Extreme Seasonal Droughts and Floods in the Madeira River Basin, Brazil: Diagnosis, Causes, and Trends

• Published in: Climate
• Main Authors: Nicole Cristine Laureanti, Priscila da Silva Tavares, Matheus Tavares, Daniela Carneiro Rodrigues, Jorge Luís Gomes, Sin Chan Chou, Francis Wagner Silva Correia
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2024
• Subjects: extreme precipitation; Amazon rivers; climate change; hydrology; Science; Q; North Atlantic; South Atlantic Ocean
• Online Access: https://doi.org/10.3390/cli12080111; https://doaj.org/article/46bae239f1ad4dfa9ef5701f4e83a863

The Madeira River, a major tributary of the Amazon River, often undergoes severe flood and drought conditions. This study seeks to investigate the climate processes associated with the opposing extreme precipitation events in the Madeira River basin and to relate them to river discharge variability based on a flood awareness dataset. Despite the uncertainty in the observational datasets, the annual precipitation cycle exhibits a rainy season from November to March. A significant result is the high correlation between the rainy season variability in the Madeira River basin and the sea surface temperature (SST) anomalies in the tropical North Atlantic Ocean and the southwestern South Atlantic Ocean. This result indicates that improving the Atlantic SST representation in climate modeling allows for capturing extreme precipitation events in the region. In addition to this impact, certain Madeira River tributaries present significant climate trends. The river discharge variability reveals an increase in hydrological extremes in recent years in the upper sector, but more significantly, in the lower basin, where it has reduced by more than 400 m 3 /s per decade. These findings highlight the need to improve in situ data and climate and hydrological modeling, with a focus on describing the intense climate variability and trends in river discharges.