Confined coasts in general, and pocket beach environments in particular, are under huge development pressures worldwide, not least due to their sheltered nature and perceived shoreline stability. However, understanding of their physical functioning is poor in comparison to that of open coast beaches. This study aims to improve understanding in terms of the existing gaps in knowledge of wave processes and nearshore currents, and also to examine the importance of local wind and tide factors in generating nearshore currents, in micro-tidal pocket beaches. The boundaries of embayments are generally recognized as important controls of their beach processes and responses, yet little detailed knowledge exists of how the exact embayment dimensions and characteristics influences these processes. One key embayment feature the influence of which is poorly understood is the downcoast headland. In this thesis, field observations plus Zanuttigh and Van der Meer’s (2008) approach, and the SWAN wave model were used to evaluate the downcoast headland effects on wave processes within Okains Bay, an example pocket beach environment. The results showed that incident wave heights and directions were significantly influenced by wave reflection processes from the downcoast headland inside the bay. The intensity of reflection effects on wave characteristics inside the pocket beach varied according to approaching wave direction. Reflection effects reduced when waves approached from angles close to parallel to the headlands, increasing towards headland-perpendicular wave approaches. Field observations and the XBeach model were used to examine whether or not tides can significantly influence nearshore currents within example and model pocket beach environments. Results indicated that tides can be the primary driver of nearshore currents close to the bed inside micro-tidal pocket beaches, depending on incident wave conditions. In areas of micro-tidal pocket beaches exposed to direct approaching waves, currents were wave driven, while in areas further into the bay that experienced headland filtering of their wave environment, currents were mainly tide generated. The results of this study demonstrated how the current circulation system within micro-tidal pocket beaches is related to the incoming directions of offshore waves. If high energy waves approach oblique or normal to the shoreline (with the assumption that the shoreline is at 90° to the headlands), the current system was found to consist of longshore currents influenced by headlands, plus a rip current in the center of the shoreline or a toporip in proximity to headlands. The location of the rip current or toporip was determined by the direction of approaching incident waves. This study also examined the behavior of local winds in a pocket beach environment and their consequent effects on nearshore currents. Results for Okains Bay show that local winds tended to blow in offshore and onshore directions, as the bay is located in a valley, so orographic effects channel and shift the wind directions to angles close to offshore and onshore directions inside the bay. Results also indicated that local winds influence the hydrodynamic currents of pocket beaches that are confined by elevated topography, producing semi-cross shore influences since the winds are topographically channelled to blow in predominantly offshore and onshore directions. This research significantly refines our understanding of micro-tidal pocket beach wave and current processes, including quantification of the filtering effects of headlands on their wave environments, revealing the various and variable influences of tides and winds compared to in open coast beaches; and, significantly, highlighting the role of downcoast headland wave reflection effects. With regard to the latter, this research elucidates some key process differences between pocket and embayed beaches and clarifies reasons why the application of embayed beach models that include refraction and diffraction but exclude reflection effects to the study of pocket beaches is inappropriate for studying pocket beaches. This research also provides methodological and topic suggestions for future research on pocket beach environments, including how to use the improved hydrodynamic knowledge of this study in future studies seeking to better understand pocket beach sediment systems, a topic that was beyond the scope of the current research.

Analisamos aproximadamente três anos de dados correntográficos, em toda a coluna d\'água, e de temperatura junto ao fundo, a fim de avaliar o comportamento hidrodinâmico e termal nas proximidades da Quebra da Plataforma Continental (QPC) de Cabo Frio (CF, Rio de Janeiro, Brasil - 23° 20\'S). A Corrente do Brasil (CB) força movimentos apontando para sudoeste, paralelos à isóbata, em todos os níveis verticais, com variação sazonal das intensidades: médias máximas para o verão (58,7 cm/s) e primavera (41,4 cm/s) e mínimas para inverno (31,0 cm/s) e outono (22,8 cm/s). Foram obtidos máximos significativos de correlação entre as correntes paralelas à isóbata, em toda a coluna d\'água, e o vento na mesma direção, com defasagem na resposta das correntes da ordem do período inercial local (31 h). Também foram obtidos máximos significativos de correlação entre as correntes de fundo normais à isóbata, e a componente paralela do vento, concordantes com mecanismos de intrusões de Água Central do Atlântico Sul (ACAS) na plataforma continental, as quais antecedem a conhecida ressurgência costeira de CF. Sazonalmente, os resultados concordaram principalmente com as variações de posicionamento da frente da CB na QPC e, secundariamente, com a variabilidade dos ventos. Os dados de temperatura indicaram presença quase permanente da ACAS no fundo, e os máximos de correlação obtidos com as correntes paralelas à isóbata indicam que águas mais quentes, oriundas do núcleo da CB (Água Tropical), se aproximam do fundo da QPC, principalmente durante o verão. As correntes de maré se mostraram fracas em todo o período avaliado, com importância decrescendo da superfície para o fundo (20 e 10% da variância, respectivamente) / Current data throughout the water column and temperatures at the bottom from about three years have been analyzed in order to evaluate the hydrodynamic and thermal behavior near the Cabo Frio (CF) continental shelf break (23° 20\'S - Rio de Janeiro, Brazil). The Brazil Current (BC) forces movements pointing to SW, isobath-aligned, on all vertical levels. The speed varies seasonally, with surface mean currents maximum on summer (58.7 cm/s) and spring (41.4 cm/s), and minimum on winter (31.0 cm/s) and autumn (22.8 cm/s). Significant maximum correlation was found between subinertial winds and driven-wind currents, both isobath-aligned, with a delay next to the local inertial period (31 hours). Significant maximum correlation were also obtained between bottom cross-isobath currents and the isobath-aligned component of the wind, consistent with the South Atlantic Central Water (SACW) transport towards the continental shelf, which antedates the well-known coastal CF upwelling. Seasonally, the results agreed mainly with the positioning variations of the BC to the shelf break and, secondly, with the local winds variability. The temperature values below the 18ºC (SACW thermohaline index) was almost permanent on the bottom of the shelf break, and the maximum correlation obtained with current along the isobath indicates that the warmer water of the BC nucleus (Tropical Water) approaches to the bottom of the shelf break, especially during the summer. Tidal currents were weak during the entire sampling period, decreasing the relative strength from the surface to the bottom (20% and 10% of the variance, respectively)

Analisamos aproximadamente três anos de dados correntográficos, em toda a coluna d\'água, e de temperatura junto ao fundo, a fim de avaliar o comportamento hidrodinâmico e termal nas proximidades da Quebra da Plataforma Continental (QPC) de Cabo Frio (CF, Rio de Janeiro, Brasil - 23° 20\'S). A Corrente do Brasil (CB) força movimentos apontando para sudoeste, paralelos à isóbata, em todos os níveis verticais, com variação sazonal das intensidades: médias máximas para o verão (58,7 cm/s) e primavera (41,4 cm/s) e mínimas para inverno (31,0 cm/s) e outono (22,8 cm/s). Foram obtidos máximos significativos de correlação entre as correntes paralelas à isóbata, em toda a coluna d\'água, e o vento na mesma direção, com defasagem na resposta das correntes da ordem do período inercial local (31 h). Também foram obtidos máximos significativos de correlação entre as correntes de fundo normais à isóbata, e a componente paralela do vento, concordantes com mecanismos de intrusões de Água Central do Atlântico Sul (ACAS) na plataforma continental, as quais antecedem a conhecida ressurgência costeira de CF. Sazonalmente, os resultados concordaram principalmente com as variações de posicionamento da frente da CB na QPC e, secundariamente, com a variabilidade dos ventos. Os dados de temperatura indicaram presença quase permanente da ACAS no fundo, e os máximos de correlação obtidos com as correntes paralelas à isóbata indicam que águas mais quentes, oriundas do núcleo da CB (Água Tropical), se aproximam do fundo da QPC, principalmente durante o verão. As correntes de maré se mostraram fracas em todo o período avaliado, com importância decrescendo da superfície para o fundo (20 e 10% da variância, respectivamente) / Current data throughout the water column and temperatures at the bottom from about three years have been analyzed in order to evaluate the hydrodynamic and thermal behavior near the Cabo Frio (CF) continental shelf break (23° 20\'S - Rio de Janeiro, Brazil). The Brazil Current (BC) forces movements pointing to SW, isobath-aligned, on all vertical levels. The speed varies seasonally, with surface mean currents maximum on summer (58.7 cm/s) and spring (41.4 cm/s), and minimum on winter (31.0 cm/s) and autumn (22.8 cm/s). Significant maximum correlation was found between subinertial winds and driven-wind currents, both isobath-aligned, with a delay next to the local inertial period (31 hours). Significant maximum correlation were also obtained between bottom cross-isobath currents and the isobath-aligned component of the wind, consistent with the South Atlantic Central Water (SACW) transport towards the continental shelf, which antedates the well-known coastal CF upwelling. Seasonally, the results agreed mainly with the positioning variations of the BC to the shelf break and, secondly, with the local winds variability. The temperature values below the 18ºC (SACW thermohaline index) was almost permanent on the bottom of the shelf break, and the maximum correlation obtained with current along the isobath indicates that the warmer water of the BC nucleus (Tropical Water) approaches to the bottom of the shelf break, especially during the summer. Tidal currents were weak during the entire sampling period, decreasing the relative strength from the surface to the bottom (20% and 10% of the variance, respectively)

El fenomen atmosf��ric de les brises marines adopta a l���illa de Mallorca caracter��stiques protot��piques, i la seva efectivitat permet una f��cil constataci�� com�� i la subseq��ent verificaci�� cient��fica. Operant simult��niament des de les diferents costes, les brises adquireixen un car��cter unitari i centr��pet que ocasiona converg��ncies d���aire a ��rees de l���interior, a on la precipitaci�� estival tendeix a focalitzar-se. L���espai agrari de Mallorca s���ha conformat hist��ricament amb el massiu desplegament territorial d���infrastructures de base cereal��stica, fonamentalment eres de batre. El principal factor de la seva localitzaci�� ��s la disponibilitat de vent, tot constituint unitats de significaci�� e��lica susceptibles d���interpretar-se en clau clim��tica. La seva georeferenciaci�� per fotointerpretaci�� de l���ortofotografia de l���any 1956 s���ha tradu��t en un mapa sint��tic d���eres, m��s una metodologia in��dita per a determinar indirectament les direccions del vent a cada empla��ament. El model ���anemogr��fic��� resultant s���ajusta amb relativa bondat amb les simulacions del sistema de brises precedents. / El fen��meno atmosf��rico de las brisas marinas adopta en la isla de Mallorca caracter��sticas protot��picas, y su efectividad permite una f��cil constataci��n com��n y la subsiguiente verificaci��n cient��fica. Operando simultaneamente desde las diferentes costas, las brisas adquieren un car��cter centr��peto que ocasiona convergencias de aire en ��reas del interior, donde la precipitaci��n estival tiende a focalizarse. El espacio agrario de Mallorca se ha conformado hist��ricamente con el masivo despliegue territorial de infraestructuras de base cereal��stica, fundamentalmente eras de trillar. El principal factor de su localizaci��n es la disponibilidad de viento, constituyendo unidades de significaci��n e��lica susceptibles de interpretarse en clave clim��tica. Su georeferenciaci��n por fotointerpretaci��n de la ortofotografia del a��o 1956 se traduce en un mapa sint��tico de eras, m��s una metodolog��a in��dita para determinar indirectamente las direcciones del viento en cada emplazamiento. El modelo ���anemogr��fico��� resultante se ajusta con relativa bondad con las simulaciones del sistema de brisas precedentes. / In Mallorca, sea breeze presents prototypical characteristics. It is so consistent that its effectiveness allows for easy common as well as scientifc verification. Daytime breezes operate simultaneously from different coasts, and penetrate inland. Its centripetal nature causes wind convergences in certain inland areas, where summer rainfall tend to focus. The agricultural area has historically made with massive territorial deployment of cereal production infrastructure, mainly threshing floors, the main factor of its location being the quantity of the wind resources available. These are small circular spaces that can be interpreted in relation to climate. A synthetic chart of threshing floors and a methodology designed to indirectly determine the dominant wind directions at each site have been developed, based on their geo-referencing by photo-interpretation of the ortho-photographs of 1956. The resulting ���anemographic��� model fits nicely with the main features of the sea breezes identifed by the theoretical-experimental and numerical simulations already tested.