period January-August 2023 compared to the same period in 2022, by -57%. Similar situation with respect to the historical average, which is -29%,” reported Alvarado.
Furthermore, the presence of El Niño is causing deficits and droughts in various parts of the Pacific, but according to the expert, on this occasion there is uneven behavior, there is no drought in all of Guanacaste, nor in the Central Valley in general.
For example, in the capital, there was a 31% decrease in rainfall compared to 2022, however, the net amount represents 7% more than normal, so it does not currently qualify as a drought.
Data for August, across the country, shows:
- South Pacific: -27% rain. In July, a 10% surplus was estimated for the following quarter.
- Northern Caribbean: -24% rain. In July, a surplus for the Caribbean side of the quarter was estimated at 10% to 15%.
- Southern Caribbean: -13% rain.
- Central Pacific: – 10%. A 15% decrease was forecast for the subsequent quarter.
- Central Valley: -3%. A deficit of 15% was forecast for August, September and October.
North Zone: -7%. In July, a surplus of 10% to 15% was forecast for the quarter.
North Pacific: +1% rain. In July, a maximum deficit of 20% was forecast.
“The drought affects farmers, but it also lowers the levels of reservoirs and the flow of rivers, which puts the supply of water for human consumption and for hydroelectric generation at risk in the medium term,” highlighted the meteorologist.
According to Marco Acuña, executive president of the Costa Rican Electricity Institute (ICE), hydroelectric energy represents 65% of electricity generation.“Given this, a drop in rainfall impacts the way the country is supplied, reducing hydroelectric generation from ICE and private plants,” Acuña explained.
For their part, the Aqueduct and Sewer authorities (AyA) warned that an increase in rain that occurred in June-July was insufficient to recover the aquifers.According to the institution’s estimate, the most affected areas will be:North pacific, North Zone, Caribbean, Chorotega, Greater Metropolitan Area.
As part of the strategy to minimize the impact, there is the incorporation of flow, minimizing leaks, termination of projects and operational maneuvers that reduce shortages.
According to the data presented by AyA, regarding the behavior of the dry season in February, Guanacaste stood out, requiring urgent intervention due to the demand for liquid.For example, in Liberia, tanker trucks were used to supply the population. Other places such as Hojancha and Flamingo join this condition.
One of the main concerns of experts at the beginning of the year when the imminent arrival of El Niño became known, is that this drought is going to join the dry season, which could worsen the impacts in the country.