Interactions between long term coastal change and human development, Dundrum Bay, Northern Ireland

Abstract

Dundrum Bay in south east Northern Ireland is a macrotidal embayment containing a broad ridge and runnel intertidal beach backed by an extensive Holocene dune system and back-barrier lagoon. Analysis of mesoscale coastal change from historical records, wave modelling and field investigations indicates a net northward transport and accretion of sediment within the northern sections of the cell that is evidenced by foreduneaccretion and spit progradation over the last 150 years. Over the same time period a coastal resort town (Newcastle), golfcourse (Royal County Down), nature reserve (Murlough) and military training ground (Ballykinler) have been developed ni the embayment. The associated history of shoreline management can be linked to natural geomorphological changes. Newcastle was developed at the updrift end of the cell and has experienced sediment loss from the intertidal beach, to which the management response has been a sequential northward construction of sea defences. This has now pro- ceeded ot the boundary of the nature reserve. Murlough Nature reserve has seen the development of a new spit at the inlet to Dundrum inner bay that is tentatively linked to reclamation works. The military training ground has seen sustained coastal accretion. The study illustrates hte role of geomorphological processes ni these reactive management approaches ot coastal planning and environmental conservation.