Thesis (Ph. D.)--University of California, San Diego, 2009. / Title from first page of PDF file (viewed July 14, 2009). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 258-267).

ABSTRACT Storm waves affect beach berm and even dunes, resulting in shoreline retreat accompanying by the formation of a submerged bar in the vicinity of the breakers. After a storm wanes, bar material originally may removed from the beachprogressively move landwards by subsequent swell which prevails at the time to assist beach recovery. Such repetitive processes are the nature way to maintain a beach profile in dynamic condition. This research essay reports an application of SBEACH software to simulate beach profile changes induced by different storm conditions. Upon applying the wave module within SBEACH , the range of broken waves during a storm is first calculated, which is in turn to help locate the range of bar crest. Comparisons are then given for bar crest position and the extent of shoreline recession simulated by SBEACH and the original beach profile data obtained from large wave tank (LWT) tests conducted of the Coastal Engineering Research Center (CERC), US Army Corps of Engineers. The effect of resetting the values to several key parameters in the sediment transport equation is also investigated. The present study confirms that cross-shore distribution of the maximum wave heights, one of the many important outputs from SBEACH, can be successfully applied for the estimation of wave breaker heights and the prediction of bar crest positions. In addition, from setting different values to some key calibration parameters used in the model (e.g., the default calibration values and Larson¡¦s (1996) calibration parameters for monochromatic waves), bar crest distance offshore Xc/Lo can be linearly related to deep-water wave steepness Ho/Lo, while bar crest position Xc/Lo versus surf similarity parameter

Thesis (M.Sc.)--University of Hong Kong, 2009. / Includes bibliographical references (p. 138-140).

Thesis (Ph. D.)--University of Hong Kong, 1973.

Along Wreck Beach the existing headland cliffs are eroding and receding under attack from terrestrial and marine agents. Valuable property is being lost and nearby structures endangered. Remedial measures were undertaken in the summer of 1974 to halt wave erosion along the cliff base. A rock groin and sand—gravel protective beach scheme was only partially success ful during the following year. To design an adequate protection system for the cliffs wind and wave effects need to be deter mined to fully understand the resulting sand movement patterns. Understanding the processes affecting Wreck Beach is the first step in controlling them. Methods used to investigate sand movement included field coverage of the study area in photographic form as well as instrument cross—sectioning over a two year period. These data were correlated with historical wind records and predictions from wave refraction diagrams to determine seasonal movement onto and off the beach face and the cyclic progression of sandbars in the longshore current direction. Annual sand trans port volumes, sand supply sources and amounts contributed are outlined. In designing a protection scheme in which longshore trans port requirements must be considered the information and calcu lations suggests that the Fraser River North Arm could amply provide the longshore transport supply requirements. However, some means in addition to the present natural processes must be available to bring this sand into a range where wind gen erated wave activity can incorporate it into the existing Wreck Beach system. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

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