Post-storm recovery : In all cases, a substantial berm was created which 

 is connected to the offshore by a broad trough. The upper foreshore of the 

 Bruun fills experienced more accretion than the artificial berm cases. These 

 results are consistent with the concept that the beach profile in a natural 

 shape can best respond to changes in the incident waves. 

 Eroded Volume and Contour Change 



In the discussion to follow, the 0-depth contour and the 1-m contour are 

 used as references (defined with respect to MSL) . It is proposed here that 

 both the 0-m and 1-m datums be used in future studies in reporting of results 

 storm-induced beach erosion. (Here, the 0.5-m contour was used as a substi- 

 tute for the 1-m contour for the Bruun fill example because of the low relief 

 of the fill in this particular case.) 



The 0-depth contour defines the lower boundary of the subaerial beach and 

 is a commonly used datum to define eroded volume and beach recession. 

 However, the shoreline position often acts as a pivot point through which sand 

 is transported; in fact, the shoreline position might even advance seaward 

 during a storm (Birkemeier, Savage, and Leffler 1988). Thus, a second refer- 

 ence is needed. Although this second contour is arbitrary, the authors 

 suggest the 1-m (3 ft) contour be used for this purpose. The advantages of 

 reporting eroded volumes and beach recession with respect to the 1-m contour 

 are (1) very small storms will not significantly impact this contour, so that 

 "noise" is eliminated from the analysis, and (2) post-storm recovery will be 

 limited at the 1-m contour, thereby avoiding a possible underestimation of 

 eroded volume and recession. Scheffner (1988, 1989) developed dune-erosion- 

 frequency of occurrence curves by using the maximum recession of any contour 

 on the profile between the 0-m depth and the dune crest. Maximum recession is 

 a good physical measure of beach erosion, but it may not be convenient for 

 issuance of permits. 

 Eroded volume 



Figs. 8 and 9 plot the time evolution of eroded volume above the 0- and 1- 

 m (and 0.5-m) contours. The eroded volume above the 0-depth contour increases 

 rapidly at the beginning of the pre-storm ("typical") wave action, describing 

 the behavior of the fill material during initial profile adjustment. In 



121 



