Abstract
The introduction of a second round of offshore wind farm leases, that will enable larger wind farms than was previously permitted, poses questions concerning sand transport, especially on sand banks. Because of engineering expediency, shipping routes and other considerations they are likely to be sited on tidal sand banks. What are the existing sand transport systems and will any scour or deposition upset the existing sand transport systems? Could this have an impact on neighbouring coasts? What is the experience from existing or planned wind farms, or wind farm analogues such as platforms, located in areas of mobile sand? This is a report of a generic study which establishes that tidal sand banks are a regular bedform and that they can be used to predict net sand transport paths provided that they are active. It describes a classification of sand banks depending on shape and setting and shows their different relationships to overall and to local bedload transport paths. A new map of sand transport paths for the entire shelf around the British Isles is drawn up and the significance of dominance is introduced. Consideration of current dominance, which currents act at any particular part of the shelf, should be an aid to the understanding of the benthos as well as to the sedimentation processes. New sand transport path maps are drawn for the three strategic areas, the Greater Wash, Thames and North West/Liverpool Bay. The impact of interference by humans on this type of natural sedimentation system is considered. The initial analysis of a valuable set of new survey data, collected in the North West/Liverpool Bay strategic area in 2004, is for the most part in support of the hypotheses and opinions of the generic study. It was found that some banks are unlike the type examples of the bank classification scheme. For instance there may be hybrid types. There was some success in demonstrating whether and how near coastal banks are linked with nearby beaches. New sand transport path maps and a new bedform zonation scheme for the eastern Irish Sea should help support considerations of benthic habitat, submarine archaeology etc.