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Dissertations / Theses on the topic 'Coastal defences'
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1
Hull, P. "Wave impact loading and its effects on blockwork structures." Thesis, Queen's University Belfast, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246333.
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2
Walkden, Michael James Alexis. "Model wave impulse loads on caisson breakwaters : aeration, scale and structural response." Thesis, University of Plymouth, 1999. http://hdl.handle.net/10026.1/2579.
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The prediction of wave impact loads on prototype caisson breakwaters from the results of physical model tests is considered, with particular attention given to the effects of air, breaker shape, structural response and scale. A review of related literature is presented from which it is concluded that the different aspects of the problem may be related through the force impulse. Large scale soliton impacts are used to show the importance of entrapped air in determining the form of the load time history. Small scale waves with artificially high levels of entrained air and highly controlled drop impacts are used to show and quantify an inverse relationship between entrained air and impact load maxima. Specially developed aeration probes and analysis techniques are used to show the influence of entrapped air on pressure maxima and quantify entrained air levels in small scale fresh water breaking waves. A definition of the force impulse is proposed and used to investigate its variation with breaker shape. The impulse magnitude is shown to be relatively invariant for regular wave impacts compared to a large scatter in impulse form. A numerical model of caisson dynamics is used to predict structural motion and to calculate a series of dynamic amplification factors. The prediction of structural response to obtain effective static loads through the use of these factors is investigated and achieved through the adoption of an 'equivalent impulse' concept. The scatter in impulse form is found to cause large variations in effective static loads between nominally identical impact events. The equivalent impulse concept is used to solve this problem. A comparison is made between the form and magnitude of the force impulses of the small and large scale waves. The results indicate that the impulse magnitude may be relatively free of scale effects. An example is given in which the results of a small scale test are interpreted, scaled and processed to account for the effects of entrained air and structural response in order to predict large scale effective static loads. These are shown to compare well with predictions made using measured large scale force time histories and the numerical caisson model.
3
Mayon, Robert Brian. "Investigation of wave impacts on porous structures for coastal defences." Thesis, University of Southampton, 2017. https://eprints.soton.ac.uk/422221/.
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There is great scientific interest in further understanding the underlying wave impact dynamics on solid and/or permeable structures for coastal defences. The accurate and validated simulation of the dynamics of the flow at microsecond temporal scale prior to, at, and after impact is an outstanding and challenging numerical problem in CFD. More advanced numerical models of free surface flow processes which include entrapment of large air pockets is required. These models will yield more insight into the trends of pulse-like forces involved at impact with solid and/or porous material and will enable the understanding of the mechanical stability and integrity of defence structures. Furthermore, the development of advanced numerical models for solving such problems will need to be made accessible as information systems to a wider community of civil engineers in order to achieve integrated design of structural defences (coastal, offshore oil and gas, hydraulic dams etc.). This research is on the development of free surface flow simulations, flow visualisation, analyses of forces of impact, and analyses of the integrity of offshore structures in an information system environment. A large dataset of compressible (and incompressible) numerical models have been generated to simulate waves impacting at solid and porous structures. Initial studies focus on the behaviour of wave impacts with a solid structure in a 2 dimensional domain. The simulations data are verified through a grid independence study. Numerical results are validated against two sets of experimental data. Air bubble entrapment and consequential multi-modal oscillatory pressure response trends are observed in the compressible simulations during wave impact. Frequency domain analyses of the oscillatory impact pressure responses are undertaken. The numerical model data sets are compared with results generated from analytic methods and experimental data with good agreement. These initial findings confirm the robustness of our numerical model predictions concerning the simulated air bubble formations when compared with theories on air bubbles at impact and their resonance frequency modes. The compressible numerical model is extended to a 3 dimensional simulation. A range of porous structure morphologies are incorporated into the domain to replace solid wall impact interface. A brief overview of previous research on the subject of fluid flow in porous media is presented. The characterisation of the porous model morphologies is examined. Various permeability flow models are discussed in detail. The methods for the generation of the various porous structures and their integration into the CFD model are described. The results from a soliton wave impact at the porous structure morphologies both with and without air entrainment effects at the free surface is investigated in detail. Finally future work to develop an experimentation specification for the analysis of fluid flow thorough a porous structure is discussed. It is envisioned that this experimental work with have dual outcomes. Firstly it will serve to validate the numerical models created over the course of this study and secondly the potential for clean, renewable energy harvesting from oscillatory pressures through the incorporation of smart sensor hardware within the porous structure will be investigated.
4
Dixon, Mark J. "Statistical analysis of extreme sea levels." Thesis, Lancaster University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296884.
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5
Lashteh, Neshaei Mir Ahmad. "Beach profile evolution in front of a partially reflective structure." Thesis, Imperial College London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299074.
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6
Franzitta, Giulio <1980>. "Effects of artificial defences and flooding on coastal habitats and assemblages." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5222/.
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Since large stretches of European coasts are already retreating and projected scenarios are worsening, many artificial structures, such as breakwaters and seawalls, are built as tool against coastal erosion. However artificial structures produce widespread changes that alter the coastal zones and affect the biological communities. My doctoral thesis analyses the consequences of different options for coastal protection, namely hard engineering ‘artificial defences’ (i.e. impact of human-made structures) and ‘no-defence’ (i.e. impact of seawater inundation). I investigated two new aspects of the potential impact of coastal defences. The first was the effect of artificial hard substrates on the fish communities structure. In particular I was interested to test if the differences among breakwaters and natural rocky reef would change depending on the nature of the surrounding habitat of the artificial structure (prevalent sandy rather than rocky). The second was the effect on the native natural sandy habitats of the organic detritus derived from hard-bottom species (green algae and mussels) detached from breakwaters. Furthermore, I investigated the ecological implication of the “no-defend” option, which allow the inundation of coastal habitats. The focus of this study was the potential effect of seawater intrusion on the degradation process of marine, salt-marsh and terrestrial detritus, including changes on the breakdown rates and the associated macrofauna. The PhD research was conducted in three areas along European coasts: North Adriatic sea, Sicilian coast and South-West England where different habitats (coastal, estuarine), biological communities (soft-bottom macro-benthos; rocky-coastal fishes; estuarine macro-invertebrates) and processes (organic enrichment; assemblage structure; leaf-litter breakdown) were analyzed. The research was carried out through manipulative and descriptive field-experiments in which specific hypothesis were tested by univariate and multivariate analyses.
7
Cox, Simon John. "Pressure impulses caused by wave impact." Thesis, University of East Anglia, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266731.
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8
Raby, Alison Caroline. "Extreme waves, overtopping and flooding at sea defences." Thesis, University of Oxford, 2003. http://ora.ox.ac.uk/objects/uuid:82fcc770-8838-4f9b-9abe-32eecdd05f9a.
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This thesis describes experiments that were carried out using focused wave groups in the UK Coastal Research Facility (UKCRF). Considerable effort was put into calibrating the UKCRF to determine the relationship between the input signals sent to the paddles and the waves generated in the facility. Focused wave groups of various sizes and phases, based on NewWave theory were generated, and measurements were made of the resulting surface elevation data, water particle kinematics, wave runup and overtopping volumes. NewWave theory models the profile of extreme waves in a Gaussian (random) sea. The thesis describes the first time this model has been applied in the context of coastal wave transformation. A method for the separation of the underlying harmonic structure of a focused wave group is described and results presented. This technique has been used in relatively deep water but is shown to work successfully in the coastal zone until wave overturning. A method has been devised to provide a theoretical Stokes-like expansion of the free and bound waves to model the surface elevation and water particle kinematics of the focused wave groups. Satisfactory agreement is achieved between the theoretical predictions of UKCRF measurements. Suggestions are made for an improved model. The underlying harmonic structure of the focused wave groups is presented as stacked time histories that give insight into the wave transformation process from deep to shallow water. Particular attention is paid to the low frequency wave generated as the wave group interacts with the beach. This is compared to the low frequency wave that is generated by a solitary wave in the UKCRF. Runup and overtopping measurements are in reasonable agreement with predictions based on certain empirical formulae, but not others. These comparisons are useful in identifying those formulae able to predict runup and overtopping of extreme waves in the coastal zone.
9
Pater, Christopher. "Coastal planning, the application of GIS and the analysis of morphological change within the Wash embayment." Thesis, University of Nottingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324062.
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10
Jackson, Juliette Elizabeth. "The influence of engineering design considerations on species recruitment and succession on coastal defence structures." Thesis, University of Plymouth, 2015. http://hdl.handle.net/10026.1/4781.
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Engineering design considerations of artificial coastal structures were tested to resemble as far as possible the nearest natural equivalent habitat, ecologically valuable rocky shores, as a potential management option. Coastal areas around the world attract urbanisation but these transitional areas between sea and land are inherently vulnerable to risk of flooding and erosion. Thus hard structures are often built in sensitive coastal environments to defend assets such as property and infrastructure (roads, railways, ports) against rising and stormy seas. The design, construction and maintenance of hard defences should wherever possible incorporate ecological considerations to enhance biodiversity, including maintaining or restoring natural habitats and wild species to ensure favourable conservation status. Artificial habitats are less topographically complex than natural rocky shores, at millimetre scales in terms of surface roughness, centimetre to meter scales for crevices and pools to tens, hundreds and occasionally thousands of meters for variation in tidal height and wave action gradients. The habitat value of design features of an existing seawall and breakwater, such as areas of different slope and orientation, and the presence of crevices and pools, that are analogous to habitat created by topographical features on a natural shore, were demonstrated by their ability to support distinct assemblages of species. X Furthermore, evidence is provided that a greater variation in the type of design features led to a higher species diversity occupying the structure, and included species that would otherwise not be present on the structure. The long term succession on artificial structures and the biodiversity reached on intertidal coastal defence structures is described to inform understanding of timescales over which successional processes operate. As a consequence of succession, artificial structures of large extent eventually resemble natural rocky shores of the same exposure. Increased surface heterogeneity of concrete armour units on Plymouth Breakwater by drilling holes was effective in adding habitat and increasing local species diversity. These can be added at the construction stage or post construction. In a real case study, added recessed pools, holes and surface texture during the construction of a tidal defence sea wall at Shaldon made heterogeneous surfaces to add habitat and influence species diversity, without compromising the engineering function or aesthetics of the structure. This study provides coastal engineers and decision makers with well researched practical design options to inform future construction and maintenance of coastal defence structures that will encourage specific outcomes to mitigate the negative environmental impact of artificial structures and contribute to conservation priorities.
11
Brown, Sally. "Soft cliff retreat adjacent to coastal defences, with particular reference to Holderness and Christchurch Bay, UK." Thesis, University of Southampton, 2008. https://eprints.soton.ac.uk/72899/.
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Coastal defences reduce sediment input and modify the sediment budget, usually resulting in a sediment deficit down-drift and an accumulation up-drift. This process results in set-back adjacent to defences. Three types of set-back were identified and these occur due to the: • terminal groyne effect, where defences stop or dramatically reduce erosion, induce a sediment deficit down-drift and cause an increase in retreat rate; • perceived terminal groyne effect, where defences stop or dramatically reduce erosion, and down-drift retreat rates remain the same or decrease; • initial groyne effect, where defences stop or dramatically reduce erosion, induce sediment accumulation up-drift and cause a decrease in retreat rate. Set-backs are found on defended coasts world-wide, and are complex evolving features dependent on numerous natural and anthropogenic factors. 200 set-back sites were identified in England and Wales, half on cliffed coasts. The terminal groyne effect theory was investigated on 17 sites on the soft cliffs of Holderness, Christchurch Bay and north-east Norfolk, UK, all of which erode naturally at 0.5m/yr-2.0m/yr. Historical shoreline analysis and a history of human intervention was undertaken for each study region and site. For 13 out of the 17 case studies, a terminal groyne effect appeared to have occurred. As time passed and the magnitude of set-back increased, the terminal groyne effect became increasingly apparent. Where increased retreat resulted, the coast was affected for tens to thousands of metres down-drift. For the remaining case studies, a perceived terminal groyne effect occurred. An initial terminal groyne effect occurred at all sites. Longshore, the continued set-back caused outflanking of defences prompting emergency works, such as repeated defence extensions up and down-drift. Over several decades of set-back, the defences formed an artificial headland and created a crenulate shaped embayment down-drift. The planform of an embayment expanded rapidly, then reduced to a steadier retreat rate. As shoreline management evolves from a highly defended to a less heavily managed coast, defence abandonment will result in rapid retreat. Set-backs may be created due to the juxtaposition of maintained and abandoned defences, as illustrated at Happisburgh, Norfolk. In the coming decades, set-backs, artificial headlands and the terminal groyne effect will remain important issues for shoreline management.
12
Richards, Julie Ann. "Cheniers of the Essex coast : morphology, sedmimentology and management for coastal defence." Thesis, Royal Holloway, University of London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.404824.
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13
Hall, James William. "Uncertainty management for coastal defence systems." Thesis, University of Bristol, 1999. http://hdl.handle.net/1983/9b1c8d07-24f0-48b9-bb7f-73d8d7c40ae6.
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14
Jolley, Elizabeth Charlotte. "The role of coastal defence structures in channeling production in coastal ecosystems." Thesis, University of Southampton, 2008. https://eprints.soton.ac.uk/63289/.
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This study assessed the interaction of coastal defence structures (CDSs), namely shore-parallel ‘low crested breakwater structures’ (LCSs), design features and hydrodynamic regime on the quantity and timings of macroalgae deposition. The employed sampling strategy comprised a spatially and temporally stratitified approach of time-lapse photography of macroalgae deposition, verified with field observations. Field surveys determined the associated ecological assemblages of the sediment infauna and rocky shore epifauna associated with the breakwater scheme, as well as for two nearby beaches with groynes. Further analysis determined decay rates, decay processes, changes in C and N stable isotope values of dominant macroalgal species and the dependence of the faunal assemblages on the decaying macroalgae deposits. Temporal analysis highlights the main factors driving macroalgal deposition were differences in spring and neap tidal range, wave height and sea temperature. Greatest deposition occurred during months of lower wave height and fewer storms, when filamentous red algae and ephemeral green algal species dominated. Results indicated to greater amounts of macroalgae deposits around LCSs than around wooden or granite groynes. Beach elevation best explained the spatial variation, both vertically and horizontally, in the benthic assemblages within the breakwater scheme, with the abundance of detritivorous deposit feeders being significantly correlated with abundance of macroalgae deposits. Orientation of LCSs, relative to wave action, was an important driver of epifaunal assemblages on the CDSs, with the eastward ends of the breakwaters providing the optimum intermediate environment with regards to wave action, exhibiting the greatest abundances of epifauna. Stable isotope analysis showed that the carbon and nitrogen isotopic values of macroalgae changed during the decomposition and were both species and time dependent. Isotope analysis illustrated that decaying macroalgae deposits were of greater trophic importance to species within the LCS ecosystem where there was large macroalgal deposition, than to species within the groyne ecosystem where macroalgal deposition was lower. Key findings of the study illustrate the importance of decaying macroalgae deposits for the local ecosystem via modification of food chain energy flows. Though the ecosystem benefits from this allochthonous resource, deposits may be a nuisance requiring controlled human intervention.
15
Miles, Jonathon Rupert. "Enhanced sediment transport near seawalls and reflective beaches." Thesis, University of Plymouth, 1997. http://hdl.handle.net/10026.1/1901.
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This thesis describes results of a field experiment to examine the effect of wave reflection on suspended sediment transport in front of a seawall. Two instrument rigs were set up on the beach at Teignmouth, South Devon, U.K., in June 1995. One rig (the seawall rig) was attached to a protruding section of seawall, positioning the instruments 1.2m seaward of the wall. The other rig (the beach rig) acted as a control and was positioned 135m downcoast where the seawall is set back so that conditions were those of a natural beach. At each rig high frequency measurements of wave elevation, current velocity and suspended sediment concentrations were made using pressure transducers (PTs), bi-axial electromagnetic current meters (EMCMs) and optical backscatter sensors (OBSs) respectively. Wave heights during the experiment were typically in the range 0.1 <Ho<0.3m in deep water outside the surf zone and incident wave periods were around 4 seconds. Measurements were made in a range of water depths from 0.5m to 2.5m. At the natural beach, the reflection coefficient (R = reflected wave amplitude / incident wave amplitude) was found to be dependent on frequency, with low frequency waves (f<0.08Hz) being preferentially reflected (0.7<R<0.9), while incident waves (O.I<f<0.45Hz) were dissipated (O.1<R<0.2). In front of the seawall the incident wave reflection coefficient was high (0.75<R<0.9), indicating only a small amount of dissipation and thus an effective doubling of energy over the sea bed. This was found to increase the suspended sediment concentrations in the water column. For similar water depths (-0.5m), and instrument heights (~ -0.2m) instantaneous maximum sediment concentrations in front of the wall reached 9kg/m3, compared with only 1.2kg/m3 on the adjacent natural beach, despite similar incident wave conditions. Mean suspended sediment concentrations in front of the wall were also enhanced, ranging from 0.08kg/m3 to 2.8kg/m3, while at the beach rig values were typically in the range 0.08kg/m to 0.8kg/m3. At the seawall, mean and maximum suspended sediment concentrations were found to be dependent on water depth. Suspended sediment concentrations increased with decreasing depth. Guza et al.'s (1984) time domain method for separating incoming and outgoing waves was adapted to allow the incoming and outgoing wave contributions to the cross-shore sediment transport to be analysed. Incoming waves transported sediment onshore in both beach and wall cases, with typical values of the oscillatory transport associated with the incoming waves being 0.0005 < Ujn'Cs'bcach < 0.011 kg/m2/s and 0.0011 < Uin'Cs'u^i < 0.0187kg/m2/s. At the beach this resulted in a net onshore sediment transport by the waves, while in front of the wall offshore sediment transport associated with the reflected (outgoing) waves balanced the onshore sediment transport. Although the net cross-shore transport in front of the wall in this case was therefore reduced by wave reflection, the gross cross-shore transport was increased by a factor of two. Sediment accretion which was observed at the top of the natural beach was not observed in front of the wall, implying that the presence of the wall inhibited beach recovery in these accretionary conditions. Mean cross-shore sediment transport rates were also larger at the wall than at the beach. Typical values were u Cs wall = 0.05kg/m2/s compared with u Cs beach = 0.002kg/m2/s. This was attributed to the larger values of mean sediment concentration at the wall. Mean cross-shore sediment fluxes at the wall were directed onshore at the depth of the instruments, although this did not lead to accretion. It is suggested that sediment was prevented from settling by increased wave stirring, and was transported downcoast by enhanced longshore currents in front of the wall. Both longshore currents and longshore sediment transport rates were found to be increased in front of the wall. Typical values of the mean longshore sediment flux were 0.0167 < v Cs UTIU < 0.320kg/m2/s, while at the beach typical values were 0.0001 < v c^ beach < 0.0142kg/m2/s in 1 m water depth. The enhanced longshore transport in front of the wall resulted in a bar forming downcoast from the end of the wall. The seawall reflects incident waves back over the beach and this results in an increase in sediment suspension. The following were all found to be enhanced by the presence of the seawall: wave reflection, mean and instantaneous maximum suspended sediment concentrations, onshore transport by the incident waves, offshore transport by reflected waves, gross oscillatory cross-shore sediment transport, mean cross-shore sediment transport and mean longshore sediment transport rates.
16
Cremonini, Edoardo. "Performance and monitoring of innovative coastal defense works." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017.
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Beach protection is today emerging as one of the most relevant environmental issues at the global level. The increasing vulnerability of beaches to human impact and the effect of climate change are determining an increasing risk which implies a significant socioeconomic threat. In fact, erosion of beaches and coastlines is observed with increasing frequency, with implications on the societal resilience to natural hazards. Several different techniques can be applied for protecting beaches and the seashore, ranging from structural methods to green and innovative solutions that are the subject of increasing attention in recent times.
The aim of this thesis is to study innovative defense works against the erosion of the coast: in particular, the study focused on a submerged concrete barrier prototype, called WMESH, whose first modules have been recently installed in an area of the sea bad of the Emilia-Romagna coast. It is a permeable submerged barrier made up of reinforced concrete with a geometry that can dissipate a substantial portion of the wave energy, to promote the sand flow down to the shore and counteract its return. The first monitoring of the positioned modules and statistical tests on the wave and tide conditions in the affected area were performed in order to see the structure's response. These tests allowed to perform computer simulations with the 2D MIKE 21 program: the obtained results show that the structure responds positively, creating a reduction in the significant wave height and generating a sediment accumulation area in the area surrounding it.
17
Ozler, Basar. "A Case Study On The Submerged Berm Type Coastal Defense Structures." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605605/index.pdf.
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Coastal defense structures are built in order to protect valuable coastal regions from the destructive effects of the waves. Due to the cost of coastal defense structures and the economical potential of the coastal regions, failure of such structures could cause loss of high amounts of investment. Therefore in the design and construction of coastal structures, it is of vital importance to achieve an optimum design which is not neither underdesigned nor overdesigned.
In this study, Submerged Berm type coastal defense structures with several different cross-sections were tested for stability under storm conditions. Damage analyses of the different models were carried out to compare the structure characteristics under storm conditions and to obtain the most economical and stable cross-section.
For the model studies, 5 different models were constructed by using Van der Meer&rsquos approach and berm design guidelines. Models were constructed with a model scale of 1:31.08 in the wave flume in the Coastal and Harbor Engineering Laboratory, Civil Engineering Department, METU. The newly designed and optimized berm type structure was proved to be successful and economical.
18
Pettit, S. J. "The management of coastal erosion and flooding in England and Wales." Thesis, Cardiff University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313891.
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Mulvaney, Heidi Sarah. "An investigation into sandy beach stabilisation through controlled drainage." Thesis, University of Southampton, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342713.
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Soderstrom, Grant William. "A model for the evaluation and improvement of a coastal defense system." Master's thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-01202010-020309/.
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Alvarez, Martinez Fernando Manuel. "Modelling the impact of coastal defence structures on the nearshore morphodynamics." Thesis, Cardiff University, 2016. http://orca.cf.ac.uk/99018/.
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Coastal areas are heavily populated in countries around the world and are a source of economic activity, both recreational and industrial. Waves and tides interact with sediments in a dynamic equilibrium which leads to coastal morphological changes at different temporal and spatial scales. Natural or human-induced changes in this equilibrium may lead to an alteration of the coastline causing environmental or economic impacts. Coastal defences are often needed in order to protect specific areas and reduce such impacts. Therefore, understanding the impact that coastal defence structures have on coastal morphological changes is important for coastal managers. There are different methods to study morphological changes in coastal areas. Process-based numerical models are powerful and precise tools but they are more effective for small to medium spatial scales (km) and short to medium-term temporal scales. Data-driven methods have been proven useful to study morphological changes in the long-term. However, data is not always available in the quantity or quality needed for such methods to provide meaningful results. This study uses jointly process-based numerical models, COAST2D, and data-driven methods, Empirical Orthogonal Functions method (EOF), taking advantage of the strengths of both methods to overcome their own weaknesses. A novel methodology for EOF components extrapolation, named Dynamic EOF method, is developed. Results show that, COAST2D is an efficient tool to simulate morphological changes in the scale of months and kilometres. These scales exceed the ones reached previously by the model, increasing the confidence on its capabilities. The Dynamic EOF method, which extrapolates both temporal and spatial EOF components, was found to yield better results than previous attempts using the EOF method to extrapolate results beyond the training period based on EOF temporal component extrapolation only. Keywords: EOF method, Dynamic EOF method, forecasting, shore-parallel breakwaters, morphological changes, COAST2D.
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Wadey, Matthew P. "Understanding defence failures and coastal flood events : a case study approach." Thesis, University of Southampton, 2013. https://eprints.soton.ac.uk/359740/.
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Extreme sea level events are a current global threat, whilst sea-level rise (SLR) and climate change over the 21st century will increase the frequency and severity of flooding in most coastal regions. Numerical model simulations can help to understand and predict coastal floods (e.g. flood mapping and forecasting) but in comparison to flood sources (waves and water levels) coastal flood pathways (defence failures and inundation) are presently less integrated within these models. This thesis develops and demonstrates a methodology to rapidly simulate and understand the consequences of coastal flood events, with an emphasis upon regions where the risks of flooding are not well understood and could change quickly with SLR. The Solent on the south coast of England is the case study, and is prone to frequent flooding. This region is currently differentiated from the UK east and west coasts by experiencing smaller storm surges, and is characterised by undefended sections of shoreline and small floodplains. Within the Solent is Portsmouth, a city of national flood significance (only London and Hull contain more people considered at risk of coastal flooding in the UK). However, life threatening floods have not occurred in living memory. An integrated modelling approach is developed, coupling loads and defence failures with two-dimensional simulations of floodplain inundation. Observations collated from a real storm surge and flood event are shown to generate a validation data set, which indicates that this model can predict floodplain water levels to a good level of accuracy, whilst highlighting implications of such data collection. Solent-wide analysis includes simulations of hypothetical coastal flood events based upon scenarios that cover the full range of coastal loadings (realistic waves and water levels) and defence failures (overflow, outflanking, overtopping and breaching). More detailed case-studies are also applied at two sites within the region (including Portsmouth). This analysis generates peak flood water depths and an overview of impacts across this spectrum of possible floods. This research improves the existing knowledge of coastal flooding in the case study, and highlights a number of generic concepts that should be applied to others. For example the combination of flood simulation methods with real flood event analysis is essential for optimising the interpretation of model outputs whilst supporting inferences about flood consequences associated with extreme loading events (including how these may change with SLR). Simple methods estimated that >24,000 properties are within a 1 in 200 year flood event outline; and incorporating defence failures, flood dynamics, validation and detailed case studies substantially refine the assessment of places likely to experience damages. Breach defence failures generate the worst flood impacts, although in the Solent this failure mechanism is presently less of a threat than outflanking, overflow and wave overtopping. The modelling system includes easily interpreted outputs, whilst being computationally fast; therefore with potential applications including supporting land-use and defence planning, and real-time flood forecasting and warning.
23
Simsek, Kemal Cihan. "A Model Study On The Stability Of Rubble Mound Coastal Defense Structure." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613860/index.pdf.
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Coastal regions are very important because they provide a lot of resources and benefits for all the humankind. Coastal defense structures protect coastal regions from wave attacks. However, the cost of construction such coastal defense structures are very high and need big investments. Hence, to reach the optimum design and minimize the risk of failure has vital importance during the design stage of these structures. Model studies are the most effective tool in optimizing the design of these structures.
Rubble mound coastal defense structures were constructed with assembly of different sizes of armor stones and front slopes. Rubble mound coastal defense structures were designed by Van der Meer
24
Ben, Abdallah Nadia. "Modeling sea-level rise uncertainties for coastal defence adaptation using belief functions." Thesis, Compiègne, 2014. http://www.theses.fr/2014COMP1616.
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L’adaptation côtière est un impératif pour faire face à l’élévation du niveau marin,conséquence directe du réchauffement climatique. Cependant, la mise en place d’actions et de stratégies est souvent entravée par la présence de diverses et importantes incertitudes lors de l’estimation des aléas et risques futurs. Ces incertitudes peuvent être dues à une connaissance limitée (de l’élévation du niveau marin futur par exemple) ou à la variabilité naturelle de certaines variables (les conditions de mer extrêmes). La prise en compte des incertitudes dans la chaîne d’évaluation des risques est essentielle pour une adaptation efficace.L’objectif de ce travail est de proposer une méthodologie pour la quantification des incertitudes basée sur les fonctions de croyance – un formalisme de l’incertain plus flexible que les probabilités. Les fonctions de croyance nous permettent de décrire plus fidèlement l’information incomplète fournie par des experts (quantiles,intervalles, etc.), et de combiner différentes sources d’information. L’information statistique peut quand à elle être décrite par de fonctions des croyance définies à partir de la fonction de vraisemblance. Pour la propagation d’incertitudes, nous exploitons l’équivalence mathématique entre fonctions de croyance et intervalles aléatoires, et procédons par échantillonnage Monte Carlo. La méthodologie est appliquée dans l’estimation des projections de la remontée du niveau marin global à la fin du siècle issues de la modélisation physique, d’élicitation d’avis d’experts, et de modèle semi-empirique. Ensuite, dans une étude de cas, nous évaluons l’impact du changement climatique sur les conditions de mers extrêmes et évaluons le renforcement nécessaire d’une structure afin de maintenir son niveau de performance fonctionnelleCoastal adaptation is an imperative to deal with the elevation of the global sealevel caused by the ongoing global warming. However, when defining adaptationactions, coastal engineers encounter substantial uncertainties in the assessment of future hazards and risks. These uncertainties may stem from a limited knowledge (e.g., about the magnitude of the future sea-level rise) or from the natural variabilityof some quantities (e.g., extreme sea conditions). A proper consideration of these uncertainties is of principal concern for efficient design and adaptation.The objective of this work is to propose a methodology for uncertainty analysis based on the theory of belief functions – an uncertainty formalism that offers greater features to handle both aleatory and epistemic uncertainties than probabilities.In particular, it allows to represent more faithfully experts’ incomplete knowledge (quantiles, intervals, etc.) and to combine multi-sources evidence taking into account their dependences and reliabilities. Statistical evidence can be modeledby like lihood-based belief functions, which are simply the translation of some inference principles in evidential terms. By exploiting the mathematical equivalence between belief functions and random intervals, uncertainty can be propagated through models by Monte Carlo simulations. We use this method to quantify uncertainty in future projections of the elevation of the global sea level by 2100 and evaluate its impact on some coastal risk indicators used in coastal design. Sea-level rise projections are derived from physical modelling, expert elicitation, and historical sea-level measurements. Then, within a methodologically-oriented case study,we assess the impact of climate change on extreme sea conditions and evaluate there inforcement of a typical coastal defence asset so that its functional performance is maintained
25
Bannon, Matthew. "The evolution of the role of Australian customs in maritime surveillance and border protection." Access electronically, 2007. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20080916.155511/index.html.
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Siu, Kwok-kin. "Chinese piracy and coastal defence in the eighteen and early nineteen centuries with an emphasis on the Canton Delta /." Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B20933952.
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Siu, Kwok-kin Anthony. "Chinese piracy and coastal defence in the eighteen and early nineteen centuries with an emphasis on the Canton Delta." Click to view the E-thesis via HKUTO, 1999. http://sunzi.lib.hku.hk/hkuto/record/B42575035.
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Huang, An-Hao. "The Maritime strategy of China in the Asia-Pacific region : origins,development and impact /." Connect to thesis, 2009. http://repository.unimelb.edu.au/10187/6718.
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Marmion, Robert J. "Gibraltar of the south : defending Victoria : an analysis of colonial defence in Victoria, Australia, 1851-1901 /." Connect to thesis, 2009. http://repository.unimelb.edu.au/10187/4851.
Full textAbstract:
During the nineteenth century, defence was a major issue in Victoria and Australia, as indeed it was in other British colonies and the United Kingdom. Considerable pressure was brought to bear by London on the self-governing colonies to help provide for their own defence against internal unrest and also possible invasions or incursions by nations such as France, Russia and the United States.From 1851 until defence was handed over to the new Australian Commonwealth at Federation in 1901, the Victorian colonial government spent considerable energy and money fortifying parts of Port Phillip Bay and the western coastline as well as developing the first colonial navy within the British Empire. Citizens were invited to form volunteer corps in their local areas as a second tier of defence behind the Imperial troops stationed in Victoria. When the garrison of Imperial troops was withdrawn in 1870, these units of amateur citizen soldiers formed the basis of the colony’s defence force. Following years of indecision, ineptitude and ad hoc defence planning that had left the colony virtually defenceless, in 1883 Victoria finally adopted a professional approach to defending the colony. The new scheme of defence allowed for a complete re-organisation of not only the colony’s existing naval and military forces, but also the command structure and supporting services. For the first time an integrated defence scheme was established that co-ordinated the fixed defences (forts, batteries minefields) with the land and naval forces. Other original and unique aspects of the scheme included the appointment of the first Minister of Defence in the Australian colonies and the first colonial Council of Defence to oversee the joint defence program. All of this was achieved under the guidance of Imperial advisors who sought to integrate the colony’s defences into the wider Imperial context.
This thesis seeks to analyse Victoria’s colonial defence scheme on a number of levels – firstly, the nature of the final defence scheme that was finally adopted in 1883 after years of vacillation, secondly, the effectiveness of the scheme in defending Victoria, thirdly, how the scheme linked to the greater Australasian and Imperial defence, and finally the political, economic, social and technological factors that shaped defence in Victoria during the second half of the nineteenth century.
30
Arikan, Gokce. "Reliability-based Design Model For Rubble-mound Coastal Defense Structures." Phd thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/3/12611602/index.pdf.
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In this thesis, a new computer model (tool) for the reliability-based design of
rubble-mound coastal defense structures is developed in which design is
carried out in a user frienly way giving outputs on time variant reliability for
the predetermined lifetimes and damage levels. The model aims to perform the
following steps:
1. Determine the sources of uncertainties in design parameters
2. Evaluate the damage risk of coastal structures which are at design stage
and are recently constructed.
3. Study the sensitivity of limit state functions to the design parameters.
Different from other reliability studies on coastal projects, a new design
computer program is developed that can be easily used by everyone working in
coastal engineering field.
31
Ferrario, Filippo <1981>. "Analysis and development of ecologically based approaches to coastal defense." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5831/.
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Climate-change related impacts, notably coastal erosion, inundation and flooding from sea level rise and storms, will increase in the coming decades enhancing the risks for coastal populations. Further recourse to coastal armoring and other engineered defenses to address risk reduction will exacerbate threats to coastal ecosystems. Alternatively, protection services provided by healthy ecosystems is emerging as a key element in climate adaptation and disaster risk management. I examined two distinct approaches to coastal defense on the base of their ecological and ecosystem conservation values. First, I analyzed the role of coastal ecosystems in providing services for hazard risk reduction. The value in wave attenuation of coral reefs was quantitatively demonstrated using a meta-analysis approach. Results indicate that coral reefs can provide wave attenuation comparable to hard engineering artificial defenses and at lower costs. Conservation and restoration of existing coral reefs are cost-effective management options for disaster risk reduction. Second, I evaluated the possibility to enhance the ecological value of artificial coastal defense structures (CDS) as habitats for marine communities. I documented the suitability of CDS to support native, ecologically relevant, habitat-forming canopy algae exploring the feasibility of enhancing CDS ecological value by promoting the growth of desired species. Juveniles of Cystoseira barbata can be successfully transplanted at both natural and artificial habitats and not affected by lack of surrounding adult algal individuals nor by substratum orientation. Transplantation success was limited by biotic disturbance from macrograzers on CDS compared to natural habitats. Future work should explore the reasons behind the different ecological functioning of artificial and natural habitats unraveling the factors and mechanisms that cause it. The comprehension of the functioning of systems associated with artificial habitats is the key to allow environmental managers to identify proper mitigation options and to forecast the impact of alternative coastal development plans.
32
Fiskin, Gokce. "A Case Study On The Stability Of Berm Type Coastal Defense Structures." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605604/index.pdf.
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Coastal defense structures have primary importance from obtainabilty of resources and benefits served by the coastal regions point of view. However, the construction of coastal defense structures demand a high amount of investment. Therefore, in order to reduce the risk of collapse of these structures, model studies should be carried during the design process.
In this study, model investigations were carried out on Eastern Black Sea Highway Project regarding the serviceability and damage thus stability parameters. 5 different models were constructed as berm type rubble-mound breakwaters using Van Der Meer&rsquos approach and berm design guidelines, with a scale of 1/31.08 and they were tested both for breaking and non-breaking waves. The experiments took place in the Coastal and Harbor Engineering Laboratory of the Middle East Technical University, Civil Engineering Department. The models were constructed and tested with different berm widths and armor stone sizes forming the back armor layer in order to examine the effect of these design parameters on the stability and serviceability of the coastal defense structure to obtain the optimum alternative cross-section. Cumulative damage was minimum for the cross-section constructed with berm width 15 m assigning the width of the prototype. Water spray and run-up values were also not significant. The test results were confirming with Van Der Meer design approach.
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Abanades, Tercero Javier. "Beach morphodynamics in the lee of a wave farm : synergies with coastal defence." Thesis, University of Plymouth, 2017. http://hdl.handle.net/10026.1/8807.
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Wave energy has a great potential in many coastal areas thanks to a number of advantages: the abundant resource, the highest energy density of all renewables, the greater availability factors than e.g. wind or solar energy; and the low environmental and particularly visual impact. In addition, a novel advantage will be investigated in this work: the possibility of a synergetic use for carbon-free energy production and coastal protection. In this context, wave energy can contribute not only to decarbonising the energy supply and reducing greenhouse emissions, but also to mitigating coastal erosion. In effect, wave farms will be deployed nearshore to generate electricity from wave energy, and therefore the leeward coast will be exposed to a milder wave climate, which can potentially mitigate coastal erosion. This thesis aims to determine the effectiveness of wave farms for combating coastal erosion by means of a suite of state-of-the-art process-based numerical models that are applied in several case studies (Perranporth Beach,UK; and Xago Beach, Spain) and at different time scales (from the short-term to the long-term). A wave propagation model, SWAN, is used to establish the effects of the wave farm on the wave conditions. The outcomes of SWAN will be coupled to XBeach, a costal processes model that is applied to analyse the effects of the milder wave conditions on the coast. In addition to these models, empirical classifications and analytical solutions are used as well to characterise the alteration of the beach morphology due to the presence of a wave farm. The analysis of the wave farm impacts on the wave conditions and the beach morphology will be carried out through a set of ad hoc impact indicators. Parameters such as the reduction in the significant wave height, the performance of the wave farm, the effects on the seabed level and the erosion in the beach face area are defined to characterise these impacts. Moreover, the role played by the key design parameters of wave farms, e.g. farm-to-coast distance or layout, is also examined. The results from this analysis demonstrate that wave farms, in addition to their main purpose of generating carbon-free energy, are capable of reducing erosion at the coast. Storm-induced erosion is significantly reduced due to the presence of wave farms in the areas most at risk from this phenomenon. However, the effects of wave farms on the coast do not lend themselves to general statements, for they will depend on the wave farm design (WEC type, layout and farm-to-coast distance) and the characteristics of the area in question, as shown in this document for Perranporth and Xago. In summary, this synergy will improve the economic viability of wave farm projects through savings in conventional coastal defence measures, thereby fostering the development of this nascent renewable, reducing greenhouse gas emission and converging towards a more sustainable energy model. Thus, wave energy contributes to mitigating climate change by two means, one acting on the cause, the other on the effect: (i) by bringing down carbon emissions (cause) through its production of renewable energy, and (ii) by reducing coastal erosion (effect).
34
Croce, Andrea. "Coastal erosion in Nørlev Strand (Denmark): modelling and defense strategies comparison." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017.
Find full textAbstract:
The Danish west coast presents a continue evolution because of its hydrodynamic and geomorphological conditions.
The main topic of the following thesis is to analyse and understand the erosion causes in Nørlev Strand, a small village in the North-West coast of Denmark, close to the most famous Lønstrup in the Hjørring Kommune.
LITPACK is the software package used as support of the study: LITDRIFT is used understand the erosion (causes and magnitude), LITLINE to simulate the yearly shore-line tendency, LITPROF to see how change the cross-shore profile in case of storm and after, restoring a “normal” condition.
Finallly, a solution to erosion is proposed based on local citizens (low visual impact and cost) and Danish Coastal Authority will (the body responsible giving permissions to any changes on the coast).
35
Huang, Zhongqing. "Ming dai hai fang de shui zhai yu you bing Zhe Min Yue yan hai dao yu fang wei de jian zhi yu jie ti /." Yilan Xian : Xue shu jiang zhu ji jin, 2001. http://catalog.hathitrust.org/api/volumes/oclc/49401347.html.
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Buckley, John Dale. "The development of RAF coastal command trade defence strategy, policy and doctrine 1919-1945." Thesis, Lancaster University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317333.
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Jane, Robert. "Improving the representation of the fragility of coastal structures." Thesis, University of Plymouth, 2018. http://hdl.handle.net/10026.1/13080.
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Robust Flood Risk Analysis (FRA) is essential for effective flood risk management. The performance of any flood defence assets will heavily influence the estimate of an area's flood risk. It is therefore critical that the probability of a coastal flood defence asset incurring a structural failure when subjected to a particular loading i.e. its fragility is accurately quantified. The fragility representations of coastal defence assets presently adopted in UK National FRA (NaFRA) suffer three pertinent limitations. Firstly, assumptions relating to the modelling of the dependence structure of the variables that comprise the hydraulic load, including the water level, wave height and period, are restricted to a single loading variable. Consequently, due to the "system wide" nature of the analysis, a defence's conditional failure probability must also be expressed in terms of a single loading in the form of a fragility curve. For coastal defences the single loading is the overtopping discharge, an amalgamation of these basic loading variables. The prevalence of other failure initiation mechanisms may vary considerably for combinations of the basic loadings which give rise to equal overtopping discharges. Hence the univariate nature of the existing representations potentially restricts their ability to accurately assess an asset's structural vulnerability. Secondly, they only consider failure at least partially initiated through overtopping and thus neglect other pertinent initiation mechanisms acting in its absence. Thirdly, fragility representations have been derived for 61 generic assets (idealised forms of the defences found around the UK coast) each in five possible states of repair. The fragility representation associated with the generic asset and its state of repair deemed to most closely resemble a particular defence is adopted to describe its fragility. Any disparity in the parameters which influence the defence's structural vulnerability in the generic form of the asset and those observed in the field are also likely to further reduce the robustness of the existing fragility representations. In NaFRA coastal flood defence assets are broadly classified as vertical walls, beaches and embankments. The latter are typically found in sheltered locations where failure is water level driven and hence expressing failure probability conditionally on overtopping is admissible. Therefore new fragility representations for vertical wall and gravel beach assets which address the limitations of those presently adopted in NaFRA are derived. To achieve this aim it was necessary to propose new procedures for extracting information on the site and structural parameters characterising a defence's structural vulnerability from relevant resources (predominately beach profiles). In addition novel statistical approaches were put forward for capturing the uncertainties in the parameters on the basis of the site specific data obtained after implementation of the aforementioned procedures. A preliminary validation demonstrated the apparent reliability of these approaches. The pertinent initiation mechanisms behind the structural failure of each asset type were then identified before the state-of-the-art models for predicting the prevalence of these mechanisms during an event were evaluated. The Obhrai et al. (2008) re-formulation of the Bradbury (2000) barrier inertia model, which encapsulates all of the initiating mechanisms behind the structural failure of a beach, was reasoned as a more appropriate model for predicting the breach of a beach than that adopted in NaFRA. Failure initiated exclusively at the toe of a seawall was explicitly accounted for in the new formulations of the fragility representations using the predictors for sand and shingle beaches derived by Sutherland et al. (2007) and Powell & Lowe (1994). In order to assess whether the new formulations warrant a place in future FRAs they were derived for the relevant assets in Lyme Bay (UK). The inclusion of site specific information in the derivation of fragility representations resulted in a several orders of magnitude change in the Annual Failure Probabilities (AFPs) of the vertical wall assets. The assets deemed most vulnerable were amongst those assigned the lowest AFPs in the existing analysis. The site specific data indicated that the crest elevations assumed in NaFRA are reliable. Hence it appears the more accurate specification of asset geometry and in particular the inclusion of the beach elevation in the immediate vicinity of the structure in the overtopping calculation is responsible for the changes. The AFP was zero for many of the walls (≈ 77%) indicating other mechanism(s) occurring in the absence of any overtopping are likely to be responsible for failure. Toe scour was found to be the dominant failure mechanism at all of the assets at which it was considered a plausible cause of breach. Increases of at least an order of magnitude upon the AFP after the inclusion of site specific information in the fragility representations were observed at ≈ 86% of the walls. The AFPs assigned by the new site specific multivariate fragility representations to the beach assets were positively correlated with those prescribed by the existing representations. However, once the new representations were adopted there was substantially more variability in AFPs of the beach assets which had previously been deemed to be in identical states of repair. As part of the work, the new and existing fragility representations were validated at assets which had experienced failure or near-failure in the recent past, using the hydraulic loading conditions recorded during the event. No appraisal of the reliability of the new representations for beaches was possible due to an absence of any such events within Lyme Bay. Their AFPs suggest that armed with more information about an asset's geometry the new formulations are able to provide a more robust description of a beach's structural vulnerability. The results of the validation as well as the magnitude of the AFPs assigned by the new representations on the basis of field data suggest that the newly proposed representations provide the more realistic description of the structural vulnerability of seawalls. Any final conclusions regarding the robustness of the representations must be deferred until more failure data becomes available. The trade-off for the potentially more robust description of an asset's structural vulnerability was a substantial increase in the time required for the newly derived fragility representations to compute the failure probability associated with a hydraulic loading event. To combat this increase, (multivariate) generic versions of the new representations were derived using the structural specific data from the assets within Lyme Bay. Although there was generally good agreement in the failure probabilities assigned to the individual hydraulic loading events by the new generic representations there was evidence of systematic error. This error has the potential to bias flood risk estimates and thus requires investigation before the new generic representations are included in future FRAs. Given the disparity in the estimated structural vulnerability of the assets according to the existing fragility curves and the site-specific multivariate representations the new generic representations are likely to be more reliable than the existing fragility curves.
38
Taskiran, Inanc. "An Economical Analysis Of Alternative Eastern Black Sea Coastal Highway Defense Structures." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/4/1120500/index.pdf.
Full textAbstract:
In order to analyze the stability of Eastern Black Sea Coastal Highway defense structures constructed with natural stone armor layers, hydraulic model tests were performed under both breaking and non-breaking waves. Eight different alternative cross-sections of the defense structures were constructed in the wave flume in Coastal and Harbor Engineering Laboratory, Civil Engineering Department, METU. Water depth was kept constant at a depth of 7.5 m in front of the structures. Model scale, λ
L, was calculated as 1:31.08 using Froude Law. Experiments were carried out for wave heights, H, ranging between 3 &ndash
7 m. with a wave period ranging between 6 &ndash
11 sec in prototype. A comparative economical analysis of the alternative cross-sections of the defense structures has proven that cost (per meter) differs almost 50% between the alternative cross-sections.
39
Baker, John M. "Routing a high value unit for optimized missile defense in coastal waters." Thesis, Monterey, Calif. : Naval Postgraduate School, 2008. http://bosun.nps.edu/uhtbin/hyperion-image.exe/08Mar%5FBaker.pdf.
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Thesis (M.S. in Operations Research)--Naval Postgraduate School, March 2008.Thesis Advisor(s): Wood, R. Kevin. "March 2008." Description based on title screen as viewed on April 28, 2008. Includes bibliographical references (p. 37-38). Also available in print.
40
Moys, Andrew J. "Evaluation of EM propagation models using data from Wallops Island Experiment (2000)." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03sep%5FMoys.pdf.
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Thesis (M.S. in Meteorology)--Naval Postgraduate School, September 2003.Thesis advisor(s): Kenneth L. Davidson, Wendell A. Nuss. Includes bibliographical references (p. 137-139). Also available online.
41
Lin, Weikai. "Ming dai de jiang hai lian fang Chang Jiang jiang hai jiao hui shui yu fang wei de jian gou yu bei yu /." Yilan Xian Luodong Zhen : Ming shi yan jiu xiao zu, 2006. http://catalog.hathitrust.org/api/volumes/oclc/124057091.html.
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Evans, Alison Jane. "Artificial coastal defence structures as surrogate habitats for natural rocky shores : giving nature a helping hand." Thesis, Aberystwyth University, 2016. http://hdl.handle.net/2160/a02e7f0b-5a07-4977-9cd9-47ca12856c87.
Full textAbstract:
Engineered coastal defence structures are proliferating around coastlines globally to protect expanding urban developments from predicted sea level rise and extreme weather events. In response to evolving marine planning policies, it is becoming increasingly necessary to incorporate ecologically-sensitive design into coastal developments, not only to minimise their environmental impacts, but also to maximise potential ecological and socio-economic secondary benefits. I investigated coastal defence structures as surrogate habitats for rocky shore biodiversity, and the potential for the design of structures to be manipulated to achieve more beneficial outcomes. I focused on three major knowledge gaps that must be addressed in order to effectively incorporate ecologically-sensitive design into coastal defences: (i) the capacity to predict ecological responses to different engineering designs for coastal defence structures; (ii) the potential for ecological engineering interventions to enhance biodiversity on structures; and (iii) stakeholder perceptions regarding the desirability of potential secondary benefits that can be built-in to developments. To address the first knowledge gap, I surveyed 125 intertidal coastal defence structures around the coast of Wales, UK, and modelled the relationship between a number of physico-environmental parameters and the biological communities colonising each structure. Using these data I developed a predictive tool and demonstrated that, given the nature of the shoreline on which a new coastal defence was required (i.e. the surrounding sediments and level of exposure to prevailing wind and waves), it would be possible to predict (with up to 62% confidence) the characteristic community that could be expected to colonise a structure, based on its broad shape, position in the intertidal zone, and abundance of microhabitats. To address the second knowledge gap, I explored the potential for a novel ecological engineering intervention (drill-cored artificial rock pools) to enhance biodiversity on an intertidal riprap breakwater. Over a 30- month period, I found that the artificial pools performed an important ecological function on the structure. They were utilised by numerous species that were not otherwise recorded on surrounding emergent rock surfaces, including taxa that have frequently been reported to be absent or scarce on coastal defences previously (e.g. mobile fauna, lower-shore taxa and proportionally-rarer taxa). Furthermore, the artificial pools were just as productive as natural rock pools and supported a comparable number of species. The composition of communities in artificial and natural pools, however, was different, largely on account of differences in sessile assemblages (i.e. algae and encrusting fauna). The intervention, nevertheless, was an effective and affordable means of ecological enhancement, and has received considerable interest from industry and practitioners. To address the third knowledge gap, I investigated stakeholder attitudes regarding desirability of different potential secondary benefits that may be built-in to coastal developments. Although this study revealed complex and nuanced perceptions across sectors, there was unanimous support for implementing multi-functional coastal defence structures in place of traditional single-purpose ones, and in general the most desirable secondary benefits were ecological ones (prioritised over social, economic and technical benefits). In this thesis I evaluate these outcomes in the context of their application to marine planning and conservation management. I finally conclude by outlining the steps that are necessary to achieve wide-scale and effective implementation of ecologically sensitive and multi-functional design for artificial coastal defence structures that are becoming ubiquitous features of urban coastlines globally.
43
Siu, Kwok-kin Anthony, and 蕭國健. "Chinese piracy and coastal defence in the eighteen and early nineteen centuries with an emphasis on the Canton Delta." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B42575035.
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Dedeoglu, Mehmet Rifat. "An Experimental Study On The Stability Of Eastern Black Sea Coastal Highway Defense Structures." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/4/1088178/index.pdf.
Full textAbstract:
Coastal regions are extensively utilized by constructing coastal structures and facilities, as a result of the economical potential they offer. In designing and construction of coastal structures, it is important to achieve an optimum design satisfying both the stability and the engineering economy requirements effectively, regarding the natural balance of the coastal region.
In this study, first step model tests on the stability of the coastal protection structures of Eastern Black Sea Highway Project under construction, proved that the structure is not stable and safe under severe wave action. As an innovative approach, using Van der Meer’
s approach and berm design guidelines alternative cross sections were generated.In the second step of the model studies, 8 different models were constructed using a model scale of 1/31.08 and they were tested both for breaking and non-breaking waves. The experiments took place in the Coastal and Harbor Engineering Laboratory of the Middle East Technical University, Civil Engineering Department. The newly designed and optimized berm type structure was proved to be successful and economical.
45
DeOliveira, Erickson H. "Harmonics and switching transients in shipboard power systems, waveform distortions in the Canadian Maritime Coastal Defence Vessel." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0003/MQ44838.pdf.
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Ziegler, Christopher Taylor. "Jeffersonianism and 19th century American maritime defense policy." [Johnson City, Tenn. : East Tennessee State University], 2003. http://etd-submit.etsu.edu/etd/theses/available/etd-1110103-111416/unrestricted/ZieglerC120103a.pdf.
Full textAbstract:
Thesis (M.A.)--East Tennessee State University, 2003.Title from electronic submission form. ETSU ETD database URN: etd-1110103-111416. Includes bibliographical references. Also available via Internet at the UMI web site.
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Andrews, Claire Elizabeth. "The measurement of the erosion of the chalk shore platform of East Sussex, the effect of coastal defence structures and the efficacy of macro scale bioerosive agents, in particular the common." Thesis, University of Sussex, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340824.
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Campen, Andrew, and Kurt Clarke. "Satellite communications for Coast Guard homeland defense." Thesis, Monterey, California. Naval Postgraduate School, 2002. http://hdl.handle.net/10945/6087.
Full textAbstract:
Approved for public release, distribution is unlimitedThe Coast Guard has developed a C4ISR infrastructure ashore to aid personnel in decision making, job performance, and information exchange, but in doing so they have neglected their most important asset; the afloat community. In an effort to explore and find a wireless connectivity solution for CG cutters, the authors examined the requirements for solutions in the area of commercial satellite connectivity. This connection is necessary for USCG afloat assets to access vital maritime, law enforcement, and Fisheries databases maintained ashore, as well as to keep those ashore informed of mission status. This connection also allows cutters to connect to CGDN+ and the Internet, improving both morale and personnel administration issues (leave, medical records, training, assignment process, etc.) With the technologies now available, the USCG must identify which solutions can best be utilized with respect to bandwidth, security, cost, equipment installation requirements, durability, and range. Primarily our research dissects Qualcomm's Globalstar satellite options, INMARSAT and capacity expander (ICE) technology, and current Navy INMARSAT technology solutions. The authors have identified technological limitations and proper requirement analysis techniques that will aid in future Coast Guard evaluations of these extremely high cost wireless networks. Finally, the authors make recommendations for near and long-term solutions to the Coast Guard's connectivity requirements.
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Lapke, John J. "The Defense Message System and the U.S. Coast Guard." Thesis, Monterey, California. Naval Postgraduate School, 1992. http://hdl.handle.net/10945/23614.
Full textAbstract:
Approved for public release; distribution is unlimitedThis thesis provides an overview of the Defense Message System (DMS) and the messaging related components of the Coast Guard Telecommunications System (CGTS). Also addressed are the seven-layer Open Systems Interface (OSI) Reference Model, the Government Open System Interconnection Protocol, and various interface devices such as bridges, routers and gateways. The DMS Program is composed of a baseline architecture and three phases that will result in the transition from baseline systems and networks to a target architecture, with a goal for complete writer-to-reader messaging services. DMS baseline components, such as the Automatic Digital Network and components of the Defense Data Network, will either be phased out or transitioned into new architectures that will lead to the target architecture. The Coast Guard telecommunications organization is addressed as well as the broad aspects of the CGTS. A key issue of this thesis is to emphasize the importance of interoperability between the DMS and the CGTS through the use of approved standards and protocols.
50
袁展聰. "舊規制新戰爭: 嘉慶. 道光年間廣東海防研究= Old military system vs. new naval warfare: a research on coastal defense of Guangdong during the Jiaqing-Daoguang era /袁展聰." HKBU Institutional Repository, 2016. https://repository.hkbu.edu.hk/etd_oa/354.
Full textAbstract:
After the capture of Taiwan, the Qing Court devoted its energy to securing China's northern border. While fending off the invasion of Russia and Dzungar, Emperors Kangxi, Yongzheng and Qianlong exposed the Southeast maritime frontier to pirates and the British merchants who continued to harass Guangdong during the Jiaqing-Daoguang era. With the support of the Tây Sơn dynasty, pirates in the South China Sea formed an alliance that controlled the major waterways of Guangdong. The discovery of new routes to the East opened new markets for European countries. England seized the opportunity to attack Macao Bocca twice, to break into Tigris and eventually to wage the Opium War. Responding to the growing threat towards her coastal defense, the Qing government dispatched several Viceroys of Liangguang (Guangdong and Guangxi) and Guangdong Commanders in Chief to launch a range of counter measures. In both wars, official used the strategic of coastal defense, in order to cut off the supplement from inland against the pirates and the United Kingdom. Although the pirates and the United Kingdom were different enemies, Qing government used the same method that was not accidental. In the early Qing, coastal defense was managed by the provincial government. Therefore, the development of coastal defense was affected by the quantity of provincial government's resource. Because of the Qing government strictly controlled provincial government's finance; Guangdong's coastal defense was a passive and conservative system. In the context of globalization, Guangdong's coastal defense was challenged by pirates and the United Kingdom. At that time, Navy of Guangdong was weaker than its opponent. As a result, Viceroys of Liangguang (Guangdong and Guangxi) and Guangdong Commanders in Chief insisted to defense the coast line. They believed the opponents would be starved in the sea, however, the result was totally different. Why officials used the same method to deal with pirates and the United Kingdom will be explored in this article, so as to reflect the situation of Guangdong's coastal defense in Jiaqing and Daoguang's era = 自收復台灣後，東南海洋一直處於和平狀態，反觀在北方國境，俄羅斯及準噶爾部卻嚴重威脅清朝的國防。經過康、雍、乾三朝的努力，清廷終於解決北部的邊防問題。但此一形勢在嘉慶、道光年間產生變化，廣東海防卻要面對兩大強敵──海盜與英國。藉着越南西山政權的幫助，廣東海盜乘勢崛興，控制航道，專注於打劫往來船隻，更組成強大的聯盟。而西方國家亦積極東來尋找市場、商品，英國亦為其中之一。為改變與中國貿易的情況，英國曾兩次試圖入侵澳門、強闖虎門，更發動鴉片戰爭，令廣東海防面臨嚴重威脅。在迎戰海盜、英國的過程中，清廷先後委任多名兩廣總督、水師提督，試圖阻止這些強敵。為方便研究，本文選擇當中的重要人物，觀察他們的應敵之道。嘉慶十年（1805），海盜組成大聯盟，勢力如日方中，而那彥成、吳熊光、百齡正是於此時出任兩廣總督。道光十四年（1834）發生律盧卑事件，清廷又先後以關天培、林則徐南下廣東，積極改善虎門防務，防止英國進犯。在兩場戰爭中，當時的官員都堅持嚴守海岸的戰略，以封鎖政策截斷內地物資供應，對抗海盜及英國。面對不同的敵人，清廷使用相同方法並非偶然。海防在清代前期由地方自行管理，所以發展受到地方資源多寡的影響。由於清廷嚴格限制地方財政，加上受地形影響，廣東海防只能維持被動和保守的體制。在全球化的背景下，海盜及英國乘時而起挑戰廣東海防。當時廣東水師實力不及對手，所以兩廣總督、水師提督都固守海岸防線，期望將對手困死海上，但是效果卻是截然不同。本文將探討為何有關官員使用相同方法，應對海盜、英國的入侵的原因，從而反映嘉慶、道光年間廣東海防的情況。