N = Number of waves (storm duration) 



N s = Stability number, HJ&D^q 



N* s = Spectral stability number, H^/AD^q * s' m 



p = Sand porosity 



P = Structure permeability coefficient 



Pk = Longshore energy flux factor 



Q = Longshore transport rate 



Q N = Net longshore transport rate 



Q G = Gross longshore transport rate 



Q R = Longshore transport moving to the right from an observer looking 

 seaward 



Q L = Longshore transport moving to the left from an observer looking 

 seaward 



R = Correlation coefficient 



Rj,R 2 = Radii of the spiral curve (headland design) 



fl c = Crest freeboard, level of crest relative to still water 



R* = Dimensionless freeboard, R c /H s * (s op /2ir) a5 



S = Ratio of sediment of fluid density (2.65) 



S = Damage level, AJD^q 



S r = Specific gravity of armor unit (p a /p w ) 



s = Fictitious wave steepness, 2irH s /gT 2 



T e = Wave period corresponding to H e 



T = Peak wave period 



T z = Average wave period 



w r = Unit weight of armor 



W 50 = Weight of the 50 percent size in the gradation 



Appendix B Notation 



B3 



