steepness of the foreshore, the existence (or lack) of a bar, and the general 

 slope of the inshore zone fronting the beach. Generally, the larger the sand 

 particles the steeper the beach slope. Beaches with gently sloping foreshores 

 and inshore zones usually have a preponderance of the finer sizes of sand. 

 Daytona Beach, Florida, is a good example of a gently sloping beach composed 

 of fine sand. 



Bavvier islands are an important part of the physical system in some areas 

 (see Fig. 1-4). These are long narrow islands or spits lying parallel to the 

 mainland. Most of the coast on the U.S. Atlantic south of Long Island and 

 along the gulf is composed of barrier islands. During severe storms these 

 barrier islands provide protection for the mainland by absorbing the brunt of 

 the wave attack. However, many barrier islands are so highly developed that 

 the protection of their beaches has become an important consideration (see 

 Fig. 1-5). 



Figure 1-4. 



Undeveloped barrier island on the gulf coast of 

 Alabama after Hurricane Frederic. 



Lagoons are shallow bodies of water separating the barrier beach from the 

 mainland. They are usually connected to the sea by narrow channels through 

 which tidal currents flow. Lagoons provide a habitat for a wide variety of 

 wildlife, and many lagoons serve as safe harbors and navigable waterways. 



An inlet is the narrow opening between the lagoon and the ocean. Inlets 

 occur at fairly regular intervals along a barrier island chain, and they 

 often, when improved, provide a navigation passage to the sea. When barrier 

 beach dunes are breached by storm wave attack, the result may be the cutting 

 of a new inlet. An inlet can permit beach material removed by storms to enter 

 a lagoon and be deposited there. It may also allow some bottom material from 

 a lagoon to be carried oceanward by tidal currents and then be transported 

 along the shore by wave action. Over time, changing conditions may cause some 

 inlets to close and new inlets to open. 



1-8 



