The characterization of the wave breaking area is of paramount importance for nearshore hydrodynamics and for sediment transport studies. The location and the extension of wave breaking zone are two of the major factors for those studies because they determine the coastal sediment budget and the stability of coastal structures.

A new wave breaking model will be developed. First, physical model tests will be done in order to study the physics of the wave breaking phenomenon and to get the quantities relevant to the establishment of a new wave breaking model. Those experiments will consider different sloping bottom configurations and incident wave conditions. The influence of the bottom slope and of the water level on the termination condition of RTFN will be analysed, using free surface and velocity measurements.

The new wave breaking model using the RTFN theory will be first included on phase resolving type wave transformation models such as: FUNWAVE, FEM_NMSL or NWO_WL since the information needed to calculate the RTFN can be obtained in those models in a straightforward way. The inclusion of the RTFN in traditional phase-averaged wave transformation models is also a task to be performed ina later phase of the work.

Two field campaigns are to be conducted, at Costa da Caparica and at Barra do Ancao, to produce a prototype data set for studying the wave breaking dynamics and the associated sediment transport. Simultaneous velocity, pressure and bed-level measurements will be obtained. The bottom level will be measured through both eco-sounds and an innovative measurement device, based on fibre optics technology. Should this device prove useful a technological patent may be applied for.

The field data will be used to validate the numerical models developed/tested during the project and to analyse the effect of the wave asymmetry and skewness in the sediment fluxes and morphodynamics. Net transport fluxes will be calculated, different empirical parameterizations for the referred wave shape quantities will be tested and new parametric formulas for the net sediment transport rate will be developed during the Project. The RTFN wave breaking parameter will be used to improve the empirical parameterizations of the referred wave shape quantities.




Objective
The main objective of the project is to contribute to the understanding and numerical modelling of the wave breaking and cross-shore sediment transport phenomena in coastal regions.
More specifically, it is intended to:

• Perform scale-model tests to determine the RTFN at the beginning, during and at the end of the wave breaking process
• Develop a new wave breaking model based on the RTFN concept and to implement it in phase-averaged and phase-resolving numerical models for wave propagation
• Analyse the effects of the sea waves non linearity on the sediment fluxes and on the beach morphodynamics
• Improve sediment transport models and empirical formulae
• Develop a device to survey bottom depth based on fiber optic cable
• Carry out field campaigns for bathymetric surveys and sea wave and current measurements

Field Campaigns
To study wave breaking dynamics and the associated cross shore sand transport two field campaigns for data acquisition are foreseen.

• Faro beach, Ancão peninsula
• Saúde beach, Costa da Caparica

In the shoaling and breaking regions of each location, flow velocities and pressures will be measured and the terrain and bottom depths will be surveyed. Data acquisition will span a period of one week.

The bottom depths will be surveyed with both the usual acoustic profiler and by an innovative optical fibre based technique. Should this technique prove itself useful, the respective patent will be registered.


Team
LNEC: Conceição Fortes, Takashi Okamoto, João Alfredo Santos, Maria da Graça Neves, Catarina Zózimo, Liliana Pinheiro, Francisco Sancho, Lígia Pinto.
Aveiro University: João Lemos Pinto, Rogério Nogueira, Paulo André, Paulo Silva.
Algarve University (CIACOMAR): Óscar Ferreira, Ana Matias, André Pacheco, Ana Rita Carrasco, Carlos Loureiro, Erwan Garel, Mara Nunes

Tasks:
The main tasks are:

1. Wave flume tests
2. Numerical modelling of wave breaking
3. Development of a new wave breaking criterion based upon the RTFN
4. Implementation of the RTFN wave breaking criterion in numerical models for wave propagation
5. Numerical modelling of sediment transport
6. Field measurements

Expected Results
In short, the project will contribute to:

• The improvement of the knowledge and of the numerical modelling of both the wave breaking and the sediment transport phenomena
• A new wave breaking model based on RTFN theory
• Improvement of phase resolving/averaged wave propagation models
• Development/Improvement of sediment transport models and empirical formulae
• Analysis of the wave nonlinear effects on the sediment flux and morphodynamics
• Formation of a data base with experimental and field data available to the scientific community
• Development of a new technique for beach-face survey using optical fibres
• Advanced training of young researchers through the preparation of M.Sc. and Ph.D. thesis
• Collaboration between three different research institutions

Other Team Projects

• MADYCOS -Análise multidisciplinar integrada da dinâmica sedimentar e da contaminação fecal em sistemas costeiros intermitentes.
• Projecto FCT - PTDC/ECM/66484/2006
• MOIA -Modelo operacional de gestão portuária.
• Projecto FCT - PTDC/ECM/73145/2006
• GUIOMAR – Geo(graphical) User Interface for Coastal and Marine Modeling .
• Projecto FCT - PTDC/AMB/67450/2006
• Novas abordagens de protecção para a costa portuguesa.
• Projecto FCT - PTDC/ECM/66516/2006
• BAYBEACH – Evolução e Gestão de Praias Encastradas em Ambientes Contastrantes,
• Projecto FCT – PTDC/CTE-GEX/66893/2006
• MICORE – Morphological impacts and coastal risks induced by extreme storm events;
• 7 th EU Framework Programme
• INSHORE – Integrated system for high operational resolution in shore monitorization,
• Projecto FCT – PTDC/AMB/73169/2006
• CIRCO – Climate changes from isotopic records during the Holocene in south-western Iberia,
• Projecto FCT – PTDC/CLI/66393/2006
• DETI – Dynamic of Ephemeral tidal inlets,
• Projecto FCT – PTDC/MAR/65585/2006
• SANDEX - Extracção de areias na plataforma continental portuguesa: impactos e evolução morfodinâmica.
• Projecto FCT - PTDC/ECM/70428/2006
• TRANSKEW - Measurements of sand transport induced by skewed waves and currents.
• Hydralab III - HyIII-Delft-1.
• EMERA - Estudo da morfodinamica da embocadura da ria de Aveiro.
• Projecto FCT - POCTI/ECM/59958/2004
• G-Cast – Aplicação da computação GRID num sistema de simulação e previsão da morfodinâmica em zonas costeiras.
• Projecto FCT - GRID/GRI/81733/2006
• MURANO – Muros das Marinhas de Sal da Ria de Aveiro.
• Projecto FCT - PTDC/ECM/65589/2006