<p> The vegetational colonization and development preceding the establishment of lichen-heath was examined on a Hudson Bay coastal raised-beach system. A continuous and directional developmental sequence of approximately 200 years was quantified on both a coastal intraridge sample sequence and on an inland interridge sample sequence. Increasing gradients of elevation, soil peat thickness and soil organic matter coincide with the vegetational development, however no appreciable changes in soil pH or concentrations of available nutrients were detected and it is concluded that these parameters have little influence on the development of lichen-heath at this site. Community composition over the ridge profile forms a second major vegetational gradient which appears to be affected primarily by environmental factors related to ridge morphology and orientation. The interactions of environmental factors in the development of lichen-heath are discussed.</p> / Thesis / Master of Science (MSc)

This study explores the (hetero)sexualized online space that is the category “Pools, Hot Tubsand Beaches” on the streaming platform Twitch.tv. The aim of the study is to gain a further understanding of how gender and sexuality is performed under the specific conditions offered by the space. Interactions between livestreamer and chat in three livestreams have been transcribed and analyzed using reflexive thematic analysis. I find that the space is characterized by the logic of the heterosexual matrix as defined by Judith Butler, as well by two foundational asymmetries that inform the way that gender and sexuality is performed in the spaces studied: the asymmetry of perspective and the asymmetry of performativity. These conditions are actively negotiated with by the subjects that interact in the space. Furthermore, relying on the work of Raewyn Connell, I find that the subjects conduct a labor of positionality with regards to notions of good and bad masculinity, basing their sense ofcommunity on the abjectification of “other men” in order to construct their own masculinity.

No description available.

<p>Recreational beaches of the Great Lakes play a critical role in the quality of life for beach goers and contribute to the economic and environmental health of the Great Lakes region. Over the past decade, concerned local residents, municipalities, and public beach goers have observed the deteriorating beach quality along the shores of the Great Lakes. Numerous problems exist at these beaches including: high levels of <em>E.coli</em>, encroachment of invasive and non-native vegetation, iron staining, loss of sand. However, the more pervasive problem appears to be increased wet conditions at beaches that use to be dry. This study was undertaken to investigate the physical and hydrological factors that control wet and dry beaches, in order to determine why these beaches exist. Combined field, laboratory, and modelling methodologies were used to characterize four beach sites and calibrate beach models along southern Georgian Bay in Tiny Township, ON. The results of this research indicate that there are three interconnected factors that influence wet and dry beaches, including: (1) texture of a beach, (2) depth to the water table, and (3) elevation of the ground surface. Texture is the primary factor that controls the moisture conditions at a beach even though all beaches were classified as sands. This is a consequence of the fact that fine grained sands have significantly higher capillary rise and retain higher moisture contents above the water table compared to coarse grained sands. Depth to the water table influences the moisture conditions at a beach through its association with the relative position of the top of the capillary rise within respect to the surface of the beach. Ground surface elevation influences the depth of sand above the water table at a beach; lower and flatter surface elevations have the water table (and capillary rise) closer to the beach surface than at beaches with steeper elevations. In summary, wet beaches have high moisture contents at and near the surface of a beach (> 10 %), shallow water tables (~ < 50 cm), and flat ground surface elevations. Dry beaches have low moisture contents at and near the surface of a beach (< 10 %), deep water tables (~ > 50 cm), and steep ground surface elevations. Using the numerical model HYDRUS-2D, four calibrated beach models provide a framework for beach managers to gain insights into beach quality issues through scenario testing. Beaches with shallow water tables and flat surface elevations (either natural or human-induced) are at greater risk of becoming wet under high lake level scenarios than beaches with steeper surfaces (dry beaches). Heavy precipitation events are temporary and do not convert dry beaches into wet beaches and high evaporation rates do not convert wet beaches into dry beaches; conversion of beaches is mainly influenced by beach surface alterations (e.g. bulldozing and removing sand dunes). The conclusion of this study is that hydrological factors are primary controls on the quality of the beaches and the associated problems along the shores of the Great Lakes.</p> / Master of Science (MSc)

Geotechnical sediment properties such as moisture content, relative density, bearing capacity, and undrained shear strength have been discussed in the context of coastal sediment dynamics. However, these properties have rarely been assessed in their respective relevance or quantitatively related to sediment transport and erodibility. Also, to date there is no framework available for collecting direct measurements of these properties for estimating initiation of motion and erosion rates. Here, it is postulated that improving the ability to measure geotechnical sediment properties in energetic foreshore environments can improve our ability to predict coastal response to climate change. Through a series of field measurements, the research presented here (1) provides a framework for conducting geotechnical measurements of beaches, (2) advances portable free fall penetrometer (PFFP) data analysis in intertidal environments through the introduction of an impact velocity dependent strain-rate correction factor, (3) relates textural and sediment strength properties derived from PFFP measurements to an erosion rate parameter and hydrodynamically driven bed-level change, and (4) uses PFFP measurements to develop a sediment classification scheme in terms of soil behavior and erosion behavior for a mixed sediment type Arctic environment. Relationships between sediment properties other than grain size, most significantly void ratio, and erodibility parameters highlight the relevance of these measurements in geomorphodynamically active sandy beach environments. For the cohesive sediments in the Arctic, undrained shear strength was also related to an erosion rate parameter, allowing for a categorical framework for erodibility classification to be developed. The cohesive framework was combined with the relationships developed for sandy sediments and used to highlight areas of active sediment transport in the context of local morphodynamic and ice gouging processes. Finally, a simple case study showed how implementing in-situ erodibility parameters was important for long-term morphological modelling. The results represent a step forward in our ability to predict and mitigate climate change related issues from coastal erosion. / Doctor of Philosophy / Climate change driven impacts on coastal environments include increasing frequency and severity of storms, coastal erosion, and inundation of populated areas. Specifically for Arctic environments, warming has caused more sediment to be introduced into coastal waters as well as accelerated rates of permafrost melting and shoreline retreat and decreases in sea ice. One aspect of understanding how these changes will continue to affect coastal communities and our ability to predict climate change effects is understanding the role of sediment properties on sediment erosion and shoreline change. Physical and geomechanical (strength) properties of coastal sediments are important for a variety of coastal applications but have rarely been investigated in the context of quantifying, predicting, and assessing erosion, specifically in the context of field measurements. Towards this end, a series of field surveys were conducted along the coast of North Carolina at a sandy beach, and in Harrison Bay, Alaska, an Arctic coastal zone with both sandy and muddy sediments. Tools for taking physical samples of the beach and seabed, measuring the sediment strength, among other properties in place were used to characterize the local sediments. Once a framework was developed for characterizing the type of sediment, the measured properties were then related to measurements of erosion rate from a series of laboratory experiments performed on physical samples taken from the sites. Finally, one of the instruments for measuring sediment strength both on land and in the water was used to develop classification schemes for seabed sediments in terms of their erodibility. The results of this work highlight the importance of geotechnical properties for coastal sediment transport processes, reveal new relationships between sediment properties and properties quantifying erosion behavior, and offer a framework for future research to classify erodibility of coastal environments in the field with a single piece of equipment. Overall, the work presented here contributes to our ability to measure, quantify, and predict coastal response to climate change.

No description available.

No description available.

Thesis (MScEng)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: On the 9th September 2009, the 178 m Panamanian bulk carrier, the Seli One, ran aground off the coast of Blouberg in Table Bay, South Africa. Due to failed salvage attempts, the vessel has remained stranded approximately 500 m off the Blouberg beachfront. Since the vessel ran aground, a gradual change in the Blouberg beach shape in the lee of the wreck has been observed. The local coastline, which has traditionally been fairly uniform, has assumed a curved shape, with significant sediment accretion being observed in the wave shadow of the wreck. Initially, the Seli One wreck remained intact. However, during a storm on the 4th September 2011, the vessel split up into three separate pieces. The impact that the wreck is having on the local wave, current and sediment transport dynamics remains undefined. This lack of knowledge results in significant risks, relating to shoreline stability and beach amenity. The objective is this study was therefore the determination of the long-term impact of the Seli One shipwreck on the Blouberg beachfront. A review of existing literature has indicated that no empirical relationships are available which could be used to calculate the impact of a shipwreck on nearby coastal processes. Numerous methods are available which can be used to determine the net longshore transport rates, but these cannot be used to quantify the impacts of shipwrecks on the local sediment transport regime. Numerical models were therefore used to determine the impact of the Seli One shipwreck. Through the analysis of simulation results, it was concluded that, as expected, the shipwreck has resulted in a significant reduction in the net longshore sediment transport rate in her lee, resulting in sediment deposition in this area. It was further concluded that the vessel does not result in the complete blockage of longshore sediment transport, and that sediment is able to periodically pass through the lee of the vessel. The simulated beach salient on the 3rd July 2011 was compared to results of a beach survey, performed on the same date specifically for this study. The simulated accretion of approximately 27 m in the lee of the shipwreck agrees well with the measured salient. It has been shown that approximately 75% of the salient accretion occurred within the first two months of the vessel’s arrival. Furthermore, shoreline erosion on the northern side of the salient resulting directly from the shipwreck has been shown to be approximately 15 m. This too occurs relatively rapidly, within approximately two months of the vessels arrival. Following the initial impact of the wreck in its intact configuration, the long-term potential impact of the vessel in its broken-up configuration was determined. This included the assumption that the vessel does not undergo any additional breaking-up, and remains in its three-piece configuration indefinitely. This has shown that the salient width resulting from the shipwreck is reduced to approximately 20 m, compared to the initial 27 m. However, shoreline erosion on the northern side of the wreck has increased from approximately 15 m initially to approximately 18 m in the long-term, which is caused by the continuous sedimentation between the vessel and the beach. A two-dimensional coupled wave, current and sediment transport model has been developed and has shown that the wave shelter resulting from the Seli One results in the formation of a submerged salient between the vessel and the shoreline. It was found that shipwrecks have the potential of significantly altering local longshore sediment transport characteristics in general. Depending on local conditions, this may pose serious risks, both in terms of jeopardizing local seaside infrastructure, as well as creating dangerous swimming conditions. Considering the impact that a shipwreck can have on local shoreline changes, with special regard to the rate at which these shoreline changes can occur, it is recommended that the results obtained from the current study be used to estimate the impact of potential future shipwreck scenarios in Table Bay. / AFRIKAANSE OPSOMMING: Op die 9de September 2009 het die 178 m lange Panamese vragskip, die Seli Een, aan die kus van Bloubergstrand in Tafelbaai, Suid Afrika, gestrand. Weens mislukte reddingspogings, het die skip ongeveer 500 m van die kuslyn gestrande gebly. Sedertdien, is ‘n geleidelike verandering in die vorm van Bloubergstrand se kuslyn waargeneem. Die kuslyn, wat tradisioneel redelik uniform en reguit was, het onlangs ‘n aansienlike geboë vorm aangeneem, met ‘n beduidende hoeveelheid sand wat in die skip se lykant neerset. Aanvanklik het die Seli Een wrak ongeskonde gebly, maar tydens ‘n storm op die 4de September 2011, het die skip in drie afsonderlike stukke opgebreek. Die impak wat die wrak op die golf, strome en sediment vervoer dinamika het,bly ongedefinieërd. Hierdie gebrek aan kennis veroorsaak ‘n aansienlike hoeveelheid risiko’s met spesifieke betrekking tot kuslyn stabiliteit en strand gerief. Die doel van hierdie studie was dus om die langtermyn-impak van die Seli Een skeepswrak op Bloubergstrand te bepaal. 'n Hersiening van bestaande literatuur het aangedui dat geen empiriese verhoudings beskikbaar is wat gebruik kan word om die impak van 'n skeepswrak op die nabygeleë kustelike prosesse te bereken nie, maar wel versekeie metodes wat gebruik kan word om die netto langsstroom sediment vervoer te bepaal. Hierdie verhoudings kan egter nie gebruik word om die impak van ‘n skeepswrak op die sediment vervoer meganisme te kwantifiseer nie, dus is numeriese modelle gebruik om die impak van die Seli Een skeepswrak te bepaal. Die skeepswrak het ‘n aansienlike vermindering in the netto langsstroom sediment vervoer veroorsaak, wat tot die afsetting van sediment in hierdie gebied lei. Dit is ook verder bepaal dat die Seli Een nie die volledige verstopping van langsstroom sedimentvervoer veroorsaak nie, maar dat sediment van tyd tot tyd in staat is om deur die lykant van die skeepswrak te beweeg. Die gesimuleerde strand aanwas van die 3de Julie 2011 is vergelyk met resultate van ‘n strand-opmeting, wat uitgevoer is op dieselfde datum, spesifiek vir hierdie studie. Die gesimuleerde aanwas, van ongeveer 27 m in die lykant van die skeepswrak, stem saam met die gemete aanwas. Ongeveer 75% van die aanwas het binne twee maande van die aankoms van die Seli Een plaasgevind. Verder is dit getoon dat aan die noordelike kant van die aanwas, ongeveer 15 m van die kuslyn weggespoel het as gevolg van die Seli Een. Na die aanvanklike impak van die wrak in sy ongeskonde konfugirasie, is die potensiële langtermyn impak van die skip in sy opgebreekte konfugirasie bepaal. Dit sluit die aanname in dat die skip nie enige bykomende breke ondergaan nie, en in sy drie-stuk konfigurasie bly. Dit het getoon dat die breedte van die aanwas, wat veroorsaak is deur die skip, verminder tot ongeveer 20 m in vergelyking met die aanvanklike 27 m. Verder is dit getoon dat die erosie aan die noordelike kant van die Seli Een vermeerder het van die aanvanklike 15 m na ongeveerder 18 m in die langtermyn. Die oorsaak hiervaan is die aaneenlopende sedimentasie tussen die wrak en die strand. 'n Twee-dimensionele gekoppelde golf, stroom en sediment vervoer model is ontwikkel en het getoon dat die golf skuiling, as gevolg van die Seli Een, sedimentasie tussen die skip en die kuslyn veroorsaak. Daar is gevind dat skeepswrakke die potensiaal het om aansienlike veranderinge aan die nabygeleë langstroom sediment vervoer stelsel te veroorsaak. Afhangende van die plaaslike omstandighede, kan hierdie ernstige risiko’s veroorsaak, beide in terme van die gevaar vir plaaslike kustelike infrastruktuur, sowel as die generasie van gevaarlike swem toestande. Met inagneming van die impak wat 'n skeepswrak op plaaslike kuslyn veranderinge kan hê, met spesiale verwysing na die tempo waarteen hierdie kuslyn veranderinge kan plaasvind, word dit aanbeveel dat die resultate wat verkryg is vanuit die huidige studie, gebruik word om die impak van moontlike, toekomstige skeepswrakke in Tafelbaai te bepaal.

O lixo marinho é um problema discutido desde a década de 1970, quando cientistas começaram a observar e quantificar materiais diversos nos mares e costas de alguns países, como por exemplo os plásticos. Nessa categoria se encontram os pellets de plástico, que constituem a matéria-prima de base para a produção da indústria mundial de insumos plásticos. Desde então o tema é tratado entre as formas de poluição marinha e costeira mais observadas. A pesquisa foi desenvolvida no litoral do Estado de São Paulo (Brasil), na qual se avaliou a presença de pellets e os mecanismos de sua distribuição, realizada em duas etapas: a primeira, em 55 praias de 15 municípios entre o Litoral Norte, a Baixada Santista e o Litoral Sul. A segunda, em 9 praias da Região Metropolitana da Baixada Santista. Pesquisa bibliográfica, documental, trabalhos de campo e de laboratório formaram as etapas da investigação, para a qual foram usados métodos de amostragem. Os resultados obtidos levaram à conclusão da maior concentração de pellets nas praias próximas às áreas consideradas pelo estudo como fontes emissoras do material no mar, como as zonas portuárias / industriais de São Sebastião, Santos e a de Paranaguá (Paraná). Ao longo das praias, foi constatado que os eventos extremos de ressacas / marés meteorológicas são os principais responsáveis pela distribuição dos pellets de plástico nas praias. A principal contribuição do trabalho foi a inclusão da temática da poluição costeira nos estudos de Geografia do Litoral, uma demanda desafiadora para a Geografia brasileira. / Marine debris is an issue discussed since the 1970s, when scientists began to observe and quantify different materials in the seas and coastlines of some countries, such as plastics. In this category are the plastic pellets, which are the basic raw material for the production of plastics industry worldwide inputs. Since then the issue is treated between forms of marine pollution and more coastal observed. The research was conducted in the São Paulo state coast (Brazil), in which it evaluated the presence of pellets and the mechanisms of its distribution, carried out in two stages: the first, on 55 beaches in 15 municipalities across the North Coast, the Baixada Santista and the South Coast. The second, on 9 beaches of Baixada Santista. Bibliographical research, documental, field work and laboratory formed the stages of the investigation, for which sampling methods were used. The results led to the conclusion of the higher concentration of pellets at the nearby beaches to areas considered by the study as sources emitting material at sea, such as port / industrial areas of São Sebastião, Santos and Paranaguá (Paraná). Along the beaches, it was found that extreme storm surge events are mainly responsible for the distribution of plastic pellets on beaches. The main contribution of this study was the inclusion of the issue of coastal pollution in the studies of Geography of the Coastline, a challenging demand for Brazilian Geography.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Devido a sua grande extensão latitudinal, a costa brasileira é influenciada por diferentes regimes climáticos e oceanográficos. Adicionalmente, a distribuição da população brasileira é caracterizada por uma alta concentração nas capitais litorâneas. Todos esses fatores levam à construção de inúmeras estruturas de engenharia que podem de alguma forma impactar o transporte de sedimento e consequentemente o balanço sedimentar de algumas praias. Uma das formas mais eficientes de recuperar esse balanço sedimentar é a alimentação artificial de praias, com sedimentos provenientes da plataforma continental com características semelhantes. Os métodos geofísicos acústicos permitem mapear de forma eficiente o fundo e o subfundo marinho para a busca de áreas fontes para a lavra de forma eficiente. O objetivo deste estudo é a identificação de padrões geoacústicos a partir de analises quantitativas e qualitativas, para a caracterização de áreas fontes de areias siliciclásticas compatíveis com sedimentos de praias em erosão na cidade do Rio de Janeiro. O mapeamento foi realizado na plataforma continental interna do Rio de Janeiro, em área adjacente à praia de Itaipuaçu (Maricá, RJ). As análises evidenciaram depósitos, localizados entre 19 e 30 metros, de areias com granulometria, textura e selecionamento em condições ideias para a recomposição de praias do Rio de Janeiro. / The Brazilian coast is afected by different oceanographic characteristics, mainly due to its large latitudinal extention. Additionally, the distribution of the Brazilian population is characterized by a high concentration in the coastal capital. These facts generate a large number of coastal engineering structures that may impact the sediment transport and consequently the sediment balance in some beaches. All these factors impact some sand beaches and the best choice for its mitigation and recovering is the beach nourishment - with sediments from the continental shelf with similar characteristics. However to find a good place for dredging in the shelf, we need to use geophysical methods that allow to map the bottom and sub bottom environments more efficiently. The objective of this study is the identification of geoacoustics patterns, following qualitative and quantitative analyzes, for characterizing source areas of siliciclastic sands in ideal conditions for recovering eroded beaches in Rio de Janeiro. The mapping was done in the shelf in front of Itaipuaçu beach (Maricá, RJ). The quantitative results showed well sorted median sand placers seaward of the closure depth, located between 19 and 30 meters, ideal for Rios beaches recovering.