\"Chovia desde o dia 16, aumentando a intensidade das chuvas a partir das 18 horas do dia 17. As primeiras barreiras começaram a ceder nas primeiras horas da manhã do dia 18 e, às 13 horas, mobilizou-se a totalidade da avalanche\" - (CRUZ, 1974). A descrição do cenário catastrófico no Município de Caraguatatuba, no mês de Março de 1967, que resultou em um dos maiores desastres naturais ocorridos no Brasil (*), fomenta a discussão sobre as probabilidades de ocorrência de eventos pluviométricos e/ou elevações do nível do mar nas Zonas Costeiras. Diante dessa realidade, surgiu essa Dissertação, que abordou aspectos hidrológicos, hidráulicos marítimos e, estatísticos, baseados em dados pretéritos de pluviômetros e marégrafos da região do Litoral Norte do Estado de São Paulo. Foram obtidos resultados práticos para futuros projetos de macro-drenagem, obras fluviais e marítimas, que associam a probabilidade de ocorrência conjugada de determinadas chuvas, com correspondentes elevações dos níveis de maré. Também foram realizados estudos da evolução desses eventos conjugados, ao longo de sessenta anos. - (*) De acordo com informações de Cruz (1974), 436 mortes foram registradas oficialmente, 400 casas destruídas, 3.000 desabrigados numa população total de 15.000 habitantes. Foram formados depósitos de 4 m a 5 m de altura no Rio Santo Antônio com blocos entre 30 t e 100 t. / \"It was raining since March 16th, increasing the intensity of the rainfall at 6:00 pm on March 17th. The first slopes started to sag in the first hours of March 18th, at 1:00 pm, occurred all the debris-flow\" - (translated from CRUZ, 1974). The catastrophic scenario of the city of Caraguatatuba, in March of 1967, previously described, resulted from one of the most serious natural disasters in Brazil. It fosters discussions about probabilities of rainfall events and /or rise in the sea level in coastal areas. Hence, this research is a consequence of this reality, which approached hydrological, hydraulic and statistical areas, based on past data of rainfall stations and tidal stations in the region of the North Coastal Zone of the State of São Paulo (Brazil). Practical results were used for future designs of macro- drainage, fluvial and maritime projects, that associate the probability of occurrence of certain types of rainfall coupled with their corresponding increase in tidal levels. There were also evaluated studies of the evolution of these events combined over sixty years.

In recent years, much research has focused on the possibility of using arrays of turbines to generate clean and predictable power from tidal currents. The first such array is now in development but a number of important questions remain unanswered. Among these, how should turbines be arranged within a tidal stream to maximise their collective performance? And what impacts will such devices have on the marine environment? In beginning to address these questions, this thesis takes two important steps toward establishing best practice in the design of tidal turbine arrays. In the first part of the thesis, the social and ecological impacts of marine energy development are reviewed. This review highlights the importance of communication and public engagement in securing support for a marine energy project and identifies the effects of increasing noise and collision risk on marine life as the most pressing ecological issues to be addressed. In the second part, theoretical models of tidal turbines are examined and a simple numerical model is used to extend existing theories on optimal turbine arrangement. The shallow water equations are used to simulate flow through an idealised channel and an actuator disc model is used to represent a single row of tidal turbines as a line sink of momentum. Optimal turbine arrangements are then sought for different and increasingly realistic flow conditions. Results provide new and important insights into the dynamics of flow through partial-width arrays and suggest that arranging turbines unevenly within the flow cross-section can increase considerably their collective power output.

Tides are the rise and fall of water level caused by gravitational forces exerted by the sun, moon and earth. Understanding sea level variation and its impact currents is very important especially in coastal regions. With knowledge of the tide-generating force and boundary conditions, hydrodynamic models can be used to predict or model tides in coastal regions. However, these models are not sufficiently accurate, and in-situ tide gauge data may be used to improve them in coastal regions. The International Hydrographic Organization (IHO) tidal data bank consists of over 4000 tide gauge stations scattered all around the globe, most of which are in coastal regions. These tide gauge data are very valuable for tidal predictions. One drawback of the IHO data is that a considerable number of stations are located in rivers or near man-made structures or small-scale, complex topographic features. Another drawback is the unknown accuracy of the IHO data. To avoid these drawbacks, quality control has been done in the present study. Each IHO tide gauge station has been categorized according to its proximity to rivers, lagoons, man-made harbors, and other factors that may influence tidal elevation. Quantitative metrics such as water depth, distance to the continental shelf break, and horizontal length scale of station site morphology have been computed. Comparisons among IHO data, the output of O.S.U. Tidal Inversion Software (OTIS), and other data sources, such as Global Sea-Level Observing System (GLOSS) data, have been done to test the quality and accuracy of IHO data. Moreover, the characteristics of stations with large error have also been examined. The good comparison of IHO with duplicate GLOSS stations shows that, as far as can be determined, IHO data are reliable and ought to be used in improving coastal tide models. The non-Gaussian character of the errors suggests that further improvements in tidal modeling will require advances in data assimilation which are robust to non-Gaussian data error.

Unmanned aerial vehicle (UAV) technology was used to determine tidal extent in Kimages Creek, a restored tidal wetland located in Charles City County, Virginia. A Sensefly eBee Real-Time Kinematic UAV equipped with the Sensor Optimized for Drone Applications (SODA) camera (20-megapixel RGB sensor) was flown during a single high and low tide event in Summer 2017. Collectively, over 1,300 images were captured and processed using Pix4D. Horizontal and vertical accuracy of models created using ground control points (GCP) ranged from 0.176 m to 0.363 m. The high tide elevation model was subtracted from the low tide using the ArcMap 10.5.1 raster calculator. The positive difference was displayed to show the portion of high tide that was above the low tide. These results show that UAVs offer numerous spatial and temporal advantages, but further research is needed to determine the best method of GCP placement in areas of similar forest structure.

John’s Pass is a stable mixed-energy inlet located on a microtidal coast in Pinellas County, Florida. It is hydraulically connected to the northern portion of Boca Ciega Bay. Morphological analysis using a time-series of aerial photographs indicated that anthropogenic activities have influenced the evolution of the tidal deltas and adjacent shorelines at John’s Pass. Previous studies have documented the channel dimensions at the location of the existing bridge and calculated the tidal prism. A chronological analysis of these data yielded an increasing trend in the cross-sectional area at John’s Pass from 1873 to 2001. Anthropogenic activities occurring in Boca Ciega Bay impacting this trend begin in the 1920’s when Indian Pass, approximately 7 km north of John’s Pass, was artificially closed. Other significant events causing an increase or decrease in the crosssectional area at John’s Pass include dredging and filling in the bay, channel dredging at John’s Pass, and jetty construction. More recent data collected from a simultaneous current meter deployment at John’s Pass and Blind Pass were used to calculate the bay area serviced by each inlet resulting in an area serviced by John’s Pass being 1.8x104 km2 and 0.33x104 km2 serviced by Blind Pass. In comparison, Blind Pass captures 14 percent of the tidal prism that John’s Pass captures and John’s Pass captures 87 percent of the bay prism while Blind Pass captures 13 percent. Using the discharge equation and assuming the channel area was largely constant the tidal prism at John’s Pass was 1.07x107 m3 during the twenty-one day deployment. Based on a historical analysis of the tidal prism this study is within 40 percent of the tidal prism calculated by Mehta (1976) and Becker and Ross (2001) and within 20 percent of the tidal prism calculated by Jarrett (1976) and Davis and Gibeaut (1990). An analysis of the current meter time-series indicated that flood velocities in the channel were influenced by a frontal system passing through the study area during the deployment increasing the amount of potential sediment being deposited in the channel thalweg. The maximum ebb and flood-tidal velocities during the deployment were 143 cm/s and 115 cm/s, respectively. Morphological analysis of cross-sectional data from 1995 to 2004 indicated that sediment tends to accumulate along the northern portion of the channel. The channel thalweg tends to accumulate more sediment east of the bridge where wave energy is lower and currents are not as strong. An average net accumulation of 0.5 m per year was estimated along all seven cross-sections. Given the length and width of the surveyed channel, 610 m by approximately 150 m, the sediment flux through the inlet is approximately 45,800 m3 /yr along the channel thalweg. A small amount of sediment accumulation has occurred southwest of the bridge in response to channelized flood flows along the newly constructed jetty. An annual sediment budget was estimated for the John’s Pass inlet system using the beach profiles and inlet bathymetry data between 2000 and 2001. Overall, the inlet system has accumulated more sediment than it has lost during this time period.

Numerical modeling systems are very important tools to study tidal inlets. In order to test its capability and accuracy of solving multi-inlet system problems, this study selected two widely used numerical modeling systems: Coastal Modeling System (CMS) and Delft3D Modeling Package. The hydrodynamics modules of the two modeling systems were tested at John's Pass and Blind Pass, Florida, a dual-inlets system, based on a similar modeling scheme. Detailed bathymetric surveys and hydraulic measurements were conducted to collect water depths, tide conditions, wave and current velocities as the input data as well as verification data for the models. A comparison study was conducted by comparing computed hydrodynamic results from both models with the extensive field measurement data. Results show that both of the modeling systems yield better prediction for water levels than for current velocity. Furthermore, under the similar modeling scheme, Delft3D was able to capture the measured tidal phase lag between the ocean boundary and the coastal inlet, therefore gave better water level prediction than the CMS model. However, the CMS yielded current velocities that are closer to the measured values than the DELFT3D model. CMS has a more user-friendly Graphic User's Interface (GUI) for input data preprocessing and plotting and visualization of output data. Delft3D has faster calculation speed.

Phreatic overgrowths on speleothems (POS) are one of many sea-level proxies available to Quaternary geologists in Mallorca; these carbonate encrustations form at the air-water interface in cave passages flooded with brackish water. POS are ideal for reconstruction of western Mediterranean sea level because they are widespread in Mallorca's caves, can be precisely dated by U-series methods, constrain sea-level stands to sub-meter elevation, and are well preserved and accessible in the subterranean environment. This research investigates the POS depositional environment, which is relatively understudied compared to the other proxies used for sea-level reconstructions. This disparity has led to assumptions on many aspects of the POS precipitation. Further, POS are typically composed of calcite, but sometimes the metastable polymorph aragonite is present instead. Two caves were studied because of the presence of a modern POS horizon of aragonite and calcite: Cova des Pas de Vallgornera (Vallgornera) and Coves del Drac (Drac), respectively. High-resolution air and water physical parameters were collected for the first time, along with monthly water samples for stable isotope and elemental analysis. This 16-month record was supplemented with detailed geochemical studies throughout the project, including water-column profiles and CO2 sampling campaigns. The water level in both caves preserves the semi-diurnal Mediterranean Sea tide signal, with a lag of approximately four hours. The fluctuation in both caves is slightly attenuated, and the direct effects of barometric pressure and precipitation could not be discerned from the primary control of tidal pumping. Calculations based on salinity and isotope analysis show that less than 20% of the solution in each cave is seawater. Degassing of CO2 from the cave water to air was documented at both locations, with sporadic calcium carbonate supersaturation. These conditions are strongly dependent on annual cave ventilation, which becomes active during winter when cold, dense tropospheric air sinks into the subsurface. In addition to seasonal thermo-circulation, fluctuating water level displaces cave air and likely initiates tropospheric exchange throughout the year. This process primarily occurs through fissures in thin overlying bedrock at Vallgornera and through the large entrance in Drac. Higher elemental ratios (Mg:Ca, Sr:Ca, Mg:Sr) known to enhance aragonite precipitation or inhibit calcite precipitation were recorded in Vallgornera's water. A linear correlation with salinity was not observed, so higher ratios in Vallgornera must be contributed from differences in lithology, bedrock weathering intensity, or nearby rising thermal waters. In summary, this research confirms POS strengths as sea-level proxies from geochemical and hydrological perspectives. These carbonate encrustations are precipitated at the air-water interface, which fluctuates as an attenuated expression of Mediterranean Sea tide. Degassing of CO2 from the cave water to air, which promotes calcium carbonate supersaturation, is the major control on POS deposition, and is facilitated by winter ventilation and likely water-level fluctuations. CO2 degassing (and theoretically precipitation of POS) in isotopic equilibrium is possible in caves with restricted ventilation (small/sealed entrances, small passages). Aragonite may be precipitated instead of calcite because of local modifications to the geochemical system from bedrock weathering or contributions from deep groundwater.

Tidal currents and rivers are promising sources of renewable energy given that suitable turbines for kinetic energy conversion are developed. To be economically and technically feasible, a velocity distribution that can give a high degree of utilization (or capacity factor), while the ratio of maximum to rated velocity is low would be preferable. The rated velocity is defined as the velocity at which rated power is achieved. Despite many attempts to estimate the resource, however, reports on the possible degree of utilisation from tidal currents and rivers are scarce. In this paper the velocity distribution from a number of regulated rivers, unregulated rivers and tidal currents have been analysed regarding the degree of utilisation, the fraction of converted energy and the ratio of maximum to rated velocity. Two methods have been used for choosing the rated velocity; one aiming at a high fraction of converted energy and one aiming at a high degree of utilisation. Using the first method, with a rated velocity close to the maximum velocity, it is unlikely that the turbine will reach the cut-out velocity. This results in, on average, a degree of utilisation of 23% for regulated rivers, 19% for unregulated rivers and 17% for tidal currents while converting roughly 30-40% of the kinetic energy. Choosing a rated velocity closer to the mean velocity resulted in, on average, a degree of utilisation of 57% for regulated rivers, 52% for unregulated rivers and 45% for tidal currents. The ratio of maximum to rated velocity would still be no higher than 2.0 for regulated rivers, 1.2 for unregulated rivers and 1.6 for tidal currents. This implies that the velocity distribution of both rivers and tidal currents is promising for kinetic energy conversion. These results, however, do not include weather related effects or extreme velocities such as the 50-year velocity. A velocity factor is introduced to describe what degree of utilisation can be expected at a site. The velocity factor is defined as the ratio U-max/U-rate at the desired degree of utilisation, and serves as an early indicator of the suitability of a site.

This study used the sediment samples collected in May (dry season) and September (wet season) 2010 in a river delta and tidal flat complex around Jhoushuei River mouth in Central Taiwan to examine seasonal sediment transport pathways and sources. Four different approaches were used in the analysis of grain-size distribution pattern. They include (1) the McLaren-Bowles method, and (2) the transport vector technique (Gao-Collins method), and (3) a combination of `filtering' and the empirical orthogonal (eigen) function (EOF) analysis technique, and (4) C/N elemental ratios of organic sediments. The results of surface grain size distributions of sediment range from clay to medium sand towards the sea, and very fine sand deposited in the river delta. On the upper tidal flat, mud content of the wet season is higher than dry season due to higher river output of organic sediment and low-energy sediment transport. In wet season, according to the fine-grained sediment from the Jhoushuei River is therefore mainly discharged to the offshore area and little remain around the tidal flat, the influence of river on the grain-size distribution is the least. The results based on McLaren-Bowles method indicate that there were two type sediment transport pathways, (1) the river carried sediment to the coast, then alone the northeast-southwest direction by the longshore current, and (2) during the flood tide, the riverine sediment move to northeast and east through the river delta and tidal creek to the upper tidal flat, respectively. The results based on Gao-Collins method indicate that there was possible seasonal variation of sediment transport pathways on the river delta front, where the significant transport was seaward in the wet season whereas the transport was the opposite in the dry season. On the tidal flat, the model results indicate that seaward transport seems to be controlled by ebb tidal current perhaps due to the sampling at low-tide.

Wetlands are one of the most productive ecosystems in the world, housing diverse biota and serving important functions as nursery habitat and feeding grounds. However, nearly 70% of coastal wetlands, including 21% of the salt marshes in Texas, have been lost since 1950, due primarily to coastal development and declines in water quality. Restoration of wetlands is essential to reestablish lost functions, but there is no standard method to assess the ecological health of restored salt marshes in Texas. Numerous recent salt marsh restoration projects in Galveston Bay have made it an ideal model system to develop and implement an ecosystem health assessment, known as a rapid assessment method (RAM). In this study, I modified an established RAM, the Mid-Atlantic Tidal Fringe Assessment, to compare the ecological health of representative reference salt marshes to restored marshes around Galveston Bay. I measured 14 biotic and abiotic characteristics at 12 restored and 6 reference sites around Galveston Bay, and then grouped those measurements into four functional groups: landscape/site characteristics, hydrology, wildlife habitat, and soil characteristics. I then developed a scoring system (minimum 0, maximum 100) to summarize the overall health of each site. Most of the restored salt marshes in this study scored lower than reference marshes. The average reference site score was 81.8 and the average restored site score was 69.7. Functional group values for landscape/site characteristics, soil, and wildlife habitat were significantly lower in restored than in reference sites. In particular, restored sites had more hydrological modifications, more fill material, and fewer macrobenthos than reference wetlands. The Galv-RAM effectively and efficiently identified restoration successes and weaknesses. With this information, management agencies can address restoration shortcomings by adapting management goals. The Galv-RAM will streamline monitoring protocols and facilitate long-term examination of restored wetland health. As a result, management decisions can be modified based on the scores received in different categories or variables to improve and or meet the goals of the project.