bluuebunny/crossref_metadata_2025 huggingface dataset:
THE BRISTOL CHANNEL BARRAGE PROJECT
Authors: Wilson Eric Montgomery , Severn Brian , Swales Martin Carson , Henery Donald
Published: February 2019

The paper outlines a proposal to barrage the Bristol channel between Cardiff and Weston-supermare. The benefits from energy generation and to road communications are assessed in detail and m monetary terms. Benefits to navigation and drainage are discussed but not assessed. The effect of the barrage on tidal range, siltation and sediment movement is considered and a suggestion, previously made by others, for a larger international airport on land reclaimed from the enclosed area, is developed. Cost estimates for the proposal are made and it is shown that the benefit/cost ratio is greater than unity even when only energy and traffic are considered.
HYDRAULIC MODEL EXPERIMENT ON THE DIFFUSION DUE TO THE COASTAL CURRENT
Authors: Higuchi Haruo , Iwagaki Yuichi
Published: February 2019

The diffusion phenomena due to the tidal current and the longshore current inside and outside a harbor are studied m a hydraulic model experiment, for which the Kashima Harbor area is used as the prototype. The tidal current, the longshore current and the effect of density are taken into account, but the direct effects of wind and waves are not considered. A model of Kashima Harbor, with horizontal and vertical scales of 1/500 and 1/63 respectively, was constructed, and a semidiurnal tide generated by an automatically controlled pneumatic tide generator and longshore current by a water circulating system were provided for it. The water level at 4 stations and current pattern were measured. The diffusion of dyed water from instantaneous point sources and a continuous point source was investigated by the photographic method and dye concentration analysis.
SHEAR VELOCITY IN A TIDAL ESTUARY
Authors: Halliwell A. Roy , O'Connor Brian A.
Published: February 2019

A study involving the determination of the bed shear stress and thence shear velocity in the Narrows of the River Mersey (a well mixed tidal estuary) is described. The two dimensional equation of motion is examined and it is concluded that in order to determine the energy slope (S) (and thence the shear stress and shear velocity) it is essential to evaluate density, inertia and kinetic energy terms as well as surface slopes. Although the density term is much smaller than the other terms it is important at periods of low slack-water. Measurements of the various terms are described and attention is drawn to the difficulties arising m the case of the surface slopes. Comparison is then made between the values of the shear velocity as predicted from the energy slope and those obtained using velocity traverses throughout the depth and with measurements of velocity at three fixed positions near to the bed. Finally consideration is given to the relationship between the cross-sectional mean velocity (U), the depth-mean velocity (U) and velocity at 3ft. above the bed (U,) and the shear velocity obtained from the energy slope. It is concluded that there is good linear correlation of each of these velocities (U, U and U ) with the shear velocity throughout the tidal cycle except for the period around low slack-water.
BUOYANCY SPREAD OF WASTE WATER IN COASTAL REGIONS
Authors: Larsen Ian , Sorenson Torben
Published: February 2019

Waste water may due to buoyancy effects spread horizontally on top of the recipient. The spreading is chiefly determined by the buoyancy flux and to a large extent unaffected by dilution and diffusion. This phenomenon is of great practical importance for larger outfalls of waste or cooling water in coastal regions.
COMPREHENSIVE TIDAL STUDY OF THE ST. LAWRENCE RIVER
Authors: Ploeg J. , Kamphuis J.W.
Published: February 2019

The St. Lawrence River is a major waterway connecting the Port of Montreal to the Atlantic Ocean. As is the case with so many natural rivers, extensive dredging has been necessary to provide adequate navigation conditions. About 100 years ago the Ship Channel of the St. Lawrence River was at several places only 10 ft deep and 150 ft wide; presently it has a minimum depth of 35 ft and a minimum width of 800 ft. However, further improvements are necessary, to meet present and future navigation requirements . The Hydraulics Section of the National Research Council is studying improvement schemes by means of a hydraulic and a mathematical model of the St. Lawrence River from Montreal to Father Point, a distance of about 350 miles. The hydraulic model has been built to a horizontal scale of 1:2000 and a vertical scale of 1-120. The mathematical study uses a finite-difference approach, employing both explicit and implicit computational schemes. This paper describes the two studies and deals briefly with the merits of operating a mathematical and hydraulic model simultaneously.
MEASURING OF SQUAT IN THE FAIRWAY TO THE PORT OF LULEA, NORTH SWEDEN
Authors: Carlstrom Carl G.
Published: February 2019

The importance of knowledge of squat and expected underkeel clearance for ships passing a fairway is essential to the navigational safety and the economy of a harbour. In order to check the squat of ships in the fairway to the port of Lulea a photographic measuring method has been evolved and used in measurements on three different ships. Determining of squat is made by levelling the position of vessels in relation to water level at the berth before sailing and en route at measuring points along the fairway. The accuracy of measurements was determined by observations on reference staffs. The order of standard deviation is 1/2 inch, at 2,400 feet distance. Observations indicate squat ranging from 1 foot 5 inches at speeds of 9 knots to 2 inches at 3>7 knots. The measured squat corresponds rather good to tneoretically calculated values according to Woltiger and Shell/Sogreah. The measuring method used has reduced the field work. The greatest advantage is that adequate values of squat will be directly recorded with only a few corrections including irregular factors such as turbulent flow, hull deformations and variable channel sections. A condition is however sheltered water and possioilities of solid foundation for instrument arrangement. 1499
FLOATING BREAKWATER FOR RESERVOIR MARINAS
Authors: Chen Kenneth , Wiegel R.L.
Published: February 2019

The concept of multiple use of reservoirs is resulting in the construction of marinas for recreational boating requiring breakwaters that can function for a large range of water levels A typical set of design criteria is an average water depth of 20 to 25 feet, wave lengths from S to 60 feet (wave periods of from 1 to 4 seconds) and wave heights from J to 5 feet Calculations based on Bulson's results showed a pneumatic breakwater to be too expensive An extensive literature search revealed that floating structures based upon the concepts of large effective mass or moment of inertia resulting from "entrained" water, or structures which can dissipate energy might be more effective than one of the floating bag types of breakwaters Several new-types of moored floating structures which combined two or more of the concepts mentioned above were tested in a wave tank, and several of the devices appear to have merit in that they were reasonably small compared with the longest design wave length and could reduce the highest design incident wave height to less than one foot, prototype, in the lee of the breakwater.
RESONANCE OP MOORED OBJECTS IN WAVE TRAINS
Authors: Hermans A.J. , Remery G.F.M.
Published: February 2019

In this paper the resonance of a moored object in wave trains is discussed and demonstrated with the help of some results obtained from model tests with a right angled barge The measured results correspond well with a simple theory which calculates the slowly varying drifting force of regular wave trains.
OIL BOOMS IN TIDAL CURRENTS
Authors: Cross Ralph H. , Hoult David P.
Published: February 2019

The classic, and most effective way to prevent the spread of oil spilled in harbors is by surrounding the spill with a floating barrier, or boom In calm water, with no currents, early devices made from telephone poles and canvas were more or less effective In the presence of currents, however, and particularly with larger spills, the problem rapidly becomes more complex, and the rational design of oil booms requires an understanding of the behavior of the oil and the boom in the current This paper presents the results of an investigation into the oil holding capacity of a boom in a steady current, and the forces and moments acting on such a boom.
RESEARCH FOR THE COASTAL AREA OF THE DELTA REGION OF THE NETHERLANDS
Authors: Dronkers J.J.
Published: February 2019

Tidal computations, wave studies, refraction computations, and morphological studies are discussed and practical results are mentioned Theoretical investigations on refraction computations, in particular the accuracy, are dealt with in detail, because difficulties occurred in the practical applications A former study of Morra, based on Kalinske's work on sand transport, has also been discussed in some detail in the section on morphological studies.
TRAPPING OF OUTFALL CONSTITUENTS BEHIND SILLS
Authors: Carstens T. , Sjoberg A.
Published: February 2019

Communication Between sucn coastal resipients of waste water as Days and fjords ana tne ocean is often tnrougn an outlet of small cross section Ine comDineu effects of a topography with transverse riages ana a bracxisn surface layer creates a rather stagnant ooay of water. The ridge or sill ueflects tne tiaal currents away from tne bottom so that only the upper part of the water column is continually flushed Ine stability of the pycnocline prevents surfacegeneratea turbulence from penetrating aownwaras, so tne turbulence in the aeep pool is weak. A scneme nas oeen proposea to store tne nutrients of sewage outfalls Denma tne sill at urjacaK in tne Oslofjora Ine storage capability of that f^ora was estimatec for a conservative outfall constituent by means of a one aimensional aispersion equation From the analysis tne gams of aeep outfalls through aiffusors comparea witn surface outfalls can De estiniatea for various perioas between aeep water inflows, wnicn are observea to occur..
SUSPENDED LOAD CALCULATIONS IN A TIDAL ESTUARY
Authors: O'Connor Brian A.
Published: February 2019

The present work describes the derivation of equations which can represent the vertical distribution of sediment in a well mixed tidal estuary The starting point for the analysis is the two dimensional longitudinal equation of motion, including the longitudinal salinity gradient term Equations are given which represent a steady state sediment profile and it is shown that these are similar to the expression used in urn-directional flow e g Rouse's equation It is argued that the derived equations could be applied to a real estuary, subject to certain restrictions on sediment size and estuary type An application of the theoretical equations to the Mersey Estuary indicates reasonable agreement between observed and predicted sediment quantities for medium and coarse sand particles Agreement is shown to be worst for fine grained sediments and it is concluded that much better results can be obtained by using the non-steady one dimensional sediment distribution equation in discrete steps throughout the tidal cycle.
PARTICLE VELOCITY MEASUREMENTS WITH A LASER DEVICE
Authors: Greated C.A. , Webber N.B.
Published: February 2019

A laser velocimeter has been used to measure particle velocities in a turbulent suspension in open channel flow. Both mean and fluctuating velocity components can be determined and the system may also be used to give records of instantaneous fluid velocities.
STATISTICAL PREDICTION OF HURRICANE STORM SURGE
Authors: Yang C.Y. , Parisi A.M. , Gaither W.S.
Published: February 2019

High water associated with a hurricane is an important design parameter in coastal engineering Long range rational predictions can be made on the basis of Gumbel's theory of extremes and Wemelsfelder's theory respectively Fundamentals and underlying assumptions of the two theories are investigated and predictions are made for Breakwater Harbor, Lewes, Delaware, and Atlantic City, New Jersey Gumbel's theory is found satisfactory according to a criterion A crucial point, the ground rule of counting exceedances, is found to be vague in Wemelsfelder's method The ground rule must be made definite in a meaningful prediction.
TURBULENCE IN HURRICANE-GENERATED COASTAL CURRENTS
Authors: Murray Stephen P.
Published: February 2019

Wind and current meter records taken during the passage of a hurricane were subjected to time series analysis Filtering techniques isolated the speed fluctuations m the 10-60 CPH frequency band These turbulent fluctuations proved to follow the Gaussian distribution for both wind and current With the passage of the storm front the turbulence intensity of the wind actually decreased, while, on the other hand, the turbulence intensity of the current rose to extremely large values, even exceeding 27 percent of the mean flow speed Three phases of the storm were examined separately, and the energy density of the wind varied with the -1 power of the frequency in all phases With respect to the energy density of the current, a -1 power dependency on the frequency was approximated by the first two phases, whereas m the third phase, which was the most intense, the energy density varied approximately as the -0 5 power of the frequency The characteristics of the spectra indicate that there is little direct transfer of energy from the wind to the current m the frequency range studied Energy is passing into the 10-60 CPH band of the current from still lower frequencies.
FODBL STUDY OF TRANSFORMATION OP TSUNAMIS IN URADO BAT
Authors: Nakamura Shigehisa , Iwagaki Yuichi , Tsuchiya Yoshito
Published: February 2019

For the city and harbour of Kochi, including Urado Bay, facing the Pacific Ocean, an experimental study has teen carried out on the problem of protection from tsunami disasters, and future harbour planning; that is, dredging, reclamation and construction of breakwaters against tsunamis. A hydraulic model of horizontal scale 1/250 and vertical l/lOO was used according to Froud's similitude. The transformation of the design tsunami m the hay was studied to find the effect of the tsunami breakwaters, dredging and reclamations by use of the model which was able to reproduce the Chilean Tsunami.
TSUNAMIS SOME LABORATORY AND FIELD OBSERVATIONS
Authors: Raichlen Frederick
Published: February 2019

A unique laboratory facility to generate waves by impulsive movements of the bottom of a wave tank is described and examples of the wave forms which result are shown An analytical model is presented for the case of rapid bottom movements which describes, in a qualitative way, certain features of the experiments Marigrams from various field stations for the tsunamis from the Chilean earthquake of I960 and the Alaskan earthquake of 1964 have been analyzed using spectral analysis techniques to determine the harmonic components of these records Comparisons are made between the spectra of the two tsunamis at each of several locations.
HEAD LOSS AT TSUNAhl-BBEAKWATER OPENING
Authors: Ito Yoshito
Published: February 2019

The head loss at breakwater opening is an important factor for evaluating the effect of breakwaters against tsunami. This paper examines the coefficient of the head loss term in the equation of motion by comparing the results of numerical calculations with the actual record observed in the Port of Ofunato at the time of 1968 tsunami. Numerical calculations are repeated changing the head loss coefficient from zero to 3.0 with the interval of 0,5. The calculated water level variation is quite different from the record if no head loss is taken into consideration. Although the most suitable value of the coefficient is not definitely determined, the value of 1.5> which has been adopted in our previous calculations, seems to be reasonable for practical purpose.
RESONANCE IN HARBORS OF ARBITRARY SHAPE
Authors: Lee Jun-Jen , Raichlen Frederic
Published: February 2019

A theory is presented for analyzing the wave induced oscillations in an arbitrary shape harbor with constant depth which is connected to the open-sea The solution is formulated as an integral equation which is then approximated by a matrix equation The final solution is obtained by equating, at the harbor entrance the wave amplitude and its normal derivative obtained from the solutions for the regions outside and inside the harbor The results of experiments conducted using a harbor model of the East and West Basins of Long Beach Harbor (Long Beach, California) are presented and compared to the theory Good agreement has been found between the theory and experiments.
SPECTRAL RESPONSE OF HARBOR RESONATOR CONFIGURATIONS
Authors: James William
Published: February 2019

An outline is given of methods devised recently "by the author to predict the spectral response of rectangular resonators, and to improve the response of resonators generally A simple small scale acoustic model of the ocean-resonator-harbor configuration was developed and is described The acoustic "ocean" is effectively decoupled from the rest of the system by means of sound absorbent material placed along the "infinite" boundaries, and standard audio-frequency equipment is used The results demonstrate that the open end contraction for rectangular resonators may not differ significantly from the contraction for resonators of similar geometry placed in a semi-infinite (or effectively decoupled) wave channel, at least if the wavelengths are not smaller than the width of the harbor entrance channel.
TIDAL MOTION IN BAYS
Authors: Shemdin O.H. , Forney R.M.
Published: February 2019

A method is proposed to investigate periodic tidal motion in single or multiple basins connected to the ocean by an inlet Non-sinusoidal tidal motion in the ocean and square friction law in the inlet are both considered The method is applied to Boca Raton inlet, Florida The calculated tidal elevation and velocity in the inlet are found to be in reasonable agreement with measured values The bottom shear friction coefficient is defined.
ON THE GEOMETRICALLY SIMILAR REPRODUCTION OF DUNES IN A TIDAL MODEL WITH MOVABLE BED
Authors: Yalin M.S.
Published: February 2019

A model design method is suggested which is based on the principles of the theory of dimensions and which is evaluated by experimental relations for the geometric properties of dunes. The model is distorted and, in general, non Froudian. The geometrically similar model dunes are reduced in vertical model scale. The scale of the flow velocity is derived from a generalised friction equation which takes into account the influence of both skin friction and form drag. The application of the method is illustrated by a numerical example. This example indicates that a practicable set of scales is obtained if the model bed is formed by a light weight material.
THE SHEAR STEESS OF SEA BREEZE ON A SWASH ZONE
Authors: Hsu Shih-Ang
Published: February 2019

Measurements of shear stress under the effect of a sea hreeze were made by simultaneous wind and temperature profiles over a shore near Fort Walton Beach, Florida It was found that the sea breeze In the surface boundary layer is in the atmospheric free-convection, regime The measured shear stress coefficient is in conformity with that obtained by other investigators by the sea surface tilt method under the unstable condition For coastal applications, the result is found to be more reliable than those assumed coefficients obtained under neutral stability for this localized coastal wind system.
ENERGY LOSSES UNDER WAVE ACTION
Authors: Treloar P.D. , Brebner A.
Published: February 2019

Wave-height attenuation measurements were made in two identical flumes of different widths and the results used to separate bottom energy losses from sidewall energy losses These energy losses, in the form of rates of energy dissipation, were then compared with their theoretical values as calculated by solving the linearized Prandtl boundary layer equations and evaluating the Rayleigh dissipation function Using these results, an adjusted formula for the wave-height attenuation modulus was determined.
OCEAN WAVE RESEARCH IN SOUTHERN AFRICA
Authors: Zwaborn J.A. , Van Schaik C. , Harper A.
Published: February 2019

Wave recording on a national basis in South Africa commenced in 1967, when an "Ocean Wave Research" project was initiated, aimed at obtaining reliable data on sea conditions around the shorelines of the Republic and South West Africa and to improve on wave prediction techniques Various instruments are being used in this programme Some of the problems encountered in practice with these instruments and the agreement between the results obtained using various wave recorders simultaneously at the same station are discussed An indication of the volume of wave data so far obtained and the methods of analysing them are included.
BREAKING WAVE SETUP AND DECAY ON GENTLE SLOPES
Authors: Hwang Li-San , Divoky David
Published: February 2019

Waves of large amplitude on a gentle slope may form spilling breakers which propagate shoreward and are slowly transformed In addition, there occurs a modification of the mean water level termed wave setup An analytical description based upon consideration of momentum flux has been developed which predicts this wave setup and the decay history of breaking wave height The results have been compared with experiments and found quite satisfactory The effect of wave setup on breaking wave transformation is particularly important near the shoreline, where setup dominates the vanishing mean depth.
CHARACTERISTICS OF WAVES BROKEN BY A LONGSHORE BAR
Authors: McNair E. Clark , Sorenson Robert M.
Published: February 2019

A two-dimensional model submerged offshore bar was installed in a Texas A&M Hydrodynamics Laboratory wave tank Monochromatic waves with a range of heights and periods were generated at this bar for three different depths of water over the bar For each wave, water surface time-histories were measured at points before and after the bar and spectral analyses of these measurements were performed The analysis of each wave record yielded an equivalent wave height which is proportional to the square root of the wave energy per unit surface area The ratio of the reformed to incident equivalent wave height is shown to relate to the ratio of incident wave height to water depth over the bar The predominant periods of the reformed waves are found to be the same as for the incident waves but the presence of energy at higher frequencies is also observed The cause of these higher frequency waves is discussed.
VELOCITY FIELDS IN THE WAVE BKsAKka ZONK
Authors: Adeyemo M.D.
Published: February 2019

The paper deals with the velocity fields in the neighbourhood of the breakers and the correlation between the wave asymmetry and the velocity asymmetry. The velocity measurements were made on two beach slopes 1 9 and 1.18. Earlier work (3) showed that the two slopes produced different breaker types; the slope of 1:9 produced plunging breakers and the slope of 1 18 spilling breakers. The velocities (velocity - tune history) of the water particles were measured at a height of 5mm above the bed using the hydrogen bubble method combined with cine photography. Two types of horizontal velocity asymmetry were defined and investigated, namely (1) horizontal velocity (Magnitude) asymmetry and (2) horizontal velocity (time) asymmetry. It was found that there are both qualitative and quantitative correlation between the asymmetry of the wave, and the asymmetry of the resulting velocity field. As a result of the correlation two alternative expressions are given for the horizontal velocity (magnitude) asymmetry.
EXPERIMENTS OF WAVE REFLEXION ON IMPERMEABLE SLOPES
Authors: Moraes Carlos de Campos
Published: February 2019

Results from experiments on the reflective power of smooth and rough impermea ble slopes are presented The importance of relative depth to the regular scatter dia gram of the function R=R (5o) and the need for an adequate computational wave theory through which no significant alterations are introduced in the determination of reflective power is pointed out Stokes 2nd order corrections are introduced These help find a superior value for the reflexion coefficient and destroy the mentioned regularity of the scatter diagram A regular scattering of experimental points, also of function R=R (5o) , where, however, for constant steepness, reflexion decreases when relative depth increases, is found in rough slope tests In this case, the more inclined is the slope, the greater is the influence of roughness.
LIMITING CONDITION FOR STANDING WAVE THEORIES BY PERTURBATION METHOD
Authors: Tsuchiya Yoshito , Yamaguchi Masataka
Published: February 2019

The purpose of this paper is to make clear the validity and limiting condition for the application of the finite amplitude standing wave theories by the perturbation method In a numerical example, the errors of each order solution of these theories for two non-linear free surface conditions are computed for various kinds of wave characteristics and compared with each other Some experiments on the wave pressure on a vertical wall by standing waves were carried out and a plot of the limiting condition for the application of these theories is proposed based on the comparison with theoretical curves In addition, as an example of the application of these theories, the change of characteristics of wave pressure of standing waves accompanying the overtopping wave on a vertical wall is discussed.
ANALYTCAL APPROACH ON WAVE OVERTOPPING ON LEVEES
Authors: Shi-igai Hiroyoshi , Kono Tsugio
Published: February 2019

An analytical approach to evaluate the amount of overtopping for given conditions is studied in this paper Here, the wave overtopping is considered as a similar phenomenon to the flow over a weir changing the depth with respect to time The theoretical approaches used by many scholars have been mostly based on the dimensional analysis In this paper, however, another kind of approach is tried, which is rather deterministic, in order to get a general view of wave overtopping mechanism.
WAVES GENERATED BY A PISTON-TYPE WAVEMAKER
Authors: Madsen Ole Secher
Published: February 2019

When a wavemaker generates a finite number of waves, it has been found that one of the first and one of the last waves in such a burst is considerably larger than the average A mathematical model, based on the linearized governing equations, is used for the particular problem of the waves generated by a sinusoidally moving piston-type wavemaker starting from rest Theoretical results for the magnitude of the large wave relative to the average agree fairly well with experiments, however, the actual wave height is smaller in the experiments than predicted by theory It is shown, by extending the classical wavemaker theory to second order, that finite amplitude effects do not offer an explanation However, pistons rarely fit the tank dimensions exactly, and an approximate evaluation indicates that the discrepancy between predicted and observed wave heights can be attributed to the effects of leakage around the piston.
PREDICTION CURVES FOR WAVES NEAR THE SOURCE OF AN IMPULSE
Authors: Miller Robert L.
Published: February 2019

The general problem of single-impulse induced waves has been under experimental investigation by the author for several years The present paper is confined to a presentation of the wave modes which are to be expected for various permutations of displacement velocity and displacement length at the impulse source Other portions of the study will be published elsewhere It is clear that a number of geometric arrangements in the laboratory may be made to generate impulse waves, for example, sudden upthrust or downdrop of a block on the tank bottom analagous to block faulting on the sea-floor in nature, or a hinged flap moving on the bottom analagous to the undulatory bottom motion which may occur during seismic disturbances on the sea floor However, it is my opinion that the impulse generator which is most simple and most easily related to contemporary generalized theory, is a single piston thrust at one end of the wave tank which pushes the fluid down channel (See Figure 1) As an additional simplification, the investigation is carried out for the flat bottom, fixed depth case, relegating the effect of varying depth to a later study.
COASTAL PROCESSES FROM SPACE PHOTOGRAPHY
Authors: Nichols Maynard M.
Published: February 2019

Photographs taken from space provide a new source of data concerning coastal processes By utilizing the high vantage point and broad view orbiting space cameras can record little known large-scale processes at short time intervals Major outflow plumes, fresh-salt water "fronts", turbidity maxima and massive effluents are among the wide range of features displayed It is shown from selected examples how coastal processes can be evaluated from space photography and how the information may be of use for solving certain problems as a supplement to field and other remote sensing data By 1972 satellite photography will be available on a routine basis for many coasts of the world Engineers are urged to consider the potential for improving their information which space photography has to offer.
MAXIMUM WAVE HEIGHT PROBABILITIES FOR A RANDOM NUMBER OF RANDOM INTENSITY STORMS
Authors: Borgman L.E.
Published: February 2019

A very general model is presented for the probability distribution function for wave heights in storms with time-varying intensities Some of the possible choices for functions in the model are listed and discussed Techniques for determining the "equivalent rectangular storm" corresponding to a given historically recorded storm are developed The final model formula expresses the probabilities for a random number of random length storms each with random intensities.
STUDIES ON THE SHORE PROCESS AND WAVE FEATURES OF THE WESTERN COAST OF TAIWAN
Authors: Chang Kenneth S.T. , Tang Frederick L.W.
Published: February 2019

The western coast of Taiwan has been accumulated to vast area of tidal flats by the sediment transported from numerous torential streams According to the aerial photographs, 53,800 hectares of tidal land are worth being reclaimed However, this coast suffers from waves generated by winter monsoons as well as waves and swells caused by typhoons in the summer Studies on the historical processes and future development of the shoreline are of great significance The ancient topographical data in An-Ping and Tseng-Pa areas as well as recent coastal line variations of Tseng-Pa and Yulm are reported in this paper, also the general features of waves along this coast are described The future of the coast is predicted as a conclusion.
STUDY OF MUDBANKS ALONG THE SOUTHSEST COAST OP INDIA
Authors: Moni N.S.
Published: February 2019

The formation and behaviour of 'Hud Banks' is a phenomenon peculiar to the Southwest Coast of India. They are unique in their formation as veil as functions. The paper deals with the history of mudbanks, their locations, causes of their formation, the nature of material and their sources. The behaviour of the mudbaaks and their influence on the stability of the coast is also reported. The mudbanks act as storehouses of littoral material. Itis also the initiator of erosion on its downdrift areas. Itis noted that the material stored in the mudbanks must be advantageously utilised in stabilising the shores adjacent to it and for reclamation. Of extreme importance is the recognition that mudbanks are closely associated with the stability of the Southwest Coast of India and is a factor to be reckoned in any programme of coastal development or protection uthis area.
AN UNDERWATER SURVEY SYSTEM FOR RADIONUCLIDE-TAGGED SEDIMENT TRACING
Authors: Brashear H.R. , Case F.N.
Published: February 2019

Survey equipment for use in tracing sediment tagged with radionuclides has been designed and field tested The system is unique in its ability to operate on the dry beach, m the surf, and in deep water, making it possible to synoptically examine the beach face, surf zone, and off-shore marine environment The ball-shaped radiation detector vehicle is towed behind an amphibious vessel Data are collected on punched tape at a rate of one set of data (position, radiation counts, time) every two seconds Gold-198 and xenon-133 have been used for tagging sand indigenous to the survey area under study Operational characteristics and detection sensitivity are discussed.
PROCESSING AND ANALYSIS OF RADIOISOTOPIC SAND TRACER (RIST) STUDY DATA
Authors: Brashear H.R. , Acree E.H. , Case F.N. , Turner P.A. , Duane D.B.
Published: February 2019

Data collected during the Radioisotopic Sand Tracer (RIST) field tests are processed through digital computers Data treatment requires computing and plotting the detector position and correcting the corresponding radiation count rates for radioactive decay The field data are recorded on punched paper tape which is then edited and transferred to magnetic tape for input to data reduction programs The navigation data, which are m the form of distances to shore-based microwave responder beacons, are tested for spurious values by comparison with the theoretical maximum travel distances of the survey vehicle between successive fixes The navigation ranges are then converted to rectangular geographical coordinates Present emphasis is in the development of computer programs to construct a count rate surface from data collected along track lines This technique facilitates machine contouring and enables numerical integration of the count rate surface The ultimate goal is to obtain an estimate of mean direction and volume of littoral transport and a radiation material balance to be used to check the results Several programs required to accomplish these tasks are operating at the Coastal Engineering Research Center (CERC) and the Oak Ridge National Laboratory (ORNL).
LABORATORY TESTS OF LONGSHORE TRANSPORT
Authors: Fairchild John C.
Published: February 2019

Tests were made in CERC's Shore Processes Test Basin witlt wayes approaching the toe of a test beach at a 30-degree angle Beach material was quartz sand with median diameter of 0 22 millimeter which, in most tests, was molded to a 1 on 10 slope before starting a test Long crested waves generated in a constant depth of 2 33 feet traveled over the beach, shoaled and were refracted before breaking near the shoreline The breaking action caused the sand to be transported along the shore in the direction of the longshore component of the wave energy flux Transport rates of 2 to 170 cubic yards per day were measured, with the lower rate within the range of laboratory rates reported by Savage^and the higher rate comparable to field rates reported by Watts^for South Lake Worth Inlet, Florida Analysis includes correlation of the measured rates to the longshore wave energy flux, and in some tests, to the longshore current Transport rates, defined by visual fit curve of the data, are about 3 times the rates indicated by the CERC TR-4 design curve for a longshore energy range of 0 016 to 0 760 millions of foot pounds per foot of shore per day.
COMPUTATION OF ALONGSHORE ENERGY AND LITTORAL TRANSPORT
Authors: Mogel Theodor R. , Street Robert L. , Perry Byrne
Published: February 2019

This work encompasses a study of the littoral regime of a section of the coastline of the city and county of San Francisco, California The study included a complete refraction analyses of all applicable deep water wave directions and periods, the determination of breaker locations, and a computation of alongshore energy and potential littoral transport for seven stations located just offshore along the thirty foot depth contour The waves are refracted from deep water locations to the shoreline using the Stanford Wave Refraction computer program Wave breaking is assumed to take place whenever the computed wave height exceeds 0 78 times the local water depth The effect of limiting the refraction coefficient is explored since the refraction theory, in analogy with its parent theory of geometric optics, fails along caustic curves and predicts unreasonably large values for the refraction coefficient.
USE OF VOLCANOES FOR DETERMINATION OF DIRECTION OF LITTORAL DRIFT
Authors: Bruun Per , Viggosson Gisli
Published: February 2019

The title of this paper may sound like a ;joke Correctly the title ought to be "Determination of Direction of Littoral Drift on the South Coast of Iceland by Geomorphological Approach" In order to check the results of such study based on the movements of river entrances and their geometry the use of an accelerometer buoy to be placed in offshore open waters for collection of wave data combined with the results of meteorological data was discussed Then the volcano Surtsey suddenly emerged from 400 ft depth (Nov 1964) and its huge outpours of volcanic material built up an "offshore pole station", where the shoreline development provided some information which supported conclusions from the shoreline study on the mainland Computation of wave energy input provided further information.
THE DYNAMICS OF A COAST WITH A GROYNE SYSTEM
Authors: Bakker W.T. , Breteler E.H.J. Klein , Roos A.
Published: February 2019

This paper is a continuation of the paper with the same name, presented on the Xlth Conference on Coastal Engineering by the first author [1] , in which a mathematical theory was given about the behaviour of a coast after the construction of a groyne system. Now this paper extends the former paper theoretically and practically. 1. Theoretically a computer program has been made in which the influence of diffraction behind the groyne has been taken into account. 2. Practically the coastal constants used in the theoretical model of the coast will be expressed in terms of wave height and wave direction, based on the theory of SVASEK [2] . Results are given of computations with a coastal model in which the coast is schematized to one line (one-line theory) and a model in which the coast is schematized to a beach line and on mshorelme (two-line theory). The influence of changing wave conditions is investigated.
LAND RECLAMATION AND GROIN-BUILDING IN THE TIDAL PLATS
Authors: Erchinger Hele Focken
Published: February 2019

Along the North Sea eoast of Germany there are two large areas where land reclamation work in the tidal flats is being carried out. One is on the coast of Schleswig- Holstem and the other in Ostfriesland, on the coast and along the estuary of the river Ems near the border with the Netherlands. Conditions and working methods for land reclamation in tidal flats as well as the development of new groin constructions on the Ostfriesian coast are described below.
THE EFFECT OF GROYNES ON ERODED BEACHES
Authors: Price W.A. , Tomlinson K.W.
Published: February 2019

Laboratory tests are described, in which the effect of impermeable groynes on an eroded beach was studied A beach was allowed to reach equilibrium for a particular wave climate and supply of littoral material The foreshore was then manually eroded, and the beach allowed to return to equilibrium with and without groynes It was found that the presence of groynes increased the rate of accretion but did not significantly build up the inshore beach beyond the stable levels Bed levels seaward of the groynes were increased.
A COMPARISON OF FLUVIAL AND COASTAL SIMILITUDE
Authors: Le Mahaute Bernard
Published: February 2019

A comparison of the conditions of similitude for movable bed scale models of rivers and estuaries on one hand, and beaches and shorelines on the other hand, is presented It is demonstrated that despite the fact that the knowledge in sediment transport by wave action is less advanced than in the case of steady current, the conditions of similitude for beaches are less stringent than for rivers In particular, the effect of relative roughness is comparatively unimportant in the case of beaches, while the necessity of similitude of head loss imposes an imperative condition in the case of scale models of rivers An introduction to a natural law of distortion for beaches is presented in analogy with the Lacey condition for rivers.
STUDY OF TOPOLOBAMPO'S BAY, MEXICO, ENTRANCE
Authors: Gutierrez Hector Lopez , Castro Daniel Cervantez
Published: February 2019

Brief examination of the geomorphological background of the Topolobampo's bay inlet is made A theoretical study of the inlet and spits, based on field data such as wind, waves, tides, currents, bathimetric charts from 1875 to 1965, was developed in order to determinate the most convenient position of an experimental channel dregged on 1963. Radioactive tracer studies, photographic and periodical surveys of the inlet and the channel gave the information for the design of the definitive channel, which at present is behaving in accordance with the predicted way in the theoretical study.
FIELD STUDY OF A TIDAL INLET, BIMINI, BAHAMAS
Authors: Harrison W. , Byrne R.J. , Boon J.D. , Moncure R.W.
Published: February 2019

The inlet bathymetry was mapped by standard photogrammetric techniques after photographing the bottom directly through the water column The channel bottom is bare beachrock or is floored with bioclastic sands and gravels (S G = 2 84) A nine-day time series of observations of current speed and direction, and water temperature and salinity was obtained at two depths at each of eight stations using tripod-mounted, telemetering sensor packages Twelve-to-l8-mmute pulsations in the flow were often observed Spectral analysis of near-surface current speeds shows significant peaks at 2 h, 3 2, k 3, 67, and 12 3 hrs Evolution of sand ripples and dunes was monitored over a 200-ft distance during one tidal cycle The pattern of growth illustrates the differences m bedform geometry which may be expected to influence friction coefficients Evidence is presented for a bottom jet that is induced by flow over the crests of sand waves Tracer sand, sorted into two size groups and color-coded for identification, was released on a flood current Sampling of color-coded tracer sand was conducted by divers using strips of grease-coated plastic tape Spatial distribution of tracers m relation to the bedforms, and the importance to gram erosion of a natural mucoid coating, are noted.
RECENT HISTORY OP EROSION AT CAROLINA BEACH, N C
Authors: Vallianos Limberios
Published: February 2019

The reaction of shores adjacent to salient features which interrupt alongshore processes has long been recognized as an important consideration in connection with the investigation of engineering works to be undertaken on shores characterized by a littoral drift regimen Particular emphasis has been placed on the evaluation of shore changes related to major control structures at navigation entrances, however, manmade interruptions of small scope, which initially appear innocuous, can produce costly damage to the adjacent shores located on the downdrlft side of the interruption The town of Carolina Beach, a seaside resort on the Atlantic Ocean in southeastern North Carolina, is a classic example of an area experiencing inordinate and costly erosion associated with an initially small manmade interruption on the updrift shore In 1952, local boating interests excavated a channel through the updrift barrier beach to connect the Atlantic Ocean and a lagoonal area traversed by the Atlantic Intracoastal Waterway The channel, located 8,000 feet north of the Carolina Beach town limits, soon developed into a small, permanent coastal inlet having a width of approximately 550 feet and a depth of 15 feet In the ensuing 17-year period, 1952-1969, this inlet entrapped over 4 million cubic yards of littoral material, resulting in a concomitant downdrift erosion which progressed southward to the town of Carolina Beach A protective beach fill placed along the town's ocean front in 1965 has suffered considerable erosion damage This paper develops and quantifies the cause and effect relationships of the problem generally in terms of the alongshore processes and, in so doing, also furnishes basic information in regard to the performance of the largescale artificial beach fill placed along the ocean front of Carolina Beach in 1965.
HIO GRANDE BAR - THE CASE HISTORY OF A LAGOON OUTLET INTO A TIDELESS SEA
Authors: Motta V.F.
Published: February 2019

Rio Grande harbour is situated inside the outlet of Lagoa dos Patos (9 910 km2) and Lagoa Mirim (3 770 km2). Most of the rivers in the State of Rio Grande do Sul, that are not tributaries of river Uruguay, flow into the two lagoons and the latter discharge through Canal do Norte into a tideless sea. Flood flows can exceed 20 000 cumecs. The outlet is on a sandy coast with littoral drift in both shoreline directions. The time history of the outlet can be divided into three periods. Before breakwater construction, the bar was extremely unstable in lay-out, position and controlling depth. The latter ranged from 2.5 to 7 m. From 1911 to 1916 two 4 km long rubble mound breakwaters were built. They deepened the entrance channel to 8 - 10 m but a new bar came about further offshore entailing objectionable navigation conditions in the approach channel. No previous dredging was carried out as the breakwater construction proceeded out to sea, and as result a total of Ik million cubic metres was scoured out between the two breakwaters and discharged offshore to build up the new bar. Some improvement by dredging was not achieved until 1962. The improvement of the approach channel lay-out as well as deepening the entrance to 14 m below datum are under consideration. Field and model investigations have been designed for this purpose.
VARIATION OF TOPOGRAPHY OF SEA-BED CAUSED BY THE CONSTRUCTION OF BREAKWATERS
Authors: Sato Shoji , Irie Isao
Published: February 2019

In Japan, many breakwaters or jetties have been constructed in the sandy beach from the past decade for new ports to cope with the development of industry It is needless to say that the construction and prolongation of breakwaters or jetties cause the change of bottom topography in their vicinity, but many points remain indistinct on this change of bottom-topography In this paper, some general properties on the change of the topography of sea-bed caused by the construction of breakwaters are discussed on the basis of the hydraulic sounding maps of several ports and the results of model tests The terminology used in this paper is given in Figure 1.
SEASONAL BOTTOM CHANGES BOLINAS BAY, CALIFORNIA
Authors: Johnson J.W.
Published: February 2019

Five bottom surveys over a period of a year were made in the north portion of Bolmas Bay, California Comparisons between successive surveys permitted an evaluation of the areas and depths of scour and fill with the seasons and were correlated with littoral current measurements Data for a 22-year period also were available on the position of the mean high-tide line over a limited length of beach These data showed a cyclic variation of the position of the high-tide line with the season with the most variation from year to year occurring during the spring months.
THE PRESSURE OP FLOATING ICE-FIELDS ON PILES
Authors: Schwarz Joachim
Published: February 2019

In order to determine the maximum ice forces against structures, the compressive strength was investigated by laboratory tests on cubes of several ice species. The results contain the influence of temperature, velocity of deformation and direction of pressure on the cubic strength. In order to employ these laboratory results for the calculation of structures, a relationship between the strength m laboratory tests and m nature was derived by measuring the pressure of floating ice-fields on a pile of a bridge, which crosses the tidal estuary of the EIDER River. The investigation leads to an equation, which allows the calculation of ice pressure against piles.