Profile development is shown by contour movement plots (Figs. 12 to 
19) of the seawardmost contour intercepts for elevations at 0.1-foot 
depth increments from +1.1 to -2.2 feet. The heavier lines for the 
-0.9-foot contour distinguish the boundary between the foreshore and 
the offshore in the figures. 
(1) Foreshore Zone. 
(a) Experiment 72A-06. Within the first 5 hours the 
foreshore developed an equilibrium shape, as shown in the contour move- 
ment plots of the foreshore during the first 10 hours of experiment 
72A-06 (Fig. 20). Along each of the ranges, material eroded from the 
elevations below the SWL (-0.1 to -0.7 foot) and deposited above the 
SWL (+0.1 to +0.7 foot) to form a steeper beach face. The steepness of 
the beach face varied across the tank, as indicated by the close spacing 
(steep slope) along range 5 and the increased spacing (flatter slopes) 
along the other ranges. At 3 hours the -0.2- to -0.8-foot contours 
moved shoreward along range 1, indicating erosion, and seaward along 
ranges 3 and 5, indicating deposition; at 5 hours these contours moved 
back to approximately their position at 1.5 hours. 
The foreshore along each range retreated almost continually through- 
out this experiment, when examined on the time scale of Figures 12, 13, 
and 14. These figures show that although the foreshore maintained the 
same shape along each range, the slopes varied across the tank, increas- 
ing from range 1 to 5, but no long-term changes in slope occurred. The 
slope at the SWL intercept along each range is given in Table 7. The, 
difference in foreshore slope along the ranges at 90 hours is shown in 
Figure 21. 
Figure 22 is a photo of the wave runup on the foreshore at 130 hours 
in this experiment. The lateral variation in the slope of the foreshore 
developed as a result of a concentration of backwash along range 1, 
which created the flatter slope. Along range 5 the uprush that washed 
over the berm crest proceeded laterally across the tank and then washed 
back along range 1. The greater volume of backwash along range 1 inter- 
fered to a greater extent with the incident wave and thus reduced the 
uprush along range 1. 
The movements of the shoreline (or 0 contour) along the three ranges 
of experiment 72A-06 are compared in Figure 23. During the first 5 hours 
the foreshore advanced 0.5 foot (15.2 centimeters) seaward as the fore- 
shore developed and then. began a gradual landward movement at an average 
rate of 0.015 foot per hour (0.46 centimeter per hour). Between 110 and 
115 hours the shoreline along range 1 moved 1.3 feet in the seaward 
direction, and then between 115 and 125 hours moved 1.5 feet in the 
landward direction. 
(b) Experiment 72A-10. The foreshore shape developed as 
the result of erosion just below the SWL and deposition above the SWL 
(see Fig. 24, which compares the contour movements in the foreshore zone 
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