Projected climate change impacts on the inflow of a Southeastern Brazilian hydropower reservoir
Drummond Marques da Silva, Nathalia (Universidade Federal de Minas Gerais. Instituto de Geociências)
Macedo, Diego Rodrigues (Universidade Federal de Minas Gerais. Instituto de Geociências. Departamento de Geografia)
Santos de Lima, Letícia (Universitat Autònoma de Barcelona. Institut de Ciència i Tecnologia Ambientals)
Bressiani, Danielle (Instituto Tecnológico de Aeronáutica. Divisão de Engenharia Civil (Brazil))

Date:	2026
Abstract:	Hydrological assessments of climate change effects remain scarce for Brazilian basins regulated by large reservoirs, despite their strategic role in national energy security. The present study evaluates how projected climate change may alter inflow regimes to the Nova Ponte reservoir basin in Southeastern Brazil, over short- (2019-2040) and medium-term (2041-2060) horizons. A SWAT ecohydrological model was forced with bias-corrected CMIP6 climate projections from two global climate models (CNRM-ESM2-1 and MRI-ESM2-0) under two IPCC AR6 scenarios (SSP2-4. 5 and SSP5-8. 5). Results consistently indicate increases in mean and median inflow relative to the reference historical period across all model-scenario combinations, accompanied by a marked amplification of intra-annual variability and extreme flow events. Projected inflows increase by approximately 30-80%, while peak discharges may exceed historical maxima by up to ~190%, particularly during the wet season and, in some cases, during traditionally dry months. These results reveal that climate change may simultaneously enhance average water availability and intensify hydrological extremes in the basin. While higher inflows could reduce the risk of energy generation deficits, the amplification of extremes may aggravate erosive processes, accelerate siltation, and pose operational and safety challenges for reservoir management. Overall, the study demonstrates that higher average inflows do not necessarily translate into lower hydropower risk, highlighting the need for climate-adaptive reservoir planning that explicitly accounts for increased variability and extremes. Our findings further shows that watershed responses to climate change vary significantly, and increased flows may pose both positive and negative challenges for hydropower reservoir management.
Note:	Unidad de excelencia María de Maeztu CEX2024-001506-M
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	AR6 scenarios ; Brazilian reservoir ; Hydrological modeling ; Hydropower ; SWAT ; Tropical basins
Published in:	Regional environmental change, Vol. 26, Num. 2 (June 2026) , art. 74, ISSN 1436-378X

DOI: 10.1007/s10113-026-02560-8

16 p, 2.1 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Institut de Ciència i Tecnologia Ambientals (ICTA)
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