Berenguer and Enriquez (1988) 



28. Berenguer and Enriquez (1988) developed design guidance for pocket 

 beaches, projects where sediment transport is laterally and frontally limited, 

 based on performance of 24 projects along the Spanish Mediterranean coast. 

 The authors noted that the longest alongshore distance between adjacent 

 salient/tombolos , L^ , was approximately twice the on-offshore distance 

 between the gap and shoreline (X + X^) , where Xg is the erosion/accretion 

 opposite the gap, measured from the original shoreline: 



L, = 2(X+ X.) (25) 



Relating this gap erosion distance to the length of gap, the authors found 

 that 



(X + Xg) = 25 + 0.85L^ (26) 



and 



X L^ = 2.5{X + XJ^ (27) 



where L^ is the alongshore center-to-center distance between adjacent 

 segments. Assuming a semicircular beach response in the area defined by 1^ 

 and X , the maximum surface area (i.e., beach fill) that could be stable S^ 

 can be calculated: 



S= 0.37 X L. (28) 



For values of Lgdg between 150 and 500 sq m, where dg is the depth at gap, 

 Berenguer and Enriquez developed a relationship to predict the gap erosion (X 

 + X ) given the average sediment size at the site D50 (Figure 5) . 

 Ahrens 



29. Ahrens extended the results of Berenguer and Enriquez (1988) by 



Personal Communication, 1989, John Ahrens, Research Physical Scientist, US 

 Army Engineer Waterways Experiment Station, Vicksburg, MS. 



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