Simulation of wave action on a moored container carrier inside Sines’ Harbour

The integrated numerical tool SWAMS (Simulation of Wave Action on Moored Ships) is used to simulate the behavior of a moored container carrier inside Sines’ Harbour. Wave, wind, currents, floating ship and moorings interaction is discussed. Several case scenarios are compared differing in the layout of the harbour and wind and wave conditions. The several harbour layouts correspond to proposed alternatives for the future expansion of Sines’ terminal XXI that include the extension of the East breakwater and of the quay. Additionally, the influence of wind on the behavior of the ship moored and the introduction of pre tensioning the mooring lines was analyzed. Hydrodynamic forces acting on the ship are determined using a modified version of the WAMIT model. This modified model utilizes the Haskind relations and the non-linear wave field inside the harbour obtained with finite element numerical model, BOUSS-WMH (Boussinesq Wave Model for Harbors) to get the wave forces on the ship. The time series of the moored ship motions and forces on moorings are obtained using BAS solver. © 2015 Taylor & Francis Group, London.

On wave action and phase in the non-canonical Hamiltonian formulation

The long time–evolution of disturbances to slowly–varying solutions of partial differential equations is subject to the adiabatic invariance of the wave action. Generally, this approximate conservation law is obtained under the assumption that the partial differential equations are derived from a variational principle or have a canonical Hamiltonian structure. Here, the wave action conservation is examined for equations that possess a non–canonical (Poisson) Hamiltonian structure. The linear evolution of disturbances in the form of slowly varying wavetrains is studied using a WKB expansion. The properties of the original Hamiltonian system strongly constrain the linear equations that are derived, and this is shown to lead to the adiabatic invariance of a wave action. The connection between this (approximate) invariance and the (exact) conservation laws of pseudo–energy and pseudomomentum that exist when the basic solution is exactly time and space independent is discussed. An evolution equation for the slowly varying phase of the wavetrain is also derived and related to Berry's phase.

Recruitment of Ascophyllum Nodosum: Wave Action as a Source of Mortality

The brown alga Ascophyllum nodosum is a dominant rocky intertidal organism throughout much of the North Atlantic Ocean, yet its inability to colonize exposed or denuded shores is well recognized. Our experimental data show that wave action is a major source of mortality to recently settled zygotes. Artificially recruited zygotes consistently exhibited a Type IV survivorship curve in the presence of moving water. As few as 10, but often only 1 relatively low energy wave removed 85 to 99% of recently settled zygotes. Increasing the setting time for attachment of zygotes (prior to disturbance from water movement) had a positive effect on survival. However, survival was significantly lower at high densities, and decreased at long (24 h) setting times, probably as a result of bacteria on the surface of zygotes. Spatial refuges provided significant protection from gentle water movement but relatively little protection from waves.

(Table 1) Frequency of wind direction reportings and duration of wave action in Mittelgrund, Eckernfoerder Bay, Germany

A detailed survey of the Mittelgrund in Eckernförde Bay shows slope breaks at 10-12 m and 15-16 m water depth. They are thought to be mainly the result of marine abrasion. Utilizing records from the Edgerton mud-penetrator, a map of holocene sediment thickness has been drawn. From the pattern of bottom echos 4 types of stratification can be recognized. An interpretation of them is attempted, as they are supposed to serve as models for other transgression contacts.

Effects of wave action on a hurricane protection structure for London Avenue Outfall canal, Lake Pontchartrain, New Orleans, Louisiana : hydraulic model investigation /

"August 1987."

Transportation of bed material due to wave action /

"February 1964."

A model study of the effect of submerged breakwaters on wave action /

Mode of access: Internet.

Development and field tests of a sampler for suspended sediment in wave action /

Mode of access: Internet.

The effect of wind and wave action on the mixing and dispersion of wastes /

Mode of access: Internet.

A preliminary study of forces in ship moorings due to wave action /

Mode of access: Internet.

Waves and wave action; a bibliography of books, periodicals and society publications appearing from 1687 through March 1946.

Mode of access: Internet.

Rock movement in large-scale tests of riprap stability under wave action /

Mode of access: Internet.

Measurement and modelling of controlled beach groundwater levels under wave action

New laboratory scale experimental data are presented on the forcing of beach groundwater levels by wave run-up. The experimental setup simulates a coastal barrier dividing the ocean from a relatively constant back beach water level, conditions approximating a closed off lagoon system or beach aquifer. The data are critically compared to an advanced numerical model for simulating wave and beach groundwater interaction in the coastal zone, and provide the first experimental verification of such a model. Overall model-data comparisons are good, but some systematic discrepancies are apparent, and reasons for these are discussed.

Abundance of sedentary consumers and sessile organisms along the wave exposure gradient of subtropical rocky shores of the south-west Atlantic

Sedentary consumers play an important role on populations of prey and, hence, their patterns of abundance, distribution and coexistence on shores are important to evaluate their potential influence on ecosystem dynamics. Here, we aimed to describe their spatio-temporal distribution and abundance in relation to wave exposure in the intertidal rocky shores of the south-west Atlantic to provide a basis for further understanding of ecological processes in this system. The abundance and composition of the functional groups of sessile organisms and sedentary consumers were taken by sampling the intertidal of sheltered and moderately exposed shores during a period of one year. The sublittoral fringe of sheltered areas was dominated by macroalgae, while the low midlittoral was dominated by bare rock and barnacles. In contrast, filter-feeding animals prevailed at exposed shores, probably explaining the higher abundance of the predator Stramonita haemastoma at these locations. Limpets were more abundant at the midlittoral zone of all shores while sea urchins were exclusively found at the sublittoral fringe of moderately exposed shores, therefore, adding grazing pressure on these areas. The results showed patterns of coexistence, distribution and abundance of those organisms in this subtropical area, presumably as a result of wave action, competition and prey availability. It also brought insights on the influence of top-down and bottom-up processes in this area.

Abundance of sedentary consumers and sessile organisms along the wave exposure gradient of subtropical rocky shores of the south-west Atlantic

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)