Late Pleistocene and Holocene environmental changes in the coastal zone of northwestern Portugal     

G. Soares de Carvalho  H. M. Granja  E. Loureiro  R. Henriques 《第四纪科学杂志》2006,21(8):859-877

This paper examines the Quaternary changes in the coastal zone of northwestern Portugal through the relationship between sediments and landforms. By interpolating the available data from geomorphology, lithostratigraphy, sedimentology and geochronology, it was possible to reconstruct existing palaeoenvironments, the oldest of which date back to the last interglacial. The main landforms are a high and a low platform bounded by scarps. River sands and silty sediments formed in a lacustrine environment (Antas Formation, MIS 5) are associated with the high platform. Two deposits are associated with the low platform: the Cepães Formation (MIS 3) consisting of a lower set of river sand beds and an upper gravel beach bed, and the Aguçadoura Formation (MIS 1) consisting of Holocene lagoonal beds. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

Massive star populations in Wolf–Rayet galaxies     

I. F. Fernandes  R. de Carvalho  T. Contini  R. R. Gal 《Monthly notices of the Royal Astronomical Society》2004,355(3):728-746

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The Fundamental Plane of E Galaxies in Compact Groups     

R. de Carvalho  I. de La Rosa  Steve Zepf 《Astrophysics and Space Science》2003,285(1):79-84

We present a study focusing on the nature of compact groups through the study of their elliptical galaxies. We determine central velocity dispersions (σ_o) for 18 bright elliptical galaxies located in the core of Hickson compact groups and a control sample of 12 brightbona fide ellipticals located in the field or very loose groups. Several tests are carried out to avoid systematic effects in σ measurements. We use these velocity dispersions to compare the position of 11 compact group galaxies in the Fundamental Plane to that of a large and homogeneous sample of elliptical galaxies (Burstein et al., 1987).We find that little or no significant difference exists, as far as the Fundamental Plane is concerned, between ellipticals in compact groups and their counterparts in other environments. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Assessment of the leachate movement in a sealed landfill using geophysical methods     

Elsa C. Ramalho  Amélia Carvalho Dill  Rui Rocha 《Environmental Earth Sciences》2013,68(2):343-354

This paper describes a case study concerning the use of integrated geophysical methods applied to environmental assessment. The study is focused on an old municipal solid waste sealed landfill site, located in Gaeiras, Central Portugal. The problem is related with leachate overproduction in this domestic and industrial waste landfill that became an environmental problem with urgent assessment, so that a solution could be planned. Due to the lack of accurate information regarding the shape, history and development of the landfill, the use of a set of classical geophysical methods was the option, since they are non-invasive and non-destructive. The available area was small, almost restricted to the landfill area. To conduct this assessment, electromagnetic RF-EM and Geonics EM34, spontaneous potential (SP), vertical electrical soundings (VES) and magnetic prospecting surveys were planned to understand the various problems that could be related with the leachate overproduction. The joint use of these classical geophysical methods was targeted to investigate bedrock depth and structure (RF-EM, EM34 and VES), waste and leachate characteristics (EM34 and magnetics) and groundwater flow (SP) in the landfill. Geophysical results were correlated with hydrogeological information, integrated and interpreted, using geographic information system tools. The results obtained were important to understand the geological mechanisms that are responsible for leachate overproduction and to suggest remedial measures.  相似文献   

Relationship between physical and chemical soil attributes and plant species diversity in tropical mountain ecosystems from Brazil   总被引：2，自引：0，他引：2  

Fernanda de Carvalho  Edward Luis Godoy  Francy J. G. Lisboa  Fatima Maria de Souza Moreira  Francisco Adriano de Souza  Ricardo Luis Louro Berbara  G. Wilson Fernandes 《山地科学学报》2014,11(4):875-883

Although the high diversity of plant species in the rupestrian fields has been primarily attributed to the existence of a set of distinct habitats, few studies support this assertion. The present study aimed to further investigate the relationship between physical and chemical attributes of soils with the diversity of plant species in this unique ecosystem. The rupestrian field is a unique vegetation formation that covers some of the southeastern Brazilian mountains in the transition of the Atlantic rain forest and the Cerrado （savanna）. Different habitats occur according to soil characteristics （e.g., presence of rocks, sand, fertility, hydrology, etc.）. These attributes ultimately influence the vegetation that is highly adapted to the harsh edaphic and climatic mountain conditions. Five distinct habitats were studied by us： rocky outcrops, peat bogs, sandy bogs, quartz gravelfields, and ＂cerrado＂ （savanna）. A floristic survey indicated that four families are found at greater frequency： Poaceae, Asteraceae, Cyperaceae, and Leguminosae. The greatest diversity of plant species was found in the rocky outcrops habitat, followed by cerrado, peat bog, quartz gravel grassland, and sandy bogs, respectively. The main difference in the floristic composition among these habitats was related to the dominant species. Trachypogon spicatus （Poaceae） was the most dominant species in the rocky outcrops, Axonopus siccus （Poaceae） in the peat bogs, Lagenocarpus rigidus （Cyperaceae） in the sandy bogs, Schizachyrium tenerum （Poaceae） in the cerrado, while Vellozia sp. 8 （Velloziaceae） dominated the vegetation in the quartz gravel grassland. This study demonstrated that physical and chemical soil properties strongly related the diversity of plant species occurring in the different habitats of rupestrian fields.  相似文献   

Assessing the severity of disturbance for intertidal and subtidal macrobenthos: The phylum-level meta-analysis approach in tropical estuarine sites of northeastern Brazil     

Paulo V.V.C. Carvalho  Paulo J.P. Santos 《Marine pollution bulletin》2010,60(6):873-887

The phylum-level meta-analysis approach was applied to assess the status of disturbance of intertidal and subtidal macrobenthos in two estuaries in northeastern Brazil that are subject to different sources of pollution. Previously published estuarine data were included in the body of knowledge considered in the meta-analysis, to improve the reliability of the assessment of the Brazilian samples. Further multivariate and distributional techniques were applied to discriminate differences between estuaries and assess the pollution status of each. Phylum-level multivariate comparisons based on community attributes succeeded in discriminating the estuaries, and species distributions against abundance separated the estuaries in terms of pollution status. The meta-analysis indicated an almost indistinguishable moderate pollution status for both systems. Addition of new comparative data to the meta-analysis did not improve its sensitivity. Although the meta-analysis yielded satisfactory results in detecting disturbance in tropical estuaries, the method is not very sensitive to differences in sources of pollution.  相似文献   

Anthropogenic influence on the degradation of an urban lake - The Pampulha reservoir in Belo Horizonte, Minas Gerais, Brazil     

Kurt Friese  Gerald Schmidt  Jorge Carvalho de Lena  Dieter W. Zachmann 《Limnologica》2010,40(2):114-125

The artificial reservoir Lagoa da Pampulha in central Brazil has been increasingly affected by sediment deposition and pollution from urban and industrial sources. This study investigates water chemistry and heavy metal concentrations and their fractionation in the lake sediment using ICP-OES, ICP-MS, and XRD analyses. Fractionation analysis was done by sequential extraction under inert gas as well as after oxidation. The lake exhibits a permanent stratification with an oxygen-free hypolimnion below 2 m depth. Nutrient concentrations are enriched for phosphorous components (SRP, PO₄). In the sediment it was not possible to detect oxygen. Carbon, sulfur, and most of the analyzed heavy metals are enriched in the top sediment layer with a pronounced downward decrease, indicating the presence of an anthropogenic influence. Statistical analysis, including correlations and a Principal Component Analysis (PCA) of depth-related total concentration data, helps to distinguish presumably anthropogenic heavy metals from geogenic components. Some samples with high element concentrations in the sediment also show elevated concentrations in their pore water. Analyses of element distribution between sediment and pore water suggest a strong bonding of heavy metals to the anoxic sediment. The trend towards elevated solubility in the pore water of oxidized samples is clear for most of the analyzed elements. Fractionation analysis reveals characteristic associations of selected elements to specific mineral bonding forms. In addition, it indicates that the behavior of heavy metals in the sediment is strongly influenced by organic substances. These substances provide buffering against oxidation, acidification, and metal release. The high nutrient loading causes reducing conditions in the lake sediment. These conditions trigger the accumulation of sediments rich in S²⁻, which stabilizes the fixation of heavy elements. In the future, care must be taken to reduce the supply of contaminants and to prevent the release of heavy metals from sediments dredged for remediation purposes.  相似文献   

Understanding the 3D Structure of a Thermal Water Fissured Granite Aquifer by Use of Geophysical Studies     

E. C. Ramalho  J. P. Carvalho  R. Gon?alves  F. A. Monteiro Santos 《Pure and Applied Geophysics》2012,169(11):2031-2046

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Education: Can a bottom-up strategy help for earthquake disaster prevention?     

G. Musacchio  S. Falsaperla  A. E. Bernhardsdóttir  M. A. Ferreira  M. L. Sousa  A. Carvalho  G. Zonno 《Bulletin of Earthquake Engineering》2016,14(7):2069-2086

To comply with the need to spread the culture of earthquake disaster reduction, we rely on strategies that involve education. Risk education is a long-term process that passes from knowledge, through understanding, to choices and actions thrusting preparedness and prevention, over recovery. We set up strategies for prevention that encompass child and adult education, as a bottom-up approach, from raising awareness to reducing potential effects of disruption of society. Analysis of compulsory school education in three European countries at high seismic risk, namely Portugal, Iceland and Italy, reveals that generally there are a few State-backed plans. The crucial aspects of risk education concerning natural hazards are starting age, incompleteness of textbooks, and lack of in-depth studies of the pupils upon completion of their compulsory education cycle. Hands-on tools, immersive environments, and learn-by-playing approaches are the most effective ways to raise interest in children, to provide memory imprint as a message towards a culture of safety. A video game, Treme–treme, was prepared to motivate, educate, train and communicate earthquake risk to players/pupils. The game focuses on do’s and don’ts for earthquake shaking, and allows children to think about what might be useful in the case of evacuation. Education of the general public was addressed using audio-visual products strongly linked to the social, historical and cultural background of each country. Five videos tackled rising of awareness of seismic hazards in Lisbon, the area surrounding Reykjavik, Naples, and Catania, four urban areas prone to earthquake disasters.  相似文献   

A 4D-variational ocean data assimilation application for Santos Basin,Brazil     

Mauricio da Rocha Fragoso  Gabriel Vieira de Carvalho  Felipe Lobo Mendes Soares  Daiane Gracieli Faller  Luiz Paulo de Freitas Assad  Raquel Toste  Lívia Maria Barbosa Sancho  Elisa Nóbrega Passos  Carina Stefoni Böck  Bruna Reis  Luiz Landau  Hernan G. Arango  Andrew M. Moore 《Ocean Dynamics》2016,66(3):419-434

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