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Numerical Modeling of Coastline Evolution in an Era of Global ChangeSlott, Jordan Matthew 16 April 2008 (has links)
<p>Scientists expect temperatures on Earth to get substantially warmer over the course of the 21st century, causing storm systems to intensify and sea-level rise to accelerate--these changes will likely have dramatic impacts on how the coastlines of tomorrow will evolve. Humans are also playing an increasingly important role in shaping Earth's coastal systems. Coastal scientists have only a general understanding of how these three factors--humans, storms, and sea-level rise--will alter the evolution of coastlines over the coming century, however. I conduct numerical modeling experiments to shed light on the relative importance of these factors on the evolution of coastline geomorphology.</p><p>In a series of experiments using a numerical model of large-scale (1 to 100's km) and long-term (years to centuries) coastline evolution that results from gradients in alongshore sediment transport, I explore how the patterns and rates of shoreline erosion and accretion are affected by shifts in 'wave climate' (the mix of influences on alongshore sediment transport of waves approaching from different directions) induced by intensified storm systems and the direct manipulation of the shoreline system by humans through beach nourishment (periodically placing sand on an eroding beach). I use a cuspate-cape coastline, similar to the Outer Banks, North and South Carolina, USA, as an important case study in my experiments. I observe that moderate shifts in the wave climate can alter the patterns of shoreline erosion and accretion, potentially increasing migration rates by several times that which we see today, and nearly an order-of-magnitude larger than sea-level rise-related erosion alone. I also find that under possible wave climate futures, beach nourishment may also induce shoreline change on the same order of magnitude as does sea-level rise.</p><p>The decision humans make whether or not to nourish their beach often depends upon a favorable economic outcome in the endeavor. In further experiments, I couple a cost-benefit economic model of human decision making to the numerical model of coastline evolution and test a hypothetical scenario where two communities (one 'rich' and one 'poor') nourish their beaches in tandem, under different sets of economic and wave climate parameters. I observe that two adjacent communities can benefit substantially from each other's nourishment activity, and these effects persist even if the two communities are separated by several tens of kilometers.</p><p>In a separate effort, I employ techniques from dynamic capital theory coupled to a physically-realistic model of coastline evolution to find the optimum time a community should wait between beach nourishment episodes ('rotation length') to maximize the utility to beach-front property owners. In a series of experiments, I explore the sensitivity of the rotation length to economic parameters, including the discount rate, the fixed and variable costs of beach nourishment, and the benefits from beach nourishment, and physical parameters including the background erosion rate and the exponential rate at which both the cross-shore profile and the plan-view coastline shape re-adjusts following a beach nourishment episode ('decay rate' of nourishment sand). Some results I obtained were expected: if property values, the hedonic value of beach width, the baseline retreat rate, the fixed cost of beach nourishment, and the discount rate increase, then the rotation length of nourishment decreases. Some results I obtained, however, were unexpected: the rotation length of nourishment can either increase or decrease when the decay rate of nourishment sand varies versus the discount rate and when the variable costs of beach nourishment increase.</p> / Dissertation
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The analysis of competitive strategies of beer market in Taiwan -Take TTL as an exampleHuang, Kuan-Jung 28 April 2010 (has links)
Because the beer market in Taiwan had been opened up, the monopoly, Taiwan Beer, has been facing intense competition. However, state-owned Taiwan Beer uses flexible strategies to respond to these challenges and always is the leading company in the industry.
This study tried to use Game Theory to analyze the competitive strategy of Taiwan Beer in different period of time and find out the relationships between Taiwan Beer and competitor. At the beginning, this research used Game theory to describe the competition in the beer industry. Then, it used Prisoner's Dilemma, the Beach Ice Cream Selling Model, entry-deny strategies, multi-brand strategy and Co-opetition to explain Taiwan Beer¡¦s interaction with others.
Finally, this study did not see the competition as the only way that can help companies survive. When the company is thinking about how to defeat others, it also has to be thinking about how to cooperate with others to derive more advantages.
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Antecedent and anthropogenic influences on the Galveston Island shorefacePitkewicz, Jennifer Lynn 15 May 2009 (has links)
Galveston Island, Texas has been experiencing high rates of erosion in recent
years, spawning an interest in developing complex beach management programs.
However, before any effective management project can be implemented we must
understand all of the processes that control the shoreface. It is only recently that
scientists have begun to recognize the importance of the role that the geologic
framework plays on the coastal evolution of the shoreline. In this region, it is the
antecedent geology as well as the anthropogenic obstructions which are the key factors
controlling the formation of the modern shoreface. This study defines the extents to
which these antecedent and anthropogenic factors influence the shoreface as well as
refines the geologic interpretations offshore of Galveston Island. Using sidescan sonar,
CHIRP seismic sonar, multibeam bathymetry data and sediment cores, the shoreface and
subsurface geology were modeled. It was determined that the thickness, extent and
slope of the modern sediment in the nearshore environment is controlled by the
topography of the Beaumont Clay, a consolidated clay deposited during the Pleistocene. Anthropogenic obstructions, including the Galveston Seawall, groin and jetty system,
have changed the sediment transport patterns in the region and have created a system of
erosion and accretion not only along the shoreline, but for the entire length of the
shoreface.
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A Geologic Characterization of the Alongshore Variability in Beach-Dune Morphology: Padre Island National Seashore, TexasWeymer, Bradley 2012 May 1900 (has links)
The alongshore variability of beach-dune systems and the response and recovery from extreme storms remains poorly understood. The height and extent of foredunes along barrier islands varies over a range of spatial scales, implying that during extreme storms, the beach-dune system should respond in different ways depending on the elevation and volume of the dunes relative to the storm surge. The purpose of this study is to use Ground-Penetrating Radar (GPR) and vibra-cores to investigate the internal structure of small, intermediate and large dunes along a 2.5 km transect of beach in Padre Island National Seashore, TX with particular attention to storm impacts. A series of dune normal and parallel GPR profiles were collected to capture the variation in beach-dune morphology at the three sites. Site locations were chosen along a transition from dissipative to intermediate beach states. Following the Sallenger (2000) storm impact model, the small dune is defined by low-lying topography that is susceptible to overwash and inundation depending on the size of the storm surge. The large dune is characteristic of the “collision regime”, while the intermediate dune represents a transition between “overwash” and “collision regimes”, with the underlying assumption that all three dunes would be impacted by the same level of surge during a single storm event. Results from the GPR survey suggest that each site contains a bright, laterally continuous radar reflector that is interpreted with the aid of the sedimentary data as an erosional layer. Different characteristic radar facies and sequence boundaries provide evidence as to how each dune evolved through and after the storm. Results from XRF scans and grain size analysis show a direct comparison between the GPR reflectors at the storm surface and spikes in calcium counts from XRF scans to distinct changes in grain size parameters at the same depth. It is argued that the location of each shell layer corresponds to a storm surface generated during a single storm, which means it is possible to interpret different recovery mechanisms. The presence of the storm layer across the backbeach and dunes provides evidence for the height and extent of the surge during the storm event. The data suggests that the small dune was overtopped by the surge, experiencing minimal erosion and recovery. The intermediate dune was completely eroded by the surge, but showed the greatest recovery of all the dune sites. The large dune was scoured at the base with marginal impact along its crest and shows minimal recovery after the storm. These results suggest that the evolution (i.e., transgression) of a barrier island varies considerably over short distances.
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Bioremediation of sandy beach contaminated by crude oilPan, Chuan-Tai 17 July 2001 (has links)
The purpose of this study is to investigate the efficiencies of bioremediation of sandy beach contaminated by crude oil. In this study, we used two lab-scale tanks, tank-A and tank-B, to simulate a sandy beach contaminated by crude oil. In the experiments, we added the bioreagents and oleophilic fertilizers (Inipol EAP 22®) in order to enrich crude oil degradation of sandy beach. The crude oil was degraded by nature culture in tank-A, while the crude oil was degraded by the mixed culture of several pure strains¡]MO-1, KS-1, DS-4, PF-4, PH-2, B-1, TF and XY-2¡^. We divided the experiment into five stages in this study.
In conclusion, we found that the oleophilic fertilizers could increase both of the growth rate of oil degradation bacteria and crude oil biodegradation rate. However, a part of the fertilizers might flow into the ocean due to idal current. The addition of mixed culture could help to improve the biodegradation rate of sandy beach contaminated by crude oil.
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Bridging the gap a symbiotic approach /Czarniecki, Nicholas. January 2009 (has links)
Thesis (B. Arch.)--Roger Williams University, 2009. / Title from title page screen (viewed on Dec. 5, 2009) Includes bibliographical references.
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Los Angeles-Long Beach Harbor Pier 400 harbor resonance study using numerical model, CGWAVE /Li, Dongcheng, January 2002 (has links)
Thesis (M.S.) in Mechanical Engineering--University of Maine, 2002. / Includes vita. Includes bibliographical references (leaves 46-49).
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Morphological Changes Associated with Tropical Storm Debby in the Vicinity of Two Tidal Inlets, John's Pass and Blind Pass, West-Central FloridaBrownell, Andrew 01 January 2013 (has links)
Tropical Storm Debby affected the Gulf coast of Florida in late June, 2012. The storm's southerly approach temporarily reversed the annual net southward longshore sediment transport. The energetic conditions associated with Tropical Storm Debby can be seen in the wind, wave and tidal measurements taken from both onshore and offshore weather stations around the dual tidal inlets system of John's Pass and Blind Pass, approximately 25 kilometers north of the mouth of Tampa Bay. The energetic and persistent southerly forcing, in addition to higher storm induced water levels and wave heights, resulted in atypical beach erosion and sediment deposition on the ebb tidal deltas of the two inlets and the surrounding beaches. The John's Pass ebb delta gained 60,000 cubic meters of sediment and the Blind Pass ebb delta gained 9,000 cubic meters as a result of the storm. Shoreline position, beach profile and offshore bathymetric surveys conducted before and after Tropical Storm Debby illustrate the changes in the coastal morphology such as the development of an offshore bar south of Blind Pass and erosion of the dry beach north and south of John's Pass. The Coastal Modeling System (CMS) was used to simulate wave and tide-driven current fields during the passage of the storm. The modeled wave field qualitatively illustrated the shadowing effect of the Tampa Bay ebb delta in reducing the southerly approaching storm wave energy arriving at the study area during the storm. The tidal flow patterns through the inlets and over the ebb tidal deltas were considerably different during the storm, as compared to normal tidal cycles.
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Identification of Environmental Plastic Samples from a Caribbean Beach Survey by Near-Infrared Spectroscopy with the MicroNIR and Chemometric AnalysisVigren, David January 2015 (has links)
MicroNIR is a portable near-infrared diffuse reflection spectroscope. Its suitability for identifying environmental plastic polymers was evaluated through a series of performance tests. The plastic samples were collected during a beach survey in the Caribbean. First a reference database was built by analysing a series of reference plastic polymers. Prediction models were constructed by using principal component analysis (PCA) and cluster analysis on 2D- and 3D-scatterplots. Measurements of samples with a surface area down to 1 mm2 were successfully identified with the prediction models. Blend spectra were created by measuring two polymers simultaneously, from which each polymer NIR-fingerprint were able to be individually extracted from the blend spectra by subtracting the NIR-fingerprint of the opposite polymer. Prediction models were used to identify the samples in the tests with household plastics and the environmental plastic samples, collected in the Caribbean. Out of the forty-eight samples collected forty (83%) were identified. Twenty-seven were identified as polyethylene (56%), eleven as polypropylene (23%), one as polystyrene (2%), and one as polyamide (2%).
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Essays on the Economics of Climate ChangeRanson, Matthew 25 July 2012 (has links)
This dissertation studies three aspects of the economics of climate change: how rising sea levels will affect coastal homeowners in Florida; how changes in weather will affect the prevalence of crime in the United States; and why skepticism about climate change is so common among the general public. Chapter 1 uses housing market data to estimate the welfare costs of shoreline loss along coastal beaches in Florida. I develop a structural housing market model and use it to provide a welfare interpretation for the coefficients from a new “discontinuity matching” hedonic research design. Using housing sales data, beach width surveys, and historical beach nourishment records, I then estimate Florida homeowners’ willingness to pay for an extra foot of sand. I find that changes in beach width have little impact on housing prices, except possibly at very eroded beaches. Chapter 2 estimates the impact of climate change on the prevalence of criminal activity in the United States. The analysis is based on monthly crime and weather data for 2,972 U.S. counties from 1960 to 2009. The results show that temperature has a strong positive effect on criminal behavior, and that between 2010 and 2099, climate change will cause an additional 35,000 murders, 216,000 cases of rape, 1.6 million aggravated assaults, 2.4 million simple assaults, 409,000 robberies, 3.1 million burglaries, 3.8 million cases of larceny, and 1.4 million cases of vehicle theft. The social cost of these climate-related crimes is between 20 and 68 billion dollars. Chapter 3 develops a model of rational skepticism about policy-relevant scientific questions. Many policy debates have three features: first, individuals initially disagree about some scientific question; second, new evidence about the question becomes available; and third, the evidence may be systematically biased. Under these conditions, Bayesian disagreements persist even in the face of an infinite quantity of new evidence. Furthermore, Bayesian updating based on the new evidence produces “skeptics”, in the sense that individuals whose prior beliefs conflict most with the observable evidence end up with the most extreme posterior beliefs about the degree of bias. These results provide insight into the phenomenon of climate skepticism.
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