Dune Coasts

A review of the processes of initiation, evolution, dynamics, geomorphology, and location of coastal dunes is provided. Four principal dune types are covered: foredunes, blowouts, parabolic dunes, and transgressive dunefields. The reasons why dunes first form and where they are formed are initially discussed, and it is concluded that dunes can be created on almost any coast in the world as long as some basic conditions are met and the coast is ice free for at least a small portion of time. In terms of location, foredunes can occur on almost all coasts of the world. Blowouts may occur anywhere as well as in conjunction with the other three dune types. Parabolic and transgressive dunefields are predominantly found on high-energy east and west coasts and in arid regions with a significant sediment supply. The initiation mechanisms vary for each dune type, but vegetation presence or absence is a major factor in all cases. The morphodynamics, landform units, and evolutionary patterns are described for the dune types, and the chapter concludes with a brief review of beach-dune interaction models.