With the changing perceptions in coastal engineering in recent time, creation of bay beach for recreation by combining artificial headlands with nourishment has become one of the favorable options for mitigating erosion and shore protection in several foreign countries advanced in coastal engineering. To achieve this goal, hydraulic model tests and numerical simulations have been applied for the planning and design of stable bay beaches. While using the latter approach, numerical computation includes four major components, these being the waves, topography changes, flow field and sediment transport. This study utilizes the so-called Modified Hsu3D model developed by Serizawa et al. (1996) and Kumada et al. (2002) in Japan for the bathymetry within a static equilibrium bay beach defined by Hsu and Evans (1989). This model enables the direct calculation of bottom bathymetry within a static bay without using not only iterative numerical steps for wave transformation and current distribution, but also the continuity equation for total sediment transport. The results of this simplified approach can be used to estimate the distribution of erosion and accretion within a static bay, hence, suitable for pre-assessment of an artificial beach nourishment project. Prior to applying the Modified Hsu3D model to a bay beach undertaken in this study, sensitivity tests are performed on the setting of several key parameters associated with this model, such as limiting slope on land , limiting slope in the water , height of the berm , alignment angle at downdrift of the bay beach, and wave incident angle . The verification results are then adopted to compare with that reported in Serizawa et al. (2000), as well as to investigate the effects of each parameters on the accuracy of the modeling, in order to enhance the reliability of this model and the setting of the parameters. Finally, the Modified Hsu3D model is applied to simulate the changes in the shoreline and bathymetry for the Sizihwan Bay in Kaohsiung, under the action of normal incident waves during summer monsoon. This study also takes the advantage of the Modified Hsu3D model to explore the effect of oblique wave incidence on the deviation of downdrift control point of a static bay, in order to assist the prediction of downdrift control point for beach changes on an artificially nourished bay beach. The results reveal that the downdrift control point does not shift, under normal incident waves with different for the breaker. On the other hand, under oblique wave action within from the external boundary line of 20 m depth offshore of a bay beach comprising sediment 0.2~0.5 mm, the offset of point (i.e., and coordinates from the original origin) versus wave incident angle can be established. By establishing a regression equation between and versus , the result can be used to assist the determination, more precisely without guess work, on locating the downdrift control point of a bay beach, while working on the MEPBAY (Klein, et al., 2003) on computer screen to assess its stability.

MAGALHÃES, Danilo Carneiro. Evolução costeira controlada por promontório no litoral de Paracuru – Ceará. 2015. 97 f. Dissertação (Mestrado em geografia)- Universidade Federal do Ceará, Fortaleza-CE, 2015. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-06-10T18:32:08Z No. of bitstreams: 1 2015_dis_dcmagalhaes.pdf: 7795450 bytes, checksum: 484b0b43e79467cdf572ad1fd5dfc279 (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-06-14T23:22:00Z (GMT) No. of bitstreams: 1 2015_dis_dcmagalhaes.pdf: 7795450 bytes, checksum: 484b0b43e79467cdf572ad1fd5dfc279 (MD5) / Made available in DSpace on 2016-06-14T23:22:00Z (GMT). No. of bitstreams: 1 2015_dis_dcmagalhaes.pdf: 7795450 bytes, checksum: 484b0b43e79467cdf572ad1fd5dfc279 (MD5) Previous issue date: 2015 / The city of Paracuru is part of the coastal area of the state of Ceará and is located 85 km from the capital, Fortaleza. Paracuru presents intense environmental dynamics that can be seen through various types of reliefs that show the exchanges between matter and energy in the coastal system. This paper took under consideration the influence of the Paracuru’s promontory in the coastal and littoral dynamics. Thus, the research was based on the analysis of littoral relief to understand the environmental dynamics of that part of city’s coast. To analyze these coastal areas, it was made bibliographic search, cartographic survey and fieldworks, plus some cabinet steps for the treatment of data. The environmental characterization and analysis of the coastal dynamics demonstrates that the Paracuru’s promontory develops determining functions in the current configuration of the coast because it controls the distribution of sediments transported by longshore drift. The analysis also shows that the variety of land uses determines historically the accumulation of environmental impacts on the coastal plain of Paracuru. / Inserido na zona costeira cearense, 85 km a oeste de Fortaleza, o município de Paracuru apresenta intensa dinâmica geoambiental expressa na forma de variados tipos de relevo que evidenciam as trocas de matéria e energia no sistema costeiro. Tomamos em análise as influências oferecidas pelo promontório de Paracuru à sua dinâmica costeira e litorânea. Assim, a pesquisa se baseou na análise do relevo litorâneo como instrumento à compreensão da dinâmica geoambiental do referido município. Realizou-se pesquisa bibliográfica em diferentes meios (livros, periódicos, internet), levantamento cartográfico para a produção de mapas temáticos, trabalhos de campo para reconhecimento e construção de análises sobre o espaço costeiro, e etapas de gabinete para o tratamento de dados e escrita do trabalho final. Desenvolveu-se a caracterização ambiental, análises sobre a dinâmica litorânea e a formação socioespacial do município considerando os principais usos do solo. Demonstra-se que o promontório de Paracuru desenvolve funções determinantes na atual configuração do litoral ao controlar a distribuição de sedimentos transportados pela deriva litorânea e ainda que a variedade de usos do solo determina historicamente o acúmulo de impactos ambientais na planície costeira paracuruense.

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ABSTRACT The Eocene Roda Formation in northern Spain documents the deposits from a range of coastal depositional environments. These include alluvial plains, distributary channels, mouth bars, upper to lower-shorefaces, and tidal shelf ridges. Eighteen progradational sand tongues that are interpreted as parasequences compose two third-order sequences. Sequence 1 accumulated in an environment with strong tidal currents and high rates of progradation, while Sequence 2 was deposited under relatively weaker currents and higher rates of aggradation, which produced a higher mudstone:sandstone ratio. The stratigraphy highlights the transgressive origin of six tidal shelf ridges, three in each sequence, that overlie regressive deltaic tongues. Sequence 1 shelf ridges are composed almost entirely of cross-bedded sandstones, whereas Sequence 2 ridges are composed of a mixture of cross-bedded and ripple-laminated deposits. Ridges in both sequences contain bioturbation that is typical of the Cruziana Ichnofacies, and that indicates a marine origin. The tidal ridges are stratigraphically located at or near the point of maximum third-order regression, and are not found within early highstand or late transgressive deposits― times of high relative sea level when the deltaic shoreline did not protrude significantly. Tidal currents were accentuated at the coast when the delta complex had prograded several kilometres into the basin, while during times of high relative sea level, the basin was wider and tidal currents were weaker, consequently leading to a lack of tidal deposits. The tidal ridges are, thus, interpreted as being headland-associated deposits. / Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2011-04-29 17:10:10.008