Modelação morfodinâmica da Ribeira de Aljezur

Mestrado em Ciências do Mar e Zonas CosteirasA morfologia de embocaduras é muito dinâmica, devido à acção combinada das ondas, marés e caudais fluviais. As alterações morfológicas são particularmente relevantes em embocaduras pouco profundas e de pequenas dimensões, dado que ligeiras alterações na batimetria podem conduzir a um efeito dramático na propagação e distorção da maré. Ocasionalmente, estas dinâmicas complexas podem levar ao fecho da embocadura e consequentemente à deterioração da qualidade da água a montante. Os modelos numéricos morfodinâmicos constituem ferramentas atractivas para o estudo destas alterações morfológicas, embora a sua aplicação seja ainda demorada e necessite de um conhecimento profundo sobre os processos relevantes. Este estudo visa analisar a morfodinâmica da embocadura de um sistema costeiro de pequenas dimensões e profundidades (ribeira de Aljezur), através da implementação, validação e exploração do sistema de modelação morfodinâmico MORSYS2D. A ribeira de Aljezur está localizada na costa sudoeste de Portugal e está sujeita às ondas e ventos do Atlântico Norte e às marés ao longo da plataforma Ibérica. A ribeira tem cerca de 36 km de comprimento, com profundidades entre 1-3 m e uma largura entre 10-40 m. Cinco campanhas de campo foram realizados entre 2008-2010, de forma a adquirir dados de batimetria, níveis de água, ondas e correntes, tanto no estuário como na praia adjacente, para a compreensão da dinâmica da ribeira e para a aplicação, calibração e validação do MORSYS2D. Este sistema 2D de modelação morfodinâmica simula os processos de transporte de sedimentos não-coesivos e a evolução batimétrica resultante em zonas costeiras. O sistema inclui um modelo de ondas (SWAN), um modelo de circulação (ELCIRC) e um modelo de transporte de sedimentos e de actualização de fundo (SAND2D). A aplicação, calibração e validação do MORSYS2D foi um procedimento sequencial, devido às inúmeras variáveis e processos envolvidos (como por exemplo, parâmetros de forçamento, fórmulas de transporte). Este procedimento iniciou-se com simulações forçadas apenas pela maré, e progressivamente foram adicionados os processos de agitação marítima e de transporte de sedimentos. Diferentes conjuntos de dados (níveis de água, velocidades, dados de ondas e batimetrias) foram utilizados para validar cada etapa. Simulações morfodinâmicas para campanhas de campo consecutivas, constituíram a validação final. De forma a investigar o efeito dos vários processos intervenientes na evolução morfodinâmica da embocadura (como por exemplo, agitação marítima e os caudais de cheia), foram realizadas simulações sintéticas. A partir da exploração do modelo, os resultados mostram que a variabilidade morfodinâmica da praia é condicionada principalmente pelas ondas, enquanto que o fluxo do rio domina a morfodinâmica da embocadura quando os fluxos de pico ocorrem. O sistema de modelos reproduz correctamente a hidrodinâmica (agitação marítima, níveis e velocidades), e produz previsões batimétricas qualitativamente correctas. Este estudo contribuiu para uma nova compreensão do sistema e da sua variabilidade.The morphology of tidal inlets is very dynamic, due to the combined action of waves, tides and river flows. The morphological changes of small and shallow inlets are particularly relevant, as even slight variations in the bathymetry may induce a dramatic effect on tidal propagation and distortion. Occasionally, these complex dynamics may lead to the closure of the inlet and thus degrade the water quality upstream. Numerical morphodynamic models constitute attractive tools to study these morphological changes, although their application is still time-consuming and requires a deep insight into the relevant processes. This study aims at analyzing the morphodynamics of the tidal inlet of a small and shallow coastal system (the Aljezur coastal stream), through the implementation, validation and exploitation of the MORSYS2D morphodynamic modeling system. The Aljezur stream is located in the south-west coast of Portugal and subject to the north Atlantic waves and winds, and tides along the Iberian shelf. The stream is about 36 km long, 1-3 m deep and 10-40 m wide. Five field campaigns were carried out between 2008-2010 to provide bathymetry, water levels, waves and currents, both in the estuary and the adjoining beach, for the understanding of the dynamics of the stream and for the application, calibration and validation of MORSYS2D. This 2D morphodynamic modeling system simulates the non-cohesive sediment transport processes and the resulting bathymetric evolution in coastal regions. The system includes a wave model (SWAN), a circulation model (ELCIRC) and a sediment transport and bottom update model (SAND2D). The application, calibration and validation of MORSYS2D were a step-by-step procedure due to the numerous variable inputs and processes involved (e.g., forcings, parameters, formulations). The procedure started with simulations forced only by the tide, and progressively were added the wave and sediment transport processes. Different data sets (water levels, velocities, wave parameters and bathymetries) were used to validate each step. Morphodynamic simulations conducted between consecutive field campaigns provided the final validation. In order to investigate the effect of the several processes on the morphodynamic evolution of the inlet (e.g., waves and peak river flows), synthetic simulations were performed. From the exploitation of the model, results show that the morphodynamic variability of the beach is dominated mostly by the waves while river flow dominates the morphodynamics of the inlet region when peak flows occur. The model system reproduces correctly the hydrodynamics (waves, levels and velocities), and produces predictions of bathymetry qualitatively correct. This study brought a new understanding of the system and its variability

Telecuidado como uma estratégia de saúde para a adesão do paciente com insuficiência cardíaca – revisão integrative

Objective: Identify tele-monitoring strategies for patients with heart failure who collaborate for adherence when it comes to treatment.Material and Method: Integrative review of the literature carried out in the databases CINAHL, PubMed, Scielo and LILACS. The elaboration of the problem was guided by the PICO strategy that gave rise to the following question: "What are the tele-monitoring strategies for patients with heart failure that contribute to their adherence to treatment?".Results: Sixteen articles met the criteria defined by the study and, therefore, participated in the analysis of this review.Conclusion: Tele-monitoring allows the monitoring of a larger number of patients, contributing to the control of signs and symptoms of heart failure. Also, It favors the optimization of pharmacological and non-pharmacological treatments, reducing rates of rehospitalization and mortality.Objetivo: Identificar estrategias de telecuidado para pacientes con insuficiencia cardíaca que colaboran para la adhesión al tratamiento.Material y Método: Revisión integrativa de la literatura realizada en las bases de datos CINAHL, PubMed, Scielo y LILACS. La elaboración del problema fue guiada por la estrategia PICO que originó la siguiente pregunta: ¿Cuáles son las estrategias del telecuidado para los pacientes con insuficiencia cardíaca que contribuyen a su adhesión al tratamiento?Resultados: Dieciséis artículos atendieron a los criterios definidos por el estudio y por lo tanto, participaron del análisis de esta revisión.Conclusión: El telecuidado posibilita el acompañamiento de un número mayor de pacientes, contribuyendo al control de signos y síntomas de la insuficiencia cardiaca. Favorece la optimización de los tratamientos farmacológico y no farmacológico disminuyendo tasas de re-hospitalización y mortalidad.Objetivo: Identificar estratégias de telecuidado para pacientes com insuficiência cardíaca que colaboram para a adesão ao tratamento. Material e Método: Revisão integrativa da literatura realizada nas bases de dados CINAHL, PubMed, Scielo e LILACS. A elaboração do problema foi norteada pela estratégia PICO que originou a seguinte pergunta: “Quais são as estratégias do telecuidado para os pacientes com insuficiência cardíaca que contribuem para a sua adesão ao tratamento?”.Resultados: Dezesseis artigos atenderam aos critérios definidos pelo estudo e portanto, participaram da análise desta revisão. Conclusão: O telecuidado possibilita o acompanhamento de um número maior de pacientes, contribuindo para o controle de sinais e sintomas da insuficiência cardíaca. Favorece a otimização dos tratamentos farmacológico e não-farmacológico diminuindo taxas de re-hospitalização e mortalidade

Variações morfológicas induzidas por uma tempestade na Praia de Carcavelos, Portugal: contribuição para a gestão costeira

Field data based information on the coastal sediment dynamics becomes even more relevant for coastal managers in the present context of climate changes. Due to the sea level rise and the increase of frequency and intensity of coastal storms, coastal managers need to implement effective and efficient solutions for increasing coastal resilience, namely through reprofiling the beach for restoring the sediment balance and providing space for the beach natural dynamics. The study characterises and quantifies the morphological changes in an Atlantic urban sandy beach under extreme wave energy and sea level conditions. The erosion of the foreshore and backshore of this particular beach was characterised as function of the intensity and duration of the hydrodynamic forcing parameters (waves and sea level). This 24-hour duration storm event, which delivered to the beach a total energy of 1.7x109 J, caused the seaward displacement by the undertow current of approximately 3x103 m3 of median well sorted sand from the beach foreshore and backshore.Informação sobre a dinâmica sedimentar costeira baseada em dados de campo torna-se ainda mais relevante para gestores costeiros no presente contexto de alterações climáticas. Devido à subida do nível do mar e ao aumento da frequência e intensidade de tempestades marítimas, os gestores costeiros necessitam de implementar soluções eficazes e eficientes para melhorar a resiliência costeira, nomeadamente através do reperfilamento da praia para restabelecer o balanço sedimentar e conceder espaço para a dinâmica natural da praia. O estudo caracteriza e quantifica as variações morfológicas numa praia arenosa, urbana e Atlântica sob ação de condições extremas de energia das ondas e nível do mar. A erosão da face e do topo da praia foi caracterizada em função da intensidade e duração dos parâmetros forçadores hidrodinâmicos (ondas e nível do mar). Este evento de tempestade com duração de 24 horas, que transmitiu à praia uma energia total de 1.7x109 J, causou a extração de aproximadamente 3x103 m3 de areia média da face e do topo da praia e o seu transporte pela corrente de retorno para maiores profundidades.info:eu-repo/semantics/publishedVersio

Measuring and modelling over wash hydrodynamics on a barrier island

Overwash hydrodynamics datasets are mixed in quality and scope, being hard to obtain due to fieldwork experimental difficulties. Aiming to overcome such limitations, this work presents accurate fieldwork data on overwash hydrodynamics, further exploring it to model overwash on a low-lying barrier island. Fieldwork was performed on Barreta Island (Portugal), in December 2013, during neap to spring-tides, when significant wave height reached 2.64 m. During approximately 4 hours, more than 120 shallow overwash events were measured with a video-camera (at 10 Hz), a pressure transducer (at 4 Hz) and a current-meter (at 4 Hz). This high-frequency fieldwork dataset includes runup, overwash number, depth and velocity. Fieldwork data along with information from literature were used to setup XBeach model in non-hydrostatic mode. The baseline model had variable skills over the duration of the overwash episode, performing better during the rising tide than during the falling tide. Model average number of events RMSE (root-mean-square-error) was 7 events each 30 minutes. The baseline model was forced to simulate overwash with different nearshore morphology, grain-size and lagoon water level. An average decrease of about 30% overwash was obtained due to changes in the nearshore morphology, mostly a small vertical growth of the submerged bar. The coarser and finer grain-sizes tests produced an 11% change in overwash, with less overwash on the coarser barrier. Changing lagoon water levels had a reduced effect on overwash hydraulics

Telemonitoring as a health strategy for the accession of the patient with heart failure - integrative review

Objetivo: Identificar estrategias de telecuidado para pacientes con insuficiencia cardíaca que colaboran para la adhesión al tratamiento. Material y Método: Revisión integrativa de la literatura realizada en las bases de datos CINAHL, PubMed, Scielo y LILACS. La elaboración del problema fue guiada por la estrategia PICO que originó la siguiente pregunta: ¿Cuáles son las estrategias del telecuidado para los pacientes con insuficiencia cardíaca que contribuyen a su adhesión al tratamiento? Resultados: Dieciséis artículos atendieron a los criterios definidos por el estudio y por lo tanto, participaron del análisis de esta revisión. Conclusión: El telecuidado posibilita el acompañamiento de un número mayor de pacientes, contribuyendo al control de signos y síntomas de la insuficiencia cardiaca. Favorece la optimización de los tratamientos farmacológico y no farmacológico disminuyendo tasas de re-hospitalización y mortalidad.RESUMO: Objetivo: Identificar estratégias de telecuidado para pacientes com insuficiência cardíaca que colaboram para a adesão ao tratamento. Material e Método: Revisão integrativa da literatura realizada nas bases de dados CINAHL, PubMed, Scielo e LILACS. A elaboração do problema foi norteada pela estratégia PICO que originou a seguinte pergunta: “Quais são as estratégias do telecuidado para os pacientes com insuficiência cardíaca que contribuem para a sua adesão ao tratamento?”. Resultados: Dezesseis artigos atenderam aos critérios definidos pelo estudo e portanto, participaram da análise desta revisão. Conclusão: O telecuidado possibilita o acompanhamento de um número maior de pacientes, contribuindo para o controle de sinais e sintomas da insuficiência cardíaca. Favorece a otimização dos tratamentos farmacológico e não-farmacológico diminuindo taxas de re-hospitalização e mortalidade.ABSTRACT: Objective: Identify tele-monitoring strategies for patients with heart failure who collaborate for adherence when it comes to treatment.Material and Method: Integrative review of the literature carried out in the databases CINAHL, PubMed, Scielo and LILACS. The elaboration of the problem was guided by the PICO strategy that gave rise to the following question: "What are the tele-monitoring strategies for patients with heart failure that contribute to their adherence to treatment?". Results: Sixteen articles met the criteria defined by the study and, therefore, participated in the analysis of this review. Conclusion: Tele-monitoring allows the monitoring of a larger number of patients, contributing to the control of signs and symptoms of heart failure. Also, It favors the optimization of pharmacological and non-pharmacological treatments, reducing rates of rehospitalization and mortality

Evolution of the hydrodynamics of the Tagus estuary (Portugal) in the 21st century

The ongoing rise in sea level affects tidal propagation and circulation in estuaries, and these changes can have far reaching consequences on the sediment dynamics, water quality and extreme water levels. This study aims at anticipating the evolution of the tidal dynamics in the Tagus (Portugal) in the 21st century, in particular due to sea level rise (SLR). The existence of a resonance mode of about 8 hours in this estuary, that selectively amplifies both semi-diurnal and quarter-diurnal tidal constituents, makes the response of the Tagus estuary to SLR unique. The study was conducted with a shallow water model, forced by present and future conditions, namely higher mean sea levels and an extrapolated bathymetry based on present sedimentation rates. Model results showed that SLR will significantly affect tidal asymmetry, in particular because the intertidal area can decrease by up to 40% by the end of the 21st century. As a result, the strong ebb-dominance of this estuary will decrease significantly. This evolution of tidal asymmetry will be counteracted by the effect of sedimentation of the salt-marsh areas. Also, SLR will enhance the resonance in the Tagus estuary. As a consequence, extreme water levels will be higher than the sum of present levels with the SLR

Measuring and modelling overwash hydrodynamics on a barrier island

Overwash hydrodynamics datasets are mixed in quality and scope, being hard to obtain due to fieldwork experimental difficulties. Aiming to overcome such limitations, this work presents accurate fieldwork data on overwashhydrodynamics, further exploring it to model overwash on a low-lying barrier island. Fieldwork was performed on Barreta Island (Portugal), in December 2013, during neap to spring-tides, when significant wave height reached 2.64m. During approximately 4 hours, more than 120 shallow overwash events were measured with a video-camera (at 10 Hz), a pressure transducer (at 4 Hz) and a current-meter (at 4 Hz). This high-frequency fieldwork dataset includesrunup, overwash number, depth and velocity. Fieldwork data along with information from literature were used to setup XBeach model in non-hydrostatic mode. The baseline model had variable skills over the duration of the overwash each 30 minutes. The baseline model was forced to simulate overwash with different nearshore morphology, grain-size and lagoon water level. An average decrease of about 30% overwash was obtained due to changes in the nearshore episode, performing better during the rising tide than during the falling tide. Model average number of events RMSE (root-mean-square-error) was 7 events morphology, mostly a small vertical growth of the submerged bar. The coarser and finer grain-sizes tests produced an 11% change in overwash, with less overwash on the coarser barrier. Changing lagoon water levels had a reduced effect on overwash hydraulics.Environmental Fluid Mechanic

Effect of Inlet Morphology and Wave Action on Pollutant Pathways and Sediment Dynamics in a Coastal Stream

Hydrodynamics and water renewal of intermittent coastal streams are highly variable, at various time scales, due to the very active morphodynamic behavior of their inlets. Due to this strong dynamics, the pathways of water-borne materials — and the consequences of contaminated discharges — can depend strongly on the morphology and environmental conditions. Predicting the fate of contaminants in these systems requires coupled numerical models accounting for the major physical and water quality processes. We aim at improving the understanding of the impact of inlet morphology and wave action on the pollutant and sediment pathways of these small coastal systems, based on a suite of calibrated and validated coupled models. Two analyses, based on particle simulations, are presented to assess sediment dynamics and pollutant pathways for several conditions. Results show that waves have a major effect on the fate of water-borne materials in the estuary. Wave-induced currents sweep away materials coming out of the estuary, while wave-induced setup has a profound effect on tidal propagation, water levels and velocities in the estuary, promoting the upstream transport of pollutants