Wave height

About: Wave height is a research topic. Over the lifetime, 5920 publications have been published within this topic receiving 100257 citations.

Cross-shore sediment transport and beach deformation model

Abstract: Based on a large amount of published laboratory results, reliable model is developed for computing beach profiles under regular wave actions. The sediment transport is separated into suspended load and bed load. The suspended load is computed as the product of the time-averaged suspended concentration and the timeaveraged velocity. The bed load is developed following the similar step as Watanabe (1983) but the applied area is different. The wave model of Dally et al. (1985) is modified and used to compute wave height transformation. The beach profile change is computed from the conservation of sediment mass. The beach deformation model is verified with small scale and large scale experiments. Reasonably good agreement is obtained between measured and computed beach profiles.

Design of the Gold Coast reef for surfing, public amenity and coastal protection: surfing aspects

Abstract: The first offshore reef developed to amalgamate world-class surfing, public amenity and coastal protection is described. The reef is at Narrowneck Beach on the Gold Coast, Australia, a long, sandy coast experiencing large cyclone waves and high net longshore transport. The reef design was based on bathymetric and wave breaking studies of world-class surfing breaks and numerical model predictions. A broad range of different shapes was numerically tested using refraction, Boussinesq refraction/diffraction and sediment transport models. The shape that met the design criteria, for both the surfing and shoreline protection characteristics, was found to be a submerged double-sided headland. The designed reef is 400 m long and extends from the natural 2 m isobath to a toe in 10.4 m depth, with the crest at 0.4 m below the Lowest Astronomical Tide. The shape allowed both 'left' and 'right' surfing waves to be included. Peel angles are rarely less than 40? (in predominant small waves) and seabed gradients of up to 1:12 produce steep plunging wave faces, making the surfing wave 'fast' and 'hollow'. In small swell, a large, focussing underwater segment will more than double the deep water wave height at the breakpoint. A slower 100 m long segment at the shoreward end is designed for surfing beginners and casual tourists. Because the adjacent beaches experience close-out conditions in big swells, a paddling channel has been placed at the offshore tip of the reef to give surfers access during large swell. A lagoon shoreward of the reef provides sheltered paddling and, at low tide, sheltered swimming for beach-goers. Wave interference patterns inshore of the reef are expected to provide challenging 'wedgey' waves for body boarders, while the offshore placement of the reef provides ideal wave jumping conditions for the sailboarder.

Trend analysis of significant wave height and energy period in southern Italy

Abstract: The Mediterranean Sea is subject to significant and variable climatic changes. In this work, an analysis of a 39-year-long wave time series was performed in order to identify ongoing trends of two synthetic parameters, significant wave height and energy period, along the coasts of the Calabria region (southern Italy). First, wave data were acquired from the global atmospheric reanalysis data set European Centre for Medium-Range Weather Forecasts Re-Analysis Interim (ERA-Interim) and were processed in order to check their quality. Then, the data were subject to a geographical transposition method in order to transfer the wave parameters at a representative water depth of 100 m. Finally, trend analyses have been performed using the nonparametric Mann–Kendall (MK) test and a graphical technique, the Innovative Trend Analysis (ITA), which allows to identify trends in the several values of a series. At annual and seasonal scale, the results deduced from MK test mainly evidenced a slight or null increase of the significant wave height and a relevant increase of the energy period, influencing the magnitude of the wave power by the occurrence of longer waves. Moreover, the ITA method highlights a general increase in the highest values of the involved wave parameters. For the studied area, these aspects have a significant impact on the retreating of the beaches and on the future field installations of wave energy converters (WECs) for electricity purposes.

The shoaling, breaking and runup op the solitary wave on impermeable rough slopes

Abstract: Variations m wave characteristics for solitary waves in shoaling water are discussed. The transition of wave character from the solitary wave to the bore is basic to the understanding of the problem. Experimental curves representing the transformation of wave height prior to breaking as well as the curves giving the breaker conditions are presented. Theories for the transformation of wave height after breaking and the prediction of the plunge point are presented and compared favorably with the laboratory measurements. Runup heights and wave quantities at the shoreline are measured to compare with the theory of a bore on a dry bed.