With a shoreline azimuth of 20 degrees , 





^ = (996.9 + 781.4 + 109.6) x 10^^ = 1.89 x 10^ m"^/year 

 south 



north 



= (28.6 + 631.2 + 1036.3 + 316.9) x 10"^ = 2.01 x 10^ m^/year 



(Qii) net = (qJ north " ^) south = ^'^^ x 10 m /year (north) 

 (Q,) gross =(Q£)north "^ K) south = ^.90 x 10^ m^/year 



Note that the computed values are suspect since the net longshore 

 transport is northward which is contrary to the field observations at the 

 adjacent areas (Table 4-6). Except for the net transport rate, the computed 

 values appear larger than those measured at various east coast locations. One 

 of the possible factors that contribute to this discrepancy is the wave data 

 used in the analysis. It is noted that hindcast wave data is for deep water 

 at a location approximately 240 kilometers east of the shoreline of 

 interest. Furthermore, energy dissipation due to bottom and/or internal 

 friction is not considered in the analysis. Consequently, higher energy flux 

 is implied in the sand transport computation. 



Since the hindcast wave statistics are available at an offshore location 

 approximately 10 kilometers off the shoreline of interest, analysis of 

 longshore sand transport should be based on this new data rather than on the 

 deepwater data listed in Table 8-4. By using the procedure shown in the 

 preceding calculations, the potential sand transport rates below are obtained. 



CO 



south 



north 



= 1.17 X 10 m /year 



= 0.66 X 10 m /year 



3 

 ^g^ = 510,000 m /year (south) 



gross 



= 1.83 X 10 m /year 



VI. BEACH FILL REQUIREMENTS 

 (See Ch. 5, Sec. 111,3) 



A beach fill is proposed for the beach south of Ocean City, Maryland. 

 Determine the volume of borrow material required to widen the beach 20 meters 

 over a distance of 1.0 kilometers. Borrow material is available from two 



sources. 



^ Station No. 32 (Corson et al., 1982). 



8-90 



