DELILAH Time Exposure Videos and Runup Profiles
The time exposure video images
are the result of averageing 10 minutes of video images at a rate of 1 frame per second.
The camera used was a dissipation camera (camera #5 discussed in Appendix B of the full
DELILAH report). It allowed for a wide field of view and provided images of bar morphology.
The image files are in JPG format and are labelled by date.
Runup Profiles
The cross-shore position of the runup is determined from the runup edge position in the timestack image.
Image coordinates of the edge are directly related to a time series of vertical runup excursion. Runup
position in the timestack is found using edge detection algorithms combined with manual refinements when edge detection fails.
After the edge detection is completed, image coordinates of the runup edge are transformed to a
time series of vertical runup elevations. The 6-Hz timestack was decimated and saved as a 2-Hz
time series. Standard Fourier wave analysis techniques were used to compute vertical runup
spectra, runup wave height (Rmo), and peak period. Total record lengths were typically 119 min
and processed in 4096-point (2,048-s) segments that overlapped 50 percent. The resulting
spectra were smoothed in frequency with a 7-point band average, resulting in spectra with
frequency resolution of 0.0034 Hz. Runup spectra were analyzed at the FRF.
The wave runup spectra were divided into three wave frequency classifications;
infragravity (0.005 to 0.04 Hz), swell (0.04 to 0.15 Hz), and sea (0.15 to 0.5 Hz). These
divisions are not necessarily definitive. Infragravity waves, for example, can sometimes fall
within the swell frequency range. Total significant runup wave height (Rmo) is computed from
the sum of energy from all three wave bands (0.005 to 0.5 Hz).
The cross-shore range of runup was determined from each time series and is available
in the following table.
.
The files are in GIF format and labelled according to the dates included in the figure.
For example, runup profiles for 7 October through 9 October are found in file rnup0709.gif.
Mean runup position, mean water level recorded at the end of the FRF pier, beach slope,
the Irribaren number, and incident wave Hmo measured at the 8-m array are
listed in the figure.
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