The evolution of coastal sand dunes

Approximately 20 per cent of the coastline of the Highlands (Land lying West and North of the Highland Boundary Fault) excluding islands, is fringed by sand accumulations in the form of dunes, links or machair. Except where sea walls and promenades protect their seaward edge, dunes are intimately linked to beaches, the margin between dune and beach being a fluctuating zone which is dominated in turn by encroaching waves or prograding vegetation. The largest sand surfaces are found in the machair plains of the Uists; long stretches are also found on the Caithness coast, the south coast of the Moray Firth and Aberdeenshire. (Author)