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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.
21

Statkraft Hydro Power Plants – Oil Spills and Valuable Areas

Enzenhofer, Klaus January 2014 (has links)
Currently, Statkraft knows that they have oil spills from their hydraulic system, but the problem is that the amount of the oil spilled is not clear. Furthermore, Statkraft is missing a tool that can be used when decisions need to be made on what power plants that should be prioritized to be renovated next or which oil system that they should be switched to. In order to answer these points a look has been taken onto the environmental effects and the amount of oil spilled from hydropower plants, the general oil system inside a power plant, and in Kaplan turbines. Furthermore, two maps were developed: one presenting areas of interest for humans and environment around the hydropower plants and a second map about the river shorelines sensitivity to oil spills represented in form of an ESI ranked river shoreline. The maps give a general overview and can be used as a starting point to include environmental aspects into the planning and decision making process. The outcomes of the study are that more detailed information about the amount of oil spills released in small amounts from the turbines is needed. The catchment areas, where Statkraft Sverige AB has hydropower plants, which are most sensitive to oil spills, are Moälven and Nätraån. The hydropower plant with the most sensitive river shoreline is the Stennäs power plant due to a large wetland close by. Those areas should therefore be prioritized in projects about reducing the amount of oil inside Statkraft`s hydropower plants.
22

A Geospatial Analysis: Impacts of Hurricane Matthew, St. Catherines Island, Georgia

Dobson, Steven 08 August 2017 (has links)
The purposes of this study were to evaluate the shoreline dynamics and environmental change of St. Catherines Island shoreline through the application of an updated shoreline model (1859-2017). Efforts were completed to document and quantify the impacts to the nearshore environments of the island from Hurricane Matthew (07-08 October 2016). This was accomplished through the measurement of Net Shoreline Movement (NSM) that was performed along the shoreface at 200-meter spacings by using aerial imagery and ground-collected GPS data. The Hurricane Matthew NSM data along with the short-term shoreline rates were used to calculate the years of change along the shoreline in response to the storm, indicating that the storm represented an average of 3.7 years of average erosion. A spatial analysis of impacts conducted along the shoreline revealed major habitat losses within the study area of 66.5 acres and the limited accretion of 3.7 acres.
23

Faunal assemblages associated with living shorelines and implications for high-wave energy ecosystems

Firth, Daniel 13 December 2019 (has links)
This study investigated the main and interactive effects of nearshore breakwaters and marsh vegetation on faunal abundance and diversity along an eroded shoreline in Bon Secour Bay, Alabama. In summer 2016, eight replicates of three vegetation treatments plots (naturally vegetated, planted, and open) were established along a breakwater-protected and an adjacent no breakwater shoreline. After which, three methods were used to evaluate nekton quarterly from summer 2016 to summer 2018; Breder traps along the shoreline and lift nets and trawls in nearshore waters. Data were analyzed using the Shannon-Weiner diversity index and ANOVA. Results showed breakwaters supported significantly more abundant and diverse communities along the shoreline and in parallel nearshore waters than similar no breakwater sites. However, the main vegetation treatment effects were not significant. These findings suggest that living shoreline projects with nearshore breakwater support can be beneficial for fisheries enhancement in high-wave energy environments.
24

Glacial Lake Shorelines in Northern Wentworth County, Ontario

Horton, James H. 03 1900 (has links)
No abstract was provided. / Thesis / Bachelor of Arts (BA)
25

Instantaneous Shoreline Extraction Utilizing Integrated Spectrum and Shadow Analysis From LiDAR Data and High-resolution Satellite Imagery

Lee, I-Chieh 30 August 2012 (has links)
No description available.
26

An Analysis of Shoreline Change at Little Lagoon, Alabama

Gibson, Glen R. 28 June 2006 (has links)
In Alabama, the term "coastal shoreline" applies to the Gulf shoreline and the shorelines of estuaries, bays, and sounds connected to the Gulf of Mexico and subject to its tides. However, Alabama shoreline studies have yet to include Little Lagoon, which has been connected to the Gulf of Mexico for most of the last 200 years, according to historical charts. This study used historical nautical charts, aerial photographs, and LIDAR derived shorelines from 1917 to 2004 to analyze shoreline change on Little Lagoon and its adjacent Gulf shoreline. The high water line was used as the common reference feature, and all shorelines were georeferenced, projected, and digitized in a Geographic In-formation System. Between 1917 and 2001, the Gulf shoreline eroded an average of 40 m over 12.7 km, with some transects eroding almost 120 m while others accreted almost 60 m. The greatest changes to the Gulf shoreline were found near natural inlets, downdrift of jetties, and coincident with nourishment projects. Between 1955 and 1997, Little Lagoon shrank 0.5%, or 51.4 km², from 10,285.9 km² to 10,234.5 km². The greatest changes to Little Lagoon were found on its southern shoreline and near inlets, human development, and hurricane overwash fans. A correlation analysis conducted on the Gulf shoreline and Little Lagoon' s southern shoreline indicated that although weak overall correlation values exist when the entire 12.7 km study area is compared, strong correlation values are obtained in some areas when compared over one kilometer sections. The strongest correlations were found in the same locations as the greatest changes. / Master of Science
27

Kusten är klar : en undersökning av Gotlands bronsåldersstrandlinje i GIS / The coast is clear : a study of the Bronze Age shoreline of Gotland

Nordin, Fredrik January 2011 (has links)
In this bachelor thesis an attempt is made to recreate the shoreline of Gotland during the Bronze Age. This has been done with the help of GIS to analyze remains dated to different periods of the Bronze Age that have been situated close to the coast. Case studies of three areas of the island have been made where dated remains together with typical Bronze Age remains like cairns and ship settings are analyzed with variables such as height over sea level and geological and topographical information. Contemporary datings from each case study have been compared to find a possible shoreline for both early and late Bronze Age. Two shorelines, one for the early Bronze Age and one for the late Bronze Age, have been created and tested on the three areas to see the placement of the remains in relation to these coastlines.
28

Review of U.S. Tide-Coordinated Shoreline

Sukcharoenpong, Anuchit January 2010 (has links)
No description available.
29

Modelling the dynamics of large scale shoreline sand waves

Van Der Berg, Niels 11 May 2012 (has links)
Shoreline sand waves are shoreline undulations with a length scale of several kilometres and a time scale of years to decades. They occur on many coasts, migrating in the direction of the dominant littoral drift and they introduce a variability into the shoreline position that can be greater than the long term coastal trend. The objective of this thesis is to provide more insight into the formation and dynamics of shoreline sand waves and, in particular, to explore the role of the so called high angle wave instability. Previous studies showed that the shoreline can be unstable under very oblique wave incidence. This high angle wave instability develops due to the feedback of shoreline changes and the associated changes in the bathymetry into the wave field. Wave propagation over this perturbed bathymetry leads to specific gradients in the alongshore transport that can cause the growth and migration of shoreline sand waves. In this thesis a quasi 2D non-linear morphodynamical model is improved and used to explore high angle wave instability and predict the formation and evolution of shoreline sand waves. The model assumes that the large scale and long term shoreline dynamics is controlled by the wave driven alongshore transport so that the details of the surfzone morphodynamics are not resolved. It overcomes some of the limitations of previous modelling studies on high angle wave instability. The wave field is computed with a simple wave module over the evolving bathymetry and an empirical formula is used to compute the alongshore transport. Cross-shore dynamics is described in a parameterized way and the model is capable of describing shoreline perturbations with a finite and dynamic cross-shore extent. The conditions under which shoreline instability can lead to the formation of shoreline sand waves are refined. Generic simulations with constant wave conditions and random initial perturbations show that the shoreline becomes unstable when the wave incidence angle at the depth of closure (i.e., the most offshore extent of the shoreline perturbations) is larger than a critical angle of about 42 degrees and shoreline sand waves develop in unison. The cross-shore dynamics plays an essential role because it determines the offshore extent of the shoreline perturbations. Using default model parameters, wave conditions and cross-shore profile, the sand waves develop with wavelengths between 2 and 5 km, the time scale for their formation is between 5 and 10 years and they migrate downdrift at about 0.5 km/yr. Simulations with a localized large scale perturbation trigger the formation of a downdrift sand wave train. Larger wave obliquity, higher waves and shorter wave periods strengthen the shoreline instability. A more realistic wave climate, with alternating high and low angle wave incidence reduces the potential for shoreline instability. A percentage of about 80% of high angle waves is required for sand wave formation. It is demonstrated that the range of low wave angles that can occur on a coast is larger than the range of high wave angles, and that the stabilizing effect produced by low angle waves (causing diffusion) is bigger than the destabilizing effect produced by high angle waves (causing growth and migration). Even if high angle waves are not dominant, the instability mechanism might still play a role in the persistence and downdrift migration of large scale shoreline perturbations. The model results are in qualitative agreement with observations of shoreline sand waves. The quasi 2D approach provides new insight into the physical mechanisms behind high angle wave instability and the occurrence of a minimal and optimal length scale for sand wave formation. Essential physical processes are wave energy dispersion due to wave refraction, wave energy focusing near the crest of a sand wave and the monotonic decrease of the gradients in alongshore transport for increasing length scales. / Les ones de sorra a la línia de costa són ondulacions de la línia de costa amb una escala espacial de kilòmetres i una escala temporal d’anys a dècades. Ocorren a moltes costes, migren en la direcció del transport litoral i introdueixen una variabilitat a la línia de costa que pot ser major que la seva tendència a llarg termini. L’objectiu d’aquesta tesi és estudiar amb més profunditat la formació i la dinàmica de les ones de sorra i, més concretament, explorar el rol de l’anomenada inestabilitat d’angle gran. Estudis previs van demostrar que la línia de costa pot ser inestable en cas d’onades obliqües que incideixen amb un angle gran. Aquesta inestabilitat d’angle gran es produeix degut a la retroalimentació entre els canvis a la línia de costa (i els que conseqüentment ocorren a la batimetria) i els canvis al camp d’onades. La propagació de les onades sobre la batimetria pertorbada crea gradients del transport de sediment longitudinal que causen el creixement i la migració de les ones de sorra. En aquesta tesi s’ha millorat un model morfodinàmic quasi 2D i no lineal per usar-lo per explorar la inestabilitat d’angle gran i predir la formació i evolució de les ones de sorra. El model assumeix que la dinàmica a gran escala i llarg termini està dominada pel transport de sediment longitudinal produït per les onades de manera que la morfodinàmica de la zona de rompents no es detalla. S’han superat algunes de les limitacions dels estudis anteriors de modelat de la inestabilitat d’angle gran. El camp d’onades es calcula amb un mòdul senzill de propagació sobre la batimetria canviant i el transport longitudinal s’estima usant una fórmula empírica. La dinàmica transversal es parametritza per descriure pertorbacions de la línia de costa amb una extensió transversal finita i dinàmica. S’han refinat les condicions sota les quals la inestabilitat d’angle gran produeix la formació d’ones de sorra. Les simulacions amb condicions constants d’onades i pertorbacions inicials aleatòries mostren que la línia de costa esdevé inestable quan l’angle d’incidència a la profunditat de tancament és major que un angle de 42 graus i les ones de sorra es desenvolupen a l’uníson. La dinàmica transversal té un rol essencial al determinar l’extensió transversal de les pertorbacions. Usant els valors per defecte dels paràmetres del model, les ones de sorra tenen espaiats d’entre 2 i 5 km i temps de creixement d’entre 5 i 10 anys, i migren en la direcció del transport a uns 0.5 km/any. Les simulacions també mostren que una pertorbació inicial localitzada desencadena la formació d’un tren d’ones de sorra. Com més obliqües i grans són les onades i com menor és el seu període major és la inestabilitat. Un clima d’onatge més realista, alternant onades d’angle d’incidència gran i petit, redueix el potencial de la inestabilitat d’angle gran. Calen almenys un 80% d’onades d’angle gran perquè es formin ones de sorra. El rang d’onades d’angle petit que poden succeir en una costa és major que el d’onades d’angle gran, i l’efecte estabilitzador de les onades d’angle petit (que produeix difusió) és més important que l’efecte desestabilitzador de les onades d’angle gran (que produeix creixement i migració). Fins i tot si les onades d’angle gran no dominen, el mecanisme d’inestabilitat pot tenir un paper important en la persistència i migració de pertorbacions de la línia de costa a gran escala. Els resultats s’assemblen qualitativament a les observacions d’ones de sorra. L’enfocament quasi 2D permet estudiar més detalls del mecanisme físic que hi ha darrere de la inestabilitat d’angle gran i del fet que existeixin longituds d’ona mínima i òptima per la formació d’ones de sorra. Els processos físics essencials són la dispersió de l’energia de l’onatge degut a la refracció, la concentració d’energia de les onades a les crestes de les ones de sorra i el decreixement monòton del transport litoral quan augmenta l’escala espacial.
30

Predicting retention of diluted bitumen in marine shoreline sediments, Southeastern Vancouver Island, British Columbia, Canada

Britton, Lee Allen Sean 22 December 2017 (has links)
Canada has become increasingly economically dependent on the exportation of bitumen to trans-oceanic international markets. As the export of Alberta bitumen from ports located in British Columbia increases, oil spill response and readiness measures become increasingly important. Although the frequency of ship-source oil spills has dramatically declined over the past several decades, they remain environmentally devastating when they occur. In the event of a marine spill, great lengths of shoreline are at risk of being contaminated. Once ashore, oil can persist for decades if shoreline hydraulic conditions are correct and remediation does not occur. Most commonly transported oils (e.g., fuel oils, Bunker C, crude oil, etc.) have been thoroughly studied, and their fate and behaviour in the event of a marine spill is well understood. In contrast, because diluted bitumen has been historically traded in relatively low quantities and has almost no spill history, there is a sizable knowledge gap regarding its effects and behaviour in both the marine environment and on coastal shorelines. The intent of this thesis was to develop a classification scheme to identify marine shorelines of high and low diluted bitumen (dilbit) retention for southeastern Vancouver Island, British Columbia. This study builds upon the outcome of former laboratory bench top dilbit and sediment research known as Bitumen Experiments (Bit_Ex). Bit_Ex investigated dilbit penetration and retention in six engineered sediment classifications ranging from coarse sand to very large pebble in accordance with the Wentworth Classification scheme. This research used Bit_Ex findings to predict dilbit retention in poorly sorted in-situ beach sediments found on shorelines representative of the southern coast of Vancouver Island, British Columbia, Canada. Field and laboratory measurements were conducted to document the occurrence of in-situ shoreline sediments and hydraulic conditions and were used to predict dilbit retention by comparing such characteristics between Bit_Ex and unconsolidated in-situ beach sediments. Saturated hydraulic conductivity (Ks) was measured using a double-ring constant-head infiltrometer. Measured Ks values were then compared to predicted Ks values generated by five semi-empirical Ks equations. A modified version of the Hazen Approximation was selected as the most appropriate. Using measured and calculated metrics, sediments were grouped as having either low or high dilbit retention. When sediments were analysed as homogenous samples, the experimental results suggested two of ten shorelines were composed of a combination of low and high retention sections, while the remaining eight sites were of low retention. Upon the isolation of coarse surface strata, results indicated two shorelines were entirely veneered with high retention sediments, and four shorelines were a combination of high and low retention. The residual four shorelines were found to be entirely composed of low retention sediments. The results illuminate the importance of shoreline stratification when predicting shoreline oil retention. This characteristic is a factor that current shoreline oil retention mapping techniques do not adequately consider. Additionally, the findings suggest that while sediments indicative of retaining weathered dilbit are relatively uncommon within Juan de Fuca and Harro Straits, high retention unweathered dilbit sediments are more common. / Graduate / 2018-06-26

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