Author(s): Luiz Maldonado; Marcelo Zaicovski; Jose Maria Farina
Linked Author(s): Luiz Henrique Maldonado
Keywords: ENSO Inflow Itaipu
Abstract: The "El Nino"-Southern Oscillation (ENSO) is a global climatic phenomenon resulting from variations in winds and sea surface temperatures over the tropical Pacific Ocean, which correlates with precipitation events and river flows, as observed in regions such as South America. The objective of this study was to verify the impact of the ENSO index on the flows of the Parana River basin, specifically for the Itaipu Hydroelectric Plant, and to assess the impact of the most recent "El Nino" event in the region. Considering the percentiles for natural and incremental flows, it was observed that higher flows (percentiles above 75 and 90) occur during "El Nino" events compared to "Neutral" and "La Nina" events. It was also noted that droughts (percentiles below 25) tend to occur when "El Nino" is not classified as "Very Strong. " Additionally, since 2016, there has been a low frequency of flows in the 75th and 90th percentiles for both natural and incremental flows, a trend similar to that observed during the 2023/2024 "Strong El Nino" event, which was characterized by negative flow anomalies. In conclusion, "El Nino, " "La Nina, " and "Neutral" events lead to significant variability in river flows, with higher flows occurring more frequently during "El Nino" conditions. However, other factors also influence precipitation and flow behavior in the region and should be further analyzed.
Year: 2025