Abstract
This contribution assesses the potential impact that proposed wave energy deployments off the West Coast of Orkney might have on morphodynamics at the Bay of Skaill, the largest sandy beach in the vicinity. Changes to wave height and hydrodynamics in the embayment are observable when wave energy extraction is included. In particular, the point of shoreline flow convergence and offshore return flow is moved northward under the energy extraction scenario. Special focus is given to changes to morphology of intertidal transects. The model demonstrated good predictability at the northern transects when compared to measured profiles but performed less well at transects further south. Inclusion of wave energy impacts on the simulated bed level changes. For all transects beach levels are higher in the upper intertidal and lower in the lower intertidal indicative of a steeper beach profile. Changes are largest for the southern two transects. Volumetric change is also impacted: volumetric variability is subdued and greater levels of accretion occur. This suggests energy extraction may help protect the world heritage site at Skara Brae, however, lower model confidence close to that area mean further investigations into impact on morphodynamics of the embayment may be prudent.