5. Coastal Engineering Design Implications . 



When weekly height and period observations were statistically compar- 

 ed with daily height and period observations, no significant difference 

 was found. This suggests that for long-term averages, weekly littoral 

 environment observations collected over several years will provide rep- 

 resentative data of average conditions. However, weekly observations 

 will not provide information on the more important extreme events. 



Experience indicates that weekly beach profile surveys adequately 

 document seasonal and year-to-year beach changes. 



The pipe profile surveying method is very useful for obtaining 

 accurate data through the breaker zone and in the nearshore region. 

 However, certain safety and logistics problems must be carefully con- 

 sidered before using this technique. 



Long-term beach changes computed for the three southeast Florida 

 beaches are relatively small when compared to changes reported for beaches 

 on more exposed coasts (U.S. Army, Corps of Engineers, Coastal Engineering 

 Research Center, 1975) . However, storm changes were found to be of a mag- 

 nitude similar to those reported for more exposed coasts, especially at 

 Jupiter. 



The underlying coquina limestone and the sheltering effect of the 

 Bahamas both have a stabilizing influence on the southeast Florida 

 beaches. The effect of storm waves from the open Atlantic Ocean is 

 greatly reduced, due to the protection afforded by the Bahama Banks. 

 Once the veneer of sand has been removed by storm waves or other forces, 

 the imderlying coquina greatly reduces further erosion. 



