ArticlePDF Available

Evaluating the Impact of Beach Nourishment on Surfing: Surf City, Long Beach Island, New Jersey, U.S.A.

Authors:

Abstract and Figures

Utilizing the Cornell University Long and Intermediate WAVE (COULWAVE) Boussinesq wave model, the effect of the construction of a conventional beach nourishment project in Surf City, New Jersey, on the quality of the local surf break is examined in detail. A 20-year-long nearshore synthetic wave record is first developed for use in creating a monthly wave climate "almanac" so that typical seasonal effects on surf-break quality can be objectively portrayed. The wave model is then run with preconstruction bathymetric conditions, and with three postconstruction surveys performed in subsequent months. Construction of the nourishment project was found to affect the quality of the surf break adversely by (1) compression of the surf zone, (2) an increase in the occurrence of "closeouts," (3) a shift in breaker type toward collapsing breakers, particularly during high tide, and (4) an increase in wave reflectioncfindings that are in agreement with anecdotal testimony offered by local surfers. On the basis of modeling results conducted using the sequential postconstruction surveys and the wave almanac, it appears to have required nominally 21-22 months for the surf-break quality to return to preproject conditions. A paradigm shift in the design and construction of beach nourishment projects in the United States is required if such effects are to be avoided, and several options are offered and discussed.
Content may be subject to copyright.
Evaluating the Impact of Beach Nourishment on Surfing:
SurfCity,LongBeachIsland,NewJersey,U.S.A.
William R. Dally
*and Daniel A. Osiecki
Taylor Engineering Research Institute
University of North Florida
Jacksonville, FL 32224, U.S.A.
SonTek/Xylem, Inc.
San Diego, CA 92121, U.S.A.
ABSTRACT
Dally, W.R. and Osiecki, D.A., 0000. Evaluating the impact of beach nourishment on surfing: Surf City, Long Beach
Island, New Jersey, U.S.A. Journal of Coastal Research, 00(0), 000–000. Coconut Creek (Florida), ISSN 0749-0208.
Utilizing the Cornell University Long and Intermediate WAVE (COULWAVE) Boussinesq wave model, the effect of the
construction of a conventional beach nourishment project in Surf City, New Jersey, on the quality of the local surf break
is examined in detail. A 20-year-long nearshore synthetic wave record is first developed for use in creating a monthly
wave climate ‘‘almanac’’ so that typical seasonal effects on surf-break quality can be objectively portrayed. The wave
model is then run with preconstruction bathymetric conditions, and with three postconstruction surveys performed in
subsequent months. Construction of the nourishment project was found to affect the quality of the surf break adversely
by (1) compression of the surf zone, (2) an increase in the occurrence of ‘‘closeouts,’’ (3) a shift in breaker type toward
collapsing breakers, particularly during high tide, and (4) an increase in wave reflection—findings that are in agreement
with anecdotal testimony offered by local surfers. On the basis of modeling results conducted using the sequential
postconstruction surveys and the wave almanac, it appears to have required nominally 21–22 months for the surf-break
quality to return to preproject conditions. A paradigm shift in the design and construction of beach nourishment projects
in the United States is required if such effects are to be avoided, and several options are offered and discussed.
ADDITIONAL INDEX WORDS: Boussinesq wave modeling, nearshore wave climate, surfing, beach nourishment
design.
INTRODUCTION
Since the creation of the Beach Erosion Board in 1930 and
the participation of the federal government in funding project
construction beginning in 1946, beach nourishment has
become the most widely used remedial measure to combat
erosion problems along many shorelines of the United States
(NOAA, 2013). With the potential acceleration in the rise of
eustatic sea level (e.g., Church and White, 2006, 2011;
Grinsted, Moore, and Jevrejeva, 2009; IPCC, 2013; Jevrejeva
et al., 2008) coupled with indications of a possible increase in
tropical and extratropical storm intensity (Elsner, Kossin, and
Jagger, 2008; Emanuel, Sundararajan, and Williams, 2008),
beach nourishment will continue to be a prevalent method of
upland protection for the foreseeable future (see, e.g., Dean and
Houston, 2016; Houston, 2016). This is particularly true at
locations where the recreational amenities afforded by a
healthy beach are essential to the local economy. However,
common practice in beach nourishment design and construc-
tion in the United States is typically to widen the dry beach as
much as possible, while narrowing the surf zone and leaving an
unnaturally steep grade down to the nearshore profile
(National Research Council, 1995, p. 204)—usually on the
order of a 1:10 slope. The fill is then left to equilibrate in
response to the subsequent wave climate. Unfortunately until
this occurs, adverse effects can be experienced that include an
increase in the rate of serious injuries to bathers (see Puleo et
al., 2016, for a comprehensive review of surf zone injury
studies), as well as a marked deterioration in the quality of the
surf break available to recreational surfers. These effects are
investigated herein in a case study of a beach nourishment
project constructed in Surf City, Long Beach Island, New
Jersey.
Surf City Site Characteristics and Nourishment Project
Design
Surf City is located on Long Beach Island on the central
Atlantic coast of New Jersey, as indicated in Figure 1, which
also shows the broad continental shelf and other bathymetric
features of the region stretching from southern New Jersey to
Long Island, including the Hudson River Canyon. The spectral
wave modeling domains and locations of the wave gauges and
hindcast archive node utilized in this study are also indicated.
Almost the entire length of Long Beach Island (LBI), stretching
27.4 km (17 miles) between Barnegat Inlet to the north and
Little Egg Inlet to the south, is a federal beach nourishment
project. A typical cross section of the native beach and the fill
template as designed for LBI is provided in Figure 2 (USACE,
1999, p. 339). Although not fully completed until 2016, an
initial nourishment fronting Surf City and a portion of Ship
Bottom (to the south) was constructed between December 2006
and February 2007. It consisted of approximately 382,600 m
3
(500,000 yd
3
) of material having a typical mean diameter of
0.35 mm, dredged from an offshore borrow site and placed
along 2700 m (8850 ft) of shoreline, as is shown in the aerial
photograph in Figure 3, taken postnourishment in July 2007.
Figure 3 shows that the local shoreline is oriented nominally
318clockwise from true north (i.e. onshore normal of 1218). The
locations of local survey monuments, herein referred to as R-1
DOI: 10.2112/JCOASTRES-D-17-00162.1 received 18 September 2017;
accepted in revision 18 November 2017; corrected proofs received
4 January 2018; published pre-print online 5 February 2018.
*Corresponding author: w.dally@unf.edu
Ó
Coastal Education and Research Foundation, Inc. 2018
Journal of Coastal Research 00 0 000–000 Coconut Creek, Florida Month 0000
through R-8, are shown, as well as the domain used for the
Cornell University Long and Intermediate Wave (COUL-
WAVE) modeling applied in this study. The native beach sand
in the area has a mean grain diameter of 0.26 mm (USACE,
1999, p. 105), and the mean tide range is 1.3 m (4.3 ft), as
indicated in Figure 2.
Surfer Concerns
During the planning of the LBI beach nourishment project by
the U.S. Army Corps of Engineers, concerns were raised by the
New Jersey Chapter of the Surfrider Foundation with regard to
the potential effects of the project on the quality of the local surf
break (see, e.g., Kushner, 2006; Weaver, 2007). Herein, ‘‘surf
break’’ refers to depth-limited breaking waves and their
characteristics that determine their ‘‘surfability’’—most im-
portantly the peel rate and the maximum sustainable board
speed (Dally, 2001a,b; Walker, 1974). Other parameters such
as breaker type (spilling, plunging, or collapsing) and the shape
of the breaking wave face also contribute to the quality of the
break (Mead and Black, 2001). Surfing on Long Beach Island in
general, and Surf City in particular, is typically a ‘‘beach
break,’’ in which the surfers are spread out along the shore,
although there are a few favored spots associated with groins
found in the area. With regard to the LBI project, the surfers’
concerns were generally based on previous experience at a
nourishment project constructed in Long Branch, New Jersey,
located 90 km to the north, near NJ001 in Figure 1. Miller,
Mahon, and Herrington (2010) provide an overview of the Long
Branch project and an initial synopsis with regard to
surfability. The large quantity of berm fill material anticipated
(an average of 138 m
3
/m) and the steep beach face slope of the
design template (1:10) were of particular concern to LBI
surfers. It was contended that: (1) three-dimensional (3D)
nearshore bars and troughs, which contributed significantly to
the creation of surfable waves, would be covered by the fill; (2)
the surf zone would become compressed, thereby shortening
rides; (3) wave reflection would increase, which disrupts the
breaking process and makes waves difficult to catch; and (4) the
breaker type would shift toward collapsing breakers and away
from the more surfable plunging or spilling breakers, partic-
ularly at high tide.
The Corps of Engineers acknowledged these concerns, but
maintained that if these conditions did occur they would only
Figure 1. Map of study area showing bathymetric contours (in meters),
locations of Surf City, WIS station 250, NDBC buoy 44025, and nearshore
slope array NJ001. Boundariesof STWAVEþmodeling domainsare shown in
black (used in model calibration) and in yellow, green, and red (used to
develop the nearshore synthetic wave record).
Figure 2. Typical design cross section for LongBeach Island storm damage reduction projectshowing dune, berm, and beach face with 1:10 slope.Dimensions are
in feet (USACE, 1999). MHW ¼mean high water; MLW ¼mean low water.
Figure 3. Postnourishment aerial photograph of Surf City (July 2007)
showing locations of survey range monuments and boundary of the domain
used in COULWAVE modeling.
Journal of Coastal Research, Vol. 00, No. 0, 0000
0 Dally and Osiecki
be temporary and that they would abate as the fill equilibrated
in response to subsequent storms (Kushner, 2006). The purpose
of this investigation was to establish if the Surfrider concerns
were valid and, if so, how much time was required for surf-
break conditions at Surf City to return to normal, with the
intent of possibly modifying the design template or construc-
tion techniques to ameliorate problems as the remainder of the
LBI project was constructed.
METHODS
The first component of the study of the surf break at Surf City
was to assemble the available topographic/bathymetric survey
data for the nourishment project and to examine the behavior
of the fill subsequent to its placement. The second component
was to establish the natural nearshore wave climate for the site
so that any effects of the nourishment could be assessed
objectively (i.e. any negative effect on waves that would not
have been surfable anyway would not be included in the
assessment). The climate results would then be used to develop
a monthly wave ‘‘almanac’’ to be used in the third component of
the study, the surf zone wave modeling with COULWAVE.
Additionally, the surf zone wave modeling was supported by
digital terrain modeling that utilized both a preconstruction
bathymetric survey and a sequence of three postconstruction
surveys to identify and examine changes to surf-break
conditions. The final component of the study was to make
recommendations as to any feasible modifications to the project
design or construction with the intent of minimizing/amelio-
rating any negative effects found.
Available Survey Data and Postconstruction Behavior
of the Nourishment Project
Six sets of survey data were available forpotential use in this
investigation.Two were construction surveys, one conducted as
dredging operations progressed starting in December 2006
(prefill) and the other immediately after construction was
completed in February 2007 (postfill). Four were ‘‘condition’’
surveys conducted in October 2006, September 2007, May
2008, and November 2008. Beach profiles were surveyed using
standard terrestrial and hydrographic methods; however, the
spacing between profiles and their length varied with each
survey, as indicated in Table 1. Sample profiles from the six
surveys in the northern region of the project at R-1, R-2, R-3,
and R-4 are presented in Figure 4, and those for the southern
region at R-5, R-6, R-7, and R-8 are shown in Figure 5. Using
the prefill profile of December 2006 (dark blue line) as a
reference, the postfill survey of February 2007 (green line)
provides an indication of the volume of material placed in the
vicinity of each monument during the project. The beach at R-1
received significantly more material than the other cross-
section locations.
The sequence of the three remaining surveys on September
2007, May 2008, and November 2008 shows the subsequent
evolution of the fill. Comparison of the September 2007 profiles
(black) with their February 2007 postfill counterparts (green)
shows significant net loss of material from the beach face and
berm at R-1 and R-2. However the remainder of the profiles to
the south generally showed little change in the beach face but
with a gain of material between the 1-m and 2-m elevations
(possibly some material from R-1 and R-2). The September
2007 profiles also show little evidence of a distinct bar-and-
trough formation characteristic of beaches after the natural
recovery phase typically experienced during the summer
months (see, e.g., Plant et al., 1999), but also a likely result of
the fill not yet beginning to equilibrate. Comparing September
2007 to May 2008 (light blue), however, strong erosion of the
beach face dominates the project. The subsequent November
2008 profiles (magenta) indicate that the beach face remained
relatively stable, because this portion of the profile essentially
Table 1. AvailablebeachprofilesurveysfortheSurfCitybeach
nourishment project.
Survey Date
No. of
Profiles
Typical
Spacing (m)
Nominal
Length (m)
October 2006 22 100 450, 1500
December 2006
75 30 450
February 2007 75 30 450
September 2007
8 300 1500
May 2008 22 100 1500
November 2008 21 100 1000, 1500
Survey was conducted by the dredging contractor over several weeks in
support of construction activities and consequently was ill-suited for use
in DTM and COULWAVE modeling.
Profile spacing was too large for the DTM to resolve bathymetric features
potentially important to the surf-break assessment.
Figure 4. Pre- and postnourishment beach profiles in northern portion of
Surf City project (see Figure 3 for range monument locations) showing
infilling of the trough by thenourishment and subsequent gradual return to
a bar-and-trough shape. Vertical datum is NAVD88. MSL ¼mean sea level.
Journal of Coastal Research, Vol. 00, No. 0, 0000
Nourishment Impacts on Surfing 0
overlays the May profiles. However, the building of a longshore
bar in the middle of the project (R-3 to R-6) is notable, likely in
response to a moderate nor’easter that occurred from Novem-
ber 5 to 7, shortly before the November 2008 survey.
Development of a Nearshore Synthetic Wave Record
and a Local Wave Almanac
A proper assessment of the local nearshore wave climate at
Surf City would require many years, if not decades, of local
measurements to capture fully the seasonal and longer term
variability of waves at the site of the beach nourishment
project. The Stevens Institute of Technology operated a
nearshore pressure-based (nondirectional) real-time wave
gauge, located only 5.75 km to the south of the middle of the
Surf City project (see Herrington, Bruno, and Rankin, 2000).
The gauge was in operation for a total of approximately 4½
years, from May 1999 to August 2000 and October 2003 to May
2007 but often experienced malfunctions. Unfortunately the
record was not suitable for development of an almanac that
portrays the mean monthly characteristics of the nearshore
waves. Transformation of long-term directional spectra from
an offshore buoy would be a second option, particularly given
the availability of segments of the Stevens data for use in
calibrating and validating the transformation model; however,
no nearby offshore buoy data were available.
Because of this lack of reliable, continuous, long-term wave
data near Surf City, it was necessary to develop a nearshore
synthetic wave record (SWR) by using a long-term hindcast
archived in deep water and transforming the time series of
directional spectra to the project site using a suitable numerical
model, which is common recourse in coastal engineering
practice (USACE, 2002). Of the several deepwater Atlantic
wave hindcasts available, including, e.g., the MSC50 (Swail et
al., 2006) and WAVEWATCH III (Tolman and Chalikov, 1994),
the WIS hindcast (Hubertz, 1992; Resio and Perrie, 1989) was
chosen because it was a readily available Corps of Engineers
open source product 20 years in length (1980–1999) at the time
of this study. Although the WIS had been archived at high
spatial resolution along the 20-m depth contour (the black dots
in Figure 1), in studies in Florida it was discovered that
nearshore wave energy was significantly overpredicted by WIS,
particularly during storms and conditions of energetic long-
period swell, even at this depth, because bottom friction losses
were not included in the original WISWAVE model (see Resio
and Perrie, 1989). Consequently, as input to a spectral wave
transformation model that does include bottom friction losses,
an archive node from much deeper water—WIS 250 in 93 m
depth—was used (see Figure 1). Options for the nearshore
transformation model included, for example, SWAN (SWAN
Team, 2013), MIKE21 SW (Sørensen et al., 2004), and others.
However, a version of STWAVE (Smith, Sherlock, and Resio,
2001) that had been modified to include wave energy losses from
bottom friction in a reliable yet numerically efficient manner by
Dally and Osiecki (2006) was employed. This model (STWAVEþ)
was found to perform well in reproducing more than 4 years
(August 29, 2001 to December 31, 2005) of continuous nearshore
wave measurements in Melbourne Beach, Florida, when
MSC50 deepwater hindcast information was used as input
and the bed friction coefficient was locally calibrated (C
f
¼0.025;
Surfbreak Engineering Sciences Staff, 2008).
Bed Friction Calibration of STWAVEþ
Themajorissueinusingadeepwaterwavehindcasttodevelop
a nearshore or shallow water wave climate is the need to validate
the wave transformation model using local wave measurements
and to calibrate it for bottom friction losses, if necessary. This is
especially true if the waves cross expanses of rough, hard bottom
or a broad continental shelf when propagating from the
deepwater hindcast node to the shallow water site of interest,
asisthecasehere(see,e.g., Ardhuin, Herbers, and O’Reilly,
2001; Young and Gorman, 1995). A model validation of this type
requires two ‘‘paired’’ wave gauges at minimum—one in the
nearshore and one offshore, and both preferably directionally
capable. The nearshore gauge should be as close to shore as
possible, yet still outside the surf zone, even during the most
severe storms. Although ideally the offshore gauge would be
collocated with the deepwater hindcast node, it should at least be
located in water sufficiently deep that local bottom friction losses
are minimized (Dally, 2017). For this exercise, the only suitable
wave data sources that were available in the region were (1)
National Data Buoy Center (NDBC) station 44025, which is a
directional 3-m discus buoy deployed 110 km northeast of Surf
City at a depth of 41 m (Figure 1), and (2) a nearshore slope array
wave gauge that was located near Long Branch, New Jersey, 90
Figure 5. Pre- and postnourishment beach profiles in southern portion of
Surf City project (see Figure 3 for range monument locations) showing
infilling of the trough by thenourishment and subsequent gradual return to
a bar-and-trough shape. Vertical datum is NAVD88. MSL ¼mean sea level.
Journal of Coastal Research, Vol. 00, No. 0, 0000
0 Dally and Osiecki
kmnorthofSurfCityin8mdepth(labeledNJ001inFigure1).
Although NJ001 and NDBC 44025 are located near the northern
end of New Jersey, to proceed, the bottom friction characteristics
are assumed to be similar near Surf City. Operated by the Corps
of Engineers from late 1991 until late 1999, the record from
NJ001 did contain significant gaps in all years except 1998 and
1999. Fortunately, the NDBC directional buoy was originally
deployed in 1997, and both the buoy and the slope array
measured on an hourly basis with a fairly good data capture rate
from November 1997 to November 1999. Following the method-
ology of Dally and Osiecki (2006), these data were screened for
times when dissipation from bottom friction was expected to be
significant, yielding 3917 suitable concurrent wave measure-
ments from the two locations. STWAVEþwas then configured
using the domain bounded by the solid black line seen in Figure
1, with a cell size of 150 3150 m to fully resolve the complex
nearshore bathymetry in this region. The directional spectra at
the buoy were reconstituted using the archived Fourier
coefficients (Longuet-Higgins, Cartwright, and Smith, 1963;
NOAA, 2017), and with this as input, STWAVEþwas run over a
range of friction factors. Again, following the procedure of Dally
and Osiecki (2006), the measurements at NJ001 were then used
to select a single reasonable value for the friction factor, C
f
¼
0.031, on the basis of wave energy dissipated between the two
measurement locations.
Generating the Nearshore SWR
With the bed friction factor for the nearshore region selected,
the nearshore SWR could be generated. Again, the goal of
developing the SWR is to establish the long-term surf climate
at Surf City as objectively as possible. The final assessment of
the effect of the beach nourishment on surfing will rely on a
subset of representative waves derived from the 20-year SWR.
This exercise removed much of the subjectivity that might be
introduced by estimating the local surf climate by other, more
anecdotal means. Because the deepwater hindcast node WIS-
250 is located nominally 130 km offshore, a triple-grid domain
scheme was employed to economize CPU requirements during
production runs. The boundaries of the three domains are
indicated in Figure 1. The offshore domain (yellow box)utilized
a square 500-m cell size, the middle domain (green box) a 300-m
cell size, and the nearshore domain (red box) a 100-m cell size.
The bed friction coefficient was set at 0.031 throughout all
three domains, although only very large, long-period swells
would be influenced by bottom friction at the depths in the
outer domain (40–90 m). Wind generation was included, using
the speed and direction record from the WIS station and
assuming uniformity over the region. Even with the economy
afforded by the system of nested grids, the directional wave
spectra in the WIS database were archived at 3-hour intervals
for a total of eight samples per day for 20 years, for a total of
58,440 model runs. However, because STWAVE is a second-
generation model, in which wave-wave interactions are
parameterized rather than computed explicitly, it is signifi-
cantly faster than, e.g., SWAN or MIKE 21 SW. Also, because
STWAVE is a steady-state model, the runs could be divided
between multiple individual computers, which rendered the
computational effort manageable without the need for high-
performance computing.
Application of COULWAVE
As discussed earlier, the use of WIS was most appropriate in
deep water, whereas STWAVEþwas better suited for trans-
forming directional wave spectra across the continental shelf
for developing the nearshore SWR and almanac. However, to
investigate the issues raised by the surfers, it was necessary to
use a phase-resolving time domain model that inherently
contains the effects of wave nonlinearity, asymmetry, break-
ing, reforming, and reflection as waves pass into and through
the surf zone over barred profiles. COULWAVE (ISEC, 2008)
was selected, being one of a rich heritage of Boussinesq models
that have been successfully applied to a variety of shallow
water wave problems (e.g., Chen et al., 2000; Kennedy et al.,
2000; Madsen and Sch¨
affer, 1998; Nwogu, 1993; Sch¨
affer,
Madsen, and Deigaard, 1993; Wei et al., 1995). COULWAVE is
open source, well documented, and readily available (ISEC,
2008). With the use of (1) bathymetric surveys of the Surf City
nearshore zone conducted both before and after the nourish-
ment was constructed and (2) appropriate wave characteristics
provided by the almanac as boundary conditions (i.e. signifi-
cant height, peak period, and mean direction), specially created
animations of the free surface were generated using COUL-
WAVE output. In developing the animation software, an
‘‘aerated roller’’ was added graphically as an embellishment
to the animation at any time when, and location where,
COULWAVE dictated wave breaking to occur. This aided
greatly in the interpretation of the results. Close scrutiny of the
animations allowed the effects of the nourishment project on
the surf break to be identified and studied in detail.
COULWAVE Breaking Algorithm
Before applying the COULWAVE model to the issue of beach
nourishment effects on surfing conditions, some description
and discussion of the model’s treatment of wave breaking is
warranted. As described in Lynett and Liu (2008), the breaking
scheme in COULWAVE follows that of Chen et al. (2000) and
Kennedy et al. (2000), which is an ‘‘eddy viscosity’’ approach in
which ad hoc, but momentum-conserving, dissipative terms
are introduced in the governing equations. Local eddy viscosity,
m, is calculated as:
m¼Bðh0þfÞft¼Bhftð1Þ
in which, h0is the still-water depth, fis the free surface
displacement, his the instantaneous total water depth, and
the subscript tdenotes the local derivative with respect to
time. Bis a variable introduced to ensure a smooth transition
between breaking and nonbreaking states:
B¼
d;ft2fb
t
dðft=fb
t1Þ;fb
t,ft2fb
t
0;ftfb
t
8
<
:
ð2Þ
in which, dis an amplification factor and the parameter fb
t
determines the triggering and cessation of breaking and is
given by:
fb
t¼
fðFÞ
t;tt0Tb
fðIÞ
tþtt0
TbfðFÞ
tfðIÞ
t;0tt0,Tb
8
>
<
>
:
ð3Þ
Journal of Coastal Research, Vol. 00, No. 0, 0000
Nourishment Impacts on Surfing 0
where, fðIÞ
tis the initial free surface transient threshold that
must be exceeded for a breaking event to start, fðFÞ
tis the
minimum transient required for breaking to continue, tis the
local time, t
0
is the time breaking started, and T
b
is a
transition time. Basically, breaking is both triggered and
stopped on the basis of the local acceleration of the free
surface. Lynett and Liu (2008) utilized the measurements of
Buhr-Hansen and Svendsen (1979) from five laboratory tests
of regular waves breaking on a planar beach of 1:34 slope to
determine optimum values of the four free parameters: d¼
6.5, fðIÞ
t¼0.65 ffiffiffiffiffi
gh
p,fðFÞ
t¼0.08 ffiffiffiffiffi
gh
p, and T
b
¼8.0 ffiffiffiffiffiffiffiffi
h=g
p. None of
the Boussinesq models, including COULWAVE, are capable
of replicating the overturning of the wave face associated
with plunging breakers, but one plunging breaker and one
plunging-spilling breaker were reported in the tests of Buhr-
Hansen and Svendsen and are included in the calibration of
COULWAVE. Also, it is unknown whether the calibration of
the breaking parameters is sensitive to changes in the bottom
slope. In examining the prefill profiles of Figures 4 and 5, the
slope seaward of the bar ranges between 1:20 and 1:32 and is
typically 1:25 (i.e. slightly greater than the 1:34 slope of the
Buhr-Hansen and Svendsen tests). Even with this issue
unresolved, COULWAVE appears to be an acceptable tool for
the purposes of conducting this type of investigation.
Digital Terrain Modeling
A digital terrain model (DTM) was first used to construct a
3D rendering of the topography/bathymetry from the raw
data for each survey, and the viability of each was assessed.
The effects of line spacing on the ability to resolve features of
the beach and nearshore bar were readily apparent, and the
effect of any gaps or holes in the data coverage were obvious.
In selecting surveys for use in the COULWAVE modeling, the
December 2006 construction survey, performed over several
weeks in support of the dredge-and-fill activities, was ill
suited to use as a ‘‘snapshot’’ rendering of the bathymetry, as
well as having missed significant sections of beach (see, e.g.,
Figure 5, R-7). In comparing the October 2006 profiles to
those of December 2006 in Figures 4 and 5, the two surveys
mimic each other, except in the northern section, where the
beach face experienced accretion after the October survey.
Nevertheless, the October 2006 survey is a reasonable
representation of the preproject beach condition. The DTM
results also showed that the profiles of the condition survey of
September 2007 were too widely spaced in the longshore
direction (~300 m, Table 1) to capture the bathymetry in the
detail desired. As the results below will show, the remaining
four surveys each had concurrent profiles with sufficiently
close spacing in the longshore direction (100 m) to resolve
major features for Boussinesq modeling purposes. In prepar-
ing the COULWAVE grid, the DTM bathymetry for each of
the four surveys was first edited to remove any erroneous
abrupt changes in depth, and then smoothed to remove any
artificially sharp structure induced by the DTM. A 1280-m
longshore by 450-m cross-shore (4200 31500-ft) section was
then clipped from the middle of the project, as indicated in
Figure 3. The grid cells were sized 0.5 m in the cross-shore
and 1.0 m in the longshore direction, and a time step of 0.7 s
was adopted.
RESULTS
Outcomes from the three major components of the study are
presented below. First, the results from the 20-yr nearshore
SWR are utilized to produce characterizations of the typical
wave climate for each month of the year, and then the
surfability of each month is quantitatively assessed. Finally,
using the typical surfable nearshore wave conditions as the
seaward boundary condition, COULWAVE results are then
presented for the preproject bathymetric conditions and for
three postproject conditions.
The Nearshore SWR and Wave Almanac
Archived results from a SWR node located in the center of
the Surf City project, in nominally 8 m depth, were used to
develop a wave almanac for Surf City. By sorting the SWR
results by month, typical wave conditions for each month
could be established. The left-hand side of Table 2 presents
the monthly averaged significant wave height (
Hmo), month-
ly averaged peak wave period ( ¯
Tp), and monthly averaged
mean wave direction (¯
hm)foralloftheresultsfromtheSWR.
Mean wave direction (h
m
) is defined as the direction from
which waves approach, in degrees clockwise from true north
(shore-normal waves have a nominal direction of 121
degrees). Seasonality is found in all three parameters, with
June, July, and August experiencing smaller, shorter period
waves that tend to approach from the south. With regard to
depicting typical surfing conditions, however, average con-
ditions are not appropriate, simply because the ‘‘average’’ at
Surf City is too small to provide a good ride. To screen the
SWR for times when the waves are more surfable, wave
height thresholds were selected, and the screened results
were then examined separately. A monthly ensemble ac-
counting of the total number of occurrences of significant
wave heights greater than 1.0, 1.5, and 2.0 m is presented in
Figure 6, and it was found that, on average, these larger wave
conditions occur a total of 340 times/y (i.e. equivalent to 42.5
days/y), 55 times/y, and 5 times/y, respectively. Inquiries
made of lifeguards and at local surf shops established that
surfers were in the water at Surf City under ‘‘decent’’
conditions at least 50 days/y, so the 1-m threshold was
selected for further consideration. That is, the two higher
Table 2. Surf City monthly wave almanac and surfing climate based on 20-
year nearshore synthetic wave record.
All Waves
Surfing Sessions
(H
mo
1.0 m)
Hmo
(m)
¯
Tp
(s)
¯
hm
(deg)
Avg. No. of
Sessions
H*
mo
(m)
¯
T*
p
(s)
¯
h*
m
(deg)
January 0.63 9.3 124.0 21.0 1.28 9.5 122.8
February 0.64 9.2 122.4 18.6 1.24 9.3 123.0
March 0.65 9.3 123.5 19.5 1.27 9.3 125.4
April 0.62 8.5 125.2 15.7 1.23 8.6 126.1
May 0.60 7.8 124.9 10.0 1.17 7.9 124.2
June 0.51 7.0 130.3 4.3 1.15 7.7 122.3
July 0.48 6.7 137.0 4.3 1.19 8.0 129.8
August 0.54 7.2 127.4 7.6 1.26 9.6 123.4
September 0.65 8.6 121.5 19.0 1.21 10.8 121.7
October 0.59 8.7 118.9 14.8 1.25 9.3 121.4
November 0.62 9.0 122.5 18.1 1.29 9.5 123.4
December 0.59 9.4 122.2 17.2 1.26 9.4 122.4
Bold indicates wave conditions used in COULWAVE modeling.
Journal of Coastal Research, Vol. 00, No. 0, 0000
0 Dally and Osiecki
thresholds were too restrictive to characterize typical surfing
days fairly at Surf City. Although surfing may take place at
Surf City when H
mo
,1.0 m, for the purposes of assessing the
effect of the nourishment project, this threshold was
considered to be suitable. The WIS/SWR information was
archived every 3 hours, which is held to be an interval
suitable for the purposes of characterizing a particular
‘‘surfing session.’’ Assuming that half the occurrences are
at night, in the right-hand section of Table 1, the average
number of surfing sessions when H
mo
1.0 m is presented by
month, along with the concomitant averages of the wave
parameters, denoted as
H*
mo;¯
T*
p;and ¯
h*
m:Again, the
seasonality in the surf-break climate is clearly evident. From
these results, wave conditions were selected for the Boussi-
nesq wave modeling described herein.
COULWAVE Results
Figure 7 presents a frame grab from the animation
developed using the October 2006 survey, with the average
surfable wave conditions taken from Table 1 for the month of
October (i.e.
H*
mo ¼1.25 m, ¯
T*
p¼9.3 s, and ¯
h*
m¼121.48). These
conditions were input as a train of regular cnoidal waves at
the outer boundary, using the ‘‘ sponge layer’’ option in
COULWAVE to absorb the fictitious outgoing wave (Lynett
and Liu, 2008). The tide stage was taken to be 0.0 m NAVD88,
which is nominally 12 cm above mean sea level. The upper
panel presents a plan view of the bathymetric contours and
the breaking wave pattern, whereas the lower panel is a cross
section of the beach profile and the results from a transect in
the middle of the domain (dashed line in the upper panel). All
of the frame grabs presented herein were captured at or near
the exact time step when the roller first appeared in the outer
surf zone on the transect, indicating the location where a
surfer might have caught the wave (e.g., cross-shore distance,
x@275 m in Figure 7). At this instant in Figure 7, three
waves are seen in the surf zone, which was nominally 100 m
wide, with the nonbreaking wave at the beach face actually
on the verge of collapsing into runup. Although the upper
panel shows that the long-crested regular wave essentially
‘‘closed out’’ because it approached almost directly onto a
nearly linear bar, any longshore nonuniformity in the
incoming wave crest from randomness in the wave field
would cause the wave to break in sections, some of which are
likely to be surfable. Nonuniformity in the profile trough
caused waves to stop breaking and reform in distinct zones
landward of the bar. Close examination of these zones show
they are associated with deeper spots in the trough, (i.e.
where holes existed), making waves in the inner surf zone
more surfable, but with rides short in duration. Some
evidence of wave uncoupling into small, higher harmonics
(Dingemans, 1994; Gobbi and Kirby, 1999) is seen in the
lower panel at x@265 m and at 300 m. As the run-down of the
swash takes place in the animation, a small reflected wave is
generated but is quickly dissipated as it encounters the
incoming shore break.
Figure 8 presents a frame grab from the animation for the
postconstruction survey of February 2007, in which the
widening of the beach and infilling of the nearshore trough
by the nourishment is clearly seen in both the upper and lower
panels. The incident wave conditions from the almanac in
Table 1 are very similar to those from October (i.e.
H*
mo ¼1.24
m, ¯
T*
p¼9.3 s, and ¯
h*
m¼123.08); however, the effects of the fill on
the surf break are striking. In the left-hand half of the domain
in the upper panel, only two waves are in the surf zone, which
in this region is nominally only 48 m wide, and in the right-
hand half, only one breaking wave is in the surf zone, which is
only 20 m wide or less. In the animation from which the lower
panel is taken, increased wave reflection is evident, which does
appear to increase momentarily the intensity of the breaking
process in the outer surf zone as the incident and reflectedwave
pass through one another.
Figure 9 presents a frame grab from the animation for the
survey conducted in May 2008, in which the dry beach is still
wide, but the nearshore bathymetry is irregular and contains
significant 3D features (but no trough), as is common for the
spring. Although the waves in May are typically smaller and
Figure 6. Monthly almanac of Surf City significant wave height developed
from a 20-year nearshore synthetic wave record, providing average number
of occurrences of exceedance for 1.0, 1.5, and 2.0-m waves. Seasonality in the
wave climate is clearly evident.
Figure 7. Frame grab from the COULWAVE animation for the October 2006
survey (i.e. prenourishment) using incident wave conditions for October
taken from the almanac presented in Table 1. At initial breaking, the waves
tend to close out on the nearly linear seaward face of the barand then reform
in irregular depressions in the trough. Note that the surf zone is nominally
100 m wide.
Journal of Coastal Research, Vol. 00, No. 0, 0000
Nourishment Impacts on Surfing 0
shorter than in the winter (
H*
mo ¼1.17 m, ¯
T*
p¼7.9 s), they
approach more obliquely from the south ¯
h*
m¼124.28and,
coupled with the irregular bathymetry, create conditions more
favorable for surfing, with several areas where the waves do
not close out (e.g., longshore distance y@120, 300, 420, 640,
and 1000 m). At the location of the transect ( y¼640 m),
although not quite three waves are in the surf zone (now 65 m
wide), other places contain three waves in which the surf zone
is approximately 75 m wide, attributed to the shorter wave
period compared with Figure 7.
Figure 10 presents a frame grab from the animation for the
survey conducted in November 2008 shortly after a nor’easter,
in which a distinct bar-and-trough formation has returned (see
Figures 4 and 5), and with
H*
mo ¼1.29 m, ¯
T*
p¼9.5 s, and ¯
h*
m¼
123.48, once again, three waves are in the surf zone, which is
nominally 100 m wide. Compared with Figure 7, however, one
can see that the bar crest is now slightly higher in elevation
(1.5 m vs.2.0 m), as is the bottom of the trough (2mvs.2.5
m), and incipient breaking occurs at x@260 m. The bathymetry
offshore of the bar crest is essentially linear and although not
fully closing out, the slightly oblique waves have a high peel
rate (~140 m/s), except in two locations (y@400 and 800 m),
where it momentarily slows to ~45 m/s, but which is still not
surfable (Dally, 2001a). At x@300 m the waves do reform, and
breaking ceases as they pass into the trough, before breaking
again at the beach face.
DISCUSSION
The COULWAVE modeling results appear to confirm the
observations and concerns of the surfing community, at least
with regard to the immediate effects of the Surf City project.
For ease of comparison, the transect results from Figures 7–
10 are compiled and enlarged in Figure 11. Referring also to
Figure 8, the findings for the immediate postfill modeling
exercise show (1) the effects of infilling of the holes and the
nearshore trough and creation of a longshore-uniform beach
face and inner surf zone, (2) a greatly compressed surf zone,
which results in significantly shorter rides, (3) evidence of
increased reflection, which makes the waves more difficult to
catch, and (4) energetic collapsing breakers at the beach face,
which are expected particularly to dominate at high tide (not
shown) and are unsurfable, as well as dangerous to bathers
(Puleo et al., 2016). The entire gamut of surf-break param-
eters, such as surf zone width, peel rate, sustainable board
speeds, ride duration, and wave reflection, could conceivably
be quantified using COULWAVE. However, to generate more
realistic surfing conditions, randomness in height, period,
and direction should be introduced and the tide elevation
varied.Suchanendeavorwasbeyondthescopeofthis
nascent investigation and is left for future work.
With regard to the duration of the effects of the nourish-
ment on the quality of the surf break, in examining the
November 2008 results, Figure 11 shows that the shape of the
subaqueous beach profile and the character of the surf zone
have returned to that of the preproject conditions of October
2006. In fact, if the October 2006 transect is shifted
approximately 25 m offshore, such that the waves in the
outersurfzonearealigned,thetwosurfzonesappear
identical. In Figure 12, the bathymetries for the four
COULWAVE runs are presented along with their respective
zones of wave breaking shaded in yellow. The effect of the fill
Figure 8. Frame grab from the COULWAVE animation for the February
2007 survey (i.e. postnourishment) using incident wave conditions for
February taken from the almanac presented in Table 1. The effect of the fill
on the character of the breaking waves is striking, with only one or two
waves in the surf zone, which is now only 15–50 m wide.
Figure 9. Frame grab from the COULWAVE animation for the May 2008
survey using incident wave conditions for May taken from the almanac
presented in Table 1. With now two or three waves in the surf zone, the
quality of the surf break is significantly enhanced by 3D bathymetry.
Figure 10. Frame grab from the COULWAVE animation for the November
2008 survey using incident wave conditions for November taken from the
almanac presented in Table 1. The seaward face of the bar has returned to a
longshore-uniform shape, with waves tending to breakin long segments and
then reforming in patchy depressions in the trough. Note that the surfzone is
once again nominally 100 m wide and contains three waves.
Journal of Coastal Research, Vol. 00, No. 0, 0000
0 Dally and Osiecki
in February 2007 is striking, and the similarity between
October 2006 and November 2008 is notable. Albeit the
number of surveys available was limited, it appears that it
required nominally 21–22 months (February 2007 to Novem-
ber 2008) for the fill to equilibrate and for surfing conditions
to return to their normal state. If more frequent profile
surveys with tighter longshore resolution (e.g., 30 m) were
available both before and after nourishment, coupled with
detailed postconstruction nearshore wave information that
could be compared with the long-term climate, more
definitive conclusions might be reached.
One additional complicating factor in judging the perfor-
mance and effects of the Surf City project is that the fill
material was significantly coarser than the native sand (0.35-
mm fill vs. 0.26-mm native), which is likely to contribute to a
steepening of the postproject equilibrium slope of the beach
face (see, e.g., Sunamura, 1984), of which there is some
evidence in Figures 4 and 5. Coarser material might also
steepen the subaqueous profile (see, e.g., Dean, 1991), and
both of these changes in the profile could conceivably be
permanent. The coarser sediment is also likely to lengthen
the time required to equilibrate to the new profile shape
(Kriebel and Dean, 1993). Benedet, Pierro, and Henriquez
(2007) reported that the placement of coarse material on
Copacabana Beach, Brazil, made the beach so reflective that
it ruined the surf break completely.
Bar Morphology and Surfing Conditions
In addition to establishing the immediate effects of beach
nourishment on the quality of the surf break and the time
required for surfing conditions to return to normal, several
other interesting findings are made evident by the COUL-
WAVE results. First, the best conditions for surfing would
appear to be in the spring when the nearshore bathymetry is
highly 3D and the longshore trough is filled in. Under these
conditions, the incoming waves are less likely to close out, and
the surf zone is wide enough to permit a reasonably long ride in
several locations, as is evident for the May 2008 survey (Figure
9 and the third panel of Figure 12). However, although surfing
conditions have improved since the postfill conditions in
February, it is unknown whether they have returned to
‘‘normal’’ for this time of year. Unfortunately, in the summer
(June, July, and August), the wave energy drops dramatically,
as indicated in the almanac of Figure 6. In examining
nearshore bar morphology inferred from 2 years of time
exposure images of incident wave breaking at the U.S. Army
Corp of Engineers (USACE) Field Research Facility in Duck,
North Carolina, Lippmann and Holman (1990) found that
rhythmic bars were observed in 68% of the data and were the
most stable features, with a mean residence time of approxi-
mately 11 days. Linear bars formed rapidly (,1 day) under the
highest wave conditions (
Hmo 1.8 m) but were unstable, with
a mean residence time of nominally 2 days, followed by the
formation of rhythmic bars in the subsequent 5–16 days as the
beach recovered. Although the longshore resolution of the
survey of Surf City in September 2007 was insufficient to
document the bathymetry in detail and conduct COULWAVE
modeling, from the findings of Lippmann and Holman (1990), a
three-dimensional structure could be expected to persist. Given
the notable increase in wave energy that typically occurs in
September (Table 1), the surfing should be at its best at this
time. However, as storms become more frequent in the fall and
winter, the nearshore bars become linear and move offshore
(October 2006, November 2008) and the surfability of the waves
is dependent on them being short-crested to some degree to
preclude closeouts (Dally, 1990, 2001b).
Recommendations for Template Modification and the
Prospects for Rainbowing
Close examination of Figures 4 and 5 reveals that the 1:10
slope of the beach face of the nourishment fill as designed is
not unlike the natural slope seen in both the pre- and
postnourishment profiles. The adverse effects on the quality
of the surf break are therefore attributed to the fact that
Figure 11. Stacked plot of COULWAVE transect results demonstrating the initial effect of the nourishment project on the character of the surf break (February
2007) and the gradual return to essentially natural conditions (November 2008). Note that although a bar-and-trough formation has returned, it is slightly
elevated (~0.5 m) from the preproject condition in October 2006.
Journal of Coastal Research, Vol. 00, No. 0, 0000
Nourishment Impacts on Surfing 0
essentially no material was placed seaward of the toe of the
1:10 slope, as was apparently intended in the design drawing
of Figure 2. This lack of ‘‘profile placement’’ is responsible for
all four of the concerns voiced by the surfing community.
Consequently, in addition to construction of a dune and wide
beach berm fronted by a steep slope, additional dredged
material should be placed as low on the profile as possible,
taking advantage of low tide in particular, and groomed to a
milder slope to broaden the surf zone as much as possible.
Although any volume placed in the surf zone most likely is
not as effective for storm protection as that placed on the
upper beach, current design practice almost unilaterally
embraces the placement of additional ‘‘ advance fill’’ on the
upper beach that is expected to equilibrate (i.e.move
offshore) during the first few years after construction
(USACE, 2002). This material should be placed into the surf
zone at the end of project construction, where it is intended to
end up anyway. However, the existence of any nearshore
hard-bottom habitat may preclude such profile placement.
Also, as opposed to placing the material in a longshore-
uniform manner, material placed in a series of mounds or
salients is recommended, perhaps leaving gaps in less
vulnerable sections to stimulate temporarily the 3D bathym-
etry favorable to surfing (see Dally and Osiecki, 2007).
Unintended consequences, such as rip current generation,
must be anticipated and investigated during design. If
material is to be placed directly in the subaqueous profile,
pay volumes might have to be determined from surveys of the
Figure 12. Plan view of COULWAVE results with zones of wave breaking shaded in yellow. Compression of the surf zone is pronounced in February 2007,
especially between 750 and 2000 m longshore. The 3D structure in the bathymetry of May 2008 appears to be the most favorable for surfing. The breaking and
reforming pattern in November 2008 is notably similar to the preproject condition in October 2006.
Journal of Coastal Research, Vol. 00, No. 0, 0000
0 Dally and Osiecki
borrow area rather than the project area. Although any
salients or subaqueous mounds are expected to be only
temporary, endorsement of future nourishment projects by
the surfing community is probable.
The single most technically feasible means of profile
placement presently available is the ‘‘rainbow’’ placement
technique, in which the loaded dredge is positioned as close to
the beach as possible (often with its bow grounded), and the fill
material is ejected in an arc from a nozzle on the ship’s bow (see
Van de Velde, 2008). In fact, if the entire project were
constructed by rainbowing, significant cost savings could be
realized because there would be no need for discharge pipeline
and no essential need for earthmoving equipment and
subsequent tilling that might be required for sea turtle nesting
habitat (K. Bodge, personal communication; W. Hanson,
personal communication). Although perhaps technically feasi-
ble, rainbow placement of a beach nourishment project not only
requires a specialized dredge or off-loading equipment, but
other issues could preclude its use. Turbidity is a major
concern, in that any fine material encountered in the borrow
area by the dredge can create plumes that, if not contained, can
spread over large areas and persist for long periods of time.
Such plumes can be harmful to fish and coral reefs (Greene,
2002; PIANC EnviCom Working Group 108, 2010; Salahuddin,
2006). Nevertheless, in Florida, permits allowing rainbow
placement have been issued for inlet bypassing and beach
nourishment in a limited number of instances by the
Department of Environmental Protection (R. Brantly, personal
communication). Rainbow placement is also commonly used on
the beaches of The Netherlands. It was also used on a massive
scale in island-building and land reclamation in Dubai, but
some harmful environmental consequences occurred (Salahud-
din, 2006).
The rainbowing technique is presently being utilized on the
Gold Coast of Queensland, Australia, in which 3 million m
3
(3.9
million yd
3
) of material is being been placed in nearshore
mounds shoreward of the 8-m contour along an 11-km stretch
of shoreline (see Sanders, 2017). Initial reaction from the local
surfing community has been highly favorable, because the
mounds have created impressive surf breaks along a coast that
normally experiences closeout beach break. The material from
the borrow area is apparently very clean sand, because no
complaints of turbidity have been reported (Sanders, 2017).
The cost of the project is $13.9 million (i.e. $4.6/m
3
[$3.5/yd
3
]),
which is substantially less than the typical cost of pipeline
placement on the dry beach. The mounds are to bemonitored by
survey in the coming months to see whether they migrate
onshore as intended.
As a final note, Mesa (1996) reported that enhanced surf
break was created by a nearshore berm constructed in 1992 at
Newport Beach, California. The berm, composed of 976,300 m
3
(1,276,000 yd
3
) of sand, was hydraulically placed in the
nearshore, between the elevations of 1.5 and 9.1 m (5and
30 ft) mean lower low water. Subsequent monitoring of the
berm indicated a pervasive shoreward migration, with little
dispersion in the longshore directions. Although not specifically
configured to enhance surf break, onshore migration of
nearshore berms placed with the intent of feeding adjacent
beaches is well documented at many places (see, e.g., Beck,
Rosati, and Rosati, 2012, for an overview).
CONCLUSIONS
On the basis of the results of a multicomponent numerical
modeling investigation of the effects of a conventional beach
nourishment project on the behavior and quality of surf break
at Surf City, New Jersey, the following conclusions can be
drawn: (1) As constructed, the beach fill initially causes the
surf zone to become significantly compressed under wave
conditions typical for surfing, reducing it from being
nominally 100-m wide to being only 50-m wide or less. Any
rides that are obtained are therefore notably shorter and less
enjoyable. Associated with this compression, the number of
breaking waves in the surf zone is reduced from as many as
three to as few as one. (2) Because of the common practice of
making the main body of a nourishment project longshore-
uniform, the occurrence of closeouts increases (i.e. refracted,
long-crested waves will break simultaneously in lengthy
segments), making rides extremely short or even unobtain-
able. (3) The steepening of the slope of the beach profile in the
nearshore promotes a shift in breaker type toward surging
and collapsing breakers, particularly during high tide, which
poses a formidable risk to surfing and is also dangerous to
bathers. (4) The predilection of the waves striking the beach
face to surge and collapse increases wave reflection, which
disrupts the normal breaking process of incoming waves,
making them more difficult to catch. All of these findings are
in agreement with anecdotal testimony offered by the surfing
communities at Long Branch and Surf City, NJ. These
findings are, of course, not applicable to all nourishment
projects, and in fact the additional material introduced by
some projects has actually enhanced the surf break once the
fill makes its way into the nearshore in response to erosive
waves and storm events or at locations where, beforehand,
there was essentially no beach (i.e. shorelines fronted by
seawalls or revetments) (Benedet, Pierro, and Henriquez,
2007).
The methodology developed herein demonstrates that, in the
case of the Surf City nourishment project, the surf break
required nominally 21–22 months to return to normal
conditions. Significant refinements in quantifying the nourish-
ment effects could be made if more frequent (e.g., monthly)
surveys of the natural beach were conducted for an extended
period before project construction, to be compared with
monthly surveys postconstruction. This methodology could
also conceivably be applied in a forecast mode to aide in the
design of beach nourishment projects, particularly in assessing
effects immediately after project construction. If a suitable
beach evolution model were available, the progression and
duration of the effects of the fill might also be estimated with
the use of a wave almanac. However, the beach evolution model
must by necessity be able to envisage the 3D formation and
behavior of bar-and-trough formations, but such a model does
not yet exist. The state-of-the-art in hydrodynamics-based
beach profile evolution models, such as CSHORE (Johnson,
Kobayashi, and Gravens, 2012), XBeach (Roelvink et al., 2010),
Mike 21 (Mike Powered by DHI, 2017), and Delft3D (Deltares,
2017) perform reasonably well in eroding the beach face and
Journal of Coastal Research, Vol. 00, No. 0, 0000
Nourishment Impacts on Surfing 0
inner surf zone and depositing the sediment offshore in a
shelflike formation during a storm, but they do not yet create
the distinct bar-and-trough formations that are critical to
correct representation of surf-break behavior. Profile recovery,
particularly the transition from storm-induced, longshore-
uniform bars to 3D crescentic bars, is a modeling capability
also yet to be attained.
With regard to the coastal engineering profession and the
practice of beach nourishment, the conclusion is that to
prevent both adverse effects to surfing as well as an increased
risk of injury to bathers (Puleo et al., 2016), there would have
to be a paradigm shift in the manner in which fill material is
placed as the project is completed. After widening the beach,
sufficient material must be placed on the subaqueous profile,
particularly in the outer surf zone, to maintain a more
natural bathymetric shape. Rainbow deposition of the
material would appear to be the most technically feasible
method, although issues dealing with turbidity, control of the
shape of the nourishment deposit, and the effects on
nearshore reefs and hard-bottom habitat, as well as in
determining pay volumes, need to be addressed.
ACKNOWLEDGMENTS
This study was originally financially supported by the U.S.
Army Corps of Engineers, North Atlantic Division, Philadel-
phia District (NAP), under contract W912BU-09-C-0016, at
which time WRD and DAO were employed by Surfbreak
Engineering Sciences, Inc. The assistance of Jeffery Gebert
and Keith Watson of NAP is greatly appreciated. The authors
are thankful for the fair and helpful comments provided by
three anonymous reviewers.
LITERATURE CITED
Ardhuin, F.; Herbers, T.H.C., and O’Reilly, W.C., 2001. A hybrid
Eulerian-Lagrangian model for spectral wave evolution with
application to bottom friction on the continental shelf. Journal of
Physical Oceanography, 31(6), 1498–1516.
Beck, T.M.; Rosati, J.D., and Rosati, J., 2012. An Update on Nearshore
Berms in the Corps of Engineers: Recent Projects and Future Needs.
Washington, D.C.: U.S. Army Corps of Engineers, ERDC/CHL
CHETN-XIV-10, 9p.
Benedet, L.; Pierro, T., and Henriquez, M., 2007. Impacts of coastal
engineering projects on the surfability of sandy beaches. Shore and
Beach, 75(4), 3–20.
Buhr Hansen, J. and Svendsen, I.A., 1979. Regular Waves in
ShoalingWater—Experimental Data. Lyngby, Denmark: Institute
for Hydrodynamics and Hydraulic Engineering, Technical Univer-
sity of Denmark, Series Paper 21, 160p.
Chen, Q.; Kirby, J.T.; Dalrymple, R.A.; Kennedy, A.B., and Chawla,
A., 2000. Boussinesq modeling of wave transformation, breaking,
and runup, II: 2D. Journal of Waterway Port Coastal and Ocean
Engineering, ASCE, 126(1), 57–62.
Church, J.A. and White, N.J., 2006. 20th century acceleration in
global sea-level rise. Geophysical Research Letters, 33, L01602.
doi:10.1029/2005GL024826
Church, J.A. and White, N.J., 2011. Sea-level rise from the late 19th
to the early 21st century. Surveys in Geophysics, 32(4), 585–602.
Dally, W.R., 1990. Stochastic modeling of surfing climate. Proceedings
of the 22nd Conference on Coastal Engineering (Delft, The
Netherlands, ASCE), pp. 516–529.
Dally, W.R., 2001a. The maximum speed of surfers. In: Black, K.P.
(ed.), Natural and Artificial Reefs for Surfing and Coastal
Protection.Journal of Coastal Research, Special Issue No. 29, pp.
33–40.
Dally, W.R., 2001b. Improved stochastic models for surfing climate.
In: Black, K.P. (ed.), Natural and Artificial Reefs for Surfing and
Coastal Protection.Journal of Coastal Research, Special Issue No.
29, pp. 41–50.
Dally, W.R., 2017. Comparison of a mid-shelf wave hindcast to ADCP-
measured directional spectra and their transformation to shallow
water. Coastal Engineering, 131, 12–30.
Dally, W.R. and Osiecki, D.A., 2006. Development & validation of
hindcast-driven nearshore wave information. Proceedings of the
9th International Workshop on Wave Hindcasting and Forecasting
(Victoria, British Columbia, Environment Canada, USACE, WMO/
IOC JCOMM), http://www.waveworkshop.org/9thWaves/.
Dally, W.R. and Osiecki, D.A., 2007. Sculpting beach nourishment to
improve surfing. Shore and Beach, 75(4), 38–42.
Dean, R.G., 1991. Equilibrium beach profiles: Principles and
applications. Journal of Coastal Research, 7(1), 53–84.
Dean, R.G. and Houston, J.R., 2016. Shoreline response to sea level
rise. Coastal Engineering, 114, 1–8.
Deltares, 2017. Delft3D Home Page. https://oss.deltares.nl/web/
delft3d.
Dingemans, M., 1994. Comparison of Computations with Boussinesq-
Like Models and Laboratory Measurements. Delft, The Nether-
lands: Delft Hydraulics, Mast-G8M note, H1684, 32p.
Elsner, J.B.; Kossin, J.P., and Jagger, T.H., 2008. The increasing
intensity of the strongest tropical cyclones. Nature, 455(7209), 92–
95.
Emanuel, K; Sundararajan, R., and Williams, J., 2008. Hurricanes
and global warming: Results from downscaling IPCC AR4
simulations. Bulletin of the American Meteorological Society,
89(3), 347–367.
Gobbi, M.F. and Kirby, J.T., 1999. Wave evolution over submerged
sills: Tests of a high-order Boussinesq model. Coastal Engineering,
37, 57–96.
Greene, K., 2002. Beach nourishment: A review of the biological and
physical impacts. Washington, D.C.: Atlantic States Marine
Fisheries Commission, ASMFC Habitat Management Series 7,
http://www.asmfc.org/uploads/file/beachNourishment.pdf.
Grinsted, A.; Moore, J.C., and Jevrejeva, S., 2009. Reconstructing sea
level from paleo and projected temperatures 200 to 2100AD.
Climate Dynamics, 34(4), 461–472, https://www.glaciology.net/
publication/2010-12-24-reconstructing-sea-level-from-paleo-and-
projected-temperatures-200-to-2100-ad/
Herrington, T.O.; Bruno, M.S., and Rankin, K.L., 2000. The New
Jersey coastal monitoring network: A real-time coastal observation
system. Journal of Marine Environmental Engineering, 6(1), 69–
82.
Houston, J.R., 2016. Beach nourishment as an adaptation strategy for
sea level rise: A Florida east coast perspective. Shore and Beach,
84(2), 3–12.
Hubertz, J.M., 1992, User’s Guide to the Wave Information Studies
(WIS) Wave Model: Version 2.0, Vicksburg, Mississippi: US Army
Corps of Engineers, Waterways Experiment Station, WIS Report
27, 41p.
IPCC (Intergovernmental Panel on Climate Change), 2013. Climate
Change 2013: The Physical Science Basis. In: Stocker, T.F.; Qin,
D.; Plattner, G-K; Tignor, M; Allen, S.K.; Boschung, J.; Nauels, A.;
Xia, Y.; Bex, V., and Midgley, P.M. (eds.), Contribution of Working
Group I to the Fifth Assessment Report of the Intergovernmental
Panel on Climate Change. Cambridge, United Kingdom: Cam-
bridge University Press, 1535p.
ISEC (Inundation Science and Engineering Cooperative), 2008.
COULWAVE: Cornell University Long and Intermediate Wave
Modeling Package. ISEC model repository, http://isec.nacse.org/
models/coulwave_description.php.
Jevrejeva, S.; Moore, J.C.; Grinsted, A., and Woodworth, P.L., 2008.
Recent global sea level acceleration started over years ago.
Geophysical Research Letters, 35(8), L08715. doi:10.1029/
2008GL033611
Johnson, B.D.; Kobayashi, N., and Gravens, M.B., 2012. Cross-Shore
Numerical Model CSHORE for Waves, Currents, Sediment Trans-
port and Beach Profile Evolution. Vicksburg, Mississippi: U.S.
Journal of Coastal Research, Vol. 00, No. 0, 0000
0 Dally and Osiecki
Army Corps of Engineers, Coastal and Hydraulics Laboratory,
Report ERDC/CHL TR-12-22, 147p.
Kennedy, A.B.; Chen, Q.; Kirby, J.T., and Dalrymple, R.A., 2000.
Boussinesq modeling of wave transformation, breaking, and runup.
I: 1D. Journal of Waterway, Port, Coastal, and Ocean Engineering,
ASCE, 126(1), 39–47.
Kriebel, D.L. and Dean, R.G., 1993. Convolution method for time-
dependent beach-profile response. Journal of Waterway, Port,
Coastal, and Ocean Engineering, ASCE, 119(2), 204–226.
Kushner, D., 2006. No quiet on the ocean front. The New Yorker, July
1, 2006. http://www.davidkushner.com/article/no-quiet-on-the-
ocean-front/.
Lippmann, T.C. and Holman, R.A., 1990. The spatial and temporal
variability of sand bar morphology. Journal of Geophysical
Research, 95(C7), 11575–11590.
Longuet-Higgins, M.S.; Cartwright, D.E., and Smith, N.D., 1963.
Observations of the directional spectrum of sea waves using the
motions of a floating buoy. In: National Academy Of Sciences
and U.S. Naval Oceanographic Office, Division of Earth
Sciences (eds.), Ocean Wave Spectra: Proceedings of a Confer-
ence. Englewood Cliffs, New Jersey: Prentice-Hall, Inc., pp. 111–
136.
Lynett, P.J. and Liu, P.L.-F., 2008. Modeling Wave Generation,
Evolution, and Interaction with Depth-Integrated, Dispersive Wave
Equations; COULWAVE Code Manual, Cornell University Long
and Intermediate Wave Modeling Package, v. 2.0, 90 p., http://isec.
nacse.org/models/users_guide/coulwave.pdf
Madsen, P.A. and Sch¨
affer, H.A., 1998. Higher order Boussinesq-type
equations for surface gravity waves—Derivation and analysis.
Philosophical Transactions of the Royal Society of London,
356(1749), 1–59.
Mead, S. and Black, K., 2001. Predicting the breaking intensity of
surfing waves. In: Black, K.P. (ed.), Natural and Artificial Reefs for
Surfing and Coastal Protection.Journal of Coastal Research,
Special Issue No. 29, pp. 51–65.
Mesa, C., 1996. Nearshore berm performance at Newport Beach,
California, USA. Proceedings of the 25th Conference on Coastal
Engineering (Orlando, Florida, ASCE), pp. 4636–4649.
Mike Powered by DHI, 2017. Mike 21 Documentation. http://manuals.
mikepoweredbydhi.help/2017/MIKE_21.htm.
Miller, J.K.; Mahon, A.M., and Herrington, T.O., 2010. Assessment of
alternative beachfill placement on surfing resources. Proceedings of
the 32nd Conference on Coastal Engineering (Shanghai, China,
ASCE), https://doi.org/10.9753/icce.v32.management.34.
National Research Council, 1995. Beach Nourishment and Protection.
Committee on Beach Nourishment and Protection, 352p. http://
www.nap.edu/catalog/4984.html.
NOAA, 2013. Coastal Erosion. https://toolkit.climate.gov/topics/
coastal-flood-risk/coastal-erosion.
NOAA, 2017. National Data Buoy Center. http://www.ndbc.noaa.gov.
Nwogu, O., 1993. Alternate form of Boussinesq equations for near
shore wave propagation. Journal of Waterway, Port, Coastal, and
Ocean Engineering, ASCE, 119(6), 618–638.
PIANC EnviCom Working Group 108, 2010. Dredging and Port
Construction around Coral Reefs. Brussels, Belgium: PIANC,
EnviCom report 108, 73p.
Plant, N.G.; Holman, R.A.; Freilich, M.H., and Birkemeier, W.A.,
1999. A simple model for interannual sandbar behavior. Journal of
Geophysical Research, 104(C7), 15755–15776.
Puleo, J.A.; Hutschenreuter, K.; Cowan, P.; Carey, W.; Arford-
Granholm, M., and McKenna, K.K., 2016. Delaware surf zone
injuries and associated environmental conditions. Natural Haz-
ards, 81(2), 845–867.
Resio, D.T. and Perrie, W., 1989. Implications of an f
4
equilibrium
range for wind-generated waves. Journal of Physical Oceanogra-
phy, 19(2), 193–204.
Roelvink, D.; Reniers, A.; van Dongeren, A.; van Thiel de Vries, J.;
Lescinski, J., and McCall, R., 2010. XBeach Model Description
and Manual. Delft, The Netherlands: Unesco–IHE Institute for
Water Education, Deltares and Delft University of Technology,
110p.
Salahuddin, B., 2006. The Marine Environmental Impacts of Artificial
Island Construction, Dubai, UAE. Durham, North Carolina: Duke
University, Ph.D. dissertation, 96p.
Sanders, M., 2017. The $13.9 Million Dollar Sandbar(s): Gold Coast
Beach Nourishing Project Creates New, Man-Made Perfect Peaks.
http://www.surfline.com/surf-news/gold-coast-beach-nourishing-
project-creates-new-man-made-perfect-peaks-the-139-million-
dollar-sandbars_149036/.
Sch¨
affer, H.A.,; Madsen, P.A., and Deigaard, R.A., 1993. A Boussinesq
model for waves breaking in shallow water. Coastal Engineering,
20, 185–202.
Smith, J.M.; Sherlock, A.R., and Resio, D.T., 2001. STWAVE: Steady-
State Spectral Wave Model User’s Manual for STWAVE, Version
3.0, Vicksburg, Mississippi: U.S. Army Corps of Engineers, Coastal
and Hydraulics Laboratory, ERDC/CHL SR-01-1, 80p.
Sørensen, O.R.; Kofoed-Hansen, H.; Rugbjerg, M., and Sørensen, L.S.,
2004. A third generation spectral wave model using an unstruc-
tured finite volume technique. Proceedings of the 29th Internation-
al Conference on Coastal Engineering (Lisbon, Portugal, National
Civil Engineering Laboratory), pp. 492–504.
Sunamura, T., 1984. Quantitative prediction of beach face slopes.
Geological Society of America Bulletin, 95(2), 242–245.
Surfbreak Engineering Sciences Staff, 2008. Development of a
Nearshore Synthetic Wave Record for Brevard County, Florida.
Orlando, Florida: Surfbreak Engineering Sciences, Inc., Report to
the Florida Department of Environmental Protection, Bureau of
Beaches and Coastal Systems, 20p.
Swail, V.R.; Cardone, V.J.; Ferguson, M.; Gummer, D.J.; Harris,
E.L.; Orelup, E.A., and Cox, A.T., 2006. The MSC50 wind and
wave reanalysis. Proceedings of the 9th International Workshop
on Wave Hindcasting and Forecasting (Victoria, British Columbia
Environment Canada, USACE, WMO/IOC JCOMM). http://www.
waveworkshop.org/9thWaves/.
SWAN Team, 2013. SWAN User Manual, SWAN Cycle III Version
40.91A, Delft, The Netherlands: Delft University of Technology,
123p. http://www.swan.tudelft.nl.
Tolman, H.L. and Chalikov, D.V., 1994. Development of a third-
generation ocean wave model at NOAA-NMC. In: Isaacson, M. and
Quick, M.C. (eds.), Proceedings of Waves—Physical and Numerical
Modelling (Vancouver, British Columbia), pp. 724–773.
USACE (U.S. Army Corps of Engineers), 1999. Barnegat Inlet to
Little Egg Inlet. Philadelphia, Pennsylvania: U.S. Army Corps
of Engineers, Philadelphia District, Final Feasibility Report
and Integrated Final Environmental Impact Statement,438p.
http://www.nap.usace.army.mil/Portals/39/docs/Civil/LBI/
LBI_FeasRpt.
USACE, 2002. Coastal Engineering Manual. Vicksburg, Mississippi:
U.S. Army Corps of Engineers, Coastal and Hydraulics Labora-
tory. EM 1110-2-1100, CECW-CE, http://www.publications.usace.
army.mil/USACE-Publications/Engineer-Manuals/
?udt_43544_param_page¼4.
Van de Velde, M., 2008. The Art of Dredging. http://www.
theartofdredging.com/rainbowing.htm.
Walker, J.R., 1974. Recreational Surf Parameters. Honolulu, Hawaii:
University of Hawaii, James K.K. Look Laboratory of Oceano-
graphic Engineering, Technical Report 73-30, 311p.
Weaver, D., 2007. Surfers OK with effects of beach project, but they’re
leery about what will happen if project continues. The Press of
Atlantic City, June 20, 2007.
Wei, G.; Kirby, J.T.; Grilli, S.T., and Subramanya, R., 1995. A fully
nonlinear Boussinesq model for surface waves. I: Highly nonlinear,
unsteady waves. Journal of Fluid Mechanics, 294, 71–92.
Young, I.R. and Gorman, R.M., 1995. Measurements of the evolution
of ocean wave spectra due to bottom friction. Journal of
Geophysical Research, 100(C6), 10987–11004.
Journal of Coastal Research, Vol. 00, No. 0, 0000
Nourishment Impacts on Surfing 0
Article
This new edition - now with Nancy Jackson as a co-author - continues the themes of the first edition: the need to restore the biodiversity, ecosystem health, and ecosystem services provided by coastal landforms and habitats, especially in the light of climate change. The second edition reports on progress made on practices identified in the first edition, presents additional case studies, and addresses new and emerging issues. It analyzes the tradeoffs involved in restoring beaches and dunes - especially on developed coasts - the most effective approaches to use, and how stakeholders can play an active role. The concept of restoration is broad, and includes physical, ecological, economic, social, and ethical principles and ideals. The book will be valuable for coastal scientists, engineers, planners, and managers, as well as shorefront residents. It will also serve as a useful supplementary reference textbook in courses dealing with issues of coastal management and ecology.
Article
Coastal managers are increasingly reliant upon the process of beach nourishment to mitigate coastal erosion due to development and sea level rise, especially along the East Coast of the United States. While beach nourishment has been found to be more effective than hard stabilization measures, the process can negatively impact marine life, natural shoreline processes and coastal recreation users. There are few studies examining coastal users' opinions of beach nourishment, especially surfers, a user group that can be substantially affected by the process. The purpose of this study was to examine surfers' perceptions of beach nourishment in Virginia and North Carolina. An online survey distributed in 2018 resulted in a sample of 500 surfers. The study found that respondents had neutral to somewhat negative perceptions of beach nourishment. Respondents from the southern North Carolina coast had significantly more negative opinions of the process that surfers in other regions. Results of the study confirm previous findings on the impacts of beach nourishment for surfers and other coastal users. The study highlights the need for additional research on the impacts of beach nourishment and the involvement of surfers as local knowledge experts in coastal management.
Article
Full-text available
For observation on the influence mechanism of environmentally and aesthetically friendly artificial submerged sand bars and reefs in a process-based way, a set of experiments was conducted in a 50 m-long flume to reproduce the cross-shore beach morphodynamic process under four irregular wave conditions. The beach behavior is characterized by the scarp (indicating erosion) and the breaker bar (indicating deposition), respectively, and the scarp location can be formulated as a linear equation regarding the natural exponential of the duration time. Overall, main conclusions are: (1) the cross-shore structure of significant wave height and set-up is mainly determined by the artificial reef (AR); (2) the cross-shore distribution of wave skewness, asymmetry, and undertow (indicating shoaling and breaking) is more affected by the artificial submerged sand bar (ASB); (3) the ASB deforms and loses its sand as it attenuates incident waves, which leads to a complex sediment transport pattern; (4) the scarp retreat is related to the beach state, which can be changed by the AR and the ASB; (5) the AR, the ASB, and their combination decrease wave attack on the beach. In conclusion, this study proves positive effects of the AR and the ASB in beach protection through their process-based influences on beach behaviors and beach states for erosive waves.
Article
Email or send a ResearchGate Message for a copy! Abstract: Beach nourishment — the addition of sand to increase the width or sand volume of the beach — is a widespread coastal management technique to counteract coastal erosion. Globally, rising sea levels, storms and diminishing sand supplies threaten beaches and the recreational, ecosystem, groundwater and flood protection services they provide. Consequently, beach nourishment practices have evolved from focusing on maximizing the time sand stays on the beach to also encompassing human safety and water recreation, groundwater dynamics and ecosystem impacts. In this Perspective, we present a multidisciplinary overview of beach nourishment, discussing physical aspects of beach nourishment alongside ecological and socio-economic impacts. The future of beach nourishment practices will vary depending on local vulnerability, sand availability, financial resources, government regulations and efficiencies, and societal perceptions of environmental risk, recreational uses, ecological conservation and social justice. We recommend co-located, multidisciplinary research studies on the combined impacts of nourishments, and explorations of various designs to guide these globally diverse nourishment practices.
Article
Full-text available
The Bruun rule is the most widely used method for determining shoreline response to sea level rise. It assumes that the active portion of an offshore profile rises with rising sea level, and the sand required to raise the profile is transported from the shoreline. It is difficult to evaluate the efficacy of the Bruun rule because sea level rise often has a lesser effect on shoreline change than that produced by sand sources, sinks, and longshore transport gradients. In addition, some shorelines have advanced seaward with rising sea level. Dean (1987) showed that equilibrium profile theory predicts that rising sea levels produce landward sand movement forced by nonlinear waves. This paper presents an equation with terms representing all phenomena affecting shoreline change including Bruun-rule recession, onshore sand transport, sand sources and sinks, and longshore transport gradients. As an example of its use, rates of onshore transport are determined along the 275-km Florida southwest coast, USA, and a 19-km portion of this coast using known values for sand sources, sinks, and longshore transport gradients. Then future shoreline changes are projected for both coasts from 2015 to 2065 and for the southwest coast from 2015 to 2100, using sea level rise projections from the Intergovernmental Panel on Climate Change. Beach nourishment is shown to be a very effective adaptation strategy for sea level rise with shoreline change projections useful to estimate required rates of beach nourishment to counter sea level rise.
Article
Full-text available
Surf zone injury and environmental condition data were collected concurrently during the summer of 2014 along the Delaware coast. Documented injury data included injury type, gender, age and activity, while measured environmental conditions included local wave height, wave period and foreshore slope. Daily water user counts were used to normalize injury rates relative to the number of beachgoers at risk. There were 280 injuries over 116 sample days along the entire Delaware coast and 169 injuries over 82 sample days within the 5-beach focused study area where water user count data were available. Injuries were not distributed randomly as tested against a Poisson distribution and occurred in clusters with up to 15 injuries occurring in a single day. There were 32 serious injuries (cervical fractures, spinal cord injuries) and 1 fatality. Water user counts throughout the course of a day exceeded 25,000 on busy weekends such that the mean injury rate was 0.02 %. Men were twice as likely to be injured relative to women, and the mean injury age was 32 years old. Tourists were six times more likely to be injured compared to local beachgoers. Wading (44 %) was the dominant injury activity followed by body surfing (20 %) and body boarding (17 %). Direct correlation between injury occurrence or injury rate and any environmental factors was weak (highest squared correlation coefficient <0.12), but the highest injury rates were associated with moderate wave height (0.6 m) with lower injury rates for both smaller and larger waves. Lack of direct correlation between injury occurrence or injury rate and environmental parameters suggests there was an important (and as yet undetermined) human element that also dictates the injury rate. Additionally, the high proportion of injuries to tourists may require alternate strategies in local beach safety and injury awareness campaigns.
Article
In conducting a cross-shelf wave transformation experiment off the Atlantic coast of north Florida, a unique opportunity was exploited in which an Acoustic Doppler Current Profiler (ADCP) instrument was installed 30 km offshore at the exact location of one of the archive-nodes of a WAM-like wave hindcast model (OWI3G). A second ADCP was installed 550 m from shore. Approximately 53 days of directional wave spectra collected with the two ADCPs are used to (a) locally test the reliability of a subsequent update of the hindcast, (b) document the loss in energy as the waves crossed the broad, relatively shallow continental shelf between the two instruments, (c) test the ability of the SWAN (Gen2) nearshore wave transformation model to replicate the measurements taken in shallow water when driven by the offshore ADCP spectra, and (d) reassess the spectral transformation results when the offshore hindcast is used as input. In addition to direct comparison of the time series of frequency spectra and the directional distribution of energy, typical spectral parameters are each subjected to standard error tests. Results indicate that the offshore hindcast performs well in replicating significant wave height, fairly well for mean period, but not as reliably for peak period. Directional spreading in deeper water is generally well-represented, although vector mean direction is not, and is believed due to the proximity of the coast to the hindcast node. The nearshore model requires an order-of-magnitude reduction in bed roughness from its default value before agreement in wave energy at the nearshore ADCP can be achieved. Outcomes of the error tests for the hindcast-driven versus the ADCP-driven nearshore results (after roughness calibration) are quite similar, but nevertheless indicate that transformed wave period, wave direction, and directional spreading require improvement.
Article
A NEED EXISTS FOR EXACT KNOWLEDGE ABOUT THE REQUIREMENTS OF AN IDEAL SURFING SITE.A NUMBER OF SITES IN HAWAII WERE STUDIED AND A CONCEPT OF A GENERAL SURF SHOAL WAS FORMULATED.FROM THIS, PROPOSED MODIFICATIONS TO SURF SITES MAY BE EVALUATED, IMPROVEMENTS TO EXISTING SITES MADE AND ARTIFICIAL SITES DESIGNED.WAVE TRANSFORMATIONS OVER A 1:30 SLOPING BOTTOM WERE STUDIED ON A HYDRAULIC MODEL.WAVE SHOALING WAS FOUND TO BE A FUNCTION OF WAVE STEEPNESS.THE CONCEPT OF THE GENERAL SURF SHOAL WAS TESTED IN THE MODEL AND IT WAS FOUND THAT FINITE HEIGHT AND BREAKING SIGNIFICANTLY AFFECTED REFRACTION PATTERNS AND COEFFICIENTS OVER THE SHOAL.WAVES DID NOT REFRACT AS CONVENTIONAL REFRACTION ANALYSIS WOULD INDICATE AND SOMETIMES LED TO WAVE DIVERGENCE OVER THE CENTRE OF A SHOAL WHERE CONVERGENCE WAS EXPECTED.(A)
Article
Stevens Institute of Technology recently established the New Jersey Coastal Monitoring Network (CMN). This system provides real-time observations and archived records of shallow water (5m) wave characteristics, water temperature, water level and meteorological conditions (wind speed and direction, temperature, barometric pressure), as well as digital images of the beach and nearshore ocean, at three locations that span the State's ocean shoreline. This information is disseminated via the Internet through the Davidson Laboratory's web site: http://www.dl.stevens-tech.edu. The system is designed to provide real-time information to local, State, and Federal emergency management personnel, and long-term records of wave, weather conditions and shoreline response for use by the coastal scientific community.
Article
When beaches are nourished with a sediment of arbitrary but uniform size, it is found that three types of profiles can result: 1) submerged profiles in which the placed sediment is of smaller diameter than the native and all of the sediment equilibrates underwater with no widening of the dry beach, 2) non-intersecting profiles in which the seaward portion of the placed material lies above the original profile at that location, and 3) intersecting profiles with the placed sand coarser than the native and resulting in the placed profile intersecting with the original profile. -from Author