Summary of the main types of dune systems

Many different types of dune system can be identified. The size, width and penetration inland depend on sediment availability, whether dominant and prevailing winds reinforce or oppose each other and the height of the hinterland. The following are the most frequently recognised types:

• Hindeshore dunes - the most common type and often the most extensive is the system which finds its best expression in exposed west-facing locations;
• Machair - a special kind of hindeshore system found only in north west Scotland and western Ireland;
• Bay and ness dune systems develop in more sheltered areas, where dominant and prevailing winds oppose each other. These can be relatively narrow;
• Spits, bars and barriers sand dunes also occur at the mouths of estuaries and other tidal inlets and deltas where the movement of sand along the shore helps to create them
• Climbing dunes may also occur high above the sea where cliffed coasts occur and wind speeds are high. In these circumstances sand may be driven many metres up and onto the cliffs creating dunes physically separated from their sediment source to create. Example occur in western Scotland and on coast of Northumberland at Bamburgh

A variant of the climbing dune is found on the west coast of Finland where the land is rising relative to the sea due to isostatic change. As new land is exposed the coastal dunes are removed from the beach and in the absence of new sediment become fossilised, the Kalajoki dune field (Heikkinen & Tikkanen 1987) is one example.

References

Heikkinen, O. & Tikkanen, M. 1987. The Kalojoki dune field on the west coast of Finland. Fennia, 165/2., 241-267.