To clarify the spatiotemporal distribution of the winter and spring larval fish assemblage in the coastal waters off Kaohsiung and Pingtung, Taiwan, larval fishes were collected during four research cruises by conducting 35 tows of the larval net in coastal waters off Zuoying, Linyuan, Linban and Fangliao in January and March 2009 and in coastal waters off Linyuan adjacent to the Kaoping River estuary in January and March 2010. Water temperature, salinity and dissolved oxygen were measured during the sampling of the fish larvae. Seawater samples were also collected for analyzing concentrations of nutrient salts. In 2009, a total of 2,023 fish larvae, representing 38 families and 74 species, were collected. The fish larvae assemblage exhibited seasonal variation in both abundance and species composition. The abundance (460 ind./1000m3) and the number of species (34 families and 66 species) of the fish larvae collected in March were higher than those (28 ind./1000m3, 14 families and 27 species) collected in January. Fish larvae also exhibited spatial variation in species composition. In January, the most dominant families of fish larvae were: Myctophidae off Linyuan, Sparidae off Linban and Nomeidae off Fangliao. In March, in the northward coastal waters off Linyuan Scombridae was the most dominant family, and in the southward coastal waters off Linyuan, Clupeidae and Sillaginidae were the dominant families. No significant differences existed in the abundance of fish larvae among the sampling areas, but the abundance of fish larvae in the sampling sites off Linyuan and Linban tended to be strongly influenced by tide. In 2010, a total of 1,959 fish larvae, representing 39 families and 59 species, were collected. These fish larvae showed diurnal and seasonal variations in abundance and in species composition. The abundance (767 ind./1000m3) and the number of species (39 families and 55 species) of the fish larvae in March were higher compared with those (26 ind./1000m3, 16 families and 25 species) in January. Moreover, the abundance of fish larvae in the nighttime was higher than that in the daytime. In March, the most dominant family in the daytime was Serranidae, whereas the most dominant family in the nighttime was Myctophidae, indicating the diurnal migration of Myctophidae these larvae. Cluster analysis indicated that the abundance and species composition of the fish larvae differed between January and March in 2009. The difference in species composition among the four sampling areas was only found significant for the fish larvae collected in the coastal waters off Fangliao in winter, and the most influenced families were Nomeidae and Myctophidae. In 2010, seasonal variations were found in the abundance and species composition of the fish larvae, and the abundance of the fish larvae showed the difference between nearshore and inshore sampling sites in the nighttime in winter. In spring, the fish larvae were all inshore fishes, but the species composition had annual variation. The temperature and salinity data obtained in the sampling sites conformed to the surface seawater of South China Sea, indicating that the occurrence of the dominant family Scombridae may be related to the seawater of South China Sea.

Internal waves are vertical displacements of stratified water which can propagate a long distance without much energy dissipation. It plays on important role in conveying nutrient from deep ocean to shallower layers, and promoting biological growth. It also affects acoustics, ocean engineering and submarine navigation. Therefore, in the last few years, many scholars have devoted the research of internal waves, especially their generation and transportation in South China Sea. This research discusses the internal wave source, through the Princeton Ocean Model (POM). There are two simulations, one has bigger grid size 3.6km for the whole Luzon Strait in the region, 118¢XE ~123¢XE 18¢XN ~22¢XN, the other has smaller grid of 1.6km, for 118.5¢XE ~123¢XE and 19.5¢XN ~21.5¢XN. The total simulation period is 25 days, The north and south bomdawes use radiation boundary condition, the east side is driven by tidal calculated from WXTide32 model, the west side also uses radiation boundary condition. Three dimensional flow field during May, 2005, is simulated temperature, baroclinic velocity distribution, baroclinic energy flux, Empirical Orthogonal Functio ns (EOF), Fast Fourior transform (FFT), buoyancy frequency and Froude number are all analyzed, The results show that, when tidal current near the Batan island has the stronger baroclinic flow downward to transmit, after through Heng-Chun ridge the baroclinic energy flux to concenter, extrapolated this time possibly produces for internal tide.

The interaction of tidal currents with Fraser Ridge in the Strait of Georgia, B.C., generates an internal lee-wave on each strong flood but, due to the ridge's asymmetry, not during ebbs. Just prior to lee-wave formation, a strong accelerated bottom jet forms with magnitudes up to 0.7 m s^-1 forms during barotropic tidal flows reaching 0.2 m s^-1. On the steepest slope, this jet forms directly above a rare glass sponge reef, and may prevent the sponges from being smothered in sediment by periodically resuspending and carrying it away. Both the accelerated jet and lee-wave remove tidal energy. At peak flood tide, the lee-wave has energy dissipation rates reaching 10^-5 W kg^-1 that removes energy at a rate of ~611 W m^-1, while the bottom boundary layer at the time of the accelerated jet has energy dissipation rates reaching 10^-4 W kg^-1 that removes energy at a rate of ~525 W m^-1. / Graduate

Thesis (Ph. D.)--University of Washington, 1993. / Vita. Includes bibliographical references (leaves [145]-169).

L’objectif de cette thèse est de développer des stratégies de commande non linéaire et robuste afin d’assurer une connexion avec succès des systèmes hydroliens dans un réseau électrique de forte puissance. Il s’agira en plus, d’étudier en simulation et en pratique le comportement dynamique de ses systèmes hydroliens commandés suite à des perturbations sévères. Dans un premier temps, nous nous sommes intéressés à la modélisation de tous les éléments de la chaine de production d’énergie hydrolienne, en partant de la marée jusqu’à la génératrice synchrone. Dans un second temps, nous avons proposé trois lois de commande non linéaire ; une pour un système hydrolien mono machine et les deux autres pour deux types de réseau électrique multi-machine. La stabilité de ces lois de commandes est prouvée en utilisant la méthode de Lyapunov et les propriétés spécifiques à la structure variable. La particularité de ces lois de commandes est qu’elles régulent simultanément la tension terminale et la fréquence en agissant uniquement sur l’excitation de la génératrice synchrone. Finalement, nous avons étudié en simulation le comportement dynamique des systèmes hydroliens commandés et les résultats obtenus sous perturbations électrique et mécanique ont montré l’efficacité de la commande proposée par rapport aux commandes CNL et AVR-PSS. Dans un souci de valider pratiquement ces résultats de simulation, la commande non linéaire proposée pour le système hydrolien mono machine est implantée sur un banc d’essai. Les résultats satisfaisants obtenus sous perturbations soutenues sont ensuite comparés à ceux obtenus pratiquement avec les commandes, CNL et AVR-PSS. / This thesis develops nonlinear and robust control strategies in order to ensure a successful connection of marine turbine systems into grid. In addition, it is a question to examine in simulation and practice the dynamic behavior of controlled marine turbine systems under severe perturbations. Firstly, we have modeled all production chain elements of marine turbine system. Secondly, we have proposed three nonlinear control strategies ; one for marine turbine system single machine connected to infinite bus and the both others for two multimachine electrical networks. The developed strategies control stability is proven mathematically by using Lyapunov method and one specific property of variable structure. These strategies control particularity is the two outputs regulation (terminal voltage and frequency) trough a single input (synchronous machine excitation). Finally, simulation results under mechanical and electrical perturbations are presented in order to highlight the robustness qualities of the proposed controllers compared to nonlinear controller CNL and classical AVR-PSS. In view of industrial applications, the proposed control for marine turbine single machine system is implemented on experimental bench. The obtained practical results under hard perturbations are very satisfactory. These results are used to realize a comparative study between the proposed control, the CNL and the AVR-PSS.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil Engineering, 1981. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Bibliography: leaves 51-54. / by Carolyn G. Rubin. / M.S.

Rivers are integral parts of Bangladesh & Bengali people’s life. The whole country is criss-crossed by more than 700 rivers including their tributaries. In other words, rivers formed this country as a delta and have been contributing to spring life to this land with agriculture, food, electricity, transportation, and tranquil beauty, creating opportunity for different occupations, and providing very comfortable moderate climate. Due to over population and urban sprawl, the current development pattern of the country is culminating in filling up wetlands, changing the course of lakes, narrowing down and in some cases killing rivers for urban development leaving great impact on environment. As a consequence, the country is being affected by frequent flood, deforestation, surge, cyclones, and rise of sea level due to global warming. The concern for introducing an adoptive sustainable architecture that interacts with rivers and water, protects environment as well as facilitates new developments has been noticed by scientists and scholars from every sector of development. This thesis will be emphasizing on establishing some unique architectural features that would especially be applicable for riverfront architectures, that leaves least impact on nature and respects the country’s tradition, heritage and lifestyle which are inseparable from rivers.

The use of tidal information and its application to, and value within, the study of climate change, sea-level rise and the tides effects on marine life is well known. However, little work has been done on the more technical aspects of tidal measurements and the use within maritime safety in accordance with international standards. This thesis will address the key technical elements in the design and realisation of the national tide gauge network around the South African coastline and how the data collected can be used to increase maritime safety around the South African coast, as well as the additional benefits the data may have both nationally and internationally. The South African Navy's national tide database, both actual records and predictions, as well as current and historical records, was used in order to establish the requirements for a sustainable tide gauge network. In addition, various case studies and data analysis were carried out, as were personal communications with various naval personnel. Establishing and maintaining a sustainable tide gauge network requires research and testing of various tide gauges. Identification of the correct locations to install the tide gauges is key to its success. Although the current South African Tide gauge network is not complete it does provide adequate coverage and is vitally important in the production of navigational products. The manner in which the raw collected tide data is processed and used for creating predictions meets international requirements and standards. Tidal predictions are a necessity for shallow water maritime operations and shallow water navigation, under keel and masthead clearances. The tide gauge network provides data to various organisations for storm surge and tsunami warnings while contributing to the “blue economy” through projects like Operation Phakisa. This thesis provides a comprehensive overview of South Africa's tide gauge network, investigates and justifies the reasons behind the locations and gives in depth examples of the essential use of tidal information for maritime safety.

In recent year, tidal gauge has progressed in temporal resolution or measurement accuracy, so that the quality of observational data tends to stable and reliable. However, setting up tidal gauge in the offshore areas restricts may apply due to many factors such as seabed topography, weather, sea state and leveling survey from land to gauge. Good tidal correction is one of key factors to the accuracy of bathymetric survey and to the area where tidal range is large. This study tried to use tide prediction data derived from the Yu(1993)¡¦s tide numerical model and verified with actual observed tide data, and further establishing a tidal zone of Taiwan Strait by tidal characteristic. Using Taichung and Mailiao tide stations as a reference tidal station, the direct tide station correction, tidal zone correction, nearest model grid correction, and virtual station correction methods were applied to evaluate the accuracy of tide calculating value by amplitude ratio and tidal phase difference. The tidal zone correction is not totally depending on the spatial distance from reference tidal station, and it is found that correction result of this approach is one of the best. However, further improvement in tide correction may need to explore due to different spatial resolution applied in different numerical models. In addition, the boundary condition of a harbor for tidal model is very complicated. This is why it is hard to make a numerical model for a harbor. In this study, two additional high accuracy radar tidal gauge were installed in Kaohsiung harbor and first-class leveling survey was performed in order to maintain tidal measurement accuracy, also to avoid the effect of errors propagation. According to the results from experiment, average tidal phase of second entrance of the Kaohsiung harbor is earlier than that of first entrance about 6 minutes, and average difference of tidal height is approximately 2-3cm. For this reason, we should pay attention to decide a proper reference tide station for tidal correction for dredging hydrographic surveying. And any possible tidal observation errors, such as meteorological tide. If two additional tidal gauges of this study are removed in the future, we still can predict tide height from fixed tidal gauge.

A combination of DGPS/GIS mapping, invertebrate surveys and environmental monitoring over one year (July 2004--July 2005) were used to examine the recovery of permanent tidal pools on a salt marsh in the lower Bay of Fundy which underwent an unmanaged restoration after breach of the dyke over 50 years ago. The results are compared to those of a nearby relatively undisturbed reference marsh. / Pools were found to represent a substantial portion of the marsh habitat, comprising 13% of the total marsh area in the recovering marsh and 4.8% in the natural marsh. Observations indicate ice may be an important mechanism of pool formation and growth in these marshes. Water temperature in the pools ranged from freezing (-2°C) to a maximum of 36°C with ice covering pools for up to one month in the winter. Salinity of the pools ranged from near freshwater (4) to hypersaline (41). Environmental variability was mainly driven by climatic conditions with increased tidal flooding of pools at low elevations tending to make the conditions more stable. / A total of 42 macroinvertebrate taxa were identified in pools of the two marshes, with species richness (S) of individual pools ranging from 13 to 23. An estimated 50 years since dyke failure, the invertebrate fauna of pools in the recovering marsh is indistinguishable from that of the reference marsh. No significant differences in macroinvertebrate communities were detected between sampling dates, pool size or pool depth. Non metric multidimentional scaling and hierarchical cluster analysis supported separating the pool invertebrate communities of this study into those occurring in regularly flooded pools, and those occurring in irregularly flooded pools. Average production of pool macroinvertebrates ranged from 1.79 to 4.03 g dry wt m-2, depending on the amount of vegetative cover in the pools. The pools are characterized by low equitability in species abundance and biomass. The numerically dominant organisms of the pools were mites (Acarina), the gastropod Hydrobia tottentei, Tubificidae oligochaetes, and Chironomus sp. larvae as well as copepods and ostracods.