This paper presents a description of a finite element numerical model, BOUSS1D_iw based upon the Boussinesq equation derived by Nwogu (1993). Special attention is given to the procedure implemented into this model for wave generation, by using a source function. In order to validate BOUSS1D_iw model, two literature test cases were chosen. First the BOUSS1D_iw model (one dimensional version) is applied to the simulation of the wave propagation over a constant depth flume considering a regular wave generated in the centre of the flume, to test the source function procedure implemented into the model. After, it is applied to the experiments performed by Dingemans (1994): i.e., the wave propagation over a submerged sill, to analyze the model's performance when simulating the main phenomena involved in nearshore wave propagation, with special attention to nonlinear effects. Comparison between the BOUSS1D_iw numerical results, experimental results and results from another numerical model (Kirby et al (1998)), for time series of water surface elevation and power spectrum, are presented and discussed.@en

This paper describes the study of the impact of energy absorption by wave farms on the nearshore wave climate and, in special, the influence of the incident wave conditions and the number and position of the wave farms, on the nearshore wave characteristics is studied and discussed. The study was applied to the maritime zone at the West coast off Portugal, namely in front of São Pedro de Moel, where it is foreseen the deployment of offshore wave energy prototypes and farms between the 30 m and 90 m bathymetric lines, with an area of 320 Km2. In this study the REFDIF model was adapted in order to model the energy extraction by wave farms. Three different sinusoidal incident wave conditions were considered. Five different wave farm configurations, varying the position of the wave farm, its number and the width of the navigation channels at each wave farm were analysed. The results for each configuration in terms of the change of the wave characteristics (wave height and wave direction) at the nearshore are presented, compared and discussed for three representative wave conditions.@en

This paper describes the experiments performed at the National Laboratory for Civil Engineering (LNEC) aiming at simulating, in a flume, the wave propagation along a constant slope bottom that ends on a sea wall coastal defence structure, a common structure employed in the Portuguese coast. The objective of these tests is to calibrate the parameters of FUNWAVE, a Boussincsq type model, for wave propagation in coastal regions. This is the first step in the validation of a methodology to combine numerical and physical models in the study of the interactions between beaches and structures. This work is performed in the framework of the Composite Modelling of the Interactions between Beaches and Structures (CoMIBBs) project, a joint research activity of the HYDRALAB III European project.@en

Laboratory experiments of wave propagation over rigid and flexible vegetation fields, with the same configurations, were conducted to understand the effect of vegetation flexibility on the drag coefficient (CD). The direct method and the least squares method (LSM), based on force and flow measurements, are applied to calculate the CD in the experimental conditions. The formulations of both methods are extended to estimate the CD for flexible vegetation cases. A video analysis was performed to account for the swaying motion. Typically, wave dissipation is lower for flexible than for rigid vegetation of the same configuration, under the same flow condition. Therefore, a proportional effect in the corresponding CD results, obtained from common CD calibration to wave dissipation without considering vegetation motion, is usually observed. However, the present results show that although the wave dissipation was 34% lower for flexible relative to rigid vegetation, the respective CD values were close. CD estimations considering vegetation motion and inertia suggest that CD of flexible vegetation was up to 13% higher relative to rigid vegetation. Accounting for inertia reduced the CD for rigid vegetation up to 7%, while raised the CD for flexible vegetation up to 13%.@en

FUNWAVE numerical model is particularly suited to model nonlinear wave phenomena in the nearshore coastal zone. However, due to its inherent limitations, no a priori values are known for the parameters to be used for a particular application of FUNWAVE. Hence every simulation provides significant knowledge on the parameters to be used on future situations, especially if complex phenomena as wave breaking and wave runup are present. In this paper, the FUNWAVE model (one dimensional version) is applied to the simulation of the experiments performed by Mase et al. (2006): i.e., the wave propagation on a channel with difirent slope profiles and a seawall, for irregular breaking wave conditions. The purpose of this study is to analyze the model's performance when simulating the main phenomena involved in nearshore wave propagation, with special attention to nonlinear phenomena and wave runup. In order to evaluate FUNWAVE'S behavior a comparison is made between experimental and numerical results for surface elevation, significant wave height, wave period, power spectrum and bispecirum and wave runup.@en

The influence of a set of wave farms for wave energy extraction on the nearshore wave climate at the pilot zone in Portugal was studied. Two different wave farms configurations (named B and C) and two representative wave conditions (winter and summer) were considered. Energy extraction did not exceed 9.1 and 21.1%, respectively, of the incident energy in the wave farms for January and July. Energy extraction was very similar for the two wave farm configurations. There were no significant differences on the wave heights observed near the coast when considering the two wave farm configurations and the case without wave farms. This is an abstract of a paper presented at the Eighteenth International Offshore and Polar Engineering Conference (Vancouver, Canada 7/6-11/2008).@en

A set of scale-model tests carried out to enlarge the range of wave steepness values analysed in run-up, overtopping and armour layer stability studies, focusing on oblique extreme wave conditions and on their effects on a gentler slope breakwater's trunk armour and roundhead, is presented in this paper. A stretch of a rubble mound breakwater (head and part of the adjoining trunk, with a slope of 1(V):2(H)) was built in a wave basin at the Leibniz University Hannover to assess, under extreme wave conditions (wave steepness of 0.055) with different incident wave angles (from 40° to 90°), the structure behaviour in what concerns wave run-up, wave overtopping and damage progression of the armour layer. Two types of armour elements (rock and Antifer cubes) were tested. Non-intrusive methodologies including a new application of laser scanning technique for the assessment of both armour layer damage and wave run-up and overtopping were used. It is expected that such work will contribute also with data to improve empirical formulas as well as to validate complex numerical model for wave-structure interaction.@en

This paper describes the Numerical and Physical Modelling components of the main project entitled "Viability study of the artificial surfing reef of S. Pedro do Estoril". These studies aim to establish the main characteristics (dimensions, orientation and location) of the artificial surfing reef for S. Pedro do Estoril and to analyze its hydrodynamic peifonnance for different incident wave conditions. The main conclusions of both studies were that the reef solution permits the improvement of the surf conditions in the area of S. Pedro do Estoril especially for the most frequent wave in the region. However, in both studies some problems related with strong reflection and vortices in the reef's corners where detected and should be improved in the final solution.@en