Centre of Atmospheric Sciences

The Wave Hub project will create the world's largest wave farm off the coast of Cornwall, Southwest England. This study is to investigate wave and tide interactions, in particular their effects on bottom friction and sediment transport at the wavefarm coast. This is an ambitious project research which includes the use of a very complex numerical modelling system. The main question to answer is how waves, tidal currents and winds affect the bottom friction at the Wave Hub site and the near-shore zone, as well as their impact on the sediment transport. Results show that tidal elevation and tidal currents have a significant effect on the wave height predictions; tidal forcing and wind waves have a significant effect on the bed shearstress, relevant to sediment transport; waves via radiation stresses have an important effect on the long-shore and crossshore velocity components, particularly during the spring tides. Waves can impact on bottom boundary layer and the mixing in the water column. Interactions between waves and tides at the Wave Hub site is important when modelling coastal morphology influenced by wave energy devices. This open-source modelling system tool will help the study of physical impacts on the Wave Hub farm area.

This study investigates the interactions of waves and tides at a wave farm in the southwest of England, in particular their effects on radiation stress, bottom stress, and consequently on the sediment transport and the coast adjacent to the wavefarm (the Wave Hub). In this study, an integrated complex numerical modelling system is setup at the Wave Hub site and is used to compute the wave and current fields by taking into account the wave-current interaction, as well as the sediment transport. Results show that tidal elevation and tidal currents have a significant effect on the wave height and direction predictions; tidal forcing and wind waves have a significant effect on the bed shear-stress, relevant to sediment transport; waves via radiation stresses have an important effect on the longshore and cross-shore velocity components, particularly during the spring tides. Waves can impact on bottom boundary layer and mixing in the water column. The results highlight the importance of the interactions between waves and tides when modelling coastal morphology with presence of wave energy devices.

Gonzalez-Santamaria R., Zou Q.-P., and Pan S., 2011. Two-way coupled wave and tide modelling of a wave This study investigates the interactions of waves and tides at a wave farm in the southwest of England, in particular their effects on radiation stress, bottom stress, and consequently the effects on the sediment transport and the coast adjacent to the Wave Hub, the wave-farm. In this study, an integrated complex numerical modelling system is setup at the Wave Hub site and is used to study the effect of wave-current interaction on current circulation, bottom shear stress, as well as the impacts in the nearshore zone. Results show that tidal elevation and tidal currents have a significant effect on the wave height and direction predictions; tidal forcing and wind waves have a significant effect on the bed shear-stress, relevant to sediment transport; waves via radiation stresses have an important effect on the longshore and cross-shore velocity components, particularly during the spring tides. Waves can impact on bottom boundary layer and the mixing in the water column. Interactions between waves and tides at the Wave Hub site are important when modelling coastal morphology influenced by wave energy devices.

This paper presents the results from an integrated modelling system investigating the effects of a wave farm on nearshore sediment transport. Wave Hub project is a large scale demonstration site for the development of the operation of arrays of wave energy generation devices located at the southwest coast of the UK where multiple field measurements took place. The two-way coupled SWAN and ROMS models with nested modelling system were set up at the Wave Hub site and run with and without a wave farm. The model results show that the presence of the wave farm has significant impacts on the nearshore circulation, bed shear stresses and sediment transport. The morphological changes are also altered by the wave farm. The study is the key element for the wave resource characterization and environmental impact assessment of the wave farm.

This study investigates impacts of a wave farm on waves, currents and coastal morphology adjacent to the wave farm, which is located in the Southwest of England (the Wave Hub). In this study, we focus on the interaction between waves and tides due to the presence of the wave farm and its effects on wave radiation stresses, bottom shear stresses and consequently on the sediment transport and the coast adjacent to the wave farm, using an integrated numerical modelling system. The modelling system consists of the near-shore wave model SWAN, the ocean circulation model ROMS and a sediment transport model for morphological evolution. The results show that tidal elevation and tidal currents can have a significant effect on waves and that tidal forcing and waves have a significant effect on bottom shear stresses. Waves can impact on the processes related to the bottom boundary layer and mixing intensity in the water column. The wave farm has an impact on the gradients of radiation shear stresses and bottom shear stresses that modify current speeds and wave heights, which in turn impact on the near-shore sediment transport and the resulting morphological changes. Bed load transport rates show a decrease when the wave farm is present, even during storm conditions. The results highlight the importance of the interactions between waves and tides when modelling coastal morphology with presence of wave energy devices.

This paper demonstrates the application of a Decision Support System (DSS) developed for decision makers and stakeholders to manage and raise awareness of coastal flood risk. The DSS is a GIS-based framework that predicts flooding consequences and is structured around the Source Pathway Receptor Consequence (SPRC) model. The DSS draws together points of view from engineering, ecology and socio-economics, allowing the comparative assessment of the consequences of a range of management interventions. The utility of the tool is demonstrated through application to an estuary field site -the Teign estuary in UK. Vulnerability maps, generated by the DSS for pre-set climate scenarios can be used to show their comparative efficacy in changing the consequences of flooding from a range of stakeholder viewpoints. Recently constructed " tidal " defences built within the estuary are shown to be highly effective.