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Thesis (M.S.)--University of Delaware, 2007. / Principal faculty advisor: Michael A. O'Neal, Dept. of Geography. Includes bibliographical references.

For the last several decades, beach nourishment has been a widely implemented erosion mitigation strategy along many developed coastlines. Measuring subsequent patterns of erosion and accretion can help elucidate local sediment transport trends, improve time scale predictions of profile equilibration, decrease renourishment intervals, and adjust future engineering design of nourishments. This study evaluates the morphologic evolution of two beach nourishment projects (e.g., characterized as a full and partial nourishment) at the same location in Boca Raton, Florida using time series beach profiles, surface sediment samples, and wave data. More than 85% of sediment volume was retained within the full nourishment six months after project completion, compared to 50% retained eight months after completion of the partial nourishment. Wave energy largely influenced immediate post nourishment change. Profile equilibration was controlled by high-energy events (i.e., hurricanes) for both nourishments. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection

Thesis (M.S.)--University of West Florida, 2007. / Title from title page of source document. Document formatted into pages; contains 152 pages. Includes bibliographical references.

Thesis (M.S.)--University of North Carolina at Wilmington, 2005. / Includes bibliographical references (leaves: 40-41)

O mapeamento da Plataforma Continental Interna visando localização, qualificação e quantificação das reservas de material litoclásticos marinho possui poucos trabalhos relacionados. O Estado de Pernambuco sofre com erosões ao longo de todo seu litoral, e principalmente junto às cidades de Recife e Olinda. Assim, este estudo contribui tanto para o conhecimento da sedimentologia da plataforma continental interna adjacente ao Porto do Recife e à Praia dos Milagres em Olinda, quanto para a execução de futuras intervenções na recuperação das praias da região. Portanto, com objetivo de identificar áreas com concentrações de granulados litoclásticos marinhos compatíveis com especificações necessárias à regeneração de praias, foram analisadas 36 amostras, que foram coletadas ao longo de seis perfis equidistantes em 1 km, perpendiculares à linha de costa na plataforma interna do Porto do Recife. Em laboratório foram realizadas análises granulométricas e o estudo composicional de todas as amostras. Os resultados granulométricos mostram a predominância de sedimentos mal selecionados, ocorrendo classes variadas de tamanho entre seixo pequeno (8 mm) e lama (< que 0,062 mm), com predominância da fração areia grossa. A análise composicional revelou uma hegemonia de carbonatos marinhos. Os dados obtidos apresentam uma redução do suprimento sedimentar terrígeno local. Também de acordo com os resultados obtidos no presente estudo, a plataforma continental interna adjacente ao Porto do Recife e à praia dos Milagres em Olinda-PE, é essencialmente recoberta por areias biogênicas mal selecionadas, oriundas da morte e fragmentação dos organismos componentes dos recifes coralíneos e algálicos que ocorrem na plataforma continental interna. Dessa forma, esta área não possui material siliciclástico suficiente para ser utilizado na exploração mineral para recuperação artificial de praias no Estado de Pernambuco. / There are few studies that map the Internal Continental Platform referring to localization, qualification and quantification of reserves of litoclastic marine material. The Brazilian state Pernambuco suffers from erosions along the whole coast and particularly in areas close to the cities of Recife and Olinda. This study offers new knowledge about the sedimentology of the internal continental platform adjacent to the harbor of Recife and the Beach Milagres in Olinda. Furthermore, it points out measures that can be used to recover regional beaches. Along 6 profiles with a distance of 1km and perpendicular to the coast line at the internal platform of the harbor of Recife, 36 samples were collected and analyzed. Thus, areas with concentrations of litoclastic marine aggregates with the necessary characteristics for the recovery of the beaches were identified. A laboratory was used for granulometry and a compositional study of all samples. The granulometric results show mainly badly selected sediments. There are different sizes from small pebbles (8 mm) to mud (< than 0,062 mm), predominantly coarse sand fraction. The compositional analysis reveals hegemony of marine carbonates. Thus the obtained data indicates a reduction of local terrigenous sedimentary supply. This is probably due to the fact that the selected area is undergoing an initial transgressive process. Also in accordance with the obtained results of this study, the internal continental platform adjacent to the harbor of Recife and the Beach Milagres in Olinda, Pernambuco, is mainly covered by badly selected biogenic sand which has its origin in the death and fragmentation of components of the coral reef of the internal continental platform. As a result the area is not indicated to mineral exploration for the artificial recovery of the beaches in the state of Pernambuco.

Long Key, on the central western coast of Florida, has been nourished repeatedly since 1975. Following nourishment, the beach has rapidly eroded. This study documents rates, processes, and mechanisms for the rapid erosion. To better understand the beach performance, it is crucial to quantify the background erosion rate when artificial beach fill is at its minimum. This year long study from February 2003 through March of 2004 provides a detailed examination of the performance of a natural beach experiencing intense erosion. The primary objective is to analyze the performance of Long Key through detailed investigation of shoreline and beach-volume changes at a time when the effects of the most recent nourishment in the summer of 2000 are a minimal influence, and the natural performance of the beach, i.e, the background erosion/accretion rate, can be determined. This study also examines, in detail, shore-parallel and cross-shore sediment properties in an attempt to link erosional, stable and accretional areas to sediment grain-size composition. Finally seasonal variations of the nearshore morphology and sediment properties of the Long Key beach were determined to identify the significance of seasonal variations on long-shore and cross-shore sediment transport. This study was conducted using monthly beach profile data and monthly sediment samples. Net longshore sediment transport at the eroding north end (Upham Beach) is to the south at a rate of 34,000 cubic meters per year. Eighty-five percent of this sediment is deposited on the central and southern portions of the island, mainly in the central portion. This is an elevated sediment transport rate as compared to the generally accepted rate of 15,000 to 20,000 cubic meters per year, which explains the rapid erosion at the north end. The greatest volume loss occurs in the winter months, ostensibly due to the passage of winter storms. There is also no significant cross-shore sediment transport in the northern portion of Long Key, beach profile results demonstrate a stable shape. However, there is slight cross-shore sediment transport in the central and southern regions of the island. At location LK 3 in the north end of the island lost 35 meters of shoreline above NGVD and 25 meters below NGVD. At location LK 11 in the south end there was a gain of 3 meters above NGVD and 15 meters below NGVD. Based on detailed sediment analysis, it is not possible to determine distinctive and persistent temporal or spatial sediment characteristics, nor are the sediment properties of Long Key indicative of longshore sediment transport.

This thesis investigated the effects of photographic and text information on respondents' attitudes and willingness-to-pay for a proposed beach protection scheme in the erosion prone Gold Coast region on the east coast of Australia. The research developed two alternative expectancy-value attitude-behaviour models to test residents' attitudes toward relevant targets and behavioural intention, expressed through stated willingness-to-pay, and compared the proposed models with one established attitude-behaviour model. The thesis set out to investigate three central research questions; one question relating to the effects of information on attitudes and willingness-to-pay, and two questions relating to the relationships between attitudes and willingness-to-pay. It was hypothesised that photographs that depicted severe erosion damage would result in more positive attitudes toward, and greater willingness-to-pay for, beach protection than photographs that showed only mild levels of erosion damage. Positive relationships were hypothesised between variables representing attitudes toward beach erosion, attitude toward beach protection, attitude toward paying for beach protection, and willingness-to-pay. Finally, it was hypothesised that the relationships between attitudes and willingness-to-pay could be adequately explained by the proposed attitude-behaviour models. The thesis describes how seven information treatments and eight attitude measurement scales were developed and tested in a pilot experiment before use in a survey of homeowners in the region of interest. Analysis of variance showed that, while respondent's attitude toward beach protection was affected by the information treatments, their willingness-to-pay for the proposed program was insensitive to information. There were no significant effects that could be attributed exclusively to text descriptions of the good but there were significant effects that could be attributed to photographic information treatments. However, none of the effects on attitudes resulted in significant effects on the behavioural intention expressed in stated willingness-to-pay. Analysis of respondents with low previous knowledge of the proposed good revealed more extensive information effects on attitudes, but still not on willingness-to-pay, and this suggests that high levels of previous knowledge in a large proportion of the sample had a moderating effect on attitude change caused by the information treatments. Regression analysis showed that seven of the eight attitude and behaviour variables in the proposed attitude-behaviour model were significant predictors of willingness-to-pay. In the final phase of the analysis, goodness-of-fit indices, estimated using Structural Equation Modelling, indicated a good fit between the data and the attitude-behaviour models tested. Standardised coefficients on the model indicated that perceived behavioural control, expected utility of outcomes, and subjective norms all had strong direct relationships with stated willingness-to-pay, and strong indirect relationships on willingness-to-pay via attitudes toward payment. These results are consistent with the relationships proposed in attitude-behaviour models and the moderating effects of these variables explain why significant information treatment effects were observed on attitude to beach protection but not on willingness-to-pay. This research showed that respondent's willingness-to-pay in a contingent valuation experiment is quite insensitive to photographic treatments when previous knowledge is high and that costly and time consuming testing procedures, recommended by authorities, may not be necessary under these conditions. It also demonstrated that measures of attitude, consistent with an attitude-behaviour model, can be collected easily in a contingent valuation study and can contribute to understanding of participant responses and to identification of protest responses.

<p>Scientists expect temperatures on Earth to get substantially warmer over the course of the 21st century, causing storm systems to intensify and sea-level rise to accelerate--these changes will likely have dramatic impacts on how the coastlines of tomorrow will evolve. Humans are also playing an increasingly important role in shaping Earth's coastal systems. Coastal scientists have only a general understanding of how these three factors--humans, storms, and sea-level rise--will alter the evolution of coastlines over the coming century, however. I conduct numerical modeling experiments to shed light on the relative importance of these factors on the evolution of coastline geomorphology.</p><p>In a series of experiments using a numerical model of large-scale (1 to 100's km) and long-term (years to centuries) coastline evolution that results from gradients in alongshore sediment transport, I explore how the patterns and rates of shoreline erosion and accretion are affected by shifts in 'wave climate' (the mix of influences on alongshore sediment transport of waves approaching from different directions) induced by intensified storm systems and the direct manipulation of the shoreline system by humans through beach nourishment (periodically placing sand on an eroding beach). I use a cuspate-cape coastline, similar to the Outer Banks, North and South Carolina, USA, as an important case study in my experiments. I observe that moderate shifts in the wave climate can alter the patterns of shoreline erosion and accretion, potentially increasing migration rates by several times that which we see today, and nearly an order-of-magnitude larger than sea-level rise-related erosion alone. I also find that under possible wave climate futures, beach nourishment may also induce shoreline change on the same order of magnitude as does sea-level rise.</p><p>The decision humans make whether or not to nourish their beach often depends upon a favorable economic outcome in the endeavor. In further experiments, I couple a cost-benefit economic model of human decision making to the numerical model of coastline evolution and test a hypothetical scenario where two communities (one 'rich' and one 'poor') nourish their beaches in tandem, under different sets of economic and wave climate parameters. I observe that two adjacent communities can benefit substantially from each other's nourishment activity, and these effects persist even if the two communities are separated by several tens of kilometers.</p><p>In a separate effort, I employ techniques from dynamic capital theory coupled to a physically-realistic model of coastline evolution to find the optimum time a community should wait between beach nourishment episodes ('rotation length') to maximize the utility to beach-front property owners. In a series of experiments, I explore the sensitivity of the rotation length to economic parameters, including the discount rate, the fixed and variable costs of beach nourishment, and the benefits from beach nourishment, and physical parameters including the background erosion rate and the exponential rate at which both the cross-shore profile and the plan-view coastline shape re-adjusts following a beach nourishment episode ('decay rate' of nourishment sand). Some results I obtained were expected: if property values, the hedonic value of beach width, the baseline retreat rate, the fixed cost of beach nourishment, and the discount rate increase, then the rotation length of nourishment decreases. Some results I obtained, however, were unexpected: the rotation length of nourishment can either increase or decrease when the decay rate of nourishment sand varies versus the discount rate and when the variable costs of beach nourishment increase.</p> / Dissertation

In the last few decades, academic and institutions advanced in coastal research in Europe and America have rigorously engaged in developing numerical models for coastal wave hydrodynamic simulations. The notable products include MIKE21 from DHI in Denmark, CEDAS (with GENESIS and SBEACH) from Veri-Tech in the United States, and the SMC from University of Cantabria in Spain. Among them, the Spanish Coastal Modeling System (SMC) is the only integrated package for coastal planning and modeling. With a unique preprocess module which pre-stores the bathymetry and wave data, the SMC provides a user-friendly interface directly using the screen display for a series of coastal planning and design applications which comprise artificial nourishment with headland-bay beach, breakwater construction and extension, and dredging of navigation channel etc., as well as the usual wave-current simulation for countermeasures in coastal protection and disaster mitigation. Despite the availability of several numerical programs for wave-current simulations and beach changes that have been developed by the coastal professional in Taiwan, and the continuous effort of the Water Resources Agency, Ministry of Economic Affairs to establish a national coastal database, it is imperative to develop/setup an integrated bathymetry-hydrodynamics-protection system, such as the Spanish SMC, as the key element in the national platform for coastal planning and modeling. This dissertation first describes the coastal environment in Taiwan, major causes for shoreline evolution and then reviews the history of shore protection since 1970s, together with the current prospective for coastal environment and strategies to sustain the natural shoreline ratio. To accomplish these goals, the Water Resources Agency has endeavored to implement artificial nourishment with headland-bay beaches, in order to raise the ratio of natural shoreline, in addition to establish a national coastal planning and simulation platform. As a response to this call for eco-engineering approach, we recommend that headland-bay beach in static equilibrium be adopted for mitigating coastal erosion, beach restoration and creation of recreational beaches, which can be designed directly on the screen using the empirical bay shape equation in conjunction with the SMC. Based on the framework of the Spanish SMC, this writer has successfully attempted the preliminary pre-process module of Baco (bathymetry) and Odin (wave climate) for Taiwan, using data from digitized nautical charts, nearshore depth surveys, and long-term wave observation results around Taiwan from the International Comprehensive Ocean-Atmosphere Data Set (ICOADS). The effort generates the first version of SMC in Taiwan. Having pre-stored the bathymetry and wave data for Dapeng bay in Pingtung County and Sizihwan Bay in Kaohsiung City, a series of coastal planning and modeling procedures for these two model sites are demonstrated in this dissertation, including a series of calculations of wave-current distribution for monsoon and storm waves, as well as planning of bay beach using artificial nourishment. Upon executing the Taiwanese version of SMC introduced in this dissertation, the modeling results can be applied to assist the planners and decision makers in comprehending the coastal environment, devising a feasible shore protection strategy, and promoting an earlier accomplishment of the so-called ¡ugeo-engineering ¡u in our country. Finally, the writer also wishes the outcome of this study could help relevant government agency to accomplish the prospective of sustainable coastal development upon implementing the strategies of establishing an appropriate coastal planning platform and promoting a systematic approach for coastal planning and design, as revealed in the "Sustainable Regeneration of Coastal Environment Project (98 ~ 103 fiscal year)".