This unpublished thesis/dissertation, including all text, maps, photographs and illustrations is copyright of the author and/or third parties. The intellectual property rights of the author or third parties in respect of this work are as defined by The Copyright Designs and Patents Act 1988 or as modified by any successor legislation. Ordnance Survey maps are © Crown Copyright/database right 2011. An Ordnance Survey/Edina supplied service. Any use made of information contained in this thesis/dissertation must be in accordance with that legislation and must be properly acknowledged. Further distribution or reproduction in any format is prohibited without the permission of the copyright holder.