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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

The effects of beach renourishment on benthic microalgae /

Carey, Erin S. January 2005 (has links) (PDF)
Thesis (M.S.)--University of North Carolina at Wilmington, 2005. / Includes bibliographical references (leaves: 40-41)
12

Panevėžio miesto mokytojų požiūris į maisto produktų kokybę ir jo sąsajos su sveikata / The attitude of teachers in Panevėžys towards foods’ quality and its links with health

Morkūnienė, Agnė 08 June 2009 (has links)
Maisto produktų kokybė - tai savybių, sąlygojančių jo tinkamumą tenkinti tam tikrus vartotojo poreikius pagal išreikštą ar numanomą paskirtį, visuma. Lietuvoje, kaip ir visame pasaulyje, vis didesnis dėmesys yra skiriamas maisto produktų kokybei dėl naujo pirkėjų požiūrio į maistą bei žmonių susirūpinimo aplinkos tarša bei įtaka sveikatai, bei galimybės pasirinkti produktus esant didelei produktų gausai ir įvairovei. Darbo tikslas. Įvertinti Panevėžio miesto mokytojų požiūrį į maisto produktų kokybę ir jo sąsajas su subjektyviu sveikatos vertinimu. Tyrimo metodika. Anoniminės anketinės apklausos pagalba buvo siekiama išsiaiškinti mokytojų požiūrį į maisto produktų kokybę ir sąsajas su subjektyviu sveikatos vertinimu. Tyrime dalyvavo 450 Panevėžio miesto mokyklų mokytojai (amžiaus vidurkis – 45,34 ± 9,06 m.). Atsakymų į anketos klausimus dažnis – 67,1 proc. Rezultatai. Panevėžio miesto mokytojams, nepriklausomai nuo amžiaus, pagrindiniai šaltiniai, kurie daugiausia suteikė žinių apie mitybą buvo specializuoti leidiniai (nuo 28 proc. iki 44 proc.), produkto etiketė (nuo 28 proc. iki 30 proc.) ir laikraščiai (nuo 25 proc. iki 38 proc.), jaunesniems nei 35 metų mokytojams internetas (27,5 proc.). Nepriklausomai nuo amžiaus mokytojai mano, kad kokybiškas maisto produktas tai natūralus (nuo 63 proc. iki 80 proc.) ir ekologiškas (nuo 59 proc. iki 64 proc.). Apie neigiamą riebalų poveikį širdies ir kraujagyslių sistemai dažniau žinojo mokytojai nuo 35 iki 54 metų, o apie tai... [toliau žr. visą tekstą] / Foods’ quality – the unit of characteristics that determines its availability to meet the particular consumer’s requirements according to predictable purpose. In Lithuania, as in the whole World, a very big attention is paid to food quality. There is a new viewpoint of customers to food. People take care of environmental damage and its influence upon human health. People also take care of possibility to choose products especially when plenty and variety is observed. Aim of the study. To appreciate the attitude of teachers in Panevėžys towards foods’ quality and its links with health. Methods. Anonymous questionnaire: 450 teachers from Panevėžys schools were involved in the research (average – 45,34 ± 9,06 years old.). Frequency of the answers to questionnaire – 67,1% Results. The main sources about nourishment containing the most information for teachers from Panevėžys, independently to age, were problem-oriented publications (28% - 44%), label of the product (28% - 30%.) and newspapers (25% - 38%), for younger than 35 years old teachers – WWW (27,5%). Teachers independently to age are thinking that qualitative foodstuffs are natural (63% - 80%) and ecological (59% - 64%). 35 – 54 years old teachers know about negative influence of fats on heart and blood-vessels system. Oulder than 55 years old teachers know that some of the solid fats have also negative influence and it is not necessary to eat meat every day. Younger than 35 years old teacher know that salt damages... [to full text]
13

Repercussões morfológicas no timo de ratos jovens submetidos à desnutrição proteíca e à renutrição precocemente corrigida. / Morphologic repercussions in young rat thymus submitted to protein undernourishment and early corrected re-nourishment.

Baptista, Josemberg da Silva 04 November 2008 (has links)
Verificou-se o metabolismo e as repercussões morfológicas no timo de forma qualitativa e quantitativa através de morfometria e estereologia.Utilizaram-se 30 ratos wistar () nos grupos Nutrido (N=10), Desnutrido (D=10) e Renutrido (R=10). O peso corporal e a ingestão foi maior no N, menor no D, e os R apresentaram valores médios em relação a estes grupos. Todos os outros parâmetros (ingestão de água, excreção de fezes e urina, %ingestão/peso corporal, %fezes/ingestão, água/peso corporal, %urina/água consumida e peso tímico) não obtiveram diferença estatística entre o N e R. O grupo D mostrou exuberante alteração nos componentes elásticos e fibrosos, menor calibre dos seus vasos, atrofia dos lóbulos tímicos (com limite córtex-medular muitas vezes indefinido), e grande quantidade de timócitos em apoptose no córtex e na medula. Poucos corpúsculos tímicos foram verificados no grupo D, diferindo dos animais N e R. Deste modo, afirma-se que os animais R conseguiram restituir a morfologia da glândula após intervenção nutricional. / The Metabolism and morphologic repercussions on thymus were verified in a qualitative and quantitative way by morfometric and stereologycal assessment. 30 wistar rats were used () in the Nourishment (N=10), Undernourishment (UN=10) and Re-nourishment (RN=10) groups. The body weight and ingestion were higher in N, lower in UN, and RN presented medium values in relation to the others groups. All the addicional parameters as water ingestion, faeces and urine excrecion, %ingestion/corporal weigh, %faeces/ingestion, water/corporal weight, %urine/water consumed and thymic weight, had no statistics difference between N and RN. The UN group showed exuberant modification on elastic and fibrous components, smaller caliber of their vessels, thymic lobule atrophy (with many times indefinite cortex-medular limit), and apoptose of timocytes in the cortex and medulla. Few thymic corpuscles were verified in UN group differing of the N and RN. Therefore, after nutricional intervencional, the gland morphology was reestablished.
14

Áreas potenciais à exploração de granulados marinhos siliciclásticos para a recuperação artificial de praias na plataforma continental interna adjacente ao Porto do Recife-PE

Andrade, Carla Danielle Pereira de January 2013 (has links)
O mapeamento da Plataforma Continental Interna visando localização, qualificação e quantificação das reservas de material litoclásticos marinho possui poucos trabalhos relacionados. O Estado de Pernambuco sofre com erosões ao longo de todo seu litoral, e principalmente junto às cidades de Recife e Olinda. Assim, este estudo contribui tanto para o conhecimento da sedimentologia da plataforma continental interna adjacente ao Porto do Recife e à Praia dos Milagres em Olinda, quanto para a execução de futuras intervenções na recuperação das praias da região. Portanto, com objetivo de identificar áreas com concentrações de granulados litoclásticos marinhos compatíveis com especificações necessárias à regeneração de praias, foram analisadas 36 amostras, que foram coletadas ao longo de seis perfis equidistantes em 1 km, perpendiculares à linha de costa na plataforma interna do Porto do Recife. Em laboratório foram realizadas análises granulométricas e o estudo composicional de todas as amostras. Os resultados granulométricos mostram a predominância de sedimentos mal selecionados, ocorrendo classes variadas de tamanho entre seixo pequeno (8 mm) e lama (< que 0,062 mm), com predominância da fração areia grossa. A análise composicional revelou uma hegemonia de carbonatos marinhos. Os dados obtidos apresentam uma redução do suprimento sedimentar terrígeno local. Também de acordo com os resultados obtidos no presente estudo, a plataforma continental interna adjacente ao Porto do Recife e à praia dos Milagres em Olinda-PE, é essencialmente recoberta por areias biogênicas mal selecionadas, oriundas da morte e fragmentação dos organismos componentes dos recifes coralíneos e algálicos que ocorrem na plataforma continental interna. Dessa forma, esta área não possui material siliciclástico suficiente para ser utilizado na exploração mineral para recuperação artificial de praias no Estado de Pernambuco. / There are few studies that map the Internal Continental Platform referring to localization, qualification and quantification of reserves of litoclastic marine material. The Brazilian state Pernambuco suffers from erosions along the whole coast and particularly in areas close to the cities of Recife and Olinda. This study offers new knowledge about the sedimentology of the internal continental platform adjacent to the harbor of Recife and the Beach Milagres in Olinda. Furthermore, it points out measures that can be used to recover regional beaches. Along 6 profiles with a distance of 1km and perpendicular to the coast line at the internal platform of the harbor of Recife, 36 samples were collected and analyzed. Thus, areas with concentrations of litoclastic marine aggregates with the necessary characteristics for the recovery of the beaches were identified. A laboratory was used for granulometry and a compositional study of all samples. The granulometric results show mainly badly selected sediments. There are different sizes from small pebbles (8 mm) to mud (< than 0,062 mm), predominantly coarse sand fraction. The compositional analysis reveals hegemony of marine carbonates. Thus the obtained data indicates a reduction of local terrigenous sedimentary supply. This is probably due to the fact that the selected area is undergoing an initial transgressive process. Also in accordance with the obtained results of this study, the internal continental platform adjacent to the harbor of Recife and the Beach Milagres in Olinda, Pernambuco, is mainly covered by badly selected biogenic sand which has its origin in the death and fragmentation of components of the coral reef of the internal continental platform. As a result the area is not indicated to mineral exploration for the artificial recovery of the beaches in the state of Pernambuco.
15

Dieta de duas esp?cies de peixes da fam?lia Cichlidae (Actinopterygii ? Perciformes) na regi?o do aproveitamento el?trico de estreito: Rio Tocantins, Ma

Reis, Luis Rog?rio Godinho dos 04 February 2013 (has links)
Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2015-07-31T21:05:08Z No. of bitstreams: 1 Disserta??o Final_Luis Rog?rio.pdf: 923746 bytes, checksum: ea087faabdb4f49cb27f0e415afb0a25 (MD5) / Made available in DSpace on 2015-07-31T21:05:08Z (GMT). No. of bitstreams: 1 Disserta??o Final_Luis Rog?rio.pdf: 923746 bytes, checksum: ea087faabdb4f49cb27f0e415afb0a25 (MD5) Previous issue date: 2013-02-04 / The inclusion of artificial barriers in freshwater ecosystems can trigger ecological, economic and social processes, affecting them. The food plasticity is an adaptive feature to the new environment, it is expected that the food of fish species under modified atmospheres follows changes in nutrient availability in the environment. To evaluate whether among the different phases of construction of Estreito barrage, Tocantins River, MA there are differences in the dietary habits of the family Cichlidae, collecting expeditions were conducted from November 2009 to 2010, (river stage) and November 2010 to April 2011 (filling phase), with an average duration of 10 days per year. The food items of dominant cichlid were analyzed using frequency and volume index, combined in Alimentary Index(IAI). The Shannon index was used to evaluate the diversity of items and classification of trophic guild. Significant differences in amplitude niche between the river and filler phases were verified by testing Hutcheson. Among cichlids found in fishes and alga influences barrage area, Geophagus proximus and Cichla proximus piquiti were dominant, being examined 26 specimens of Geophagus proximus in river stage and 6 specimens in filling stage, with results suggesting an omnivorous diet, predominantly f item in river stage and insects item for filling phase. The Cichla piquiti were examined 28 specimens in river stage and 32 specimens during stage filling, suggesting a piscivorous diet in both phases of the barrage. The number of food categories ranged between 09, during river phase and 08 the filling phase to Ciclha piquiti and between 14 during river phase and 12 the filling phase to Geophagus proximus. The test of difference in niche amplitude between the two phases revealed a nonsignificant difference for Cichla piquiti and significant for Geophagus proximus. It is concluded that the change in the hydrological regime caused by different stages in construction of the Estreito barrage (river and filling) led to changes in dietary habits in only one of two species of fish of the Cichlidae family in the region. Cichla piquiti presented itself more specialized as to its feed, preserving the two phases of the barrage piscivorous habit as that Geophagus proximus proved to have a greater trophic plasticity, having a greater amount of food items and diversifying them, in the two phases of the barrage, but not diversifying its trophic guild. / A inclus?o de barreiras artificiais em ecossistemas aqu?ticos continentais pode desencadear processos com repercuss?es ecol?gicas, econ?micas e sociais. A plasticidade alimentar ? uma caracter?stica ? adapta??o ao novo ambiente, esperando-se que a alimenta??o de esp?cies de peixes em ambientes modificados acompanhe as mudan?as na disponibilidade de nutrientes do ambiente. Para avaliar se entre as diferentes fases de constru??o da Barragem de Estreito, Rio Tocantins, MA houve diferen?as no h?bito alimentar em duas esp?cies de peixes (Geophagus proximus e Cichla piquiti) da fam?lia Cichlidae, expedi??es de coleta foram realizadas de novembro de 2009 a 2010, (fase rio) e novembro de 2010 a abril 2011(fase enchimento), com dura??o m?dia de 10 dias por campanha. Os itens alimentares de cicl?deos dominantes foram analisados pelo m?todo de freq??ncia de ocorr?ncia e ?ndice volum?trico, combinados no ?ndice de Import?ncia Alimentar (IAI). O ?ndice de Shannon foi usado para avalia??o da diversidade de itens e classifica??o de guilda tr?fica. As diferen?as significativas na amplitude de nicho entre as fases rio e enchimento foram verificadas atrav?s do teste de Hutcheson. Entre os Cicl?deos encontrados na ?rea de influ?ncia da Barragem, Geophagus proximus e Cichla piquiti foram dominantes, com os resultados sugerindo uma dieta on?vora, com predomin?ncia de peixes e algas para a fase rio e de insetos para a fase enchimento. O n?mero de categorias alimentares variou entre 09 na fase rio e 08 na fase enchimento para Ciclha piquiti e entre 14 na fase rio e 12 na fase enchimento para Geophagus proximus. O teste de diferen?a de amplitude de nicho entre as duas fases revelou uma diferen?a n?o significativa para Cichla piquiti e significativa para Geophagus proximus. Conclui-se neste trabalho que a mudan?a no regime hidrol?gico causado pelas diferentes fases de constru??o da Barragem de Estreito (rio e enchimento) causou modifica??es nos h?bitos alimentares das duas esp?cies de peixes da fam?lia Cichlidae da regi?o. Cichla Piquiti revelou-se mais conservativa quanto a sua alimenta??o, apresentando poucas modifica??es em sua dieta nas duas fases da barragem enquanto Geophagus proximus revelou ter uma maior plasticidade tr?fica, tendo uma maior quantidade de itens alimentares e com varia??es nos itens dominantes entre as duas fases da barragem, por?m n?o variando sua guilda tr?fica.
16

Characteristics of a Chronically, Rapidly Eroding Beach: Long Key, Pinellas County, Florida

Saint John, Alyssa L 19 November 2004 (has links)
Long Key, on the central western coast of Florida, has been nourished repeatedly since 1975. Following nourishment, the beach has rapidly eroded. This study documents rates, processes, and mechanisms for the rapid erosion. To better understand the beach performance, it is crucial to quantify the background erosion rate when artificial beach fill is at its minimum. This year long study from February 2003 through March of 2004 provides a detailed examination of the performance of a natural beach experiencing intense erosion. The primary objective is to analyze the performance of Long Key through detailed investigation of shoreline and beach-volume changes at a time when the effects of the most recent nourishment in the summer of 2000 are a minimal influence, and the natural performance of the beach, i.e, the background erosion/accretion rate, can be determined. This study also examines, in detail, shore-parallel and cross-shore sediment properties in an attempt to link erosional, stable and accretional areas to sediment grain-size composition. Finally seasonal variations of the nearshore morphology and sediment properties of the Long Key beach were determined to identify the significance of seasonal variations on long-shore and cross-shore sediment transport. This study was conducted using monthly beach profile data and monthly sediment samples. Net longshore sediment transport at the eroding north end (Upham Beach) is to the south at a rate of 34,000 cubic meters per year. Eighty-five percent of this sediment is deposited on the central and southern portions of the island, mainly in the central portion. This is an elevated sediment transport rate as compared to the generally accepted rate of 15,000 to 20,000 cubic meters per year, which explains the rapid erosion at the north end. The greatest volume loss occurs in the winter months, ostensibly due to the passage of winter storms. There is also no significant cross-shore sediment transport in the northern portion of Long Key, beach profile results demonstrate a stable shape. However, there is slight cross-shore sediment transport in the central and southern regions of the island. At location LK 3 in the north end of the island lost 35 meters of shoreline above NGVD and 25 meters below NGVD. At location LK 11 in the south end there was a gain of 3 meters above NGVD and 15 meters below NGVD. Based on detailed sediment analysis, it is not possible to determine distinctive and persistent temporal or spatial sediment characteristics, nor are the sediment properties of Long Key indicative of longshore sediment transport.
17

Evolution and Equilibration of Artificial Morphologic Perturbations in the Form of Nearshore Berm Nourishments Along the Florida Gulf Coast

Brutsché, Katherine Emily 26 June 2014 (has links)
Inlets and channels are dredged often to maintain navigation safety. It is beneficial to reintroduce the dredged material back into the littoral system, in the form of beach or nearshore nourishments. Nourishment in the nearshore is becoming an increasingly utilized method, particularly for dredged material that contains more fine sediment than the native beach. This research examines the morphologic evolution of two different nearshore nourishments. A nearshore berm was constructed at Fort Myers Beach, Florida using mixed-sized sediment dredged from a nearby channel. The nearshore berm was placed in water depths between 1.2 and 2.4 m with the berm crest just below MLLW in the shape of a bar. The nearshore berm migrated onshore while the system was approaching a dynamic equilibrium. Near the end of the fourth year, the beach profiles had returned to the equilibrium shape characteristic of the study area. Gaps in the berm allowed water circulation and should be considered as a design parameter. The fine sediment fractions in the original placed material was selectively transported and deposited offshore, while the coarser component moved onshore. The dry beach maintained the same sediment properties throughout the study period and was not influenced by the fine sediment in the initial construction of the berm. Another nearshore nourishment was placed along eastern Perdido Key, Florida in 2011-2012 using maintenance dredged material from nearby Pensacola Pass. Different from the Fort Myers Beach berm, the material was placed within the swash-zone, with a maximum elevation of +0.91 m NAVD88 (or 0.62 m above MHHW). The low constructed berm elevation allowed natural overwash processes to occur frequently, which resulted in net onshore sediment transport and growth of the active beach berm. Sediment volume gain west of the project area due to longshore spreading of the nourishment occurred mostly in the trough between the shoreline and the bar, rather than on the dry beach. The swash-zone berm evolved back to the natural equilibrium profile shape maintained in the study area within 8 months. The performance of the swash-zone nourishment was compared to two previous beach nourishments at the same location in 1985 and 1989-1991, with higher berm elevations, at +3 m and +1.2 m NAVD88, respectively. The 1.2-km 1985 nourishment performed the poorest with a shoreline retreat rate of 40 m/year. The 7.3-km 1989-1991 nourishment performed the best with a retreat rate of 11 m/year. This suggests that high berm elevations do not necessarily lead to better nourishment performance. Longshore extent of a nourishment may play an essential role. The distant passage of two tropical storms (Tropical Storm Debby and Hurricane Isaac) generated high waves for the study areas. The two berm nourishments responded differently to the storm. Response was also compared to a beach nourishment in Sand Key. The bar-shaped Fort Myers Beach berm was split into two smaller bars, while a storm berm developed for the swash-zone nourishment at Perdido Key. In both cases, the energetic storm conditions accelerated the evolution of the berm profiles toward equilibrium. As compared to the measured nearshore waves by this study, CMS-Wave accurately propagated the WIS Hindcast waves. SBEACH accurately captured the maximum water elevation, consistent with measured upper limit of morphology change. The model correctly predicted beach and nearshore erosion during the storms. The growth of the storm berm at the Perdido Key swash-zone nourishment was predicted reasonably well by the SBEACH model. However, the magnitudes of the storm-induced erosion and the locations of the offshore bar were not accurately predicted consistently.
18

Attitudes and Information Effects in Contingent Valuation of Natural Resources

Raybould, Michael, n/a January 2006 (has links)
This thesis investigated the effects of photographic and text information on respondents' attitudes and willingness-to-pay for a proposed beach protection scheme in the erosion prone Gold Coast region on the east coast of Australia. The research developed two alternative expectancy-value attitude-behaviour models to test residents' attitudes toward relevant targets and behavioural intention, expressed through stated willingness-to-pay, and compared the proposed models with one established attitude-behaviour model. The thesis set out to investigate three central research questions; one question relating to the effects of information on attitudes and willingness-to-pay, and two questions relating to the relationships between attitudes and willingness-to-pay. It was hypothesised that photographs that depicted severe erosion damage would result in more positive attitudes toward, and greater willingness-to-pay for, beach protection than photographs that showed only mild levels of erosion damage. Positive relationships were hypothesised between variables representing attitudes toward beach erosion, attitude toward beach protection, attitude toward paying for beach protection, and willingness-to-pay. Finally, it was hypothesised that the relationships between attitudes and willingness-to-pay could be adequately explained by the proposed attitude-behaviour models. The thesis describes how seven information treatments and eight attitude measurement scales were developed and tested in a pilot experiment before use in a survey of homeowners in the region of interest. Analysis of variance showed that, while respondent's attitude toward beach protection was affected by the information treatments, their willingness-to-pay for the proposed program was insensitive to information. There were no significant effects that could be attributed exclusively to text descriptions of the good but there were significant effects that could be attributed to photographic information treatments. However, none of the effects on attitudes resulted in significant effects on the behavioural intention expressed in stated willingness-to-pay. Analysis of respondents with low previous knowledge of the proposed good revealed more extensive information effects on attitudes, but still not on willingness-to-pay, and this suggests that high levels of previous knowledge in a large proportion of the sample had a moderating effect on attitude change caused by the information treatments. Regression analysis showed that seven of the eight attitude and behaviour variables in the proposed attitude-behaviour model were significant predictors of willingness-to-pay. In the final phase of the analysis, goodness-of-fit indices, estimated using Structural Equation Modelling, indicated a good fit between the data and the attitude-behaviour models tested. Standardised coefficients on the model indicated that perceived behavioural control, expected utility of outcomes, and subjective norms all had strong direct relationships with stated willingness-to-pay, and strong indirect relationships on willingness-to-pay via attitudes toward payment. These results are consistent with the relationships proposed in attitude-behaviour models and the moderating effects of these variables explain why significant information treatment effects were observed on attitude to beach protection but not on willingness-to-pay. This research showed that respondent's willingness-to-pay in a contingent valuation experiment is quite insensitive to photographic treatments when previous knowledge is high and that costly and time consuming testing procedures, recommended by authorities, may not be necessary under these conditions. It also demonstrated that measures of attitude, consistent with an attitude-behaviour model, can be collected easily in a contingent valuation study and can contribute to understanding of participant responses and to identification of protest responses.
19

Numerical Modeling of Coastline Evolution in an Era of Global Change

Slott, 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
20

Establishing a Coastal Protection and Planning System in Taiwan

Yu, Meng-Jiuan 05 September 2011 (has links)
In the last few decades, academic and institutions advanced in coastal research in Europe and America have rigorously engaged in developing numerical models for coastal wave hydrodynamic simulations. The notable products include MIKE21 from DHI in Denmark, CEDAS (with GENESIS and SBEACH) from Veri-Tech in the United States, and the SMC from University of Cantabria in Spain. Among them, the Spanish Coastal Modeling System (SMC) is the only integrated package for coastal planning and modeling. With a unique preprocess module which pre-stores the bathymetry and wave data, the SMC provides a user-friendly interface directly using the screen display for a series of coastal planning and design applications which comprise artificial nourishment with headland-bay beach, breakwater construction and extension, and dredging of navigation channel etc., as well as the usual wave-current simulation for countermeasures in coastal protection and disaster mitigation. Despite the availability of several numerical programs for wave-current simulations and beach changes that have been developed by the coastal professional in Taiwan, and the continuous effort of the Water Resources Agency, Ministry of Economic Affairs to establish a national coastal database, it is imperative to develop/setup an integrated bathymetry-hydrodynamics-protection system, such as the Spanish SMC, as the key element in the national platform for coastal planning and modeling. This dissertation first describes the coastal environment in Taiwan, major causes for shoreline evolution and then reviews the history of shore protection since 1970s, together with the current prospective for coastal environment and strategies to sustain the natural shoreline ratio. To accomplish these goals, the Water Resources Agency has endeavored to implement artificial nourishment with headland-bay beaches, in order to raise the ratio of natural shoreline, in addition to establish a national coastal planning and simulation platform. As a response to this call for eco-engineering approach, we recommend that headland-bay beach in static equilibrium be adopted for mitigating coastal erosion, beach restoration and creation of recreational beaches, which can be designed directly on the screen using the empirical bay shape equation in conjunction with the SMC. Based on the framework of the Spanish SMC, this writer has successfully attempted the preliminary pre-process module of Baco (bathymetry) and Odin (wave climate) for Taiwan, using data from digitized nautical charts, nearshore depth surveys, and long-term wave observation results around Taiwan from the International Comprehensive Ocean-Atmosphere Data Set (ICOADS). The effort generates the first version of SMC in Taiwan. Having pre-stored the bathymetry and wave data for Dapeng bay in Pingtung County and Sizihwan Bay in Kaohsiung City, a series of coastal planning and modeling procedures for these two model sites are demonstrated in this dissertation, including a series of calculations of wave-current distribution for monsoon and storm waves, as well as planning of bay beach using artificial nourishment. Upon executing the Taiwanese version of SMC introduced in this dissertation, the modeling results can be applied to assist the planners and decision makers in comprehending the coastal environment, devising a feasible shore protection strategy, and promoting an earlier accomplishment of the so-called ¡ugeo-engineering ¡u in our country. Finally, the writer also wishes the outcome of this study could help relevant government agency to accomplish the prospective of sustainable coastal development upon implementing the strategies of establishing an appropriate coastal planning platform and promoting a systematic approach for coastal planning and design, as revealed in the "Sustainable Regeneration of Coastal Environment Project (98 ~ 103 fiscal year)".

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