168. Runup normalized by H rms for irregular waves was plotted versus 

 seaward bar angle in Figure 78. Runup values for monochromatic waves were 

 included in the plot to illustrate the differences between wave types. Runup 

 of irregular waves was higher than that of monochromatic waves of equivalent 

 deepwater wave steepness, which is attributed to some waves overtaking others 

 and causing a higher uprush, and the back wash of large waves obliterating the 

 incoming smaller waves, which results in measurements of only higher runup 

 events . 



0.30 



R/Ho and R/(Hrms)o 



































Ho/Lo 



0.25 





A 









0.09* 

 0.07" 

 0.05* 

 0.03' 

 0.0085* 



0.20 

 0.15 





~-x 









B^^ 3 — ~~— >-p&^ 



V 





- — -* 



-0- 



0.050 





.^^^ 





^ ' 





-A- 



0.030" 



0.10 



~w 





0.05 



■Jr-—^*^---® 







<b — 



i 



-07tf22 



i 



10 



15 



30 



Monochromatic waves 

 Irregular waves 



35 



20 25 



P, (cleg) 

 Figure 78. R/H^ as a function of f) 1 



40 



45 



Measurement Errors 



169. All tests were conducted with utmost care. However, some error 

 was introduced because of equipment limitations. 



170. A description of the data collection system used can be found in 

 Turner and Durham (1984) . Wave rods were calibrated before the first test of 

 the day using the microcomputer that collected the wave data. Calibration 

 began when a signal was sent from the microcomputer to the motors attached to 

 the wave rods. The signal caused the motors to move the wave rods a predeter- 

 mined vertical distance, and a voltage reading was taken by the rod at the 



141 



