Marine and Environmental Sciences Centre

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Organizational Unit

Publications

Simulated hydropower production under climate change scenarios at Torrão reservoir, in northern Portugal

Publication . Diogo, Paulo; Mujtaba, Babar; Beça, Pedro; Simoes, Sofia; Fortes, Patricia; Amorim, Filipa

ABSTRACT: Climate conditions have a significant impact on energy demand and production. The project CLIM2POWER, completed in 2021, aimed to develop a climate service at European scale for the planning of the power infrastructures operations using seasonal forecasts and long-term climate projections. This work presents part of the project, and focus on assessing the climate change impacts on hydropower production of Torrão Dam. Torrão reservoir is located on the Tâmega river, a tributary of the Douro river in northern Portugal. The long-term (2016-2100) climate data used is obtained from the EURO-CORDEX simulations, on a daily time scale. Two different combinations of regional and global climate models for scenarios RCP 4.5 and 8.5 (four combinations) were used: ICHEC-EC-EARTH-CLMcom-CCLM4 (CCLM4) and ICHEC-EC-EARTH-DMI-HIRHAM5 (HIRMAM5). Long-term precipitation data was bias-corrected using the multiplicative shift method, and for rainfall-runoff simulation, HEC-HMS model was used. The results showed that 30-years total annual precipitation for future periods (i.e, 2016-2040, 2041-2070 and 2071-2100) was 3.4%-28.1% lower than the historical one. 30-years annual total discharges of all future periods decreased for both models and RCPs (1.2%-30.2% less than the historical ones). Regarding future 30-year annual average capacity factors, there was reduction (1.8%-24.8%) with respect to historical one, except in two future periods for CCLM4 model of RCP 4.5 scenario i.e., 1.2% increased in the period 2016-2040 and 1.5% increased in the period 1971-2100. This suggest that hydropower production is not only dependent on future precipitation trends but also on the hydropower production procedures.

2022-06Conference object

Open access

New data on the palynology of the Triassic Jurassic boundary of the Silves Group, Lusitanian Basin, Portugal

Publication . Vilas Boas, Margarida; Pereira, Zélia; Cirilli, Simonetta; Duarte, L. V.; Fernandes, Paulo

ABSTRACT: New evidence is presented on the Triassic-Jurassic boundary in the northern Lusitanian Basin, Portugal, based on miospore assemblages from a composite Upper Triassic to Lower Jurassic succession of the Silves Group. The latter comprises, from base to top, the Conraria, Penela, Castelo Viegas and the Pereiros formations. Three informal palynological zones have been documented and compared with coeval palynozones from West and South Europe providing new biostratigraphic data to detail the age of the lower and upper formations of the Silves Group and to review previous age attribution. A Norian, possibly earliest Rhaetian age, is documented for the Conraria Formation on the basis of a palynological assemblage referable to the Classopollis meyerianus-Granuloperculatipollis rudis (CG) zone. The Penela and Castelo Viegas formations did not allow a palynostratigraphic revision, due to the not promising lithology for palynological studies. The Pereiros Formation is dated on the basis of microflora assemblages referable, from bottom to top, the Ischyosporites variegatus-Kraeuselisporites reissingeri (IK) zone of late Rhaetian-earliest Hettangian age and Pinuspollenites minimus (Pm) zone of Hettangian age. The discontinuity between the underlying Castelo Viegas Formation and the overlying Pereiros Formation did not allow to define the lower boundary of the IK palynozone. The Triassic-Jurassic boundary lies in the lower part of Pereiros Formation within the IK zone. The microflora assemblages from the Lusitanian Basin show close affinity to those of eastern N America and western Tethys areas. (C) 2021 Elsevier B.V. All rights reserved.

2021Journal article

Open access

Heterogeneity of the mixed siliciclastic-carbonate deposits of the upper Cabo Carvoeiro formation (Lower-Middle Jurassic), Lusitanian Basin, Portugal

Publication . Barata, Joao; Duarte, Luis; Azerêdo, Ana Cristina; Gomes, J.

ABSTRACT: The upper CC5 member of the Cabo Carvoeiro Formation (Toarcian-Aalenian(?)) of the Lusitanian Basin is characterized by grainstone facies with quartz grains, ooids and intraclasts. These facies are observed exclusively at Peniche, contrasting with the hemipelagic marly sediments of coeval outcrop sections in the basin. A detailed facies scheme reveals the relative local heterogeneity of the succession on outcrops, while the analysed subsurface data helps to better understand its regional heterogeneity. Lateral facies variability on outcrop is observed to occur through gradation, interfingering or pinching-out geometries. Coeval sections in the analysed offshore wells are generally characterized by micritic mudstone facies, which might transition laterally into the Peniche grainstones through similar geometric relationships based on the existing conceptual model. The relative heterogeneity of this sedimentary system is defined in this study by integrating outcrop and subsurface data, allowing for its perception at different observation scales.

2025-04Journal article

Open access

Caracterização de pegadas de terópodes no Oxfordiano superior do Cabo Mondego, Bacia Lusitânica

Publication . Carvalho, Ismar; Cunha, Pedro; Figueiredo, Silvério

RESUMO: São analisadas dez pegadas de dinossauros, ocorrendo em dois estratos do topo das “Camadas com Pholadomya protei” (Oxfordiano superior) do Cabo Mondego (Figueira da Foz), sector norte da Bacia Lusitânica. Trata-se de pegadas que podem ser observadas na superfície das camadas ou em seção transversal, por vezes representando estruturas que deformam muito o substrato. O material icnológico encontra-se distribuído em duas camadas sucessivas, cada uma constituída por uma base de marga arenosa e topo de arenito de grão muito fino a médio. Os depósitos destas camadas correspondem a um ambiente litoral de planície de maré, num delta.

2025-04Journal article

Open access

Aspetos microfaciológicos da formação da Leba, Proterozoico (Sudoeste de Angola)

Publication . Duarte, Luis; Barata, Joao; Oliveira, C. L.

RESUMO: A Formação da Leba é uma unidade carbonatada de referência do Proterozoico do Cratão do Congo, Sudoeste de Angola, composta por dolomitos silicificados com laminitos microbianos e estromatólitos. Este trabalho preliminar descreve as principais microfácies que caracterizam esta unidade, baseada no estudo de várias secções do Planalto da Humpata. Os resultados confirmam o domínio da dolomite em toda a sucessão, localmente fortemente silicificada. As fácies são bastante diferenciadas, compreendendo bioconstruções microbianas, incluindo micro domos estromatolíticos, e uma grande variabilidade de outras texturas, desde dolomicritos/mudstones a grainstones intraclásticos e extraclásticos. Tendo em conta que a dolomite é de origem primária, são identificados vários processos diagenéticos, incluindo dolomitização e diferentes fases de silicificação.

2025-04Journal article

Open access