transport rate because the shoreline eventully tends to reach an equilibrium 

 condition. 



Some types of currents, such as rip currents, may be controlled in spacing 

 by other parameters; i.e., edge waves or other wave height variations along 

 the shore, or the surf zone width. However, irregular nearshore topography, 

 which also may be manifest by shoreline protuberances, can produce 

 nearshore circulation (Sonu 1972). In such cases wave height variations may 

 not exist. Aerial photography may be helpful in assessing the location of 

 some types of currents, their patterns, and possibly their movement. Loca- 

 tions of rip currents can sometimes be detected using side-scan sonar if 

 characteristic channels have been scoured in the seafloor (Morang and 

 McMaster 1980). 



75 



Chapter 4 Investigation of Environmental Factors 



