River discharge in South America: agreement and contradictions between recent alteration and projected changes

• Published in: RBRH
• Main Authors: Pedro Torres Miranda, Rodrigo Cauduro Dias de Paiva, Cléber Henrique de Araújo Gama, João Paulo Lyra Fialho Brêda
• Format: Article in Journal/Newspaper
• Language: English; Portuguese
• Published: Associação Brasileira de Recursos Hídricos 2023
• Subjects: Climate change impacts; South America; Discharge alteration; Robustness; Technology; T; Hydraulic engineering; TC1-978; River; lake; and water-supply engineering (General); TC401-506; Geography. Anthropology. Recreation; G; Environmental sciences; GE1-350; Northeast Atlantic
• Online Access: https://doi.org/10.1590/2318-0331.282320220085; https://doaj.org/article/cd26cb1358134b61939d5e03c2b9ce05

ABSTRACT Climate scenarios are important information for water planning, but, in some cases, they disagree with recent climate alterations, which affects their robustness and reliability. Robustness evaluation can help identifying areas that should be prioritized by in water sector adaptation to climate change. Although crucial, this kind of analysis has been overlooked in most climate change assessments, for instance in South America. This study assesses the robustness and reliability of river discharge scenarios by comparing them with observed and modelled data. Areas where current changes and scenarios agree are more likely to experience changes and, therefore, water planners should pay special attention to them. Tocantins-Araguaia, São Francisco, Western Northeast Atlantic and upper La Plata basins agreed with a discharge decrease, indicating that climate change should be prioritized in planning. Orinoco and upper-western Amazon basins showed strong disagreement between recent and projected discharge alterations, with positive change in last decades, showing that scenarios in these regions should be carefully interpreted. With this, water planners could interpret Northeastern and upper-central South America as presenting more likely scenarios in comparison to Amazon and Orinoco basins.