Over the last decade, the development of Offshore Wind Farms (OWF) has received significant attention. In March 2002, a FEPA licence was granted for the development of the first UK OWF, within coastal waters, at Scroby Sands, Great Yarmouth, Norfolk. This site was regarded at the time as the worst-case scenario in terms of potential impacts on coastal processes, involving the emplacement of 30 turbines situated upon monopile foundations 4.2 m in diameter in an environment with fast tidal currents and mobile bed sediments. During this licensing process, two environmental issues arose of major potential importance to the development of the adjacent inshore region, namely:
- the potential for the OWF to cause wave focussing on parts of the adjacent coastline (studied in the Defra-funded project AE1227), and;
- the potential for the OWF to alter sediment transport and consequently affect the stability of large-scale coastal geomorphic features, such as the sandbanks themselves and the associated channels.
This project performed research to investigate the latter issue, of sediment transport and sandbank stability.
A programme of research and monitoring was undertaken at the Scroby Sands OWF, to observe, measure and quantify potential impacts of OWFs on coastal processes. This was achieved by a series of seabed surveys (side-scan sonar, swathe bathymetry) and deployment of seabed landers (Cefas ‘MiniLanders’) before, during and after construction of the OWF. These have been used to provide evidence of changes in seabed bathymetry, bedforms, currents, waves and suspended sediment concentrations that may lead to disturbance of sedimentary environments or sediment transport pathways.
Acknowledgement: This article was identified by the Crown Estate Wave and Tidal Knowledge Network.