Artigos de Revista
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Saltwater Intrusion in the Upper Tagus Estuary during droughts
Droughts reduce freshwater availability and have negative environmental, economic,and social impacts. In estuaries, the dynamics between the saltwater and the freshwater can bea ected during droughts, which can impact several natural resources and economic sectors negatively.The Tagus estuary is one of the largest estuaries in Europe and supports diverse uses and activitiesthat can be a ected by the saltwater intrusion (e.g., agriculture). This study assesses the saltwaterintrusion in the upper reaches of the Tagus estuary using a process-based model to explore di erentscenarios of freshwater discharge and sea level rise. For the river discharge and mean sea levelrise scenarios analyzed, salinity can reach concentrations that are inadequate for irrigation whenthe mean Tagus river discharge is similar or lower than the ones observed during recent droughts(22
Ano: 2019
Número Páginas:
15p.
Autor(es): Rodrigues, M.; Fortunato, A. B.; Freire, P.
Revista: Geosciences
Editor: MDPI
Volume:
Volume 9(9), 400.
Keywords: Sea level rise; River discharge; SCHISM; Estuaries
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The closure of a shallow tidal inlet promoted by infragravity waves
Tidal inlets connect the ocean to inner water bodies and are present worldwide. Shallow inlets display fast morphological changes, due to complex interactions between tides, waves, and shallow depths. Their closure is commonly observed under storm waves, but the underlying processes remain only partly understood. Here, we present new field evidence that infragravity waves contribute to the closure of shallow inlets. The analysis of new field data collected at a shallow inlet under storm waves reveals that infragravity waves up to 0.4 m high can propagate inside the lagoon during flood but are blocked by opposing currents during ebb. At the passage of an infragravity wave crest, currents peak over 2.5 m/s and increase instantaneous sand fluxes by 2 orders of magnitude. Large accumulations of sand at the lagoon entrance damp tidal propagation until full inlet closure. This mechanism provides a new explanation for the closure of shallow inlets observed worldwide.
Ano: 2019
Número Páginas:
6804-6810pp.
Autor(es): Bertin, X.; Mendes, D.; Martins, K.; Fortunato, A. B.; Lavaud, L.
Revista: Geophysical Research Letters
Editor: Wiley
Volume:
46 (12).
Keywords: Ocean; Inlets
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Infragravity wave energy changes on a dissipative barred beach: a numerical study
The influence of bars on the infragravity wave energy changes in dissipative beaches is analysed through numerical simulations of random wave propagation. The analysis of the simulated data includes the cross-shore evolution of the significant short and infragravity wave heights, the phase-lag between the radiation stress and the infragravity wave oscillations and the balance between the infragravity wave energy flux gradient and the rate of work done by the radiation stress. These simulated data were subjected to a sensitivity analyses aiming to assess the influence of the water depths over the bar crest and of the JONSWAP peak-enhancement factor.The presence of a bar induces partial short wave dissipation through depth-induced breaking. Over the bar, the infragravity wave energy flux gradient is almost balanced by the work done by the radiation stress for the analysed range of water depths and JONSWAP peak-enhancement factors.Nonlinear energy transfers between short and infragravity wave frequencies are therefore the most important physical process to explain the infragravity wave energy changes that occur over a dissipative bar. For the shallowest test case, infragravity wave dissipation, probably induced by depth-induced breaking, can play a role on the downward slope of the bar. The water depth over the bar crest controls the infragravity wave energy changes that occur between the bar crest and the shoreline.A transition range associated to Ursell numbers between 0.3 and 1 separates two clusters associated to nonlinear energy transfers. For Ursell numbers below this range, nonlinear energy transfers occur from the short to the infragravity wave frequencies. In contrast, for Ursell numbers above this limit they occur from infragravity to the short wave frequencies. A parametrization widely used in operational wave models performs satisfactory for Ursell numbers between 0.1 and 1 over the simulated dissipative barred beach profiles.
Ano: 2018
Número Páginas:
136-146pp.
Autor(es): Mendes, D.; Pinto, J. P.; Pires Silva, A.; Fortunato, A. B.
Revista: Coastal Engineering
Editor: Elsevier
Volume:
140.
DOI:
10.1016/j.coastaleng.2018.07.005 https://www.sciencedirect.com/science/article/pii/S0378383918300322
Keywords: numerical study; Infragravity
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A numerical study of the February 15, 1941 storm in the Tagus estuary
On February 15, 1941, a storm caused one of the major natural disasters in the IberianPeninsula in the past century. The storm made landfall in the north of Portugal, leading to alarge surge in the Tagus estuary. Adverse meteorological conditions combined with a highspring tide led to extensive flooding of dry land, causing severe damage and casualties. A suiteof regional and local scale models is developed to analyze the event and the relativecontributions of the different forcing agents to the extreme water levels. Quantitative andqualitative validations show that the models adequately reproduce this type of events. Themodels are then used to assess the inundation in the upstream reaches of the estuary whereextensive agricultural lands are protected by dikes. Results show that over 25 km2 could beinundated today, a value that would increase threefold for a sea level rise of 0.5 m. Then, therelative importance of the different forcing mechanisms on the extreme water levels isinvestigated through numerical experiments. It is shown that the regional surge and the setupinduced by swell are the two main drivers of the inundation. In particular, the modulation of thewave setup by tides induces a semi-diurnal signal which is amplified by resonance inside theestuary.
Ano: 2017
Número Páginas:
50-64pp.
Autor(es): Fortunato, A. B.; Freire, P.; Bertin, X.; Rodrigues, M.; Ferreira, J.; Liberato, M.
Revista: Continental Shelf Research
Editor: Elsevier
Volume:
Volume 144, sem número.
Keywords: SCHISM; Flooding; Numerical modeling; Tide-surge interaction; Portugal; 2010 xynthia storm
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An oil risk management system based on high-resolution hazard and vulnerability calculations
A new oil risk management system is proposed herein. Risk is computed in a quantitative way, combining a detailed hazard maps generated with a process-based oil spill model over an unstructured computational grid, and a spatially detailed methodology for vulnerability analysis. The system has a web interface that serves as a single point of access to both emergency-driven and risk-management products. The system
Ano: 2017
Número Páginas:
1-18pp.
Autor(es): Azevedo, A.; Fortunato, A. B.; Epifânio, B.; Boer, S.; Oliveira, E.; Alves , F.; Jesus, G.; Gomes, J. L.; Oliveira, A.
Revista: Ocean & Coastal Management
Editor: Elsevier
Volume:
Volume 136.
Keywords: Coastal zones; Spatial vulnerability analysis; Unstructured grid; High-resolution oil spill model; Aveiro lagoon; Quantitative risk analysis
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Assessment of a three-dimensional baroclinic circulation model of the tagus estuary (Portugal)
Circulation patterns and physical regimes play a major role in estuarine ecosystems.Understanding how different drivers, like climate change, may affect the estuarine dynamics is thusfundamental to guarantee the preservation of the ecological and economical values of these areas.The Tagus estuary (Portugal) supports diverse uses and activities, some of which may benegatively affected by changes in the hydrodynamics and salinity dynamics. Numerical modelshave been widely used in this estuary to support its management. However, a detailedunderstanding of the three-dimensional estuarine circulation is still needed. In this study, athree-dimensional hydrodynamic baroclinic model was implemented and assessed using themodeling system SCHISM. The model assessment was performed for contrasting conditions inorder to evaluate the robustness of the parametrization. Results show the ability of the model torepresent the main salinity and water temperature patterns in the Tagus estuary, including thehorizontal and vertical gradients under different environmental conditions and, in particular, riverdischarges. The model setup, in particular the vertical grid resolution and the advection scheme,affects the model ability to reproduce the vertical stratification. The TVD numerical scheme offersthe best representation of the stratification under high river discharges. A classification of theTagus estuary based on the Venice system regarding the salinity distribution for extreme riverdischarges indicates a significant upstream progression of the salt water during drought periods,which may affect some of the activities in the upper estuary (e.g., agriculture). The modeldeveloped herein will be used in further studies on the effects of climate change on the physicaland ecological dynamics of the Tagus estuary.
Ano: 2017
Número Páginas:
763-787pp.
Autor(es): Rodrigues, M.; Fortunato, A. B.
Revista: AIMS Environmental Science
Editor: AIMS Press
Volume:
Vol.4, N6.
Keywords: Estuarine circulation; Venice system; Temperature; Salinity; Schism modelling system
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Cera: an open-source tool for coastal erosion risk assessment
Coastal zones are socially and economically very important, leading to a high pressure for its permanentdevelopment. Simultaneously, these zones are subject to several maritime hazards, able to causecoastal erosion. Therefore, a thoughtful management of these zones is required in order to protectsociety, economy and natural environments. This work presents a GIS-based tool that aims to provide aquick assessment to coastal erosion risk, called CERA: Coastal Erosion Risk Assessment. The simpleprocesses and small amount of data required by the tool provides a viable alternative to other methods,which are often more complex and difficult to apply. The assessment method used in CERA is divided intwo parts. The first part is a vulnerability assessment, which combines several parameters that influencecoastal erosion, each being classified in a scale of 1e5. The second part, a consequence assessment,follows the same procedure, but considering socio-economic aspects. Then, a risk matrix is applied todetermine a risk classification, also divided in 5 classes, from I to V. Aveiro, in Portugal, and Macanetaspit, in Mozambique, were selected to test the application. Data was gathered for both locations. Whilein Aveiro it was used a considerable amount of available georeferenced data, for the Macaneta spit thedata was mainly prevenient from previous publications and local expert knowledge. The results showthat both study areas have similar vulnerabilities to coastal erosion, with classes IV and V dominatingalong the areas closer to the shoreline. On the other hand, the consequence classification in Aveiro ishigher than in Macaneta, resulting in a higher risk level in several regions in Aveiro district. The higherlevel of detail in Aveiro data also resulted in a more even distribution across all class levels in theresults.©
Ano: 2017
Número Páginas:
1-14pp.
Autor(es): Narra, P.; Coelho, C.; Sancho, F. E.; Palalane, J.
Revista: Ocean & Coastal Management
Editor: Elsevier
Volume:
142.
Keywords: Macaneta; Aveiro; GIS; Exposure; Hazard; Consequence; Vulnerability
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Operational forecast framework applied to extreme sea levels 1 at regional and 2 local scales
The design, implementation and demonstration of a novel and generic computational forecast framework for multi-scale prediction of extreme sea levels and associated flooding is presented. Denoted Water Information Forecast Framework (WIFF), it integrates process-based models for waves, tides and surges from regional to local scales, predicting the flooding of coastal areas, and supporting the routine and emergency management of coastal resources. WIFF manages the simulations and the real-time monitoring data, archives the data and makes the information available through a WebGIS that targets users with distinct access privileges. Additionally, the web component of WIFF adapts automatically and transparently to any device. WIFF also provides ways to assess the model accuracy and generates tailored products based on model results and observations. WIFF is demonstrated in the prediction of extreme water levels in the Portuguese coast, simulating processes at different scales: at basin scales, waves are simulated in the North Atlantic and in the Portuguese shelf, and sea levels due to tides and atmospheric forcings are simulated in the North-east Atlantic; at estuarine scales, high-resolution, fully coupled wave/circulation predictions are performed in the Tagus estuary to account for wave current interactions.User-oriented georeferenced products are generated, including automatic model/data comparisons, targeting the needs of civil protection agents and combining for the first time an agile, service-oriented platform with high-resolution, process-rich predictions of the Tagus dynamics.
Ano: 2017
Número Páginas:
1-15pp.
Autor(es): Fortunato, A. B.; Oliveira, A.; Rogeiro, J.; Costa, R.; Gomes, J. L.; Li., K; Jesus, G.; Freire, P.; Rilo, Ana; Mendes, A.; Rodrigues, M.; Azevedo, A.
Revista: Journal of Operacional Oceanography
Editor: Taylor & Francis
Volume:
Volume 10, nº. 1.
Keywords: Storm surge; Real-time information framework; Tagus estuary; Portuguese shelf; WebGIS; Forecast systems
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Storm-induced marine
There is a growing interest for marine flooding related to recent catastrophic events and their unintended consequences in terms of casualties and damages, and to the increasing population and issues along the coasts in a context of changing climate. Consequently, the knowledge on marine flooding has progressed significantly for the last years and this review, focused on storm-induced marine submersions, responds to the need for a synthesis. Three main components are presented in the review: (1) a state-of-the-art on marine submersions from the viewpoint of several scientific disciplines; (2) a selection of examples demonstrating the added value of interdisciplinary approaches to improve our knowledge of marine submersions; (3) a selection of examples showing how the management of future crises or the planning efforts to adapt to marine submersions can be supported by new results or techniques from the research community. From a disciplinary perspective, recent progress were achieved with respect to physical processes, numerical modeling, the knowledge of past marine floods and vulnerability assessment. At a global scale, the most vulnerable coastal areas to marine flooding with high population density are deltas and estuaries. Recent and well-documented floods allow analyzing the vulnerability parameters of different coastal zones. While storm surges can nowadays be reproduced accurately, the modeling of coastal flooding is more challenging, particularly when barrier breaches and wave overtopping have to be accounted for. The chronology of past marine floods can be reconstructed combining historical archives and sediment records. Sediment records of past marine floods localized in back barrier depressions are more adequate to reconstruct past flooding chronology. For the two last centuries, quantitative and descriptive historical data can be used to characterize past marine floods. Beyond providing a chronology of events, sediment records combined with geochronology, statistic analysis and climatology, can be used to reconstruct millennial-scale climate variability and enable a better understanding of the possible regional and local long-term trends in storm activity. Sediment records can also reveal forgotten flooding of exceptional intensity, much more intense than those of the last few decades. Sedimentological and historical archives, combined with highresolution topographic data or numerical hindcast of storms can provide quantitative information and explanations for marine flooding processes. From these approaches, extreme past sea levels height can be determined and are very useful to complete time series provided by the instrumental measurements on shorter time scales. In particular, historical data can improve the determination of the return periods associated with extreme water levels, which are often inaccurate when computed based on instrumental data, due to the presence of gaps and too short time-series. Longterm numerical hindcast of tides and surges can also be used to provide the required time series for statistical analysis. Worst-case scenarios, used to define coastal management plans and strategies, can be obtained from realistic atmospheric settings with different tidal ranges and by shifting the trajectory of storms. Management of future crises and planning efforts to adapt to marine submersions are optimized by predictions of water levels from hydrodynamic models. Such predictions combined with in situ measurements and analysis of human stakes can be used to define a vulnerability index. Then, the efficiency of adaptation measures can be evaluated with respect to the number of lives that could be potentially saved. Numerical experiments also showed that the realignment of coastal defenses could result in water level reduction up to 1 m in the case where large marshes are flooded. Such managed realignment of coastal defenses may constitute a promising adaptation to storm-induced flooding and future sea level rise. From a legal perspective, only a few texts pay specific attention to the risk of marine flooding whether nationally or globally. Recent catastrophic events and their unintended consequences in terms of death and damages have triggered political decisions, like in USA after hurricane Katrina, and in France after catastrophic floods that occurred in 2010.
Ano: 2017
Número Páginas:
151-184pp.
Autor(es): Eric Chaumillon; Bertin, X.; Fortunato, A. B.; Bajo, M.; Schneider, Jean-Luc; Dezileau, L.; Walsh, J.; Michelot, A.; Chauveau, E.; Créach, A.; Hénaff, A.; Sauzeau,T.; Waeles, B.; Gervais, B.; Jan, G.;
Revista: Earth-Science Reviews
Editor: Elsevier
Volume:
Volume 165.
Keywords: Vulnerability; Storm flood deposits; Storm surge; Public policies; Coastal realignment; Submersions forecast; Barrier breaching; Overtopping; Overflowing; Numerical model; Risk; Historical archives; Past marine floods; Climate change; Marine flooding
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The contribution of historical information to flood risk management in the Tagus estuary
Estuarine areas are often affected by flood episodes with significant infrastructural andhuman damages caused by the overlap of different triggering factors. Currently flood riskmanagement practices are subject to increased scrutiny by the public and relevantstakeholders requiring rigorous justification by flood risk managers and careful validationof the technical options and human and financial resources allocated to the managementpractice. Therefore, flood risk diagnosis through historical sources might constitute animportant and effective first approach to public policies validation.In this paper is presented an estuarine flood damage database based on historicalinformation and discussed as to the extent these types of sources can contribute to improveestuarine flood risk management in the Tagus estuary (Portugal). The paper discusses themethodological findings and limitations and highlights the usefulness of historicalinformation integrating the results into the International Risk Governance Council (IRGC)risk management framework.
Ano: 2017
Número Páginas:
22-35pp..
Autor(es): Rilo, Ana; Tavares, A.; Freire, P.; Santos, P.; Zêzere, J. L.
Editor: Elsevier
Volume:
Nº 25.
Keywords: Public policies; Risk; Flood impacts; Database
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Comunicações
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Non-linear infra-gravity and sea-swell wave-wave interactions at S. Jacinto beach
Non-linear wave-wave interactions between sea-swell waves (0.5 < f < 0.04 Hz) and infragravity waves (0.04 < f < 0.004 Hz) are studied in detail from field data using bispectral analysis. This methodology allowed to understand the direction and magnitude of the non-linear energy transfers within the spectrum. Field measurements of pressure data were collected at S. Jacinto beach during a full tidal cycle on a cross-shore transect at the subtidal and intertidal zone. Bispectral estimates showed triad interactions between two sea-swell waves and one infra-gravity wave at the surf zone. The non-linear transfers were out of phase which indicates the presence of bound waves. These results evidenced the presence of energy transfers from infra-gravity to sea-swell band where the sea-swell waves are more energetic, during shoaling and breaking.
Ano: 2016
Número Páginas:
187-190pp.
Autor(es): Mendes, D.; Pires Silva, A.; Fortunato, A. B.; Pinto, J. P.
Revista: Actas das 4 as Jornadas de Engenharia Hidrográfica
Editor: Instituto Hidrográfico
Keywords: Wave observations; Bispectral analysis; Non-linear wave-wave interactions; Infra-gravity waves
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Observations of infra-gravity waves at S. Jacinto beach
Generation mechanisms of infra-gravity motions are analysed using field observations at S. Jacinto beach. These observations were, tipically, bottom-pressure time series collected in June 2015 during a full spring tidal cycle from the subtidal to the intertidal zone. Bound wave and breakpoint generation mechanisms were assessed using the parameters proposed in the available literature. The results put in evidence the importance of infra-gravity wave energy close to the shoreline. An increase of up to 0.42 m was estimated. The clearest generation mechanism was the bound wave release. The breakpoint generation also contributed but to a less extent and only during high-water.
Ano: 2016
Número Páginas:
191-194pp.
Autor(es): Mendes, D.; Pires Silva, A.; Fortunato, A. B.; Pinto, J. P.
Revista: Actas das 4 as Jornadas de Engenharia Hidrográfica
Editor: Instituto Hidrográfico
Keywords: Surf beat; Wave observations; Breakpoint generation; Bound wave release; Infra-gravity waves
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Salinity evolution in the Tagus estuary relative to climate change
Climate change represents a potential threat for estuaries, via potential landward intrusionof saltwater, inundation of low-lying areas, acceleration in the nutrients cycling and disruption ofaquatic ecosystems. The Tagus estuary, one of the largest estuaries in Europe, holds a major naturalreserve and supports diverse activities, some of which may be negatively affected by the landwardintrusion of saltwater (e.g. agriculture). In this study, a new three-dimensional hydrodynamicsbaroclinic model is implemented and validated in the Tagus estuary. A preliminary analysis of thesalinity distribution relative to different river flows and sea level rise is also performed. Results showthat the model adequately represents the main patterns observed, with significant improvements fromprevious applications. The classification of the estuary, based on the Venice system, showscontrasting situations regarding the salinity distribution for extreme river flows, and the progressionfurther upstream of the saltwater due to mean sea level rise.
Ano: 2016
Número Páginas:
179-182pp.
Autor(es): Rodrigues, M.; Fortunato, A. B.; Freire, P.
Revista: Atas das 4 as Jornadas de Engenharia Hidrográfica
Editor: Instituto Hidrográfico
Keywords: River flow; Sea level rise; Salinity; Venice system; Numerical modelling
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Scale issues in local vulnerability assessment: implications in risk and urban planning
The assessment of vulnerability provides valuable knowledge in the risk assessment steps of a risk governance process. Given the multiscale, multilevel and multisectorial aspects of flood risk, the diversified entities that directly and indirectly intervene in risk management require specific outputs from the assessment studies. Vulnerability assessment methodologies should, therefore, produce the most adequate information considering their final end-users. Urban areas in estuarine margins are particularly exposed and vulnerable to flooding due to the high dynamics of such natural and human systems. That interface conditions are found in the Old City Centre of the Seixal municipality, located in the left margin of the Tagus River, near Lisbon (Portugal). In this study area two distinct methodologies were applied for the assessment of territorial vulnerability to estuarine flooding. After a description of the assessment procedures results are presented, compared and discussed. A first, lower-scale, methodology explores the application of the statistical procedure based on the SoVI® at the statistical block level. The second, higher-scale, methodology is based in data collected through field matrices at the building and statistical sub-block level. The comparison of both vulnerability classifications revealed that the lower-scale vulnerability assessment provides information with the ability to identify vulnerability drivers at the regional and municipal level. Nevertheless, only at a higher-scale it is possible to characterize and differentiate the smaller units of analysis that compose the Old City Centre of Seixal. It is argued that the most efficient implementation of local flood risk management strategies in the study area
Ano: 2016
Número Páginas:
455-462pp.
Autor(es): Santos, P.; Tavares, A.; Freire, P.; Rilo, Ana
Revista: Atas do ICUR 2016 - International Conference on Urban Risks
Editor: CERU
Keywords: Risk management; Multiscale; Vulnerability; Flood hazard
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The effect of storm events in the Tagus estuarine margins
Floods in estuaries can be forced by factors associated to ocean and inland sources. In the particular case of the Tagus estuary, the water level variability is mostly driven by tides and storm surges. One of the most recent flood events with the greatest impact in this estuary occurred on February 2010 associated with the passage of the Xynthia storm by the Portuguese coast. In the present study this flood event and related impacts are characterized considering two different territorial contexts: urbanised and productive agricultural areas. The territorial characterization of the potential flooding areas for a similar event considering a sea level rise scenario, obtained through numerical modelling, shows important contrasts in flooding extensions and in the exposed elements typology. These results are relevant for flood risk management, contributing to the definition of adaptation measures to improve the capability to cope with future extreme events.
Ano: 2016
Número Páginas:
231-264pp.
Autor(es): Freire, P.; Fortunato, A. B.; Rodrigues, M.; Santos, P.; Rilo, Ana; Tavares, A.
Revista: Actas das 4 as Jornadas de Engenharia Hidrográfica
Editor: Instituto Hidrográfico
Keywords: Territorial context; Sea level rise; Estuaries; Flood; Storm surge
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A DIMENSÃO LONGILITORAL NA RESILIÊNCIA DUNAR DURANTE TEMPESTADES MARÍTIMAS
Durante temporais marítimos que atingem a costa ocorre, frequentemente, a erosão de sistemas praia duna. Apesar da componente transversal dos processos costeiros ser predominante relativamente à componente longitudinal durante eventos deste tipo, é importante conhecer como os gradientes longitudinais da geomorfologia afetam a morfodinâmica do sistema praia-duna no seu todo. Este estudo teve como objetivo analisar o efeito da variação longitudinal da morfologia da duna frontal na morfodinâmica do sistema praia-duna sob ação de ondas incidentes oblíquas e variação do nível do mar devida à ação das marés astronómica e meteorológica. A insuficiência de dados de campo ou laboratório deste tipo para condições de temporal marítimo é uma limitação à compreensão dos processos costeiros subjacentes. Por isso, nesta análise recorreu-se a um modelo numérico 2DH de morfodinâmica baseado nos processos costeiros. A morfologia do caso de estudo foi simplificada para limitar a complexidade dos fenómenos físicos envolvidos e, assim, melhor se identificarem os mecanismos responsáveis pela evolução morfológica verificada. Inicialmente apenas a altura da duna frontal variava na direção longitudinal. Contudo, no decorrer da tempestade, com a erosão da duna, outras características morfológicas no topo e acima da face de praia deixaram de ser uniformes na direção longitudinal. Apesar do volume de sedimentos erodidos da zona face de praia-berma-duna frontal ser mais elevado para os trechos de duna mais alta e o recuo da duna frontal ser maior para os trechos de duna mais baixa, a nova topo-hidrografia das zonas de rebentação e face de praia continuou bastante uniforme na direção longitudinal. Concluiu-se que parte do volume de sedimentos erodidos da zona face de praia-berma-duna frontal dos trechos de duna mais alta é transportada pela corrente longitudinal e depositada na área submersa dos trechos de duna mais baixa, atenuando assim os gradientes longitudinais da topo hidrografia das zonas de rebentação e face de praia.
Ano: 2015
Número Páginas:
11p.
Autor(es): Oliveira, F. S. B. F.
Revista: VIII CPGZCPEP
Editor: Universidade de Aveiro
Keywords: Proteção costeira; Temporal marítimo; Morfodinâmica; Erosão; Praia
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Avaliação do transporte sedimentar coesivo na Ria de Aveiro
A Ria de Aveiro sofreu alterações hidrodinâmicas e morfológicas ao longo da sua evolução, que conduziram a modificações nos padrões de circulação e sedimentares. A dinâmica dos sedimentos em suspensão reveste-se de enorme importância local, na medida em que o transporte dos sedimentos em suspensão pode provocar alterações batimétricas pontuais.Neste trabalho foi simulada a concentração de sedimentos em suspensão na Ria de Aveiro através da utilização de um modelo numérico, efetuando-se análise da sensibilidade dos seus resultados face a diferentes cenários de caudais fluviais afluentes à Ria de Aveiro, associados a períodos de retorno de 2, 10 e 100 anos, em situações extremas e médias de maré. As velocidades do escoamento, a concentração de sedimentos em suspensão e os fluxos de água e sedimentos foram determinados em secções de estudo, localizadas na entrada dos principais canais.Os resultados evidenciaram a exportação de sedimentos da Ria de Aveiro e da sua bacia hidrográfica no sentido do oceano. O aumento dos caudais fluviais apenas induz alterações na magnitude dos fluxos sedimentares em suspensão em situação de maré viva, não ocorrendo quaisquer alterações em situação de maré morta e maré média.
Ano: 2015
Número Páginas:
15p.
Autor(es): Costa, S.; Picado, A.; Vaz, N.; Coelho, C.; Portela, L. I.; Dias, J. M.
Editor: APRH
Keywords: Velocidades de escoamento; Períodos de retorno; Fluxos sedimentares; Concentração de sedimentos em suspensão; Caudais fluviais
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Aveiro lagoon fine sediment laboratory tests
Cohesive sediment transport is not directly related to easilymeasurable parameters. Erosion and deposition properties are usually described bycritical bed shear stresses, erosion rate coefficients and settling velocities. Toimprove the reliability of numerical models, these parameters should bedetermined from observations and experiments, either in situ or in the laboratory.This work presents some results of laboratory tests (settling column, annular flumeand straight, recirculating flume tests) with fine sediments collected in the AveiroLagoon, in order to contribute to that improvement. The results indicate thatlaboratory tests can indeed provide insight into erosion and deposition properties.The results also suggest that fine sediment transport depends partly on cohesiveproperties, such as flocculation, and partly on particle size.
Ano: 2015
Número Páginas:
14p.
Autor(es): Coelho, C.; Costa, S.; Portela, L. I.; Ribeiro, F.; Cunha, R.
Editor: World Scientific
Keywords: Lagoon; Sediment
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Desenvolvimento de um sistema operacional de previsão de temporais na costa portuguesa
As inundações em zonas estuarinas e costeiras podem causar danos significativos, como os que ocorreram no inverno 2013/2014 na costa Portuguesa. No entanto, estes danos podem ser mitigados se os eventos forem previstos com antecedência. Com vista a fornecer a informação necessária às autoridades, desenvolveu-se um sistema operacional de previsão dos níveis do mar na costa Portuguesa. Este sistema tem por base a simulação da agitação marítima e dos níveis devidos à maré e aos agentes atmosféricos, a escalas regionais e locais.À escala regional, simula-se a agitação marítima com o modelo WaveWatch III no Atlântico Norte, com uma malha encaixada na costa Portuguesa. Paralelamente, simulam-se os níveis devidos à maré e agentes atmosféricos no Atlântico Nordeste com o modelo SCHISM. Numa segunda fase, estes modelos regionais são utilizados para forçar modelos locais que simulam de forma acoplada a agitação marítima e os níveis com base no código SCHISM-WWM. Como teste piloto a nível local, implementou-se um modelo do estuário do Tejo, incluindo zonas inundáveis na margem sul. O conjunto de modelos é executado diariamente, de forma automática, produzindo previsões de 48 horas. Os resultados são integrados na plataforma WIFF (Water Information and Forecasting Framework - http://ariel.lnec.pt) que os disponibilizam de forma ágil através de um browser.
Ano: 2015
Número Páginas:
1-15pp.
Autor(es): Fortunato, A. B.; Costa, R.; Rogeiro, J.; Gomes, J. L.; Oliveira, A.; Li., K; Freire, P.; Rilo, Ana; Mendes, A.; Rodrigues, M.
Editor: APRH
Keywords: Agitação marítima; Marés; Níveis extremos; Estuário do Tejo; Costa portuguesa; Oceanografia operacional
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Estudo de soluções alternativas de dragagens para a estabilização da Lagoa de Óbidos
Na lagoa de Óbidos, a forte interacção entre ondas e correntes de maré induz rápidas alteraçõesmorfológicas na sua embocadura. Esta laguna possui um prisma de maré reduzido e uma dominância deenchente em termos de níveis. Estes dois factores promovem um equilíbrio dinâmico instável na suaembocadura que migra frequentemente para junto das margens e coloca em risco as construçõesexistentes (Oliveira et al., 2006). As soluções implementadas nos últimos anos correspondemmaioritariamente a dragagens com o objectivo de prevenir o fecho da embocadura. No entanto, estasmedidas com carácter provisório não foram capazes de impedir o fecho da embocadura da lagoa deÓbidos em Janeiro de 2014. Este estudo visa contribuir para a gestão costeira da lagoa de Óbidos e tempor objectivo avaliar dois planos de dragagens alternativos, comparando-os com o plano que foiimplementado na última década, através de um modelo morfodinâmico. A discussão de resultados seráefectuada através da análise dos prismas de maré, das diferenças de duração entre a vazante e a enchente edos volumes de sedimentos que atravessaram a embocadura durante um período de cinco meses após asdragagens.
Ano: 2015
Número Páginas:
45-46pp.
Autor(es): Mendes, D.; Fortunato, A. B.; Pires Silva, A.; Li., K
Editor: Universidade do Algarve
Keywords: Lagoa de Óbidos
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Livros
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Capítulos de Livros
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Evaluating the geomorphologic stability of an estuarine sandy beach. Integrated Coastal Zone Management
The hydrodynamics and sediment dynamics of a low energy estuarine beach was analysed. The beach is subjected to local wind waves generated in an area of restricted fetch, wake waves generated by catamarans and a semi diurnal meso-tidal regime. Only storm events of short duration modify the beach profile, which, once the normal hydrodynamic conditions are restored, naturally recovers its initial shape. The beach is characterised by having a steep upper slope until mean sea level, followed, seaward, by a low gradient terrace, and a bimodal sediment distribution. To investigate the hydro sedimentologic beach behaviour, wind, topo-hydrographic and sedimentologic data were used as input and validation of process based numerical modelling. Wave generation and transformation in an area of restricted fetch, nearshore circulation, sediment transport and morphological evolution were simulated for average annual conditions and storm conditions. The statistical analysis of a six-year wind data series allowed to derive the average wind regime, based on which, the average annual wave regime and the average annual longshore sediment budget, 14.5x103 m3year-1, were calculated. The contribution of the individual components of the representative wave regime, discretised by directional sector and height class of incidence, was evaluated as well as the spatial distribution of the longshore sediment transport in the active part of the beach profile. The characteristics of the wave groups generated by the passage of catamarans at different speeds were estimated and their action on the beach morphology was simulated. Although when the catamarans travel at 20 knots speed the average annual wake wave energy dissipated at the beach is 2.5 times higher than the average annual wind wave energy, the erosion effect on the beach profile is still not relevant for the present traffic. In opposition, short duration storm events generate the formation of an erosion scarp at the upper part of the beach face. The numerical modelling of this phenomenon allowed to acknowledge on the protective effect that the low gradient terrace has on the beach face.
Ano: 2009
Número Páginas:
pp. 35-49.
Autor(es): Oliveira, F. S. B. F.; Vargas, C.
Editor: Wiley-Blackwell Publishing
Volume:
Integrated Coastal Zone Management.
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Teses de Doutoramento
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Three-dimensional modelling of cohesive sediment transport in estuarine environments
N/A
Ano: 1995
Autor(es): Costa, R.
Editor: ******
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A Two-Dimensional Hydrodynamic Model Using a Finite-Volume Approach
A two-dimensional model of wind-driven circulation in a closed basin was developed using a finite-volume technique for generalized curvilinear grids and applying some of the recent developments in hydrodynamic modeling. The terms in the Navier¬Stokes equations were treated separately according to the fractional step method and the propagation step, including the continuity equation and the pressure and stress terms in the momentum equations, was solved using a conjugate gradient method.The model was then applied to a number of test cases to examine the feasibility of the approach used by comparing with results obtained with the two-dimensional version of the three-dimensional model CH3D. These included a square basin with constant slope and with a V-shaped bottom and Lake Okeechobee, in South Florida. To evaluate the long-term numerical stability of the model, a ten-day model simu¬lation with varying wind was also run for Lake Okeechobee.
Ano: 1989
Autor(es): Capitao, J.
Editor: ******
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Flow-Fine Sediment Hysteresis in Sediment-Stratified Coastal Waters
An examination of the causes for generation and dynamics of turbidity maxima in estuaries reveals the critical role of sediment tidal pumping phenomenon and, to a lesser extent, of the well-known effect of residual gravitational circulation due to salt water penetration. Both phenomena depend on the vertical sediment concentration profile and, consequently, on the magnitude of the vertical mass transport fluxes. Where high concentration suspensions occur regularly, the erosion/deposition fluxes can be drastically modified by sediment stratification, consequently influencing sus¬pended sediment response to currents and wave action. This influence is inherent in flow-sediment hysteresis, which therefore reflects the role of vertical mass transport in the estuarine and coastal suspended fine sediment regime.A vertical transport numerical model was used to investigate the influence of several key parameters describing sediment settling, bed properties and stabilized diffusion on the concentration profile. The model was also applied to simulate the influence of the same parameters on the time-lagged sediment response to flow variations, reflected in the characteristics of flow-sediment hysteresis loops.Field data obtained in Hangzhou Bay (People´s Republic of China), a high concentration environment, showed typical features of flow-sediment hysteresis and confirmed the importance of the vertical mass fluxes in contributing to sediment transport in the bay. A qualitative simulation provided by the numerical model, using settling parameters corresponding to local sediment, while confirming the importance of the hysteresis phenomenon, also revealed the critical need to use algorithms describing adequately stabilized diffusion and bed fluxes.Additional evidence of hysteresis was obtained through analysis of microscale variables, such as the Reynolds stresses and the variances of the velocity components resulting from combined effects of wave action and turbulence. Spectral analysis of the measured random variations did not support the commonly accepted hypothesis of similarity between the responses to turbulent flow of sediment concentration and temperature. The normalized turbulent intensities for all the measured veloc¬ity components showed their highest values during the period of lowest sediment concentration; this result is consistent with the hypothesis of turbulent intensity damping by suspended sediment.
Ano: 1989
Autor(es): Costa, R.
Editor: ******
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Alimentação artificial de praias
A contribution to increased use and development of the method of artificial nourishment of beaches is the main objective of this thesis. It also aims at being a guide for the design of the reconsctrution or outright creation of beaches.In the first chapter, the subject is introduced and the objectives of the thesis are outlined. The second chapter cover´s some general considerations on littoral dynamics, beach equilibrium and sediment budget.Since the theoretical foundations of the artificial nourishment of beaches still leave much to be desired, a description of this method and its principles are presented in the third chapter. Important technical and economic aspects are included, such as: sampling, analysis and characterization of native and borrow material; selection Of nourishment sources; extraction and transport of borrow sand; and characteristics of the theoretical final beach profile. Such problems as the integration of ecological aspects, and cost-benefit analysis are also treated.in the fourth chapter, the Portuguese experience in this domain is described. The experience of such countries as France and the U.S., where this method has frequently been used is also mentioned. In this way a considerable amount of hitherto scattered information is presented in a unified way.The fifth chapter, treats briefly the problem of coastal model similitude, both as a support for the experimental work: which was carried out and to help engineers in the design of a coastal physical model or in merely assessing the possibilities of such a model.In the sixth chapter, an experimental study is described of the influence of both the grain size of borrow material and the nourishment method on the redistribution of sediments after the nourishment. The obtained results are compared with existing theoretical methods and some prototype results.Finally, in the last chapter the main conclusions and recomendations of the thesis are presented.
Ano: 1987
Autor(es): Clímaco, M.
Editor: ******
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Solution of Advection-Dominated Transport by Eulerian-Lagrangian Methods Using Backwards Method of Characteristics
We provide a systematic analysis of the consistency, stability, convergence and accuracy of the numerical solution of the transport equation by a general Eulerian-Lagrangian Method (ELM). The method involvesthree basic steps: the backwards tracking of characteristic lines following the flow, the interpolation of concentrations at the feet of these lines, and the solution of dispersion taking such concentrations as initial conditions. The first two steps constitute the Backwards Method of Characteristics (BMC); the third step involves a time-discretization along the characteristic lines, and a spatial discretization of the dispersion operator, both based on conventional techniques (e.g.. Euler or Crank¬Nicholson for time; finite-elements or finite-differences for space).The choice of the spatial interpolator is shown to impact the consistency, stability and convergence, as well as the accuracy of the BMC. Most interpolators ensure consistency, but only a few ensure stability, hence convergence; stability criteria are derived from a newly developed generalized Fourier analysis, which can account for non-linearities introduced by quadratic grids. The comparison of formally derived propagation and truncation errors, complemented by numerical experimentation, provides a reference for the choice of the interpolator, given a specific transport problem characterized by prevailing concentration gradients.The BMC potentiates the use of large time-steps, well above Courant number of order one. In the limiting case of pure advection, optimal accuracy would be obtained for a At close to the total time of interest; the presence of dispersion constrains, however, the size of At, especially in the case of non-uniform flows. The comparison of the truncation errors for the three basic steps of ELM provides a reference to select At. as a function of Ax, of the spatial interpolators and time-discretization schemes, and of the gradients of flow and concentrations.
Ano: 1987
Autor(es): Melo Baptista, A.
Editor: ******
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Accurate Numerical Modeling of Advection-Dominated Transport of Passive Scalars. A Contribution
Apresenta-se um estudo sistemático, baseado simultaneamente em análises formais e em experimentação numérica, da precisão e estabilidade da solução da equação de transporte por um método Euleriana-Lagrangeana (MEL). 0 método decompõe a equação de transporte em equações separadas de advecção e de difusão, resolvendo a primeira pelo método das características regressivas no tempo (MCR), e a segundo por um método de elementos finitos, do tipo Galerkin.Mostra-se que as interpolações no espaço requeridas pelo MCR são um factor limitativo da precisão global do MEL, e comparam-se diversas técnicas alternativas de interpolação, algumas das quais originais. A combinação de esquemas compactos e não-compactos de interpolação, baseados em polinómios de Lagrange, é apontada como uma potencial solução óptima.Demonstra-se que, para uma adequada escolha do esquema de interpolação, o MCR é consistente, estável e convergente e tem boas características de precisão. Escolhas inadequadas do esquema de interpolação podem, no entanto, causar instabilidade e inconsistência.Estabelece-se a dependência da precisão do MCR no passo de cálculo, mostrando-se que essa precisão aumenta, em geral (para um tempo total fixo), quando se reduz o número de passos de cálculo, isto é, quando se aumenta o passo de cálculo (uma propriedade simultaneamente pouco habitual e muito conveniente). No entanto, na gama de valores muito pequenos do Número de Courant, a precisão é praticamente independente do passo de cálculo, o que evita que o método se torne divergente.Analisa-se brevemente o efeito de malhas irregulares e pluridimensionais sobre a aplicabilidade e precisão do MCR. Apesar de sensível à irregularidade da malha, o método mantém boas características de precisão desde que as distorções geométricas não sejam excessivas. Malhas pluri-dimensionais, quando simultaneamente irregulares, levantam problemas específicos de aplicabilidade de esquemas não-compactos de interpolação; esses problemas poderão se resolvidos através da utilização conjugada de esquemas compactos e não-compactos, para um mesmo problema. Investigação adicional a ainda requerida nestas áreas.Mostra-se ainda que a presença de mecanismos físicos de difusão beneficia tanta a precisão da solução da equação de advecção como a precisão global do MEL.Finalmente, demonstra-se a eficácia da aplicação do MEL (numa forma particular, restricta a esquemas de interpolação compactos) à simulação do transporte de poluentes em águas costeiras. 0 método permite, em particular, realizar simulações longas (várias marés) a custos moderados, mesma para malhas irregulares com elevado número de nós, e, também, evitar a necessidade do uso de difusividades artificiais como garante de estabilidade; em geral, e nestes dois aspectos em particular, o método revela-se superior a métodos Eulerianos, mais convencionais (por exemplo, métodos de elementos finitos, do tipo Galrkin ou Petrov-Galerkin, aplicados à equação de transporte indivisa).
Ano: 1986
Autor(es): Melo Baptista, A.
Editor: ******
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Sobre a Avaliação de Parâmetros de Qualidade de Água por Detecção Remota: Suspensões
No âmbito de um projecto de investigação intitulado caracterizarão de Formações Estuárias e do Meio Marítimo Litoral Por Técnicas de Detecção Remota , insere-se o estu¬do da avaliação de suspensões na água do mar com recurso à aplicação de técnicas de detecção remota como meio de caracterização de parâmetros de qualidade de água. 0 trabalho que se apresenta foi desenvolvido com os seguintes objectivos:1- Desenvolvimento de metodologias de análise e quantificação de suspensões na água do mar a partir de dados de satélite;2- Implementação sob forma de programas para computador de modelos de quantificação de suspensões orgânicas e inorgânicas na água do mar, a aplicar aos dados do radiómetro CZCS do satélite NIMBUS-7;3- Aplicação e verificação do modelo ao litoral português.Corn vista à consecussão destes objectivos, começa-se por apresentar uma extensa análise das formas de abordagem do problema, enumerando-se os diversos métodos actualmente seguidos, nomeadamente o Empírico, o Teórico e, neste, os métodos microscópico e macroscópico.Com base nesta análise, propõe-se um modelo numérico de quantificção das suspensões a partir dos dados do radiómetro CZCS do satélite NIMBUS-7, o qual, embora empírico na sua formulação como a maioria dos actualmente existentes, se apoia no comportamento radiomótrico da água do mar e dos seus constituintes típicos, cujas características se apresentam também.A implementação prática do modelo exige a filtragem da componente atmosférica presente nos dados rediométricos. Com este objectivo, apresenta-se um modelo baseado na metodo¬logia correntemente utilizada. Consiste na consideração da difusão simples, causada pelos constituintes básicos da atmosfera (moléculas gasosas, aerosóis e ozono) na gama de comprimentos de onda considerada (440, 520, 550 e 670nm). Esta metodologia conduz, porém, a um sistema de equações indeterminado e que é resolvido pela consideração de uma equação ´exterior´ ao processo de transferência radiativa que tem lugar na atmasfera. Para este efeito, utilizou-se a equação de Smith e Wilson por ser a mais divulgada, ressalvando-se, contudo, a necessidade de verificação da sua efectiva aplicação às águas do litoral português, o oqe não foi possível concretizar dada a inexistência de dados.
Ano: 1986
Autor(es): Oliveira, E. M.
Editor: ******
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Eulerian-Lagrangian Analysis of Pollutant Transport in Shallow Water
A numerical method for the solution of the two-dimensional, unsteady, transport equation is formulated, and its accuracy is tested.The method uses a Eulerian-Lagrangian approach, in which the transport equation is divided into a diffusion equation (solved by a finite element method) and a convection equation (solved by the method of characteristics). This approach leads to results that are free of spurious oscillations and excessive numerical damping, even in the case where advection strongly dominates diffusion. For pure diffusion problems, optimal accuracy is approached as the time-step, At, goes to zero; conversely, for pure-convection problems, accuracy improves with increasing At; for convection-diffusion problems the At leading to optimal accuracy depends on the characteristics of the spatial discretization and on the relative importance of convection and diffusion.The method is cost-effective in modeling pollutant transport in coastal waters, as demonstrated by an illustrative application to a case study (sludge dumping in Massachusetts Bay). Numerical diffusion is eliminated or greatly reduced, raising the need for realistic estimation of dispersion coefficients. Costs (based on CPU time) should not exceed those of conventional Eulerian methods and, in some cases (e.g., problems involving predictions over several tidal cycles), considerable savings may even be achieved.
Ano: 1984
Autor(es): Melo Baptista, A.
Editor: ******
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Sobre a Propagação de Ondas do Mar em Regiões Costeiras. Análise pelo Método dos Elementos Finitos
0 principal objectivo desta tese é mostrar a habilidade do métodos dos elementos finitos e do método dos elementos de fronteira na modelação das ondas gravíticas de superfície.Na análise linear, as equações reduzidas do movimento ondulatório são resolvidas pelo método dos elementos finitos, levando em linha de conta a reflexão parcial, a radiação e o atrito de fundo. A modelação da radiação é feita com elementos infinitos ou com elementos de radiação, sendo estes encarados como um caso particular dos elementos de reflexão. 0 atrito de fundo é introduzido após a discretização e é levado a efeito através de um coeficiente empírico que se pode relacionar com o coeficiente de Chezy.Quer o modelo determinístico quer o modelo estocástico, obtido do primeiro com base na noção do estimador natural, permitem a realização de ensaios de ressonância ou de agitação. Nos ensaios de ressonância de uma bacia portuária tem particular interesse o conhecimento do espectro de resposta ao ruído bran¬co de banda limitada.A título de exemplo de aplicação mostram-se alguns aspectos do estudo das condições de ressonância do porto de Leixões.Logo que não sejam válidas as hipóteses simplificativas que permitem uma abordagem linear das ondas gravíticas de superfície, são resolvidas as equações não lineares do movimento ondulatório com superfície livre, pelo método dos elementos de fronteira. As suas peculiaridades permitem, sem qualquer dúvida, considerar o método dos elementos de fronteira como o mais vocacionado para este tipo de análise.Os programas de cálculo automático para o estudo da análise não linear estão ainda em fase de teste, pelo que não se apresentam exemplos de aplicação.
Ano: 1982
Autor(es): Portela, A.
Editor: ******
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Numerical simulation of the tidal flow in homogeneous estuaries
Este trabalho é dirigido principalmente para o uso da simulação numérica dos escoamentos em estuários como uma ferramenta pa¬ra estudos de engenharia. Fazem-se algumas considerações gerais sobre a definição e classificação de estuários seguidas por uma descrição sumária da hidrodinâmica dos estuários. Descrevem-se e comparam-se as várias técnicas utilizadas na solução de problemas de hidradinâmica de stuários.Faz-se a dedução formal de um modelo matemático do escoamento em estuários homogéneos e integram-se verticalmente as suas e¬quações, obtendo-se as conhecidas equações do escoamento em águas pouco profundas ("shallow water equations"). Estas equações são discretizadas utilizando os métodos dos elementos finitos e das diferenças finitas, respectivamente no espaço e no tempo.Faz-se a descrição de um sistema de cálculo para determinar a solução do modelo matemático discretizado e tecem-se várias considerações acerca do seu desenvolvimento e uso.Finalmente apresentam-se os resultados de alguns testes utilizados para verificar o funcionamento do sistema de cálculo.
Ano: 1981
Autor(es): Figueira, P.
Editor: ******
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Relatórios
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Extracção de areias na plataforma Continental Portuguesa: Impactos e evolução morfodinâmica - Evolução da linha de costa
N/A
Ano: 2010
Número Páginas:
51pp.
Autor(es): Proença, B.; Oliveira, F. S. B. F.
Editor: LNEC
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Impacte das alterações climáticas na embocadura da Lagoa de Óbidos - Relatório de actividades do Doutor Nicolas Bruneau no projecto G-CAST
N/A
Ano: 2010
Número Páginas:
27pp.
Autor(es): Bruneau, N.; Fortunato, A. B.; Oliveira, A.
Editor: LNEC
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Caracterização hidrodinâmica e sedimentar do Esteiro dos Frades, Ria de Aveiro - Observações em 2009
N/A
Ano: 2009
Número Páginas:
31pp.
Autor(es): Portela, L. I.; Freire, P.
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Coluna de sedimentação - Velocidade de queda de sedimentos do Esteiro dos Frades, Ria de Aveiro
N/A
Ano: 2009
Número Páginas:
31pp.
Autor(es): Portela, L. I.; Brito, F.
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Modelação numérica de praias encaixadas
O objectivo do presente trabalho é o melhoramento da simulação do equilíbrio depraias encaixadas através da adaptação de um modelo de evolução de linhas decosta. Foram aperfeiçoadas as componentes do modelo que simulam a difracção emsaliências fixas e os seus efeitos sobre a movimentação das areias e morfologia dapraia.Com vista a aferir as melhorias obtidas recorreu-se à comparação dos resultados damodelação com a formulação semi-empírica de previsão da morfologia de praiasparabólicas e com casos reais de praias encaixadas da costa portuguesa.
Ano: 2009
Número Páginas:
39pp.
Autor(es): Vicente, C.; Pisco, V.
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MODELAÇÃO NUMÉRICA DE QUEBRA-MARES DESTACADOS
A crescente utilização internacional de quebra-mares destacados na estabilização deorlas costeiras levou à sua inclusão no modelo de evolução de linha de costa,Litmod, desenvolvido pelo LNEC.Foi introduzido no modelo este tipo de obras e simulados os efeitos da difracção eda variação da altura ao longo da linha de rebentação sobre a intensidade dotransporte das areias.Foram efectuados testes de desenvolvimento de salientes e formação de tômbolostendo-se verificado uma boa concordância entre os resultados obtidos e osprovenientes de dados da natureza e de modelos físicos, apresentados pordiferentes autores.
Ano: 2009
Número Páginas:
69pp.
Autor(es): Vicente, C.; Clímaco, M.; Pisco, V.
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HIDRODINÂMICA E DINÂMICA SEDIMENTAR DA ORLA COSTEIRA
O presente relatório refere-se ao estudo de investigação Hidrodinâmica e Dinâmica Sedimentar daOrla Costeira do projecto de investigação Morfodinâmica de Praias, enquadrado na área temática doDepartamento de Hidráulica e Ambiente (DHA) Hidrodinâmica e Dinâmica Sedimentar em Sistemasde Águas Superficiais e na área temática do Laboratório Nacional de Engenharia Civil (LNEC)Ambiente e Sustentabilidade, do Plano de Investigação Programada (PIP) do LNEC para 2005-2008.
Ano: 2008
Número Páginas:
115pp.
Autor(es): Oliveira, F. S. B. F.; Freire, P.; Sancho, F. E.; Clímaco, M.; Trovisco, L.
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Outros
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Estuarine and coastal morphodynamics
N/A
Ano: 2015
Autor(es): Fortunato, A. B.; Bertin, X.; Coco , G.; Concejo, A.; Dias, J. M.; Fernandes, E.; Larson, M.; Matias, A.; Oliveira, A.; Silva, P. A.; Dias, J. A.; Azeiteiro, U.; Costa , M.; Boski, T.
Keywords: coastal; Estuarine
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