which would normally replace that lost to longshore currents has been 

 interrupted. 



Again, the concepts o£ beach erosion and the effects of structures 

 are intimately related to all facets of the preceding discussions. 

 Numerous examples of beach erosion and the effect of structures on 

 beaches are discussed in many of the references cited and in the proceed- 

 ings of the biannual coastal engineering conferences published by the 

 American Society of Civil Engineers. 



19 



