Publicações

Artigos de Revista

Info Energy rate balance applied to coastal engineering problems by using RANS-VoF models in numerical wave flumes

Info An assessment of 3D scanning methods in physical models

Info Analytical and numerical modelling of wave dissipation over rigid and flexible vegetation in a flume: Drag coefficient calibration

Info Deep Neural Network Enhanced Early Warning System for Ports Operations

Info Development of a Bayesian network-based early warning system for storm-driven coastal erosion

Coastal hazards such as flooding and erosion can cause large economic and human losses. Under this threat, early warning systems can be very cost-effective solutions for disaster preparation. The goal of this study was to develop, test, and implement an operational coastal erosion early warning system supported by a particular method of machine learning. Thus, the system combines Bayesian Networks, and state-of-the-art numerical models, such as XBeach and SWAN, to predict storm erosion impacts in urbanized areas. This system was developed in two phases. In the development phase, all information required to apply the machine learning method was generated including the definition of hundreds of oceanic synthetic storms, modeling of the erosion caused by these storms, and characterization of the impact levels according to a newly defined eerosion iimpact index. This adimensional index relates the distance from the edge of the dune/beach scarp to buildings and the height of that scarp. Finally, a Bayesian Network that acted as a surrogate of the previously generated information was built. After the training of the network, the conditional probability tables were created. These tables constituted the ground knowledge to make the predictions in the second phase. This methodology was validated (1) by comparing 6-h predictions obtained with the Bayesian Network and with process-based models, the latest considered as the benchmark, and (2) by assessing the predictive skills of the Bayesian Network through the unbiased iterative k-fold cross-validation procedure. Regarding the first comparison, the analysis considered the entire duration of three large storms whose return periods were 10, 16, and 25 years, and it was observed that the Bayesian Network correctly predicted between 64% and 72% of the impacts during the course of the storms, depending on the area analyzed. Importantly, this method was also able to identify when the hazardous conditions disappeared after predicting potential consequences. Regarding the Regarding the second validation approach, second validation approach, the k-fold cross-validation procedure was applied to the peak of a set of varying storms and it demonstrated that the predictive skills were maximized (63%

Ano: 2024

Número Páginas: 1-15pp.

Autor(es): Garzon, J.L.; Ferreira, Ó.; PLOMARITIS, T.A.; Zózimo, A. C.; Fortes, C. J. E. M.; Pinheiro, L.

Revista: Coastal Engineering

Editor: Elsevier

Volume: Vol 189 (104460).

DOI: https://doi.org/10.1016/j.coastaleng.2024.104460

Keywords: HIDRALERTA; Sandy beaches; Bayesian networks; Numerical modeling; Prediction system

Info Development of a Bayesian network-based early warning system for storm-driven coastal erosion

Coastal hazards such as flooding and erosion can cause large economic and human losses. Under this threat, early warning systems can be very cost-effective solutions for disaster preparation. The goal of this study was todevelop, test, and implement an operational coastal erosion early warning system supported by a particularmethod of machine learning. Thus, the system combines Bayesian Networks, and state-of-the-art numericalmodels, such as XBeach and SWAN, to predict storm erosion impacts in urbanized areas. This system wasdeveloped in two phases. In the development phase, all information required to apply the machine learningmethod was generated including the definition of hundreds of oceanic synthetic storms, modeling of the erosioncaused by these storms, and characterization of the impact levels according to a newly defined eerosion iimpactindex. This adimensional index relates the distance from the edge of the dune/beach scarp to buildings and theheight of that scarp. Finally, a Bayesian Network that acted as a surrogate of the previously generated informationwas built. After the training of the network, the conditional probability tables were created. These tablesconstituted the ground knowledge to make the predictions in the second phase. This methodology was validated(1) by comparing 6-h predictions obtained with the Bayesian Network and with process-based models, the latestconsidered as the benchmark, and (2) by assessing the predictive skills of the Bayesian Network through theunbiased iterative k-fold cross-validation procedure. Regarding the first comparison, the analysis considered theentire duration of three large storms whose return periods were 10, 16, and 25 years, and it was observed that theBayesian Network correctly predicted between 64% and 72% of the impacts during the course of the storms,depending on the area analyzed. Importantly, this method was also able to identify when the hazardous conditionsdisappeared after predicting potential consequences. Regarding the Regarding the second validationapproach, second validation approach, the k-fold cross-validation procedure was applied to the peak of a set ofvarying storms and it demonstrated that the predictive skills were maximized (63%

Ano: 2024

Autor(es): Garzon, J.L.; Ferreira, O.; PLOMARITIS, T.A.; Zózimo, A. C.; Fortes, C. J. E. M.; Pinheiro, L.

Revista: Coastal Engineering

Editor: Elsevier

Volume: 189 (2024) 104460.

DOI: doi.org/10.1016/j.coastaleng.2024.104460

Keywords: HIDRALERTA; Sandy beaches; Bayesian networks; Numerical modeling; Prediction system

Info Experimental investigation of wave severity and mooring pretension on the operability of a moored tanker in a port terminal

Info Experimental study of an onshore dual chamber oscillating water column device

A wave flume is used to study a scaled model of a stepped bottom dual-chamber Oscillating Water Column (OWC) installed onshore. Compared to traditional single-chamber OWCs, the use of dual-chambers is expected to widen the range of sea states in which the OWC is more efficient, and the step, in front of the first chamber, boosts the capturing energy capacity of the device. The Power Take-Off (PTO) system is modelled as an air opening in the pneumatic chambers. Several experiments combining regular incident waves and PTO damping conditions are performed. Results of the amplitudes of the free surface elevations inside the chambers show that the device can amplify the incident wave amplitude up to 1.57 times in chamber 2. Results of the primary efficiency show that the device is highly dependent on the PTO damping characteristics and can reach around 40% for a wide range of wave periods. Results of the reflection analysis show that the reflection coefficient is also dependent on the PTO damping characteristics but remain lower than 0.6 for all the studied cases. Sloshing phenomenon (mostly in the cross-section direction) was observed for a wavelength close to the cross-section dimension, impacting negatively on the device pneumatic performance.

Ano: 2024

Número Páginas: 16p..

Autor(es): Gadelho, J.; REZANEJAD, K.; Guedes Soares, C.; Santos, J. A.; Anastas, G.; Fortes, C. J. E. M.

Revista: Ocean Engineering

Editor: Elsevier

Volume: Volume 300 (117240).

DOI: https://www.sciencedirect.com/science/article/pii/S0029801824005778

Keywords: Reflection coefficients; Efficiency improvement; Breakwater; Experiments; Oscillating water column

Info Experimental study on drag coefficient of flexible vegetation under non-breaking waves

Info Exploring Wave

Comunicações

Info Modelação numérica não-linear da propagação e deformação de ondas em zonas costeiras. Análise pelo método dos elementos finitos

Info Modelos de Elementos Finitos de Propagação de Ondas, DREAMS e EPE_CG. Aplicação à Marina do Lugar de Baixo

Info Modelos numéricos de propagação de ondas marítimas. Validade da aproximação linear

Info Pacote numérico para simulação de manobras de navios na entrada de portos sob a acção das ondas

Info Propagação da agitação marítima até junto à praia do Porto Santo

Info Propagação da agitação marítima e simulação numérica da entrada de navios no porto do Caniçal

Info Rubble-mound breakwater inspection in Portugal

Info Simulação numérica da entrada de navios no porto do Caniçal

Capítulos de Livros

Info Multi-functional artificial reefs for coastal protection

Teses de Doutoramento

Info Trapped-mode propagation along irregular coasts

Info Probabilistic Assessment of the Safety of Coastal Structures

Info Unsteady Nearshore Currents on Longshore Varying Topographies

Info Simulação da agitação irregular. Técnicas matemáticas

Relatórios

Info As Provas de Governo e Manobra do N/T "Bornes". Relatório Final

Info Ensaio em modelo reduzido das obras marítimas do sector de recreio náutico do porto da Ericeira. Ensaios de estabilidade e galgamentos.

Info Ensaios de modelo de quebra-mares de talude. Características dos modelos de blocos artificiais de betão existentes no LNEC.

Info Ensaios em modelo reduzido das obras marítimas da marina de Cascais. Ensaios de agitação.

Info Ensaios em modelo reduzido das obras marítimas da marina de Cascais. Estudo de estabilidade e galgamentos.

Info Ensaios em modelo reduzido do troço NATO do molhe de Ponta Delgada. Ensaios tridimensionais de estabilidade e galgamentos.

Info Estudo em modelo reduzido do molhe oeste do porto da Madalena. Ensaios de estabilidade.

Info Missão ao 27º Congresso Internacional de Navegação Osaka, 20 a 26 de Maio de 1990. Relatório Final

Info Notas sobre períodos de retorno.

Info Observação sistemática das obras de abrigo dos portos de Portugal Continental.

Outros

Info Risk Perception of Coastal Flooding in Praia da Vitória, Azores

Info Social Surveys Indicating the Resilience of Urban Coastal Localities in Macaronesia to Coastal Flooding

Info Avaliação da Estabilidade do Quebra-Mar Destacado do Porto Inglês (Ilha do Maio

Info Physical modelling of wave-induced plant drag coefficient

Info Evaluation of wave overtopping consequences for risk assessment using ANP methodology

Adverse sea conditions can cause emergency situations associated to wave overtopping, which endanger the safety of people and goods, with negative impacts for society, the economy and the environment. Therefore, a methodology to assess the overtopping risk in port and coastal areas is essential for a proper planning and management of these areas.The Portuguese National Laboratory for Civil Engineering (LNEC) has been developing the HIDRALERTA system, an integrated decision-support tool for port and coastal management, which focus in preventing and supporting the management of emergency situations and the long-term planning of interventions in the study areas. It enables the user to calculate the risk for various port and coastal activities, starting with the characterization of sea-waves, wind field and tide levels at the study regions.HIDRALERTA was already tested at different places in Portugal: Costa da Caparica beach, in Almada, and port of Praia da Vitória, in the Azores. However, in both cases, the evaluation of wave overtopping / flooding consequences was carried out using a quite simple approach. In fact, such consequences were assessed only at a global and qualitative level, based on information provided by the responsible authorities.This paper aims at testing a quantitative methodology to evaluate overtopping consequences: the Analytic Network Process (ANP). This methodology was proposed to solve complex decision-making problems and its objective is to calculate the priorities among decision elements which will define their final weights on the consequences. The ANP approach can produce interdependencies between criteria and compute the respective weight of each criterion. Such a network model with dependence and feedback improves the priorities derived from judgements and makes prediction more accurate. So, the ANP allows comparison among clusters of elements. Furthermore, in this methodology we take into account the impacts of alternatives on the importance of criteria, by normalizing the comparison matrix. Thus, the given alternatives can influence the ranking of criteria.Application of the ANP methodology to the case study of Praia da Vitória port is presented and a consequences level map is obtained.

Ano: 2016

Autor(es): Lourenço, I.; Santos, J. A.; Fortes, C. J. E. M.; Reis, M. T. L. G. V.; Poseiro, P.; Craveiro, J.

Keywords: Praia da Vitória port; Analytic Network Process (ANP); Risk; Wave overtopping

Info Sistema de alerta para a navegação em portos

CONSTRUÇÃO DA EXPANSÃO DO PORTO DE SAL-REI 1ª FASE (ILHA DA BOAVISTA CABO VERDE) Ensaios bidimensionais em modelo reduzido Parecer Técnico

Info Definição da Geometria para um Recife Artificial Multifuncional em Leirosa (Poster)

Info Probabilistic Assessment of Hazards from Overtopping of Seawalls in Urban Environments: Annual Report of pOST-dOCTORAL rESEARCH

Info Guidelines and Recommendations for River Information Services - PIANC