scholarly journals MORPHODYNAMICS OF A CARIBBEAN BEACH FRINGED BY A CORAL REEF

2012 ◽  
Vol 1 (33) ◽  
pp. 119 ◽  
Author(s):  
Amaia Ruiz de Alegria-Arzaburu ◽  
Ismael Mariño-Tapia ◽  
Cecilia Enriquez ◽  
Rodolfo Silva-Casarín ◽  
Mariana González-Leija
Keyword(s):  
Coral Reef ◽  
Wave Model ◽  
Wave Climate ◽  
Differential Gps ◽  
Incoming Wave ◽  
Morphological Response ◽  
Fringing Reef ◽  
Wave Measurements ◽  
Current Profiler ◽  
Offshore Wave

The morphological response of two adjacent beaches, on the Mexican Caribbean coast, exposed to the same offshore wave climate is compared, where one of the beaches is fringed by a coral reef and the other is not. Detailed topographic and bathymetric measurements were collected from 2007 to 2011using a differential GPS and double-frequency echo-sounder. Offshore waves were continuously measured by the NOAA 42056 directional buoy, and nearshore waves were measured from May to September 2007 using an acoustic wave and current profiler to validate the use of offshore waves in the analysis of beach morphodynamics. Investigations showed that the beach with the fringing coral reef was the more stable under the same offshore energetic wave conditions of different directions. The implications of the fringing reef on the local hydrodynamics and energy dissipation were evaluated with the SWAN third-generation spectral wave model. The model was first validated with wave measurements collected at intermediate (forereef) and shallow waters (reef lagoon) with Aquadop profilers. Numerical results indicate that during shore-normal energetic conditions, the fringing reef is capable of reducing the incoming wave energy by up to 65%.

An Atlas of the Wave-Energy Resource in Europe

1996 ◽  
Vol 118 (4) ◽  
pp. 307-309 ◽  
Author(s):  
M. T. Pontes ◽  
G. A. Athanassoulis ◽  
S. Barstow ◽  
L. Cavaleri ◽  
B. Holmes ◽  
...  
Keyword(s):  
Wave Energy ◽  
Energy Resource ◽  
Wave Model ◽  
Wave Climate ◽  
Weather Forecasts ◽  
Wave Measurements ◽  
Directional Wave ◽  
Offshore Wave ◽  
Climate Statistics

An atlas of the European offshore wave energy resource, being developed within the scope of a European R&D program, includes the characterization of the offshore resource for the Atlantic and Mediterranean coasts of Europe in addition to providing wave-energy and wave-climate statistics that are of interest to other users of the ocean. The wave data used for compiling the Atlas come from the numerical wind-wave model WAM, implemented in the routine operation of the European Centre for Medium Range Weather Forecasts (ECMWF), in addition to directional wave measurements from the Norwegian offshore waters.

scholarly journals Complex coastlines responding to climate change: do shoreline shapes reflect present forcing or "remember" the distant past?

2016 ◽  
Author(s):  
Christopher W. Thomas ◽  
A. Brad Murray ◽  
Andrew D. Ashton ◽  
Martin D. Hurst ◽  
Andrew K. A. P. Barkwith ◽  
...  
Keyword(s):  
Climate Change ◽  
Wave Climate ◽  
Quasi Equilibrium ◽  
Morphological Response ◽  
Antecedent Conditions ◽  
Coastline Evolution ◽  
Aspect Ratios ◽  
Order Of Magnitude ◽  
Offshore Wave ◽  
Hysteresis Behaviour

Abstract. A range of planform morphologies emerge along sandy coastlines as a function of offshore wave climate. It has been implicitly assumed that the morphological response time is rapid compared to the time scales of wave-climate change, meaning that coastal morphologies simply reflect the extant wave climate. This assumption has been explored by focussing on the response of two distinctive morphological coastlines – flying spits and cuspate cusps – to changing wave climates, using a coastline evolution model. Results indicate that antecedent conditions are important in determining the evolution of morphologies, and that sandy coastlines can demonstrate hysteresis behaviour. In particular, antecedent morphology is particularly important in the evolution of flying spits, with characteristic timescales of morphological adjustment on the order of centuries for large spits. Characteristic timescales vary with the square of aspect ratios of capes and spits; for spits, these timescales are an order of magnitude longer than for capes (centuries vs. decades). When wave climates change more slowly than the relevant characteristic timescales, coastlines are able to adjust in a quasi-equilibrium manner. Our results have important implications for the management of sandy coastlines where decisions may be implicitly and incorrectly based on the assumption that present-day coastlines are in equilibrium with current conditions.

scholarly journals WAVE CLIMATE ANALYSIS FOR ENGINEERING PURPOSE

1976 ◽  
Vol 1 (15) ◽  
pp. 2 ◽  
Author(s):  
Hans H. Dette ◽  
Alfred Fuhrboter
Keyword(s):  
Wave Climate ◽  
Incoming Wave ◽  
Offshore Area ◽  
The North ◽  
Wave Measurements ◽  
Wind Velocities ◽  
Wave Heights ◽  
The North Sea ◽  
One Year ◽  
Climate Analysis

The North Sea (Fig. 1) is known as a random sea with depths in the southern part between 40 m and 100 m so that in contrary to the Atlantic and Pacific coastlines deep sea wave conditions do not exist. After four years of comprehensive wave measurements in the offshore area of the Island of Sylt near the Danish border a general analysis of the wave climate in that region was possible. In this paper results and suggestions will be presented under the aspect of replacing qualitative judgements by quantitative statements which are derived from the knowledge of the adjacent wave climate. Because the wave action varies from year to year a general time unit is not advisable for the evaluation of shore processes; therefore the time scale should be substituted by the integral of incoming wave energy occurring after a certain time. The investigated method of expressing the total energy of one season or one year in the electrical unit Kilowatthour (kWh) per meter (m) width of shoreline could prove in future as a feasible way of classifying the irregular seasonal and yearly wave intensities. It is further shown that wave measurements over a period of several years can be sufficient for the investigation of correlations between the wind velocities occurring from all directions and the resulting wave heights. In case of satisfying correlation factors it will then be possible to carry out feedback operations for periods from which only records of wind velocities and directions are available and even to hindcast the wave heights for certain not yet measured wind velocities.

Nearshore Wave Modelling in a Norwegian Fjord

2020 ◽  
Author(s):  
Christos N. Stefanakos ◽  
Birgitte R. Furevik ◽  
Øyvind Knutsen ◽  
Konstantinos Christakos
Keyword(s):  
Wave Model ◽  
Wave Climate ◽  
Wave Modelling ◽  
Good Accordance ◽  
Norwegian Fjord ◽  
Wave Conditions ◽  
Wave Models ◽  
Model Setup ◽  
Offshore Wave

Abstract Phase averaged wave models is a good supplement of in situ measurements for the study of wave climate in a specific location. In spite of having been tested in smoothly varying coastal areas, they haven’t previously been systematically validated in complex topography (coastline and bathymetry) such as Norwegian fjords, due to lack of measurements. However, in planning for large fjord crossings, the Norwegian Public Roads Administration have launched a number of buoys which allow for validation of model setup. In the present work, nearshore wave conditions in the area of Sulafjord, central Norway, are investigated as derived from numerical modelling with several different setups, and are compared against in situ buoy measurements with good accordance. The analysis is carried out by transferring offshore wave conditions to the nearshore area by successive applications of the well-known third-generation wave model SWAN. As input has been used a very detailed bathymetry of the area, and time series of wind and wave parameters derived from ERA5 and NORA10 datasets. Various scenarios reconstructing the wave input spectra have been considered.

scholarly journals Inner harbour wave agitation using boussinesq wave model

2015 ◽  
Vol 7 (1) ◽  
Author(s):  
Jitendra K. Panigrahi ◽  
C.P. Padhy ◽  
A.S.N. Murty
Keyword(s):  
Water Waves ◽  
Wave Model ◽  
Wave Climate ◽  
Short Wave ◽  
Operating Conditions ◽  
Critical Threshold ◽  
Random Waves ◽  
Near Shore ◽  
Wave Models ◽  
Offshore Wave

ABSTRACTShort crested waves play an important role for planning and design of harbours. In this context a numerical simulation is carried out to evaluate wave tranquility inside a real harbour located in east coast of India. The annual offshore wave climate proximity- to harbour site is established using Wave Model (WAM) hindcast wave data. The deep water waves are transformed to harbour front using a Near Shore spectral Wave model (NSW). A directional analysis is carried out to determine the probable incident wave directions towards the harbour. Most critical threshold wave height and wave period is chosen for normal operating conditions using exceedence probability analysis. Irregular random waves from various directions are generated confirming to Pierson Moskowitz spectrum at 20m water depth. Wave incident into inner harbor through harbor entrance is performed using Boussinesq Wave model (BW). Wave disturbance experienced inside the harbour and at various berths are analysed. The paper discusses the progresses took place in short wave modeling and it demonstrates application of wave climate for the evaluation of harbor tranquility using various types of wave models.

scholarly journals Coastal vulnerability of a pinned, soft-cliff coastline – Part I: Assessing the natural sensitivity to wave climate

2014 ◽  
Vol 2 (1) ◽  
pp. 295-308 ◽  
Author(s):  
A. Barkwith ◽  
C. W. Thomas ◽  
P. W. Limber ◽  
M. A. Ellis ◽  
A. B. Murray
Keyword(s):  
Wave Climate ◽  
Climate Data ◽  
Morphological Response ◽  
Coastal Morphology ◽  
Transport Dynamics ◽  
Erosion Rates ◽  
The Past ◽  
Potential Impact ◽  
Offshore Wave ◽  
The Impact

Abstract. The impact of future sea-level rise on coastal erosion as a result of a changing climate has been studied in detail over the past decade. The potential impact of a changing wave climate on erosion rates, however, is not typically considered. We explore the effect of changing wave climates on a pinned, soft-cliff, sandy coastline, using as an example the Holderness coast of East Yorkshire, UK. The initial phase of the study concentrates on calibrating a numerical model to recently measured erosion rates for the Holderness coast using an ensemble of geomorphological and shoreface parameters under an observed offshore wave climate. In the main phase of the study, wave climate data are perturbed gradually to assess their impact on coastal morphology. Forward-modelled simulations constrain the nature of the morphological response of the coast to changes in wave climate over the next century. Results indicate that changes to erosion rates over the next century will be spatially and temporally heterogeneous, with a variability of up to ±25% in the erosion rate relative to projections under constant wave climate. The heterogeneity results from the current coastal morphology and the sediment transport dynamics consequent on differing wave climate regimes.

Transferring Wave Conditions From Offshore to Nearshore: The Case of Nordfold

2014 ◽  
Author(s):  
Christos N. Stefanakos ◽  
Grim Eidnes
Keyword(s):  
Wave Model ◽  
Wave Climate ◽  
Third Generation ◽  
Satellite Altimeter ◽  
Northern Norway ◽  
Area Of Interest ◽  
Wave Parameters ◽  
Long Time ◽  
Wave Conditions ◽  
Offshore Wave

In the present work, an analysis of the wave climate in Nord-fold area in the northern Norway has been performed. The analysis was carried out by transferring offshore wave conditions to the nearshore area of interest by successive applications of the well-known third-generation wave model SWAN. The area presents a particular interest, since it has a very deep and complex bathymetry near the coast and a very complicated coastline. Analysis has been carried out using a very detailed bathymetry of the area provided by the Norwegian Mapping Authority. Moreover, as input, five year long time series of directional spectra of offshore wave parameters have been used, after being calibrated using the best available satellite altimeter dataset.

scholarly journals Assessing the natural morphological sensitivity of a pinned, soft-cliff, sandy coast to a changing wave climate

2013 ◽  
Vol 1 (1) ◽  
pp. 855-889 ◽  
Author(s):  
A. Barkwith ◽  
C. W. Thomas ◽  
P. W. Limber ◽  
M. A. Ellis ◽  
A. B. Murray
Keyword(s):  
Wave Climate ◽  
Climate Data ◽  
Morphological Response ◽  
Coastal Morphology ◽  
Transport Dynamics ◽  
Erosion Rates ◽  
Sandy Coast ◽  
Potential Impact ◽  
Offshore Wave ◽  
The Impact

Abstract. The impact of future sea level rise on coastal erosion as a result of a changing climate has been studied in detail over the past decade. The potential impact of a changing wave climate on erosion rates, however, is not typically considered. We explore the effect of changing wave climates on a pinned, soft-cliff, sandy coastline, using as an example the Holderness coast of East Yorkshire, UK. The initial phase of the study concentrates on calibrating a model to recently measured erosion rates for the Holderness coast using an ensemble of geomorphological and shoreface parameters under an observed offshore wave climate. Stochastic wave climate data are perturbed gradually to assess the sensitivity of the coastal morphology to changing wave climate. Forward-modelled simulations indicate the nature of the morphological response of the coast to changes in wave climate over the next century. Results indicate that changes to erosion rates over the next century will be spatially and temporally heterogeneous, with a variability of up to ±25% in the erosion rate relative to projections under constant wave climate. The heterogeneity results from the current coastal morphology and the sediment transport dynamics consequent on differing wave climate regimes.

scholarly journals Complex coastlines responding to climate change: do shoreline shapes reflect present forcing or “remember” the distant past?

2016 ◽  
Vol 4 (4) ◽  
pp. 871-884 ◽  
Author(s):  
Christopher W. Thomas ◽  
A. Brad Murray ◽  
Andrew D. Ashton ◽  
Martin D. Hurst ◽  
Andrew K. A. P. Barkwith ◽  
...  
Keyword(s):  
Climate Change ◽  
Wave Climate ◽  
Quasi Equilibrium ◽  
Morphological Response ◽  
Antecedent Conditions ◽  
Coastline Evolution ◽  
Aspect Ratios ◽  
Order Of Magnitude ◽  
Offshore Wave ◽  
Hysteresis Behaviour

Abstract. A range of planform morphologies emerge along sandy coastlines as a function of offshore wave climate. It has been implicitly assumed that the morphological response time is rapid compared to the timescales of wave climate change, meaning that coastal morphologies simply reflect the extant wave climate. This assumption has been explored by focussing on the response of two distinctive morphological coastlines – flying spits and cuspate capes – to changing wave climates, using a coastline evolution model. Results indicate that antecedent conditions are important in determining the evolution of morphologies, and that sandy coastlines can demonstrate hysteresis behaviour. In particular, antecedent morphology is particularly important in the evolution of flying spits, with characteristic timescales of morphological adjustment on the order of centuries for large spits. Characteristic timescales vary with the square of aspect ratios of capes and spits; for spits, these timescales are an order of magnitude longer than for capes (centuries vs. decades). When wave climates change more slowly than the relevant characteristic timescales, coastlines are able to adjust in a quasi-equilibrium manner. Our results have important implications for the management of sandy coastlines where decisions may be implicitly and incorrectly based on the assumption that present-day coastlines are in equilibrium with current conditions.

scholarly journals DESIGN OF AN OVERTOPPING BREAKWATER

1980 ◽  
Vol 1 (17) ◽  
pp. 116
Author(s):  
P.D. Treloar ◽  
B. Nagle
Keyword(s):  
Wave Energy ◽  
New South ◽  
Fixed Bed ◽  
Wave Model ◽  
Wave Climate ◽  
Port Development ◽  
Reflected Wave ◽  
North East ◽  
South Wales ◽  
Offshore Wave

The Maritime Services Board of New South Wales, Australia, is constructing a major new port facility on the northern foreshores of Botany Bay. A principal part of this project has been the construction of a large armoured revetment from the northern shores. The entrance to Botany Bay faces southeast and it is from this direction that a large proportion of offshore wave energy arrives. Some of the wave energy which is directed onto the Bumborah Point revetment is reflected towards Yarra Bay on the northern shores of Botany Bay. Yarra Bay is largely undeveloped, but a sailing club has stood for many years on the beach at the southern end. As a consequence of this reflected wave energy being directed towards Yarra Bay, its wave climate has been changed considerably so that during the storms of May-June, 1974, Foster (6), damage was suffered by the club-house. Additionally the more severe wave climate and consequent steeper beach have made it much more difficult to launch sailing boats. The Maritime Services Board is charged with the responsibility to carry out remedial works where damage is caused by the port development. Figure 1 shows the revetment and sailing club site. To assist in coastal engineering design aspects of the port development, a large fixed bed wave model of Botany Bay has been built to an undistorted scale of 1:120. This model, some aspects of which have been described by Lawson (4), has pneumatic wave generators which enable offshore wave directions between east-north-east and south to be generated with prototype periods in the range of 5 to 16 seconds. A pneumatic tide generator enables a sinusoidal tide to be generated.

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