VOL. 6

Yo}. 6 A}.

DEPARTMENT OF THE ARMY
CORPS OF ENGINEERS

WOODS HOLE
OCEANOGRAPHIC INSTITUTION
JAN 15 1952
WOODS HOLE, MASS.

THE "Do tof Bi RAI ENT Be 4
Keer ee ton a

BULLETIN :

Palosstenepenennic

OF THE

BEACH EROSION BOARD

OFFICE, CHIEF OF ENGINEERS
WASHINGTON, D.C.

JANUARY 1, 1952 NO.1

DEPARTMENT OF THE ARMY

CORPS CF ENGINEERS

TABLE OF CONTENTS

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VOL. 6

January 1, 1952

wn

22

30
34

NO.

SUMMARY REPORT ON STUDIES OF SAND TRANSPORTATION
BY WAVE ACTION

Se FOREWORD

The following report is a summary of investigations conducted by
the Department of Engineering, University of California, under contract
W-49-055-Eng-2 with the Beach Erosion Board. Individual reports
summarized herein and listed at the end of the report are on file in
the Board's library. They are available on 30-day loan upon request.

Introduction

The purpose of this investigation was to define the more important
factors involved in the littoral transportation of sand by wave action.
The scope of this study was relatively broad and included both model
‘and field studies. The model studies consisted of investigations of
(a) sand movement with two dimensional wave motion, (b) influence of
groins on beach stabilization, and (c) the movement of sand by waves
acting at an angle to a straight beach. The field studies consisted of
(a) a comprehensive analysis of all available field data to determine
a generalized relationship between sediment, beach and wave character-—-
istics, (b) the masurement of the wave characteristics and the sand
accumula tion at Santa Barbara Harbor in order to estimate the average
rate of sand transport that might be expected from given wave conditions.
Eventually, it is telieved that model and field studies as conducted
in this investigation will permit the coastal engineer to estimte
expected rates of littoral drift at any given location on a coast ex-
posed to wave action.

In addition to the model and field studies mentioned above, wave
recorders were operated at various locations along the Pacific Coast.
nocerlethe recorddys from these recorders were analyzed for the significant
height and period, and the data then summarized in tabular form for
distribution to interested agencies.

A supplementary task order to this contract was thé ‘compilation
of certain data of a classified nature. Because of the classification,
this material is not summarized in this report.

MODEL STUDIES OF SAND TRANSPORTATION
BY WAVE ACTION

Sand Movement in Two Dimensional Wave Motion

Before the investigation described below in items B and C could
be conducted, it was necessary to determine whether certain relatively

at

fine sands would actually form a beach under laboratory conditions.
Because of the economy of time in setting up such experiments and be-
cause of the flexibility permitted in varying the experimental conditions,
a series of experiments were made in the one-foot wave channel located

in the Fluid Mechanics Laboratory of the University of California (for
complete details see the report Issue No. 5, Series 14, as listed in,
Part VI). The purposes of this investigation were:

a. To study the action of waves on beaches where no littoral sand
transport occurs; comparing the profiles formed by normal waves (0°
angle) for various selected wave-steepness ratios.

b. To observe the movement of beach sand under the action of
waves perpendicular to the beach with and without tides,

ce To determine whether very fine grained sands will make a beach
or what minimum grain sizes could be used for forming a model beach
under existing experimental conditions.

d. To determine the amount of mterial in suspension due to wave
action on these fine sands, and the particle-size distribution through—
out the channel bed.

e. To show the formation of a beach starting from an initially
uniform slope to its final stable condition. Further, to show how a
beach (where no littoral transport occurs) changes shape when the period
is suddenly varied.

Summary

The movement of waves impinging upon the sand beach and the subsequent
movement of the sand particles were observed through a glass—walled
wave channel. After each beach tested had reached a stable condition,
the lengths of the foreshore beach and the berm height were measured.
Both of these values, for a given sand and a given wave steepness, were
found to be directly proportional to the square of the wave period.
More experimental data are required to establish a relationship be-
tween the berm height and the foreshore slope to both the steepness
ratio and the grain diameter.

Observation showed that receding tides tend to flatten or smooth
out the entire beach profile while a rising tide keeps the original
beach profile intact but moves the beach position landward.

It was found that only the sand mixtures having a grain-size dis-—
tribution curve similar to the natural beach sands resulted in the for-
mation of a stable model beach. Furthermore, in contrast to this, it
was found that if a sand mixture was used that had a relatively wider
range of the grain sizes than that occurring in natural beach sands,
the particles tended to segregate. This resulted in the beach becoming

2

unstable and the profile consequently being unpredictable.

A series of experiments were made to determine the amounts of
material that were thrown into suspension due to the action of the
waves on a beach. All of ths tests indicated that the maximum con-
centration of suspended material occurred in the breaker region.

It was also observed that the orientation of the sampling tube in the
wave stream affected the measured concentration of the sand particles.

Because of the number of waves required to develop a stable con-
dition in the model beaches for the particular wave periods used, it
is “questionable whether a corresponding prototype beach in nature,
under the natural wave and tidal actions, would result in an equilibrium
state.

The qualitative observations made on ripple formation indicate
that the wave height appeared to be the controlling element in forming
the size and shape of the ripple. A wave of greater amplitude, having
a relatively large particle movement, gave greater ripple amplitudes
and spacing than the wave heights of lower amplitudes.

Recommendations

After a review of recent literature on wave action on granular
material and in view of the rather limited tests discussed above, it
appears desirable that further study of two-dimensional wave action
be conducted on the following problems:

a. In the light of recent investigations on wave forces on
particlesx a comprehensive study should be made on the forces which
cause bed moverent by wave action. The variables in these tests should
include the wave characteristics and the specific gravity and mechani-
cal analysis of the material.

bo The movement of sand exposed to two-dimensional wave motion
and the nature of profile changes should be investigated under con-
ditions where a tide is introduced and where the wave characteristics
are changed.

ec. Gbservations under the controlled conditions of a wave channel
should be made on the nature of suspended-matter distribution in and
near the surf zone. The variables should include the characteristics
of both the sediment and the waves.

Influence of Groins on Beach Stabilization

Erosion of a beach occurs when the supply of sand to it is less
than the rate at which the sand is transported along the beach. fo
control erosion groin systems often are used to promote the accretion
and stabilization of beaches where the littoral drift induced by the

3
) ~ y/, ae
x Zoot 0 weAiotwtT A ~ bo Vr
(oe af ROAR Los: 7, R LO Lé

wave action is a significant factor. As part of the research program
on this contract, a study was made of two types of groins: one,

the sloping, impermeable groin; and second, the high, permeable groin.
This investigation was intended to determine the relative influence

of the high permeable groins and the sloping impermeable groins for
stabilizing a beach where littoral transport occurs.

In this study a sand beach was placed at one end of a model basin.
Waves were generated at the opposite end of the basin and moved toward
the beach. These waves breaking along the shore induced a current
which caused a littoral movement of the sand, The relative effect of
a particular type of groin was determined by comparing the topography
of a straight, unobstructed beach which had reached an equilibrium
profile with the topography of a beach which had reached equilibrium
after a groin or system of groins were installed,

The experimental program for studying the groin influence on the
littoral sand movement was carried out under the following conditions:

a. With no groins in place (for establishing the base equili-
brium condition);

b. With one high, permeable groin in place;

c. With a system of two high, permeable groins in place;

d. with a system of three high, permeable groins in place;

e. witha system of ten sloping, impermeable groins in place;
f. with a system of ten high, permeable groins in place;

g. introducing dyed sand particles in the bed of the beach to
study currents.

Prior to placing a particular groin, or groins, in position, the
littoral transport rate was determined (i.e. for the steady state con-
ditions obtained with a specific set of wave characteristics). The
sand composition was the same throughout the tests. The stable profile
of the beach then became the base for evaluation of subsequent changes
in the beach configuration. The effects of tide were not studied.

(For complete details see the report Issue No. 6, Series No. 14, as
listed in Part VI).

* O'Brien, M. P. and Morison, J. R.3; The Forces Exerted by Waves on
Objects; Transactions, American Geophysical Union, (In Press).

J
A

Summar

The ratio of the rate of sand transport without groins to the
rate of sand transport with groins perhaps is the best criterion for
evaluating the effectiveness of a particular groin system. In this
series of experiments, once the equilibrium rates were established
the shore line was considered to be ina stable position. The intro-
duction of fixation works produced a rate of change peculiar to that
particular type of structure. These rates in turn developed the sub-
sequent volume changes that were computed on a percentage basis using
the stable profiles of the beach without any structures in place asa
reference.

A review of the experimental data for the tests made with the
systems uSing three permeable sroins indicates that where there is
proper nourishment to the beach, the permeable structures have a small
but effective influence on the beach. Significantly, for both sets
of tests the runs made with one groin in place produced a marked
scour area in the region dowmcoast from the structures. The tests
substantiate the fact that for sand trapping purposes the permeable
groins should not be used as individual units isolated along the beach
but in a4 group, i.¢., in a system of groins. Care also must be taken
when placing the groins in the beach, for if they are placed further
apart than their influence area, each would act as an undesirable in—
dividual unit. y/

With a RANG cn input to the surf zone, the first set of
tests made on the permeable groins showed that there was a 26 per cent
deposit of sand on the beach, with the structures in place, over the
base condition, with a straight unobstructed beach. The second set
of tests on the permeable groins, mde with a different set of wave
conditions, showed only an 11 per cent beach fill. Comparison of the
data on the types of fixation works tested, where the littoral
current is a significant factor, showed that the impermeable groins were
more effective in the accretion of sands that the permeable groins.

The retention, or holding power, of the impermeable groins is re—
latively large. Ina particular series of tests where there was no
feed material introduced, the total decrease or the amount of scour
that occurred from the base reference volume (taken at the start of a
test) amounted to a reduction slightly less than 20 per cent ina
run that exceeded 54 hours in duration.

The experiments show that, when the beach is adequately nourished
and the littoral current is an effective force, the impermeable groins
rapidly accrete the sediment. The building or filling-up of the area
between groins follows a very definite pattern. In general, the sand
begins to move around the seaward tip of a groin and fills in the
Space near the downcoast side of the groin. Then the sand moves at an
angle across to the next groin and fills in the upcoast face. Then the

5

center portion of the area becomes filled. The following sand and
grains are then forced to move over the groin tops (which are now
flush with the built-up sand bed) and seaward of the structures.

This essentially causes the beach face to be moved seaward and, after
a tim, the groins are completely buried beneath the sand and the new
beach is relocated further seaward. The behavior of the beach appears
to be predominately dependent upon the transport rate as to whether
the body of the beach face is to remin ina stabilized state or not,

In order to observe the path that the littoral current takes
through the permeable groins, a dye was introduced in the breaker-to-
shore region where the probable maximum littoral velocity occurs.

The results were indicative of where the sand usually builds up and/
or scours around the groins, as determined from the other experiments.
The fact that the dye went through the first two groins in an even
"fan pattern would tend to show that the littoral current was still
great enough to also carry the sand particles through the slat section.
Furthermore, it would tend to indicate that should permeable groins be
contemplated for a comparable prototype situation, they should be used
in groups of three or more groins.

In tests made to study the bed load movemant of the sand particles
in the breaker region, the sand grains were observed generally to follow
a definite pattern. The initial wave action first covered the grains
in the bed, then the following waves uncovered the grains and moved them
a short distance in both a seaward and lateral direction. Succeeding
waves again covered the particles and the process began to be repeated.
The cycle occurred within approximately 1 minute (60 waves for this
particular test). This cyclic particle movement also has been observed
in the one-foot wave channel as discussed in Section "A™ above.

The Movement of Sand Transported by Wave Action Along a Straight Beach

Waves breaking at an angle to a beach generate a current that
moves parallel to the beach; this is known as the littoral current.
The purpose of this investigation was to study to what extent a change
in wave characteristics and beach affected the rate of transportation.
The experimental program began with a continuation of previous ex-
periments on sand transport.*% A wave machine and a model beach were
arranged in a model basin approximately 66 ft. by 122 ft. in plan and
two feet in depth. The wave machine was of the flap type in which the
period of the waves could be varied by changing the speed of the driving
motor, and the wave energy could be changed by adjusting the throw on
crank arms connected to the wave flaps. The wave height and wave
length were determined by the period and energy settings. A sand beach
was molded initially to a 1/10 slope by screeding, and then allowed
to develop its profile under the action of the waves. A sand trap and

xSaville, Thorndike, Jr.3; Model Study of Sand Transport Along an In-
finitely Straight Beach, Trans. Amer. Geoph. Union, Vol. 31, 1950

6

weighing device for recording the rate of littoral sand transport in-
duced by direct wave action and by the littoral current was installed
at the downbeach end. This device consisted of a metal hopper sus—
‘pended on a beam which rested on a fulcrum. On one end of the beam

a counterweight was attached (for zero setting), and the other end

of the beam rested on a sylphon bellows which was liquid-filled and con-
nected by tubing to a clock-driven Bourdon—type pressure recorder. The
recorder was calibrated by placing known weights into the sand hopper.
The efficiency of the sand trap was determined under operating con-
ditions by feeding known weights of. sand into the flow at the entrance
to the unit.

To insure that all sand transported along the baach would be
carried into the weighing device, it was necessary to induce a flow in-
to the basin containing the hopper. This pumping action was necessary
in order to prevent the littoral current, upon reaching the trap, from »
flowing seaward; since such a seaward current would oppose the waves,
sand deposition would occur in this region, and thus progressively
change the rate of transport into the trap. The flow from the pump
was returned to the main basin through a channel of relatively large
dimensions at a corresponding low velocity, so that no large scale
circulation was induced in the basin. Thus, the length of beach studied
approxinated a section of beach of infinite length. The beach angle
was varied between 10° and 50°.

Summary.

The following statements summarize the experimental work made on
the movement of one particular sand transported along a straight
beach unobstructed by fixation works. In the prototype the sand used
would correspond to pea gravel; the stable model beach corresponds to
a prototype gravel beach.

a. The waves impinging upon a beach set at 30° to the wave zene-
rator developed a greater rate of sand transport than did that created
by the beach set at a 10° angle.

be In the region of flat waves (low steepness ratios) the trans—
port rate sharply increases for small increases in the Ey lt ratio,
until a peak value of around Hy /Lo = ©.023 is reached. Here, in this
region, the major portion of the sand that is moved drifts along the
beach as bed load, whereas in the region of steep waves (high steepness
ratios, Hy/Ip exceeding 0.025) the curve of the transport rate takes
on a negative, or opposite, slope when compared to the curve for the
waves in the low steepness region. The slope for the transport rate
curve is less steep and a smali change in wave shape does not material-
ly affect the movement of sand. In the region of steep waves the sand
is moved by a combination of beach drift and that thrown up into sus-
pension, with the latter accounting for the principal amount of trans—
port. Most of the beach drift occurs at the toe of the beach face and
the material in suspension is carried along just shoreward of the off-
shore bar.

co The beaches developed by waves of low steepness had a re-
latively straight or smooth beach face with little separation taking
place between the foreshore beach and the offshore section, whereas,
for high wave steepness ratios, at least one or more offshore: bars
were formed and the foreshore was at a steeper anede than that being
formed on the offshore bed.

d. The experiments indicate for the range of angles tested, that
the transport rate is dependent upon the littoral current. Further,
the maximum rate of sand transport occurred where the value of the
littoral current reached a maximum value, namely at a 43° deep-water
angle.

e. As was found by other experimenters, despite appreciable
changes in wave characteristics there was no significant sand sorting
along the beach in the longitudinal direction. However, perpendicular
to the beach the larger sand particles moved inshore with the fine
sediment being carried seaward.

Recommendations

In view of these exploratory experiments, which pertain to only
one sand size, further investigations are desirable to determine the
effect of sand size on the laws of transport. The experiments dis—
cussed in this report provide information on the most desirable size
of wave tank for conducting future tests, namely a width of basin not
to exceed 15 to 20 feet and a length of basin which will depend on
the equilibrium slope of the finest material used in the tests.
Simultaneously with such tests, if not before, a fundamental investi-
gation should be made of the magnitude and character of the forces
acting on bed particles due to wave action as recommended under Item A
of Part II of this report.

\
FIELD STUDIES OF SAND TRANSPORTATION BY WAVE ACTION

The Relationship Between Sand Size and Beach Face Slope

Introduction — Under the sponsorship of the Office of Naval Res-
earch and the Beach Erosion Board, a University of California field
party visited and repeatedly surv eyed some 40 beaches on the Pacific
Coast of the U. S. in the years 1944 to.1948. These beaches ranged
from southern California to northern Washington and included steep
and flat beaches under winter and summer conditions and in high and
low surf. Details of beach conditions from the dunes to beyond the
breaker zone were surveyed and noted; sand samples were taken at mny
points; the effect of surf conditions on each beach was recorded;
and an elaborate program of breaker measurements was conducted. A
total of about 500 profiles (from dunes to minus 30 feet) were made
and over 600 sand samples were taken in the course of these investi-
gations. With its irregularities, the U. S. Pacific Coast is thousands .
of miles long and quite probably includes most of the possible ocean
beach conditions and configurations.

8

The scope of this report includes only sandy beaches in which sand
is defined as ranging in size from 0.05 mn. to 1.0 mm (U. S. Bureau of
Soils classification). Although there are afew pebbles, gravel, and
cobble beaches on the coast studied, the largest material found on
extensive beaches subjected to systematic sampling was 0.8 mm sand, It
seems reasonable to believe that the curves can de extended smoothly
upward when data om beaches composed of coarse material are available.

The importance of using standardized measurements can scarcely
be overstated and other researchers are urged to consider the use of the
"reference point” discussed below in future beach examinations so that
data will be comparable. This report is concerned with comparing
western U. S. Reaches on the basis of median sand size and beaach—face
slope and shows the probable limits of each. The beach face in this
instance is synonomous with shoreface or foreshore. The importance of
surf action in changing slopes from a profile of deposition to one of
erosion is show as are the variations in slope with exposure.

Reference Point ~ The necessity for standardizing beach sampling
and measurement procedures became increasingly evident as data were
reduced from widely separated beaches between which it was desirable
to make comparisons, Tne apparentiy simple job of determining the
Slope of a beach from a plotted profile raised perplexing questions
of how and where to make the measurement. Sand samples froma single
beach differed so much in median diameter (because of different sample
locations) that first atcempts at correlation wers failures. Eventual-
ly however, by plotting the mass of data in various ways, pattems
began to take shape. This work ultimately led to a decision to
standardize on a specific location so that valid comparisons could be
made across time and distance. The point selected was the part of the
beach face subiert, to wave action at mid—tide elevation-—now known as
the reference point. All slope measurements and sand samples referred
to in this report wers taken at that point. The several illustrations
discussed below develop the reasons for its selection and indicate the
results that may be obtained by its use. VCertain advantages are claimed
for this technique: (1) a line investigator with simple equipment can
take measurements rapidly and easily (2) the variables being samples
are those of the present time (the existing waves placed the sand
sampled at the slope measured) (3) the inter-—tidal beach face slopa seems
to be a major criterion for the potential use of the beach (4) some pre-
vious investigators have used this location and their data are usable
for comparison, The reference zone my be fairly wide; it is delibrate-
ly described somewhat loosely as being the part of the beach subject to
wave action at mid—tide stage since the technique would be highly im—
practicable if it were necessary to locate some exact elevation. Any
reference point in this zone is presumed to have approximately the same
characteristics. Since the backrush is only slightly below, and the
uprush may be considerably above the average sea level, these measure-
ments will be somewhat above the mid—tide level. This part of the
beach seems to be the most stable and consistent results usually can
be obtained there. Mid-—-tide refers to a level half-way between the

9

previous high tide and the succeeding low. It is convenient to keep
this dimension flexible because the inter—tidal zone on open ocean.
beaches my be above or below its predicted positions this is caused
by piling up of water on a beach due to wave action, wind drag on the
sea surface causing either higher or lower tides, and changes in sea
level due to barometric pressure gradients. On steep beaches, the re—
ference zone may be as narrow as twenty feet while on flat beaches it
may be over a hundred feet wide.

Relationship Between Beach and Sediment Characteristics - A complete
discussion of the analysis of the various field data appears in the

report Issue No. 2, Series 14 (see Part VI). Briefly, the results of
this study show the following information, (a) a generalized distribu-
tion of sand size across a beach from the dunes to an offshore depth
of approximately 30 feet, (b) typical sand sizes and beach slopes of
Pacific Coast beaches, (c) the changes in beach slope with erosion

and deposition, (d) the variation of sand size and beach slope with the
degree of protection from wave action, (¢) and the relationship between
sand size and slope of the beach face.

Conclusions - From the results of this comprehensive study of a
large number of Pacific Coast beaches, the following conclusions appear
reasonable

1, Sandy beach-face slopes (reference zone) on U. S. Pacific
Goast beaches range from 1:4 to 12100.

2. Median diameter of beach material from the reference point
on sandy beaches range upward from 0.17 mn.

3. As beaches mild and erode, the slope of the beach face at
the reference point will change considerably, apparently in response
to the H/L factor of the waves. An eroding beach will flatten; a
building beach will steepen.

4. Distribution of sand by size along a profile is predictable
with reasonable accuracy if the median diameter of the sand at the
reference point is known. Yarge grains are found at points of
maximum turbulence; sizes get smaller as turbulence decreases.

5, The slope of the beach face is related to the median diameter
of the sand and the amount of wave energy reaching that point. The
amount of energy is a function.of the refraction conditions; consequent—
ly, beaches that are protected are steeper for any given sand size
than exposed beaches.

Investigation of Coastal Sand Movements; Santa Barbara, California

Introduction — Little is known about many of the factors which in-
fluence littoral transport. Basic questions have never been answered,

110

such as~¢ What is the relationship between the wave components

height, period, steepness, angle of attack) and littoral flow of sand?
To what depth of water does the sand move? What is the relationship
between longshore sand movement and offshore-onshore sand movement?

What is the influence of sand size and density on littoral transport?
How can sand flow be estimated if all wind, wave and current data arse
known? A major objective of this study is to secure all possible infor-
mation which may throw some light on the solution of these and other
problems «.

Santa Barbara is a logical site for the investigation of littoral
transport on several scores:

a. Complex as the conditions are, they represent a great simplifica-—
tion of an open coast situation. Santa Barbara may be regarded as a large
scale model in which variables are held tq a minimum. Mave direction,
with the exception of one or two southeasterly storms a year, is nearly
always at 235° (SW). Winds are held within 180° by the high Santa
Ynez range nearbys velocities greater than 15 knots are unusual and
direction is reasonably constant for any given time of day. This leaves
the wave characteristics (which would be the variable in a model ex-—
periment) the principal unknown.

b. Santa Barbara is unique in that it is both easy and necessary
(for dredging purposes) to measure the quantity of littoral drift. It
appears evident that all sand moving along the coast is trapped in a
small area of the harbor and average rates of flow between surveys
are easily determined.

Cc. Santa Barbara is similar to a large part of the coast of
southern California which is highly developed and which has similar
sand problems. Presumably any solutions or explanations which are
usable at Santa Barbara are valid, by extension, at Ventura, Hueneme,
Santa Monica and other nearly areas.

d. There is immediate economic pressure for obtaining a specific
solution to the problems locally. This amounts to about $60,000 per
year for dredging plus aniunestimated value of inconvenience to the
users of the harbor. Several changes in the shape and layout of the
breakwater and harbor have been suggested by various agencies; these
have not been completely evaluated as yet, partly because of a dearth
of information on the movement of the sand.

e. The beaches are constant in several important respects.
They seem to have a common source of sand; exposure to waves is about
the same, and beach slopes are reasonably constant.

The major variables all can be measured and are controlled by the
physical circumstances. The problem than, is to correlate the

specific causes and effects that are measured and to attempt to arrive

dal

at a law that relates them. Of primary importance is the relationship
between wave characteristics and rate of sand flow. The principal
efforts were made in this direction.

Other problems which should be considered are: Where do today's
flow rates stand? Are there other causes of sand movement besides wave
action? Is sand sorting by size or minerals of any Be eaace either

in the fill or on the feeder beaches?

Examination of Prior Data - In order to get the necessary back—
ground for the layout of details of this program, a great deal of ex--.
isting data were obtained from the sponsor and studied by University
engineers, Past surveys were of great help in selecting stations for
repeat surveys and study. House Tocument 761 was used as a handbook
because of its valuable summaries of statistical data.

Three specific uses were made of these past data. (a) Times of
important changes (both accretion and erosion) were selected with a |
view to having wave hindcasts made which would be comparable with
University-obtained sand flow data. No hindeaster was available and
this part of the work has been postponed for the future. (b) Rate of
sand flow past a series of survey points was plotted graphically in
two ways in an effort to ascertain the validity of the theory of sand
waves. This theory proposes that periods of storm move large quantities
of sand from the feeder beach; this sand travels as a unit for some
distance along the beach until brought to rest by a period of light
seas; another stormy period moves it along again. Eventually, of
course, the sand unit, or sand wave, is spread too thin to be re-
cognized. This motivating storm series might be the winter season, in
which case the period of the sand wave would be one year. A limited
examination indicates that this may be true and a wave length of
6000 feet may exist. Further study is required on this phenomena
before definite conclusions can be made. (c) The data on harbor
accretion has been reduced to graphic form, mostly to get a basis for
comparison of the new data.

Surveys — Three types of location were deemed necessary to obtain
an adequate picture of the sand changes in the Santa Barbara area.

a. A beach outside the "problem area" of accretion or erosion
which responds only to seasonal changes. This. was used to determine
whether changes in the area under study are temporary (offshore-onshore )
or permanent (along-shore). The location selected for this was at
Arroyo Burro={Hendry's Beach}. In addition to the characteristic noted
above it is the mouth of an important drainage area and if any apprecia—
ble sediment had been brought down by a heavy runoff, the delta formed
would have been surveyed. Two ranges on West Beach (which is believed
to be stable ) are expected to show the same seasonal change.

12

be. The harbor fill area-inside the breakwater is the most
critical area. Here the rate of accretion can be calculated readily.
The outline and profile of the fill at the start of the surveys is
known and complete outlines and profiles were made at each regular
hydrographic survey. To establish a rate-of-fill, regular checks
of the principal fill area were made at shorter intervals. These
checks consisted of simple measurements made from fixed poies in the
fill to the edge of the breakoff (which is very abrupt and mkes a de-
finite point). Slope of fill (angle of repose) remains constant and
accretion was determined.

Gc. The erosion areas at Palm Park extending eastward to the
anticipated limits of the principal erosion of the two-year cycle
(between dredgings). This comprises the bulk of the surveys since
the easterly limit is not known.

Wave Recorders — Pressure type wave recorders were installed at
Santa Barbara, Elwood, and Pt. Arguello. The Santa Barbara unit was
installed in 30 feet of water off the west end of the breakwater, with
the recording unit being located in the harbormaster's office. Asa
means of checking wave characteristics and to generally assume con-
tinuity of the wave record, a Beach Erosion 3o0ard step-resistance
gage and a Wark IX underwater pressure wnit were installed on the
Signal O11 and Gas Company pier at Elwood. Unexplained corrosion
of the contact points of the step-resistance gage prevented this gage
from yielding records; hence, it was removed from the pier.

The Elwood-Santa Barbara wave meters record highly refracted waves
just before they break on the channel shore. To get at more basic
wave information, it was decided to re-activate the Pt. Argyello re-
cording station so that unrefractel ocean waves could be compared both
with the channel waves and the deep-sea conditions as estimated by fore-
casts.

Wind Recorders — A "Dynes® type wind velocity and direction recorder
was installed at the harbormaster's office at the start of the study.
This instrument is basically a recording pitot tube - weather vane
arrangement. Its purpose is to keep track of influence due to winds
which might act to lower or reinforce arriving waves or generate currents,
and to allow appraisal of sand movements due to wind. In the event that
channel storms appear to be an important factor in the sand movement,
this would be a great aid in hindcasting local wave conditions due to
winds not shown on small scale meteorological maps. This instrument has
worked satisfactorily from the beginning and the winds appear to follow
a regular pattern with storm conditions rarely arising.

Summary - A summary of the work accomplished in the Santa Barbara
study is presented in the report Issue 8, Series 14 (see Part VI).
As indicated in this report most of the effort to date has been directed
toward installing equipment, instituting a program of measurement, and
obtaining data. Additional data should be obtained, however, in order

13

that usable, valid conclusions be reached. It can be said that the
work is now thoroughly organized; personnel are familiar with the
area and its problems, waves and winds are being recorded, and inex-
pensive program of measuring sand flow rates is underway, and enough
data have been obtained to determine the best course for future in-
vestigations. These results are somewhat intangible but probably

are most valuable if the work is continued, Suggestions are made
below for a continuing program. The emphasis needs to be on the
solution of general coastal problems and the relation of the physical
aspects of the ocean to the works of man on its shores. Data from
the field has been analyzed and reduced to usable form and made
graphical. The analytical part of the work should be done concurrent-
ly with the collection of additional data. When the statistics are
considered in the light of personal impression, which is sometimes
impossible to record, they will have mch greater meaning o

Recommendations - Various references have been made to the value
of having a continuing program of data collection and study. These
are now briefly reviewed. It is emphasized that the value of much of
this information lies in its continuity and even short gaps may | make
the record of limited value.

a. The wave recorders in Santa Barbara channel and on the open
coast should be mintained.

b. Surveys of the perimeter of the fill should be made twice
monthly with full suwveys at four to six month intervals so there are
flow rates of sand for short periods of time for correlation with wave
action.

Both of these programs should be carried forward concurrently until
at least a full year of record is obtained. This is particularly im-
portant if the dredging is to be delayed a year at a time that appears
to be a maximum in sand flow. This should be started as soon as
possible so that there will be no break in the record between the end
of the present investigation (January 1, 1951) and the start of any
additional one.

¢. The movements of the sand before it reaches the harbor should
be studied with a view to determining its primary source and the
route and means by which it is moved into the critical area. It is
particularly desirable to know whether an appreciable amount of the
sand comes from beyond Point Conception. A study of mineral content
of the sand and a petrological study of the rocks being moved would be
of value in tracing the source. Roundness and sphericity ratios be-
tween the quartz and Feldspar might help determine the distance the de-
tritus travels.

d. Qonsiderable time needs to be spent in investigating the basic

causes of sand movement. Present and past data need to be considered
in the light of detailed observation of a large area of beach.

14

@. Waves need to be hindcast for the several stated periods so
that past sand flow data will be comparable on a cause-and-effect basis
with waves.

f. Other surveys which would be of value are (1) check surveys on
_ the various profiles under study, especially at the feeder beach, (2)
surveys of beaches much further to the west (near Pt. Conception),

(3) pump probings to determine thickness of sand at westerly beaches
which may be a major source of sand supply.

ge The nature of the bottom off Point Arguello and the possibility
that sand is moving around the point in 60 feet of water should be ex-
plored.

WAVE RECORDERS AND WAVE DATA

For the past few years a number of wave recorders have been in-
stalled and operated along the Pacific Coast more or less continuously
by various institutions and government agencies. The University of
Galifornia, Berkeley, in cooperation with the U. 5. Navy, instituted
a program of wave recording at Several points along the Pacific Coast
in 1947. Gharts from these records have been analyzed for the sig-
nificant wave height and the wave period. Wave direction also was
determined in some instances from synoptic weather charts by the wave
forecasting method. These various data were summarized in tabular
form and distributed to various individuals, commercial concerns, and
government agencies that were interested in this type of informtion..
In a limited number of cases summries of wave data have been pube
lished. (1) (2)

As part of this contract with the Beach Erosion Board the various
wave recorders previously installed in cooperation with the Navy were
maintained in operation and the records analyzed for the significant
height and period. Because of the limited funds available for this
phase of the study no purchase of recording equipment, cable, and off-
shore pressure elements was possible; hence, as an offshore unit be—
came inoperative and required replacement the station was discontinued.

Stations that once were in operation included Heceta Head, Oregon;
Pt. Pinos, Galifornia; Pt. Sur, California; Pt. Arguello, California;
and Santa Barbara, California. A summary of dates for which wave data

(1) An Analysis of Bata from Recorders on the Pacific Coast of the U.S.
by Re, L. Wiegel, Trans. Amer. Geoph. Union, Vol. 30, No. 5, 1949

(2) Southern Swell Observed at Oceanside, California from May through
September, 1949, by R. L. Wiegel and H. L. Kimberley; Trans. Amer.
Geoph. Union (in press).

15

are available at these and other Pacific Coast stations is presented
in the report Issue No. 4, Series No. 14 (see Part V1).

Recommendations — It is highly desirable that certain key wave re—
cording stations along the entire Pacific Coast be maintained in con-
tinuous operation to provide (a) statistical wave data for design pur-
poses, (b) data for checking wave hindcasts which might be desired for
intermediate localities, and (c) data for the development of storm
tracking techniques and other investigations of tth peacetime and
wartime importance.

The most expensive part of wave recording installations is the
armored submarine cable, Fortunately, the cables at the inactive
California stations are still usable. The cable at Heceta Head, Oregon,
probably is no longer usable; however, a supply of cable for this in-
stallation is in storage at Astoria, Oregon.

CLASSIFIED RESEARCH

Because of the classification of the research work completed
under this task, no summary of the material is presented in this
report. It should be mentioned, however, that the funds expended
in this investigation were greater than originally anticipated;
consequently, the scope of the investigations reported above and con-
ducted under this contract was of necessity reduced.

LIST QF REPORTS

Institute of Engineering Research
(Series No. 14)

No. 1

(Classified Research) - 3 Vols.

No. 2 — The Relationship Between Sand Size and Beach Face Slope: W.
N. Bascom, April 1951

No. 3 — Initial Surveys and Instrumentation; Sand Transport Study,
Santa Barbara, California, W. N. Bascom.

No. 4 — Wave Records on the Pacific Coast of the United Statess J. W.
Johnson, September 1950.

No. 5 — Sand Studies in Two Dimensional Wave Motion: E. A. Shay and
J. W. Johnson, November 1950.

No. 6 — Influence of Groins on Beach Stabilization; &. A. Shay and J.
We Johnson, January 1951.

No. 7 — Model Studies on the Movement of Sand Transported by Wave
Action Along a Straight Beach: E. A. Shay and J. W. Johnson,
February 1951.

16

No. 8 ~ Investigation of Coastal Sand Movements Near Santa Barbara,
California; W. N. Bascom, January 1951, Two parts.

No. 9 - Final Report on Sand Transportation by Wave Action: May 1951.

Ge OP) Ee ae

ANNOUNCEMENT QF PUBLICATION

a

The Beach Erosion Board announces the publication
of its Technical Memorandum No. 25, “The Slope of Lake Surf
aces Under Variable Wind Stresses” and Technical Memorandum
No. 26, "Sand Movement on the Shallow Inter-Canyon Shelf At
Ia Jolla, California.” Copies are being mailed to those
individuals and institutions on the mailing list for tech-
nical publications.

A limited number of copies are available for dis-—
tribution upon request to the President, Beach Erosion
Board, Corps of Engineers, 5201 Little Falls Road, N. W.,
Washington 16, De Co

ne,

DISCUSSION

A METHOD FOR DRAWING ORTHOGONALS SEAWARD FROM SHORE

The Bulletin is always glad to receive discussion of its articles,
and is pleased to present the following discussion of Mr. Saville's
article “A Method for Drawing Orthogonals Seaward from Shore™ which
appeared in the October 1951 issue of the Bulletin. The discussion is
by Mr. Kenneth Kaplan of the San Francisco District, Corps of Engineers.

In 1949 and 1950 this office was engaged in a general study of
possible small-craft harbors on the northern California coast. This
study required the drawing of many refraction diagrams, and for conven—
jience, many refraction fans. The first attempts at drawing these fans
were mde merely by reversing Isaac's orthogonal technique; that is
using for Aa that value determined from the standard nomograph with
the calculated Al/Lay value and a value for angle designated by the
author as @’ . This method, quite naturally, was found to be highly
inaccurate for any situation in which the Aa was relatively large.

Accordingly, Mr. R. W. Lowe, formerly of this office, developed,
in late 1949, a method which essentially consists of taking the first
approximation of a successive approximation series for the determination
of Aa . The angle between the level line between contours and the
normal to a seaward projected orthogonal is measured (call it @’ ) and
a value (say) da’ is determined from Isaac's nomograph with this and
the correct 44/La, value. These two values @’éAq’are added to find
the approximate value of @ , which in turn is used to find the ap—
proximately correct 4@ . The method is simple, requires the use of
no protractors (the drafting machine's two arms are ideal), and permits
the drawing of orthogonals well within the accuracy desired.

The method the author presents is, of course, a refinement of the
above but, since it makes necessary the use of additional protractors,
I believe the refinement introduced is unwarranted. For the construction
of a fan diagram either method will give approximately the same results,
and the simpler one is to be preferred. In addition, an orthogonal
constructed by use of either method cannot safely te used as a true
orthogonal but merely as an indication of the correct deep-water position
and direction of approach.

This last statement needs some amplification. A level line between
two contours is established by averaging the angles between a projected
orthogonal and the two contours. (See Johnson, O'Brien and Isaacs, H. 0.
Publication No. 605, page 26, step 6). Reference to the following
figure shows that a level line so determined with a shoreward projected
orthogonal may wel] differ from one determined with a seaward projected

18

ANGULAR DIFFERENCE

SHOREWARD DRAWN

SAN. FRAN. METHOD

SAVILLE METHOD
MAXIMUM

BOLINAS LAGOON

ORTHOGONALS:
SHOREWARD PROJECTED.

SEAWARD PROJECTED
(SAN FRANCISCO DIST. METHOD)

DEPTH CURVES IN -—- SEAWARD PROJECTED.
FATHOMS, SMOOTHED (SAVILLE METHOD )
FROM U.S.C. &G.S.

FIELD SHEET H-4975

10

COMPARISON OF METHODS OF
DRAWING ORTHOGONALS

Figure |.

orthogonal. The figure is exaggerated to be sure, but since the
determination of an angle of turning depends on the “accurate™
determination of the direction of a level line, it can be seen that
a seaward projected orthogonal need not coincide with one projected
shoreward over the same underwater topography. Since this is so,
it would seem that the simpler method of constructing a seaward
orthogonal is to be preferred.

2eep water ee

Contour evel fide ——

Level line ——sfalfow to %EoH

Jeep to Shallow

Contour

Sholloww wey te la

It might be pointed out that the means prescribed in H. 0. Publ.
No. 605 for the determination of a level line is the one mjor weakness
of the orthogonal method as presented in that paper. Assumption 5 on
page 19 requires that a level line (make) "....equal angles with the
adjacent contours ...", that is, that its direction is to be determined
by a normal to a line representing the gradient between contours. An
orthogonal projfcted rarely coinciies with this direction of shortest
distance between contours.

Figure 1 is a drawing comparing the accuracy of the two methods
of seaward orthogonal projection with a standard shoreward pro jection.
It was constructed by first drawing a standard orthogonal, and with
the shallow water position and direction so determined constructing
the two seaward projected orthogonals. The total angle of turning is
indicated by the azimuths given at the seaward and shoreward ends of
the orthogonals.

Author's Comments:

It is interesting to note the similarity in the two mthods of
solution to the problem of drawing orthogonals seaward from shore.
The use of the new protractor represents a logical extension of Mr.
Lowe's method, and since it substitutes a mechanical determination of
the angle change for a mathematical computation, would seem to be
preferable. Both methods, as indicated in Mr. Kaplan's figure, give
almost identical results.

20

It might also oe noted that, in actual practice, the direction
of level bottom is usually determined by mentally interpolating an
extra contour midway between the two contours being considered, and
taking the direction of level bottom as a line tangent to this contour
at its intersection with the orthogonal. It is thought that this
method giyes a more accurate determination than that given in H. Q.
Publ. No. 605 and referred to by Mr. Kaplan, and, in addition, has the
advantage of giving the same direction for level bottom regardless of
which direction the orthogonal is being drawn in,

21

_ ses

ON THE EXPANSION OF SEA WAVES DUE TO THE EFFECT OF WIND
(based on measurements in shallow tidal waters)

by

Hans Ulrich Roll

This paper appeared in the German publication
“Deutsche Hydrographische Zeitschrift", Vol. 2,
No. 6, 1949. An English translation is on file
at the Beach Erosion Board Library. An abstract
of which is presented herewith.

Recent wave and wind measurements made in the tidal waters of
the "Neuwerk Shallows® in the North Sea at the mouth of the Elbe
River are described and are compared with the theoretical results based
on the methods employed by Sverdrup and Munk. Most wave measurements
were made where the wave length-water depth ratio was slightly greater
than 2, the accepted transition value between deep and shallow water
wave theory. However, in slightly over 80 per cent of the cases, the
maximum deviations of wave height and velocity from the deep water
values were only 7 per cent for the wave height and 4 per cent for the
velocity, so for at least 80 per cent of the cases it should be ex-
pected that the relationship between_wave velocity and length would be
satisfactorily expressed by C =/$44, as used by Sverdrup and Munk.
The wave velocity measurements have been adjusted where necessary for
the effect of tidal currents.

The adjusted values of wave velocity and the measured values of
wave length follow the curve of the theoretical relationship
(c=(Zt Qw-Q 2ry7 ) relatively well (shown in Figure 1) ex-

Zr QwtQe £(Qyt @.
cept that the main body of plotted points lies below the curve, in-
dicating that the theory seems to represent the upper limit of the
, measured values rather than their average. As shown in Figure 2 the ©
2.author relates this negative deviation of measured +heatwinead wave
velocities as computed from the LaPlace formla C= 5 tan, a theprelical

to the wave steepness and wind velocity. Empirically it is indicated
that this negative deviation becomes larger as the waves become steeper
with a fixed wave length, and becomes smaller with an increase in wind
velocity.

The empirical relation between wave steepness and wave age as
developed by Sverdrup and Munk is compared with the measured values at
Neuwerk, and is shown in Figure 3. The author suggests that it
appears problematical that this relatively wide dispersion of plotted

22

400

200

100

Wave velocity C in cm./sec.

oa ile
fo} oO

BS
{o)

w
°

Wave velocity "C' depending on wave

wow

length L

3

cs)
@
(77)
Ss
E
roy
=
oO
> 20
=
rz)
&
@
>
wy)
>
iS)
=

iGo {L bee 2
Theory:¢ ae — + Ras
r

wree)

200 300 400 500

214+—~ 88

(oa T T To Scar T T =a

Percentage Deviation AC of the measured wave
velocity C from the Laplace Formula (C* g= tsh@zh)
as a function of the reciprocal steepness L/H and
the wind velocity U Lode

< em/s —+
WE = 4

—_—

+——+
25s _, 7103 40

,7 Figures = Number of single values averaged
Reciprocal steepness

- Reciprocal steepness L/H as a function
“ wave age C/U

Number of measurements:

Values used by Sverdrup and Munk
Schumacher
° Hinterthan

Figure 3 Neuwerk measurements

Wave length L in cm. ——e

600 700

90I gOl ~Ol P10) | 20!

182 SlUaWaINSDAW YyJaMNal e
61 UNI puD dnipseAs Aq pasn sanjoA +

eVi6

sjuawesnsoaw 4O JequNN
2n/J6 yo suoijouny so 2/46 puo ave)
4 YD}2) 2ADM JO JOUANIjUI

ae
YUN) PUD dnspsaas +

YUN puDd dnspseAS

Ol

\-Ol ° 2-0l

> a4nbi4

points can be represented by a curve, but if it is attempted "it
might be expedient to depart from the curve given by Sverdrup

and Munk somewhat in the manner indicated by the dashed line in
Figure 3." He states further that a very considerable increase in
steepness is assumed with the youngest waves immediately after their
formation, then their steepness very quickly approaches the relation
as shown by the dashed line in Figure 3, and that the relationship
between steepness and wave age is not yet completely explained.

The influence of the fetch on wave height and wave age as de-—
veloped by Sverdrup and Munk is compared with that indicated by the
Neuwerk wave measurements in Figure 4, and generally speaking, agree-
ment may be regarded as satisfactory. Differences that are apparent
are believed by the author to be not wholly the result of inaccurracies
in measurement, but probably are due more to the minor descrepancies
previously shown between theory and measured values. However, the
author regards the results of the Neuwerk wave and wind measurements
as a verification of the Sverdrup-Munk theory on the growth of sea
waves due to the influence of the wind.

25

THE GENERATION OF WATER WAVES BY WIND

by

Gerhard Neumann

This paper appeared in the German publication
"Deutsche Hydrographische Zeitschrift", Vol. 2,
No. 5, 1949. An English translation is on file

' at the Beach Erosion Board Library. An ab-
stract of which is presented herewith. The au-
thor is. currently a visiting professor to the
staff at New York University

~

Glassical considerations of wave formation by others have been
investigated by the author, and a new treatment of this problem is
presented. Theory is presented for computing the length and amplitude
of initial waves generated by incident winds of different velocities,
which ig valid until the initial waves attain a steepness where they
are no longer stable and turbulence occurs. The energy supplied by
the wind to the water surface is computed, assuming dynamic equilibrium
of the effective shearing stress of the wind and resistance to this
stress offered by the water surface. An empirical relationship be-
tween the effective shearing stress of the wind and the wind velocity
has been determined. Surface resistance has been considered as the
resistance due to pressure differences for both capillary and gravity
waves, and that due to frictional stresses, Values of a “resistance
coefficient™ have been computed for different values of wind velocity,
and this coefficient is indicated empirically to be simply proportion-
al to the wave steepness. The energy dissipated by the wave motion
is considered for a water layer of finite depth, and is computed as -
that consumed by inner friction in the water and that dissipated
through bottom friction. For the generated wave to be propagated
and maintained, it is necessary that the energy transmitted to the
wave by the wind be greater than that dissipated by the wave motion.
From this consideration, equation 18 below is obtained.

i P _ @,=o* a_[xXOv /

sels toh pcan ease 18
Ce xvas OI cay) meme oF
where ¢ j

kinematic viscosity
= Wave no. = 2%7/y
water depth

wave amplitude

P= density of air

@ = density of water

S = screening coefficient

Um= Wind velocity

@ = wave transmission velocity

AYRuU

"ou

26

It follows that there is a lower limit of wind velocity below which
waves will not be generated. The change in the wave amplitude with
time is computed from a consideration of the difference of the energy
supplied and that dissipated by the wave with respect to time, and
can be expressed in the following form:

da_¢ 0 w-0)7 Be) URED
SS oes toh y (2 oe 20
at 2 oO (% 2) = is ” Sib (2xh) & (0)

Integration of equation 20 gives:

GaGa 2a
Cy C1-CnQ ag
where a is the wave amplitude at the beginning of the time interval
and ¢ s 7 :
2 8 OBC) ord Gye Buin =p LAD

BPD G é sith (2h)

Experimentally it has been shown that there’ is a definite maximum wave
amplitude for a given wind velocity which cannot be exceeded regardless
of the duration of the wind velocity.

The author deduces that any wind with a velocity greater than 69.5
cm. per second is capable of generating waves, and the combined effect
of capillarity and gravity produces two separate wave trains. Table I
gives the computed values of the length and height of wavesof maximum
steepness that can be generated in depths greater than the wave length,
by winds with velocities from 70 to 122.7 cm. per second.

TABLE I

oy (cm/sec 70 80 90 LOO

Toes (cm) 3 205 DAS a Bowl, Os80 2) Sel Oo57 98 GOS On44

& (cm/sec): 2303 ; 26.9 3) BOLO ; 33.2
Zofp : 0.00782 —-::0.01590 : 0.0254 : 0.0366
0.00591 ; 200343: 0.00279 : 024 0. OOQLY/

2 a =H (cm): 0.032 0.017: 0.118 0.0055 : 0.264 0.0032 : 0.49 0.0022

moet Ym (cm/sec) 22 rou

Xo (em) sOe46) Oo28
@ (cm/sec) : Aline
2o/A 5 :0.069 0.00184:

2a. =H (cm):1.444 0.0010 :

27

ai Qt

With an increasing wind velocity,
the shorter, capillary waves de-
crease rapidly in contrast with
the increasing gravity waves,
until with wind velocities of about
90 to 100 cm per second they
practically disappear. It is
indicated that waves with the
maximum stable steepness ratio
(height to length) of 1 to 7 are
attained with a wind velocity

of about 122.7 cm, par -3eand -

The plot in Figure The 3rd sentence should read; "The plot in

~ itial waves with th Figure 1 shows graphically — the variation of the
Tables II a and b g wave length and stationary height for initial
puted time required waves with the wind velocity."

LAC

itial wave to "mtu. S
or to grow to a stationary con-
dition, for wind velocities of 80 pa one

and 122.7 cm. per second. Ds = oO
} Si iy SC
Further computation has been Figure 1 — Wave length }, and wave
made by the author for the gen- height 2 ag with stationary in-
eration of waves by winds over itial waves in their dependency on
shallow water layers, or where the wind velocity v.

the wave length is greater than

the water depth. It is signifi-

cantly shown that as the water

dep thzbeeause for a given wind velocity the length of the ‘initial waves

“becomes shorter, and the wind velocity necessary for the generation of

elearly ena uee eile wave trains becomes greater. Ths time required

for “mature'* waves to be gensrated in shallow water depths is essential-
ly less than that required for greater depths. Table III gives, for
several water depths, the lengths of initial waves with a stsepness
(amplitude divided by wave length) of 0.07, and also the wind velocities
required to generate these waves.

TABLE II a
1) Principal Wave ( Xo = 3.71 om. )

Bl Cite OREO OL

0.
scicr 0 Loi Lo
2) Secondary Wave ( Ns = 0.80 cm.)

cn O 0.0005 0.0010 0.0020 0.0027

a
G Sec. 0) 0.09 0.205 0.59 1.86

28

TABLE II b

a cm. 0) Ail: Oe One 0.4 0.5
t sec OQ WA BAe Ale 6255 O35
a cM. On6 0.7
t sec. 138 272
TABLE IIT
h_ (cm) Ap Gm. Um em/sec
055 1,35 204
i@ 2,75 160
0) 4545 135
BAO) 6,10 130
5,0 8,5 125
AO 9,8 1232
10,0 10,3 12S I.
10,5 123,0
Co

Table IV indicates, for a water depth of 1 cm and wind velocity of
160 cm. per second, the time required for the initial wave of steepest
form ( Ag = 2.75 em.) to approach the stationary amplitude.

TABLE IV

BREACH BROSION STUDIES

The principal types of beach erosion control studies of specific
localities are the following:

a. Cooperative studies (authorization by the Chief of Engi-
neers in accordance with Section 2, River and Harbor Act
approved 3 July 1930).

be Preliminary examination and surveys (Congressional author-.
ization by reference to locality by name).

ce Reports on shore line changes which may result from im=
provements of the entrances at the mouths of rivers and
inlets (Section 5, Public Law No. 409, 74th Congress).

d. Reports on shore protection of Federal property (author-
ization by the Chief of Engineers).

Of these types of studies, cooperative beach erosion studies are
the type most frequently made when a community desires investigation of
its particular problem. As these studies have greater general interest,
information concerning studies of specific localities contained in these
quarterly bulletins will be confined to cooperative studies. Information
about other types of studies can be obtained upon inquiry to this office..

Cooperative studies of beach erosion are studies made by the Corps
of Engineers in cooperation with appropriate agencies of the various
tates by authority of Section 2, of the River and Harbor Act approved
5 July 1930. By executive ruling the cost of these studies is divided
equally between the United States and the cooperating agency. Informa-
tion concerning the initiation of the cooperative study may be obtained
from any District Engineer of the Corps of Engineers. After a report on
a cooperative study has been transmitted to Congress, a summary the reof
is included in the next issue of this bulletin. A list of authorized
cooperative studies followse

AUTHORIZED COOPERATIVE BEACH EROSION STUDIES
NEW HAMPSHIRE

HAMPTON BEACH, Cooperative Agency: New Hampshire Shore and Beach Pre=
servation and Development Commission.

Probkeme To determine the best method-of preventing further erosion
and of stabilizing and restoring the beaches, also to
determine the extent of Federal aid in any proposed plans
of protection and improvement.

30

MASSACHUSETTS

PEMBERTON POINT TO GUENET POINT. Cooperating Agency: Department of
Public Works, Commonwealth of Massachusetts.

Problem: To determine the best methods of shore protection pre-
vention of further erosion and improvement of beaches,
and specifically to develop plans for protection of
Crescent Beach, The Glades, North Scituate Beach and
Brant Rock.

STATE OF CONNECTICUT. Cooperating Agency: State of Connecticut (Acting
through the Flood Control and Water Policy Commission).

Problem: To determine the most suitable methods of stabilizing and
improving the shore line. Sections of the coast are
being studied in order of priority as requested by the co-
operating agency until the entire coast has been included,

NEW YORK
JONES BEACH. Gooperating Agency. Long Island State Parks Commission
Problem: To determine behavior of the shore during a 12-month
cycle, including study of littoral drift, wave refraction
and movement of artificial sand supply between Fire
Island and Jones Inlets.
NEW JERSEY
OCEAN CITY. Cooperating Agency: City of Ocean City
Probleme To determine the causes of erosion or accretion and tl
effect of previously constructed groins and structures,
and to recommend remedial measures to prevent further

erosion and to restore the beaches.

STATE OF NEW JERSEY° Cooperating Agency; Department of Conservation and
Economic Deve lopment.

Problems To determine the best method of preventing further erosion
and stabilizing and restoring the beaches, to recommend
remedial measures, and to formulate a comprehensive plan
for beach preservation of or coastal protection.

VIRGINIA

VIRGINIA BEACH, Cooperating Agency: Town of Virginia Beach.

32

Problem: To determine the methods for the imrpovement and pro-
tection of the beach and existing conerete sea wall.

FLORIDA .
PINELLAS COUNTY. Cooperating Agency: Board of County Commissioners.

Problem: To determine the best methods of preventing further
recession of the gulf shore line, stabilizing the gulf
shores of certain passes, and widening certain beaches
within the study area.

LOUISIANA

LAKE PONTCHARTRAIN. Cooperating Agency: Board of Levee Commissioners,
Orleans Lévee Bistrict. :

Problem; To determine the best method of effecting necessary re—
pairs to the existing sea wall and the desirability of
building an artificial beach to provide protection to
the wall and also to SRE additional recreational
beach area,

TEXAS

GALVESTON COUNTY. Cooperating Agency: County Commissioners Court af
Galveston County.

Problem: To determine the best method of providing a permanent
beach and the necessity for further protection or extend-
ing the sea wall within the area bounded by the Galveston
South Jetty and Hight Mile Road.

To determine the most practicable and economical method

of preventing or retarding bank recession 6h the shore

of Galveston Bay between April Fool Point and Kemah.
CALIFORNIA

STATE OF CALIFORNIA. Cooperating Agency. Division of Beaches and
Parks, State of California.

Problem; To conduct a study of the problems of beach erosion and
shore protection along the entire coast of Califomia.
The current study tcovers the Santa Cruz area.
WISCONSIN
RACINE COUNTY. Cooperating Agency: Racine County.

Proolem; To prevent erosion by waves and currents, and to

32

determine the most suitable methods for protection,
restoration and development of beaches.

KENOSHA, Cooperating Agency: City of Kenosha.

Problem; To determine the best method of shore protection and
beach erosion control.

OHIO

STATE OF OHIO. Cooperating Agency: State of Ohio (Acting through the
Superintendent of Public Works).

Problem: To determine the best method of preventing further
erosion of and stabilizing existing beaches, of re-—
storing and creating new beaches, and appropriate
locations for the development of recreational facilities
by the State along the Lake Erie shore lines. Sections
of the coast are being studied in order of priority as
requested by the cooperating agency until the entire
coast has been included.

TERRITORY OF HAWAII

WAIKIKI BEACH
WAIMHA & HANAPEPE, KAUAI. Cooperating Agency: Board of Harbor Com—
missioners, Territory of Hawaii.

Problem: To determine the most suitable method of preventing
erosion, and of increasing the usable recreational
beach area, and to determine the extent of Federal
aid in effecting the desired improvement.

BEACH EROSION LITERATURE

The first national conference on Coastal Engineering, sponsored
by the Department of Engineering and the Division of Engineering
Extension of the University of California, was held at Long Beach,
California, in October 1950. The-Proceedings of the conference, pub-—
lished by the Council on Wave Research, my be ordered from Professor
J. W. Johnson, Waves Council, 245 Hesse Hall, University of California,
Berkeley 4, California. A second conference was held in Houston, Texas,
in November 1951, the Proceedings of which will probably be publisied
at a later date.

The contents of the Proceedings of the first conference are as
follows: \

Part I
Fasic Principles of Wave Motion

Chapter 1
Origin and Generation of WaveS ..cccoccccscccsccvs0cv0c0000000000 Lb
Walter H. Munk

Chapter 2
Blements of Wave! Pheorys erect clot sic cote oa lole 9 /e1e) ola) olollelo!m clellole clot ctula lolol omnes
R. Lo. Wiegel and J. W. Johnson

Chapter 3
The Transformation of Waves in Shallow Water ..cccosccceccccnsen0se AA
Martin A. Mason

Chapter 4
Rifraction and DPiftir@esion: Miaerams seo sooo fa cleric alot clea
James W. Dunham

Chapter 5
Nearshore Circulation ..c..coccacccccccccccnnrvcecverve000e000e00 DO
Francis P. Shepard and Douglas Inman

Chapter 6
Harbor Surging
Vito se Vanent and Joka He Carros. oc. insole ocr ter reO

Part 2
Basic Design Data
Chapter 7
Wave Recorders ....000 Bi I ORS Bc TRS eee RE OME Cet craton cle: saNtapa rane ysKeKoNmOG)

F,. B. Snodgrass

———————————

Chapter 8
Wave Forecasting and Hindcasting .occccccecccvccvvers 000000000000
Robert §. Arthur

Chapter 9
The Engineering Application of Sea and Swell Data ..ccccoccvccscve
Richard H. Fleming and Charles C. Bates

Chapter 10
Results of the Wartime Historical and Normal Map Program ...ocecece
H. Wexler and M. Tepper

Chapter 11
Goast and Geoddtic survey Tata e©evo0goodgoodco ooo eoondoon oo oOHvn co evoHe oe KaHF9 FC oCO 80 a 8
Rear Admiral Robert F. A. Studds

Chapter 12
The Bea ch Brosion Board eo0oo0ogno0nv gn egHeH Hoe FOF HeTHKOKHHFCeHOSFHKHHHAF9HFT09E8 9TH 709 O
Dabney O. Elliott

Part 3
Coastal Sediment Problems

Chapter 13
The Geological Aspects of Coastal Engineering ....ceccecccccvcce
John W. Handin

Chapter 14
Hstimating Quantities of Sediment Supplied by Streams to a Coast
Hans Albert Einstein

Chapter 15
Littoral Processes on Sandy (GoastS cccceevccccccccc0c 0020200000
Richard O. Haton

Chapter 16
Littoral Processes in Lakes e©eoovr0eo0gn0en000 GF G0HHA9eGHHDHST7FTHGCGHLHKCHKeGCO0SEBO
W. Ge Krumbein

Chapter 17
Contribution of Hydraulic Models to Coastal Sedimentation
Studies e©rcre0eo ooo Hn oo HoH OHH Ee HTD FCHoO CH CH OKFCHVKHFeF 90 eC 000970790 FF9T70F998 O80

Henry 38. Simmons

Chapter 18
Dredging at Inlets on Sandy Coasts e0n070 0000000000907 080009098090008
Berkeley Blackman

Chapter 19
The Seagoing Hopper Dredge @oo0o000007000000000000000000600°009909009099908
George P. Reilly

35

82

88

98

102

126

133

Wey)

“140

155

161

169

175

Part 4

SITE GRITERIA AND THE DESIGN AND CONSTRUCTION OF COASTAL WORKS

Chapter 20

Location of Har bors eoo0ern0eFF07HHHOOCOHDOHOCOHDHOFOODHOHHOOHLFHLFGHBF7HO0FF7OH9VO0O0

Kenneth P. Peel

Chapter 21

Factors Influencing and Limiting the Location of Sewer Ocean
Outfalls ooo0erG0eo00gv7LFT7HFOROoCOHOOSCHOHHOHOHO OCHO HO OHO ABHGFF0OHF0F LEC TCO KB GO

A. M. Rawm and F. R. Bowerman

Chapter 22

Seawalls and Breakwaters eooe770F07OoHO0FHFLOFOO7HO0F00000000

James R. Ayers

Chapter 23

©000002000000

The Hydraulic Model as an Aid in Breakwater Design .ccccccceecoce

Robert Y. Hudson and L. Frank Moore

Chapter 24

Design of Breakwaters 02000890000080000000000000000000000009000000

Kenneth Kaplan and Henry E. Pape, Jr.

Chapter 25

Breakwater Construction eo707FDF0F0LHOHHOHAOHXHFHHOOFFCOOHOOFOODeBeD0 FOF HOOD OO

A. Ge Streblow

Chapter 26

WASH Bldel Comsimmeinlonl cht JOuMEIOS5soca5oooaco0000G0000000000000
R. E. Hickson and F. W. Rodolf

Chapter 27

179

186

192

205

213

223

227

Pesicn and Construction Of sGrodns cole oc cisiclc(s oa c\ers olotclororofoler sorrento

Donald F. Horton

Chapter 28

° ° ©
Design of Piling ©000000000600080080000000000000000070000900008000

Jo Re. Morrison

Case Histories of Coastal Prox cts

Chapter 29

Part 5

History of Los Angeles Harbor ©0000000000000000000008000000090080

Ho Wo McQuat

Chapter 30

Santa Monica Bay Shore Line Development PlansS ....ccccecceccevven

A. G. Johnson

36

254

259

a7L

——————

— TLL

Chapter 31

History of Ocean Outlets, Los Angeles County Flood Control

DUS ga56 0000600000000 000000000 00000000000 sDnGuaGd0NbnoGOKD ili
Edgar C. Kenyon, Jre

Chapter 32
FES EOI? Oi) Colioimlosial Fae dOUMVEHOS ooocecageaoann oo an0eq0aoensen EY
Re BE. Hickson and F. W. Rodoif

Chapter 33
History of New Jersey Coastline eooov0eovonovgn0H GH CODD FH HHH KH OHH HFT 07FC OD 299
Ce ive Wicker

Chapter 34
By-Passing Sand At South Lake Worth Inlet, Florida......cccccoe 320
Joseph M. Caldwell

Chapter 35

Erosion and Corrosion on Marine Structures, Elwood, California. 326
He Je Schaufele

3%

Pree. a)

tot