were generally lowest in northern sections of the study area, increasing rap- 

 idly southward towards Cape Romain and Charleston, and then decreasing towards 

 Savannah, GA. Wave power flux calculated from WIS data (Figure 5) mimics the 

 general trends of average wave height and period. A net increase in wave 

 energy flux of approximately 80 percent is evident from the northern end of 

 the study area to the southern end. This does not agree with Hubbard, Barwis, 

 and Nummedal (1977) and Nummedal et al . (1977), who based their conclusions on 

 1970 Naval Weather Service Command data Summary of Synoptic Meteorological 

 Observations (SSMO) . The WES investigators feel that the differences are a 

 result of the longer period of record and more frequent along-the-coast inter- 

 val of WIS data. 

 Tides 



13. The coast of South Carolina has been classified as mesotidal (2- to 

 4-m tidal range) by Hayes (1975) based on a classification system by Davies 

 (1964). Brown (1977) and Hubbard, Hayes, and Brown (1977) indicate mean tidal 

 range and spring tidal range increase towards the south along this coast (Fig- 

 ure 6) . Calculations based on predicted tide tables (US Department of 

 Commerce 1986) show an increase of 1 . 7 to 2 .4 m in maximum tidal range from 

 Wilmington, NC, to Charleston, SC, and an increase of 2.4 to 3.2 m from 

 Charleston to Savannah, GA. Overall, there is an 88 -percent increase in 

 maximum tidal range from north to south in the study area, while wave power 

 flux increased 80 percent from north to south. Finley (1978) describes the 

 tide at North Inlet as being semidiurnal, with a diurnal inequality averaging 

 0.37 m. Annual variations in tide level are also present (Figure 6). Annual 

 variation is due to a variety of factors including effects of storms. 



Storms 



14. Short-term increases in tidal height within the study area occur 

 with passage of storms. Coastal flooding is one of the most significant storm 

 damages in this area because adjacent land elevations are so low. The study 

 area is subject to late summer and fall tropical cyclones (minimum wind speed 

 of 64 km/hr) and hurricanes (minimum wind speed of 118 km/hr) , and extratropi- 

 cal northeast storms during winter. The scientific literature includes dis- 

 cussions of relative damages produced by northeast storms and tropical storms 

 along the east coast of the United States; however, most researchers (e.g., 

 Machemehl 1974; Myers 1975) contend that extratropical storms play a subordi- 

 nate role within this study area. Simpson and Miles (1971) report a 



17 



