Coastal Dunes 



Coastal dunes (Figure 18) occur where there is a sufficient sediment 

 source, onshore winds of sufficient velocity to transport the available material, 

 and a flat or low-relief space inland of the coastline to accommodate dune 

 formation. Sources of dune material are usually the dry portion of sandy 

 beaches. The wider the beach, the greater the surface area exposed to wind 

 transport and, consequently, the greater the volume of material available to 

 form dunes. Flat, dissipative shorelines, where large volumes of sand are 

 stored subaerially at low water, are highly suited for foredune development 

 (Short and Hesp 1982). 



Figure 18. Partly vegetated coastal sand dunes. Eastern Alabama near Florida/Alabama 

 state line (March 1991). This area was devastated by Hurricane Frederic in 

 1979 



Chapter 3 Variable Coastal Features 



47 



