L. Erikson et al. / Coastal Engineering 52 (2005) 285302
(presently with Han-Padron Assoc.) who was instru-
were predicted with a previously published empirical
mental to implementing the experiment. Mr. Lasse
Johansson at the Swedish Meteorological and Hydro-
The model was tested with data from a small wave
logical Institute kindly provided vessel generated
tank experiment conducted for this study. Energy
wave measurement data. We would also like to thank
spectra of the swash depth at the SWS indicate that
anonymous reviewers for detailed critiques of the
there is significant short wave energy remaining at
paper. Financial support from the Swedish Research
this point and thus it may be inferred that the model
Council and VINNOVA (as part of the project dThe
describing shoreline motion as a result of collapsing
interaction between large and high-speed vessels and
bores at the SWS is applicable. Wave groups
the environment in archipelagosT) is gratefully
consisting of increasing and subsequently decreasing
acknowledged. Support for the laboratory experiment
wave heights and representing idealized vessel gen-
was provided by the Coastal Inlets Research Program,
erated wave trains were employed in the experiment.
Results for four cases, one with a slope of tanb=0.20
Inlet Channels and Geomorphology Work Unit.
and three with slope tanb=0.07, are presented. Model
results show that there is significant improvement in
predicting the maximum run-up length if swash
interaction is accounted for on the milder slope cases.
The largest change in error associated with predicting
Baldock, T.E., Holmes, P., 1999. Simulation and prediction
the maximum run-up length is reduced from 117% to
of swash oscillations on a steep beach. J. Coast. Eng. 36,
7% (case B10) and the root-mean-square errors of the
entire time series for all three cases are substantially
Baldock, T.E., Holmes, P., Horn, D.P., 1997. Low-frequency
decreased. For the case with tanb=0.20 there is no
swash motion induced by wave grouping. J. Coast. Eng. 32,
improvement when swash interaction is accounted for.
Cross, R.H., 1967. Tsunami surge forces. J. Waterw. Harb. Div. 93
An equation predicting the duration of the up-rush
(WW4), 201 231.
and back-wash including effects of friction was
Erikson, L., Hanson, H., 2005. A method to obtain wave tank data
developed. The equation was applied to the laboratory
using video imagery and how it compares to conventional data
data for which it was found that the total swash
collection techniques. J. Comp. Geosci. (in press).
duration (up-rush plus back-wash) was predicted to be
Hibberd, S., Peregrine, D.H., 1979. Surf and run-up on a beach: a
uniform bore. J. Fluid Mech. 95, 323 345.
much longer than the incident wave period for the
Ho, D.V., Meyer, R.E., Shen, M.C., 1963. Long surf. J. Mar. Res.
cases with milder foreshore slopes (tanb=0.07). The
21, 219 230.
longer duration of the swash as compared to incident
Holland, K.T., Puleo, J.A., 2001. Variable swash motions associated
periods correctly predicts that there would be sub-
with foreshore profile change. J. Geophys. Res. 106 (C3),
stantial interaction between subsequent swash waves.
Hughes, M., 1992. Application of a non-linear water theory to
The total predicted swash duration for the case with a
swash following bore collapse on a sandy beach. J. Coast. Res. 8
steeper foreshore (tanb=0.20) was slightly less than
(3), 562 578.
the incident wave period. This was true for the most
Hughes, M., 1995. Friction factors for wave up-rush. J. Coast. Res.
part, with the exception of the first two waves of the
11 (4), 1089 1098.
packet which did meet up within the swash zone.
Hughes, M., Masselink, G., Hanslow, D., Mitchell, D., 1997.
Toward a better understanding of swash zone sediment trans-
port. Proc. Coastal Dynamics '97, pp. 804 813.
Irribarren, C.R., Nogales, C., 1949. Protection des ports. Sect. 2,
Comm. 4, 17th Int. Nav. Cong., Lisbon, pp. 31 80.
Johansson, L., 2000. Personal communication. Swedish Meteoro-
Many thanks to Dr. Steve Hughes, Coastal
logical and Hydrological Institute.
Kemp, P.H., 1975. Wave asymmetry in the nearshore zone
and breaker area. In: Hails, J., Carr, A. (Eds.), Nearshore
and Development Center (CHL) for providing the
sediment dynamics and sedimentation. Wiley-Interscience, New
code to generate waves in the laboratory tank, Dr.
York, pp. 47 67.
Nicholas Kraus, CHL for valuable discussions and
Kirkgoz, M.S., 1981. A theoretical study of plunging breakers and
providing access to the tank, and Dr. Atilla Bayram
their run-up. J. Coast. Eng. 5, 353 370.