Development of a coupled wave tide and sediment model of the UK shelf seas using ROMS
M. Reza Hashemi1, S. P. Neill1 Matthew James Lewis1
1Centre
for Applied Marine Sciences, School of Ocean Sciences, Bangor University, UK.
The UK shelf seas are one of the most attractive regions in the world for the development of wave
and tidal energy projects. The study of the impacts of the marine renewable energy projects upon the
natural environment, and within the context of natural variability, is a necessary step in those projects.
Further, in many regions for marine energy development (e.g. Pembrokeshire, Orkney) concurrently
experience a high wave and a high tidal energy resource. Hence, wave-tidal interactions needs to be
considered for many of these marine energy schemes. Therefore, the development of dynamically
coupled wave – sediment – tide hydrodynamic models appears to be necessary in order to correctly
understand the marine energy resource and their impact upon systems such as offshore sand banks.
In the present research, ROMS (Regional Ocean Modelling System) and SWAN wave model were
employed to develop a coupled wave tide and sediment model of the UK shelf seas. A same
curvilinear gird with a resolution of 1/24° resolution was used for discretization of both models. After
model validation at several tide gauge stations and wave buoys around the UK, tide and wave and
their interactions and the potential impacts on sediment transport were studied for a typical energetic
month (Jan-2005). Several issues such as computational cost, validation, selecting the proper model
physics and type of the interaction (1-way versus 2-way) were discussed.
The results showed the significant impact of the tide on waves in some regions. Nevertheless, many
processes of wave tide interactions should be considered with higher resolution models for a specific
site of interest. Further, the natural variability of the wave climate appears to be an importance
consideration to understand the environmental impact of these marine renewable schemes. Further
research is underway in this respect.