Publications

Numerical modeling of the interaction between waves and coastal structures is a challenge due to the many nonlinearphenomena involved, such as wave propagation, wave transformation with water depth, interaction between incident andreflected waves, runup/rundown and wave overtopping. For simulating such complex free-surface flows, numerical modelsbased on Lagrangian formulation, such as Smoothed Particle Hydrodynamics (SPH), are on option. Even though validationof these numerical models is essential, comparing numerical results with experimental data is not an easy task. In thepresent paper, an SPH numerical model is validated comparing numerical results of waves interacting with a compositebreakwater with data obtained from physical model tests carried out in one of the LNEC

Groins are cross shore structures built to promote shoreline stabilization. However, the specific impact of these structures on the wave conditions and velocity field nearshore (and hence, on sediment transport) is still poorly understood. Therefore, this study wishes to extend this knowledge using a numerical model, COULWAVE, previously validated with field data. For that, a typical bar-trough profile is considered and different groin lengths and orientations are tested, under the influence of different significant incident-wave heights and sea-surface levels.The hydrodynamics factors are found to have a greater impact on the nearshore wave conditions than the groin geometry. The variation of significant incident-wave height imparts the greater changes in wave height nearshore, where the groin would be located. The typical tidal range is also important, since a 2 m change in sea surface level can cause great depth changes over bathymetric features and thus influence wave propagation. Although less important, the geometry of the groin should also be considered. The greater the length, the greater the sheltering effect expected, extending further to the lee-side of the groin. The impact will also reach a broader region. With a smaller impact verified, the best orientation of the groin is hard to unravel.

The study of ways of converting ocean wave energy into a useful one and the improvement of theexisting equipment are complex engineering problems and very important issues in today

The length of the Portuguese coast, the severity of the sea conditions and the concentration of population and economic activities on its coastal zone justify the importance of studying wave-induced risks and, in particular, flooding due to wave action. Indeed, emergency situations caused by adverse sea conditions are frequent and put in danger the safety of people and goods, with negative impacts for society, economy and natural heritage. So, assessing the risk of flooding of coastal and port areas is essential for the proper planning and management of these areas. In this framework, a methodology for the flood risk assessment in coastal and port areas is under development. The methodology is embedded into the HIDRALERTA system, a novel integrated system for port and coastal management, designed to prevent emergency situations, to support their management and to forecast incidental long-term interventions. The present paper describes the methodology, the HIDRALERTA system and a case study, the São João da Caparica beach, on the Lisbon

Para reducir la agitación en el interior del puerto de Vila do Porto, Azores, se ha proyectado una modificación del muelle interior de atraque de los ferries, con el objetivo de aminorar la reflexión y disminuir el rebase, sin que con eso se reduzca demasiado el área útil de la dársena portuaria. La solución propuesta es una plataforma de forma triangular en planta apoyada en pilares rectangulares, bajo la cual se ha colocado un talud de escollera para disminuir la reflexión. Se presentan los resultados de ensayos en modelo físico 3D y los obtenidos con dos modelos numéricos RANS en lo que se refiere a presiones en la plataforma y reducción de la reflexión (el modelo IH-2VOF y el FLUENT).

Submarine outfalls need to be evaluated as part of an integrated environmental protection system forcoastal areas. Although outfalls are tight with the diversity of economic activities along a denselypopulated coastline being effluent treatment and effluent reuse a sign of economic prosperity, precautionsmust be taken in the construction of these structures. They must be designed so as to have the leastpossible impact on the environment and at the same time be economically viable. This paper outlines theinitial phases of a risk assessment procedure for submarine outfall projects. This approach includesa cost-benefit analysis in which risks are systematically minimized or eliminated. The methods used inthis study also allow for randomness and uncertainty. The input for the analysis is a wide range ofinformation and data concerning the failure probability of outfalls and the consequences of an operationalstoppage or failure.As part of this risk assessment, target design levels of reliability, functionality, and operationality weredefined for the outfalls. These levels were based on an inventory of risks associated with suchconstruction projects, and thus afforded the possibility of identifying possible failure modes. Thisassessment procedure was then applied to four case studies in Portugal. The results obtained were thevalues concerning the useful life of the outfalls at the four sites and their joint probability of failureagainst the principal failure modes assigned to ultimate and serviceability limit states. Also defined werethe minimum operationality of these outfalls, the average number of admissible technical breakdowns,and the maximum allowed duration of a stoppage mode. It was found that these values were inconsonance with the nature of the effluent (tourist-related, industrial, or mixed) as well as its importancefor the local economy. Even more important, this risk assessment procedure was able to measure theimpact of the outfalls on human health and the environment.

Neste artigo descreve-se a ferramenta numérica SWAMS que se baseia nos modelosnuméricos DREAMS, BOUSS-WMH e MOORNAV para caracterizar a resposta dum navioamarrado no interior dum porto sujeito à acção da agitação marítima. Os dois primeirosmodelos simulam a propagação de ondas lineares e não lineares em zonas abrigadas deprofundidade variável, tendo em conta os fenómenos da refracção, difracção, reflexãoparcial, dissipação de energia devida ao atrito de fundo e rebentação das ondas. Enquantoo modelo DREAMS é um modelo linear baseado na equação de declive suave, o modelonão linear BOUSS-WMH é baseado nas equações de Boussinesq. O comportamento donavio amarrado é simulado com o pacote numérico MOORNAV que engloba um modelonumérico para resolver, no domínio da frequência, os problemas de radiação e de difraçãoda interacção de corpos flutuantes com ondas e um modelo que converte os resultadosdaqueles problemas do domínio do tempo para o domínio da frequência e que monta eresolve as equações do movimento do navio amarrado, BAS.Apresentam-se asmodificações introduzidas no modelo WAMIT para calcular as forças de difracção com basenas relações apresentadas em Haskind. Tais relações, porque utilizam o potencial develocidades obtido com o modelo DREAMS ou com o modelo BOUSS-WMH, permitemlevar em conta a refracção, difracção ou reflexão que podem ocorrer na propagação dasondas para o interior de uma bacia abrigada. Para além da descrição dos modelosnuméricos na ferramenta SWAMS, apresenta-se a forma como os resultados sãotransferidos entre eles bem como aplicações da mesma para ilustrar as suas capacidades.

The current study proposes prediction formulas both for random wave runup and mean overtopping discharge at seawalls constructedon land or in very shallow water. Although several existing formulas for runup and overtopping use the incident wave characteristicsat the toes of seawalls, this study adopts the equivalent deepwater wave characteristics and an imaginary seawall slope for easy application of theformulas, especially in relation to seawalls constructed on land. The prediction formulas for overtopping use the predicted runup values. For thewave runup prediction formulas two sets of experimental data are used; i.e., a new set of data and the data obtained in a previous study. For thewave overtopping prediction formulas, the experimental data measured in a previous study are used. Comparisons with measurements showgood performances of both new prediction methods.

This paper presents the new boundary condition implemented in the LNEC SPH numerical model based on theSPHysics model and on a standard Smoothed Particle Hydrodynamic formulation: the piston-type wave maker includesnow dynamic wave absorption and allows simulating a semi-infinite flume. Verification of the active wave makerabsorption is carried out through the simulation of the interaction between a regular incident wave and an impermeablevertical breakwater. Results show that the active wave-maker allows outgoing waves to be absorbed and reflection at thewave-maker to be avoided

Este artigo aborda a análise comparativa entre as medições de agitação marítima efectuadas na Praia da Cornélia (Costa da Caparica, Portugal), durante os dias 12 a 14 de Maio de 2010, e os resultados numéricos da aplicação do modelo não-linear do tipo Boussinesq, COULWAVE. Esta análise tem como principal objectivo a avaliação do desempenho deste modelo numérico na simulação da propagação de ondas em condições reais, pretendendo evidenciar, deste modo, as suas potencialidades e limitações.As condições de fronteira do modelo foram geradas com base em séries temporais de elevação medidas a uma profundidade aproximada de 7.6 m (relativa ao zero hidrográfico

An aerial monitoring system was developed for the maritime structures protecting the foundation columns of the airport infrastructure of the Madeira Island Airport, in the scope of research project MEGE, to complement the already existing monitoring program of visual observations. For the aerial monitoring of the berm breakwater, with about 770 m in length, a fast data acquisition system was envisaged. Imaging techniques acquired through a high-resolution camera coupled to an unmanned aerial vehicle (UAV) were used, which allowed for a very fast and efficient automated procedure, compatible with the difficult accessibility to the structure on the seaside. Point clouds corresponding to the breakwater geometry were obtained from the set of aerial images from the camera on board of the UAV, using photogrammetric techniques. In this paper, the two complementary parts of the monitoring of this structure are described and corresponding results are shown.

This paper aims to evaluate the impact of ships on fenders during the berthing process. Physical tests and numerical simulations with MOORNAV tool were performed with versions of the GulfStream ship in still water and under a set of different conditions. A comparative analysis was made between outputs of the two models considering specific conditions. The MOORNAV application resulted in a standard deviation from the physical model of 3% to 6% in relation to the maximum force exerted on each fender.

This paper aims to evaluate the impact of ships on fenders during the berthing process. Physical tests and numerical simulations with MOORNAV tool were performed with versions of the GulfStream ship in still water and under a set of different conditions. A comparative analysis was made between outputs of the two models considering specific conditions. The MOORNAV application resulted in a standard deviation from the physical model of 3% to 6% in relation to the maximum force exerted on each fender.

Neste trabalho, descreve-se a aplicação do programa OSOM+ às obras marítimas do Porto de Sines, em especial ao quebra-mar oeste. Assim, serão apresentados resultados de comparação entre as situações observadas em 2018 e 2020 no âmbito de inspeções visuais e com drone, mediante apreciação e análise de fotografias georreferenciadas, ortomosaicos, nuvens de pontos, modelos numéricos de superfície e perfis selecionados. É também ilustrada a forma como a aplicação e base de dados ANOSOM-WEB pode ser empregue quer durante as campanhas de observação, quer em gabinete. Conclui-se este trabalho com a apresentação das vantagens da recente atualização da metodologia e do que se julga ser a sua importância na tomada de decisões sobre a necessidade ou não de realizar obras de manutenção e/ou reparação nestas estruturas, ou similares.

Os mapas de risco costeiro, integrados em modelos de risco, são excelentes ferramentas de apoio à tomada de decisão no âmbito da gestão e proteção costeira em situações normais e de emergência [1], ajudando aproteger as populações e infraestruturas em risco de inundação costeira e galgamento oceânico proteger as populações e infraestruturas em risco de inundação costeira e galgamento oceânico.

SAFEPORT safety system aims at forecasting and alerting, on a regular basis, emergency situations regarding ships operation in port areas caused by extreme weather-oceanographic conditions. It uses forecasts provided offshore of the area under study of sea agitation, wind and tide. The characterization of the response of the free and moored ships at a berth is performed using the numerical package SWAMS. The system issue alerts, through danger levels associated with risk levels of exceedance of recommended values for movements and forces imposed on ship mooring systems. SAFEPORT can be adapted to any port. So far, it has been developed and adapted to three terminals of the port of Sines, where three different ships were simulated. This paper presents the developments made to date of the safety system, which includes tests performed in storm situations. The numerical models run every day, in real-time mode, in a computer cluster and the system provide forecast results for the next 72 hours. The results are disseminated on a web page and a mobile application in a variety of formats. It was concluded that the SAFEPORT safety system issued alerts according to the observed reality during the storm Dora. It has also been shown to be a computer tool for the optimization of ship mooring systems. The system is currently in testing and validation phase therefore, forecasts should be interpreted as indicative.

A autoridade portuária do arquipélago dos Açores, Portos dos Açores, SA, identificou a necessidade de dispor de um sistema de alerta precoce para os riscos associados à agitação marítima, nomeadamente os relacionados com os galgamentos costeiros e com os navios amarrados. No âmbito do Projeto ECOMARPORT, associaram-se com a Universidade dos Açores e o LNEC para o desenvolvimento de três novos protótipos do sistema HIDRALERTApara os portos de S. Roque do Pico, Madalena do Pico e Praia da Vitória. Os novos protótipos têm, para além da previsão de eventos de galgamento das proteções portuárias, a capacidade de prever esforços e movimentos de navios amarrados. As situações de emergência podem ser previstas, permitindo que as autoridades portuárias possam tomar medidas de mitigação para evitar a perda de vidas e minimizar os danos.

Early warning systems (EWS) are fundamental tool to reduce risks in coastal areas since they provide in advance the necessary information for the responsible authorities to mitigate the effects of possible emergency situation due to storms.

The case studies are Costa da Caparica coastal area and Ericeira port, both on the West Portuguese Coast.

The To-SEAlert project (Fortes et al. 2019) aims to include a set of tools/methodologies into the Early Warning Systems (EWS) HIDRALERTA, (Poseiro, 2019, Fortes et al., 2021, Santos et al., 2020, Zózimo et al., 2021, Ferreira, et al. 2021a) to make it more efficient reliable and robust.

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