The purpose of the research was to determine if pesticides were being transported from the place of application by the shallow groundwater and discharged into the Chesapeake Bay and Atlantic Ocean, and quantify the pesticides if they were transported. One reference (undeveloped) and four agricultural sites were tested over a 11 month period from April 1992 to February 1993. Over 500 groundwater samples were analyzed from both shallow wells and seepage meters placed in the Chesapeake Bay and Magothy Bay. The samples were analyzed in accordance to EPA Method 525.1 by solid phase extraction with octadecyl bonded disks followed by gas chromatography. The samples were examined for 5 of the most commonly used pesticides: atrazine, alachlor, carbofuran, cyanazine, and metolachlor. Pesticides were detected in only 16 samples. All the detections were at low concentrations, with only one being over 1 μg/L. The study concluded that if pesticides were being transported by the groundwater, they were below a μg/L (ppb). / Master of Science

Den här studien undersöker hur filmmusik har använts som ett berättande verktyg i Peter Jacksons filmer Hobbit: En oväntad resa (2012) och Sagan om ringen: Härskarringen (2001). Till totalt sex filmer har Howard Shore skapat musik för att beskriva miljöer, karaktärer och folkslag i en värld som baseras på J.R.R Tolkiens fantasyroman från mitten av 50-talet.  Då filmerna inom varje trilogi har släppts med relativt korta mellanrum så jämförs ett antal scener i den första filmen ur vardera trilogi där tidsspannet mellan utgivningsåren är betydligt längre. Urvalet av scener representerar liknande aspekter ur vardera trilogi och analyseras därefter utifrån ett audiovisuellt perspektiv där Johnny Wingstedts teorier om berättarfunktioner ligger som grund. Eventuella likheter och skillnader diskuteras i uppsatsens avslutande kapitel.  Resultaten visar på hur musiken används för att komplettera och förstärka scenerna i filmerna, men också hur musiken vägleder narrativet genom upprepade användningar av ledmotiv i olika versioner. Ledmotiven används på så vis som ett berättande verktyg utöver filmens dialog och visuella aspekter.

The following chapters presented here use modern ecological data and modern marine systems to evaluate past marine depositional settings and the preservation potential of various environments in the geological record. While the chapters in this dissertation vary in terms of study area, sedimentary systems (carbonate vs. siliciclastic), depositional environment, and organisms, all projects are based on developing and using quantitative models to evaluate the present as a means for understanding the past. Chapter one focuses on the preservation potential of rocky intertidal environments. The rocky intertidal zone is one of the most poorly preserved fossil-rich environments in the geological record. However in most coastal marine habitats today, it is one of the most diversity rich environments. Chapter one also focuses on the analytical advantages of hierarchical sampling of gastropod communities across San Salvador Island, the Bahamas to quantify community and species level preservation potential in rocky shore environments. Chapters two and three are based on the fossil-rich sedimentary deposits from the Po coastal plain in northeastern Italy. These deposits have been widely studied in terms of their sedimentology and stratigraphy, resulting in a highly resolved sequence stratigraphic architecture. The integration of sequence stratigraphy with paleobiology can enhance our understanding of spatiotemporal biotic patterns recorded in the fossil record. Used in conjunction with the highly-resolved stratigraphic framework, biotic patterns can be used to assess depositional cycles and bathymetry through time. Chapter two integrates sequence stratigraphic patterns and paleoecological data to develop bathymetric models across fossiliferous marine successions of the Po coastal plain, Italy. Chapter three evaluates the modern ecological dataset used to derive the bathymetric models. The last chapter also explores water depth distribution for selected taxa recorded in the Quaternary sediments and observed in present-day habitats. The dissertation research explored here demonstrates that modern ecological systems are essential to evaluating past geologic events. Through direct observation and quantitative analysis, I have learned that modern and fossil communities behave differently depending on environment (e.g. energy, salinity, water depth, etc.). These variables affect the distribution of living organisms today and through my research, delineate fossil distributions through time. With these observations, new questions have arisen about the latitudinal variability of rocky intertidal fossil preservation and extrapolating the quantitative bathymetric models to deeper time intervals. These questions will lead to future endeavors and pointedly add to the field of geology and stratigraphic paleobiology. / Ph. D.

Cette thèse concerne les possibles définitions et intégrations de l'idée de « zone à attractivités fiscales » dans les documents concernant les paradis fiscaux, vieux problème devant lequel les chercheurs bloquaient depuis longtemps. Ici le problème est repris d'une toute autre façon en particulier dans le traitement des taux d'imposition, et dans des comparaisons des régimes fiscaux de chacun des pays du Proche Orient. Tout cela nous a conduit à introduire le concept de notation fiscale. Nous le faisons en tenant compte autant que possible de tout critère possible qui nous permette de déduire théoriquement une notation générale. Il ressort de cela que dans une comparaison avec plusieurs pays du Proche Orient le Liban n'est pas, théoriquement du moins, une soi-disante « zone à attractivité fiscale »... Cela conduit à introduire une approche relativisée dans une tentative de définition scientifique des paradis fiscaux. C'est ainsi qu'on peut considérer qu'à chaque instant peuvent naître un ou plusieurs paradis fiscaux en fonction des changements de critères ou de leurs modalités. L'intérêt de cette approche est de permettre de considérer une définition plus scientifique des paradis fiscaux. Empiriquement, nous avons mis en place une importante enquête auprès de 300 personnes, englobant des contrôleurs fiscaux, des employés de banque et des gens d'entreprises. Nous en déduirons que la notion de paradis fiscal est loin de pouvoir s'appliquer au Liban et que ce ne serait en fait qu'une légende. / This thesis aims at defining and integrating the ‘zone of fiscal attractions' notion within the framework of Tax Havens, an old problem in front of which the investigators have not reach any solution since longtime before. Over here, the problem is considered from another angle, namely the treatment of tax rates, hence a comparison of fiscal regimes for each country of the Near-East was necessary to be able to deduce a fiscal notation. Taking into consideration every possible criteria which allows us to deduce theoretically a general notation, Lebanon, through the comparison between several countries of the Near-East, is not supposedly a “zone of fiscal attraction” theoretically…this leads us to introduce the approach of the relativity which has served to define scientifically the Tax Haven. For this reason, one or several Tax Haven can be created each and every moment with the changes incurred in the criteria and variables. The interest of this approach is to enable us to define scientifically the idea of Tax Haven. Empirically, an important questionnaire carried on fiscal controllers, bank employees, and firm employees, to demonstrate that the idea of Lebanon as a Tax Haven, is only a legend. This has been deduced through a group of 300 interviewed people.

L'ordre public économique sociétaire est défini comme l'ensemble des règles de droit impératif et de principes d'ordre public qui jouent un rôle dans la structuration et l'organisation juridique des sociétés et la limitation de la liberté des particuliers dans cette structuration et organisation; les sociétés sont vues dans cette perspective comme les expressions juridiques des entreprises, organisations socio-économiques impliquant une multiplicité d'intérêts, mais aussi comme des « lieux » d'organisation du pouvoir privé économique, ne pouvant par conséquent être laissées absolument au jeu de la liberté contractuelle, notamment pour ce qui concerne les formes sociétaires les plus développées. Sous le terme français de montages on peut par contre regrouper des efforts de l'autonomie privée d'exploiter au maximum les marges de liberté en droit des sociétés, des efforts qui souvent se meuvent vers les limites du licite ou même poursuivent des finalités sans aucun doute illicites. Les montages peuvent être définis dans leurs rapports avec l'ordre public économique sociétaire, comme des efforts des particuliers d'aménager des effets de règles de cet ordre public, de contourner l'application normale de ces effets ou même d'instrumentaliser des blocs de règles de cet ordre public à des finalités atypiques ou même illicites. Les montages peuvent consister à des actes sociétaires de droit organisationnel (statuts, décisions des organes sociaux) ou à des actes relevant du droit des contrats (contrats de la société avec ses associés ou dirigeants, pactes entre associés - notamment actionnaires- ou des associés avec des tiers); ils peuvent aussi instrumentaliser les sociétés au delà de leur finalité type légale de constituer des formes juridiques d'entreprises-entités autonomes (ainsi les groupes de sociétés) ou même au-delà de toute utilisation comme formes juridiques d'entreprises. Il en résulte le besoin d'étudier les différents montages rencontrés dans la pratique des deux pays sous comparaison et l'attitude de leurs droits à l'égard de ces montages, en examinant les mécanismes de base du droit français et du droit grec pour le partage du licite et d'illicite, l'application de ces mécanismes dans la prise en compte des montages et les mécanismes de sanction des montages illicites. / The economic public order of the legal entities of commercial law (companies, partnerships,entities with limited liability of their members) is the total of mandatory rules and mandatory principles which act in the legal organization and structuring of the above entities and put the limits of the freedom of the individuals in this domain. ln this perspective, the entities of commercial law are seen as the legal expressions of the enterprises, socioeconomic organizations implicating a multitude of different interests, but also "places" of the private economic power, which cannot be totally abandoned in the domain of contractual freedom, especially regarding the most developed forms of such entities. The french term "montages" expresses on the contrary the endeavor of the individuals and of their autonomy to exploit to the maximum the margins of freedom let by the law of the entities of commercial law, moving often toward the limits between the legal and the illegal or even pursuing ends beyond doubt illegal. These montages can be defined in their relationship with the economic public order of the entities of commercial law, as the efforts of the individuals to adjust the normal effects of this public order, or to evade these effects, or to manipulate sets of rules of this public order to serve ends atypical or even unlawful. The montages can be acts of organizational law (acts of constitution, decisions of the organs of the entities of commercial law) or acts of the law of contracts (contracts of the entity with its members or directors, contracts between the members of the entities - especially shareholders-, contracts between these members and persons exterior to the entity) ; they can also use and manipulate the entities of commercial law themselves beyond their destination to be legal forms of enterprises-autonomous economic unities (especially this is the case in the groups of legal entities of commercial law) or even beyond any use as legal forms of enterprises. The result of these considerations is the need to study the different montages found in the practice of the two countries under comparison and examine the attitude of their laws toward those montages, by the examination of their basic mechanisms of distinction between the lawful and the unlawful and of the application of these mechanisms on the different montages and by the study of the mechanisms of sanction of the unlawful montages.

Les littoraux sableux dominés par l'action des vagues sont des zones très dynamiques où l'aléa érosion menace les activités humaines et la sécurité des personnes. Comprendre et prévoir les évolutions du trait de côte est crucial pour informer et guider les gestionnaires du littoral. Actuellement, aucun modèle numérique ne permet de reproduire les évolutions du trait de côte sur l'ensemble des échelles spatio-temporelles et des configurations de côte requises du fait de limitations numériques et physiques. Cette thèse se concentre sur le développement de nouveaux outils de modélisation à complexité réduite pour simuler les évolutions du trait de côte le long des littoraux sableux dominés par l'action des vagues sur des échelles de temps allant de l'heure à plusieurs décennies avec des temps de calcul réduits. D'abord, un modèle statistique de trait de côte s'appuyant uniquement sur les occurrences saisonnières de régimes de temps est développé. Ce modèle permet de simuler la variabilité du trait de côte à l'échelle pluriannuelle, sans avoir besoin de connaitre les conditions de vagues ou de modéliser le transport sédimentaire. Puis, un nouveau modèle numérique de trait de côte basé sur les vagues (LX-Shore) est développé en intégrant entre autres les forces de certains modèles existants. Il inclut les processus cross-shore et longshore, et couple la dynamique du trait de côte à la propagation des vagues via le modèle spectral de vagues SWAN. Ce modèle permet de simuler l'évolution de formes complexes comme par exemple les flèches sableuses. Ces outils ouvrent aussi la voie vers une meilleure évaluation des évolutions futures du trait de côte, ainsi que de la contribution respective des processus impliqués. / Wave-dominated sandy coasts are highly dynamic and populated systems increasingly threatened by erosion hazard. Understanding and predicting shoreline change is critical to inform and guide stakeholders. However, there is currently no numerical model able to reproduce and predict shoreline evolution over the full range of temporal scales and coastal geometries owing to numerical and physical limitations. This thesis focuses on the development of new reduced-complexity models to simulate shoreline change along wave-dominated sandy coasts on the timescales from hours to decades with low computation time. First, a statistical shoreline change model based on the seasonal occurrences of some oceanic basin weather regimes is developed. This model allows simulating shoreline variability at the seasonal and interannual scales, without resorting to wave data or sediment transport modeling. Second, a new so-called LX-Shore numerical wave-driven shoreline change model is developed, which takes the best from some existing models and includes additional numerical and physical developments. LX-Shore couples the primary longshore and cross-shore processes and includes the feedback of shoreline and bathymetric evolution on the wave field using a spectral wave model. LX-Shore successfully simulates the dynamics of coastal embayments or the formation of subsequent nonlinear evolution of complex shoreline features such as flying sandspits. It is anticipated that LX-Shore will provide new and quantitative insight into the respective contributions of the processes controlling shoreline change on real coasts for a wide range of wave climates and geological settings.

Thesis (MScEng (Civil Engineering))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: Calculation of longshore sediment transport rates is a typical part of coastal engineering work. One of the important inputs to such calculations is the sediment grain size. A single, representative grain size is typically required. The inter-tidal beach is the most convenient and common area from which grain size data can be obtained. Yet only a fraction of the longshore transport occurs at the beach, with the bulk of the transport occurring in the surf zone, where sampling is difficult. Sediment transport calculations can be improved if the representative grains size is also characteristic of this area. A better understanding how the grain size in the longshore transport zone compares to the beach grain size is required. A review of relevant literature indicates that limited attention has been given to quantifying the grain size in the longshore transport zone. No previous investigations were found that tried to link the longshore transport zone grain size to that found on the beach. A comprehensive analysis of beach and longshore transport zone grain sizes was therefore undertaken and is described in this thesis. Beach grain sizes were compared to those in the longshore transport zone for three different locations around the world: Published grains size information, together with detailed wave and profile data, was obtained from the US Army Field Research Facility at Duck; a second data set was obtained from measurements done at Bogenfels in Namibia; a third dataset was compiled from sampling undertaken by the author in Table Bay, South Africa. A total of 189 samples were collected at four sampling lines in Table Bay between September 2005 and September 2006. Samples were collected across the entire profile from the primary dune to a water depth of 10 m. Samples were collected by grab in the offshore, and by swimming and diving in the surf zone. The location of the four Table Bay sampling lines was chosen so as to obtain data from beaches with different wave and grain size characteristics. Together with the Duck and Bogenfels data, data from six different beaches was therefore available for study. A settling tube was used to determine the grain sizes. Verification of the settling tube analyses against conventional sieving indicated a good comparison. However, the settling tube proved unsuitable for processing of samples with coarse to very coarse material, for which sieving was conducted instead. The grain size at the mid-tide level has been used to characterise the beach. The limits of the longshore transport zone were defined by calculating the cross-shore distribution of longshore transport with the Unibest model. Simpler methods, such as the depth of closure, either overestimated or underestimated it, depending on which wave condition was used in the depth of closure formula. It was found that the beaches with steeper mid-tide beach slopes, such as Bogenfels and northern Table Bay, had coarser median grain sizes than more gently sloping beaches such as found in the south of Table Bay. On energetic beaches, the mid-tide beach grain sizes were significantly coarser than those in the surf zone, by more than twice. At less exposed locations, such as Duck and the central Table Bay beaches, this difference was less. At sheltered locations, such as the southern sampling lines in Table Bay, the mid-tide beach grain sizes are virtually the same as those found in the surf zone. The surf similarity parameter was used to compare the characteristics of the different sites. This parameter was defined using the average wave height seaward of breaking, and the mid-tide beach slope. The ratio between the longshore transport zone grain size and the mid-tide beach grain size was found to be similar to the inverse of the surf similarity parameter for the six beaches that were studied. These findings have led to an improved understanding of the grain size in the longshore transport zone and allow a better characterisation of the representative grain size to use for sediment transport calculations. / AFRIKAANSE OPSOMMING: In kusingenieurswese word langstrandse sedimentvervoer (langsvervoer) gereeld bereken. Belangrike invoer vir sulke berekeninge is die verteenwordigende korrelgrootte van die sand. Die sandkorrelgrootte van die benatte strand is die maklikste om te bepaal, al vind net ‘n klein gedeelte van die langsvervoer op die benatte strand plaas. Die grootste gedeelte van die langsvervoer kom in die brandersone voor, waar dit moeilik is om monsters te neem. Sedimentvervoerberekeninge kan verbeter word as die korrelgrootte ook hierdie sone verteenwoordig. Dit is dus van belang om te verstaan hoe die korrelgrootte van die benatte strand met die gemiddelde korrelgrootte oor die algehele langsvervoersone vergelyk. ‘n Literatuursoektog dui aan dat min aandag al gegee is aan hoe die korrelgrootte op die benatte strand met dié in die langsvervoersone vergelyk. ‘n Ontleding van sandkorrelgroottes op die benatte strand en in die langsvervoersone is dus onderneem en word in die tesis uiteengesit. Strandkorrelgroottes word met dié in die langsvervoersone vergelyk vir drie verskillende gebiede in die wereld : (1) Gepubliseerde data oor korrelgroottes, sowel as strandhellings en golwe, is van die Field Research Facility by Duck in die VSA verkry ; (2) ‘n tweede stel data is van opmetings by Bogenfels in Namibie verkry; (3) die derde stel data is saamgestel deur die skrywer tydens opmetings in Tafelbaai, Suid-Afrika. ‘n Totaal van 189 monsters is tussen September 2005 en September 2006 by vier verskillende opmetingslyne in Tafelbaai geneem. Monsters is geneem van die duin tot in 10 m waterdiepte. In dieper water is grypmonsters geneem, terwyl dié in the brandersone verkry is deur te duik. Die posisie van die vier Tafelbaaise opmetingslyne is gekies om strande met verskillende golftoestande en korrelgroottes te dek. Tesame met die data van Duck en Bogenfels is dus ses datastelle vir ontleding beskikbaar. ‘n Valbuis is gebruik om die korrelgroottes te bepaal. Die valbuismetode het goed met gewone sifresultate vergelyk, behalwe vir monsters met baie growwe korrels. Hiervoor is sifwerk gebruik. Die korrelgrootte van die benatte strand is gebruik om die strand te karakteriseer. Die grense van die langsvervoersone is bepaal deur die dwarsstrandse verdeling van die langsvervoer met die Unibest-model te bereken. Eenvoudiger metodes, soos die berekening van die sluitingsdiepte, het minder betroubare resultate gelewer. Daar is gevind dat steiler benatte strande, soos Bogenfels en Noord-Tafelbaai se strande, groter gemiddelde korrelgroottes as platter benatte strande, soos dié in suidelike Tafelbaai, het. Op blootgestelde strande is die benatte strand se korrelgrootte tot meer as twee keer groter as dié in die brandersone. By gedeeltelik beskutte strande, soos Duck en Sentraal- Tafelbaai se strande, was die verskil minder. Op beskutte strande, soos die Suid-Tafelbaai se strande, is gevind dat die benatte strand se korrelgrootte amper dieselfde as dié in die brandersone is. Die brandergelyksoortigheidsfaktor is gebruik om die verskillende strande te vergelyk. Die golfhoogtes net buite die branderlyn en die benatte strandhelling is gebruik om die veranderlike te bereken. Daar is gevind dat by die ses strande wat ondersoek is, die verhouding van die korrelgrootte in die langsvervoersone en dié van die benatte strand ongeveer gelyk aan die omgekeerde brandergelyksoortigheidsfaktor is. Die bevindings het tot ‘n beter begrip van die wisseling van die korrelgroottes in die langsvervoersone gelei. Gevolglik kan ‘n akkurater verteenwoordigende sandkorrelgrootte bepaal word.

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.

Thesis (MScEng)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Innovative and versatile coastal protection structures made of Geotextile Sand Containers (GSCs) are increasingly being incorporated into coastal management solutions because of their cost effective and environmentally friendly characteristics. This is as opposed to conventional ‘hard’ coastal protection solutions that utilise rocks and or concrete units to protect the coastline. With GSC structures being a relatively new coastal protection solution, few design and construction guidelines are available. Research into the behaviour of GSC structures under wave attack is on-going with particular emphasis on the hydraulic processes that affect GSC structures and cause them to fail. The use of GSC revetments as coastal protection solutions has become more popular in South Africa during recent times, particularly along the coastline of KwaZulu-Natal. However, the chosen design of these GSC revetments falls outside the range of applicability of the available design charts and stability equations. Therefore the hydraulic stability of these structures is largely unknown. The primary objective of this study is to investigate the effect of structure slopes and packing arrangements on the hydraulic stability of GSC revetments. The application of available design charts and stability equations was also evaluated. Two-dimensional physical modelling was undertaken and a total of 12 GSC revetment permutations were tested during the physical modelling test series. The results of the physical modelling showed that the structure slope had the most significant effect on the hydraulic stability. Steeper structure slopes were more hydraulically stable than gentler structure slopes. The packing arrangements of the GSCs had less of an effect on the hydraulic stability of the GSC revetments. Single layer GSC armour revetments matched or out-performed the equivalent double layer GSC revetments; while GSC revetments with GSCs orientated with the long axis perpendicular to the wave attack performed marginally better than the equivalent GSC revetments with GSCs orientated with the long axis parallel to the wave attack. The available design charts and stability equations were assessed against the results of the physical modelling and showed varying degrees of correlation. The stability equation proposed by Recio (2007) proved to be particularly accurate. / AFRIKAANSE OPSOMMING: Innoverende en veelsydige kusbeskermingstrukture wat van geotekstielsandhouers (GSH’s) gemaak is, word al hoe meer by kusbestuursoplossings ingesluit weens die kostedoeltreffendheid en omgewingsvriendelike aard daarvan. Dít is in teenstelling met konvensionele ‘harde’ kusbeskermingsoplossings, wat van rotse en/of betoneenhede gebruik maak om die kuslyn te beskerm. Aangesien GSH-strukture ’n betreklik nuwe kusbeskermingsoplossing is, is weinig ontwerp- en konstruksieriglyne beskikbaar. Navorsing oor die werkverrigting van GSH-strukture onder golfaanslag duur voort, met bepaalde klem op die hidrouliese prosesse wat GSH-strukture beïnvloed en die werking daarvan benadeel. Die gebruik van GSH-bedekte hellings as kusbeskermingsoplossings het in die laaste tyd al hoe gewilder geword in Suid-Afrika, veral langs die kus van KwaZulu-Natal. Tog val die gekose ontwerp van hierdie GSH-bedekte hellings buite die toepaslikheidsbestek van die beskikbare ontwerpriglyne en stabiliteitsvergelykings. Die hidrouliese stabiliteit van hierdie strukture is dus grotendeels onbekend. Die hoofoogmerk van hierdie studie was om ondersoek in te stel na die effek van struktuurhellings en pakformasies op die hidrouliese stabiliteit van GSH-bedekte hellings. Die toepaslikheid van beskikbare ontwerpriglyne en stabiliteitsvergelykings is ook geëvalueer. Tweedimensionele fisiese modellering is onderneem en altesaam 12 GSH-bedekte hellings is gedurende die fisiese-modelleringstoetsreeks getoets. Die resultate van die fisiese modellering toon dat die struktuurhelling die beduidendste effek op hidrouliese stabiliteit het. Steiler struktuurhellings was hidroulies meer stabiel as platter hellings. Die pakformasies van die GSH’s blyk ’n kleiner effek op die hidrouliese stabiliteit van die GSH-bedekte hellings te hê. GSH-bedekte hellings wat met ’n enkele laag GSH’s versterk is, het ewe goed of beter presteer as die keermure met ’n dubbele laag GSH’s, terwyl GSH-bedekte hellings met die lang-as van die GSH’s loodreg op die rigting van die golfaanslag effens beter presteer het as dié met die lang-as parallel met die golfaanslag. Die beskikbare ontwerpriglyne en stabiliteitsvergelykings is geëvalueer aan die hand van die resultate van die fisiese modellering, en het ’n wisselende mate van korrelasie getoon. Veral die stabiliteitsvergelyking van Recio (2007) blyk besonder akkuraat te wees.

Thesis (MScEng)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Groynes are hydraulic structures typically constructed from gabions to extend from the outer bank of a river channel into the main flow. The principal uses for groynes are as river training structures, and to protect the riverbank from erosion. This is done by deflecting the current away from the riverbanks, dissipating energy and creating lower flow velocity zones, reducing the effects of erosion. Groynes have been used extensively in the Western Cape since the early 1990s as a means to protect agricultural lands. There is, however an absence of published manuals for the design of groynes around bends as a means of riverbank protection. This study was done to better understand the flow, scour and sediment deposition patterns associated with implementing a series of groynes around a bend. A physical model of a typical sinusoidal South African river was constructed in the Hydraulics Laboratory at the University of Stellenbosch. The model consisted of two succesive 90˚ bends to best simulate erosion patterns. Different layout designs for a series of groynes were tested to determine the optimal design for the given situation in terms of the projection lengths of the groynes, the spacing between the groynes as a factor of the projection length, and the orientation of the groynes with regard to the oncoming flow. An integrated software package, that was developed at the National Centre for Computational Hydroscience and Engineering, at the University of Mississippi, named CCHE2D was used to simulate the physical model numerically. The model was calibrated by adjusting the Manning‟s n value of the sediment, and the normal tailwater depth was calculated and used for the physical and numerical models. The flow rate used during the physical model experiments was also used for the numerical model. The model was validated by comparing scour depths obtained from the physical model to the resulting depth in the hydrodynamic model. From the results obtained from the physical and numerical models, it was found that groynes with a perpendicular orientation to the direction of the oncoming flow were optimal. Groynes with an upstream orientation resulted in excessive scour around the nose of the groynes, while recirculating flow patterns occurred at a velocity which caused bank failure. Groynes with a downstream orientation created very little recirculation of flow, resulting in less scour protection for the outer bank than found for groynes with perpendicular orientation. Finally, the optimal design was identified as a perpendicular groyne orientation with a projection length L and a spacing of 3.5 xL. For the given design, eddy currents covered the entire area between consecutive groynes, causing low flow zones near the outer banks, promoting sediment deposition and decreasing the potential for scour. Recommendations for further studies include the investigation of the effects of different bend radii, the sediment size, as well as various channel widths, flow rates and river slopes. The use of a three-dimensional hydrodynamic model would also be advantageous in order to better understand the flow and scour mechanics associated with different designs. / AFRIKAANSE OPSOMMING: Groynes is hidrouliese strukture, tipies gebou uit skanskorwe in Suid Afrika, wat vanaf die buiteoewer van 'n rivier strek na die hoofkanaal. Groynes word hoofsaaklik aangewend as rigmure in riviere en om rivieroewers te beskerm teen erosie. Erosiebeskerming word geskep deur vloei weg te deflekteer van die rivieroewer en energie te dissipeer. Sodoende vorm areas met lae vloeisnelhede naby die oewer wat die potensiaal vir erosie verminder. Groynes is sedert die vroeë 1990s in die Wes-Kaap gebruik as 'n manier om landbougrond teen erosie te beskerm. Daar is egter 'n tekort aan gepubliseerde ontwerpriglyne vir die gebruik van groynes vir erosiebeskeriming in riviere. Hierdie studie is gedoen om die vloei-, uitskuringsen sediment neersettingspatrone, geassossiëer met die implementering van groynes, te ondersoek. 'n Fisiese model van 'n tipiese kronkelende Suid-Afrikaanse rivier is gebou in die Hidrouliese Laboratorium by die Universiteit van Stellenbosch. Die model bestaan uit twee opeenvolgende 90˚ draaie om die erosie-patrone te simuleer. Verskillende uitlegte vir 'n reeks groynes is getoets om die optimale ontwerp vas te stel in terme die projeksielengte van die groynes, die spasiëring tussen opeenvolgende groynes as 'n faktor van die projeksielengte en die oriëntasie van die groynes ten opsigte van die aankomende vloeirigting. 'n Geïntegreerde sagteware pakket wat ontwikkel is by die “National Centre for Computational Hydroscience and Engineering”, by die Universiteit van Mississippi, genaamd CCHE2D is gebruik om die fisiese eksperimente numeries te simuleer. Die model is gekalibreer deur die Manning n waarde van die sediment aan te pas, die stroomaf waterdiepte wat bereken is, en die vloeitempo wat waargeneem is tydens die fisiese eksperimente. Die model is bekragtig deur uitskuurdieptes van die fisiese- en hidrodinamiese modelle te vergelyk. Vanuit die resultate wat verkry is in die fisiese- en numeriese modelle, is daar gevind dat groynes met 'n loodregte oriëntasie met betrekking tot die aankomende vloei optimaal is. Daar is gevind dat groynes met 'n stroomop oriëntasie oormatige uitskuring rondom die neus van die groynes ondervind, terwyl hersirkulasie van vloei teen 'n hoë snelheid plaasvind, wat erosie van die oewer tot gevolg het. Groynes met 'n oriëntasie na die stroomaf kant het baie min hersirkulasie van vloei tot gevolg gehad, wat tot minder erosiebeskerming van die buitebank gelei het. Die optimale ontwerp is geïdentifiseer as groynes met loodregte oriëntasie, 'n projeksielengte van 0.675 m en 'n spasiëring van 3.5 keer die projeksielengte. Vir die gegewe ontwerp is werwelstrome gevind wat die hele area tussen opeenvolgende groynes dek, wat area van lae vloei sones veroorsaak naby die oewer, wat sediment deponering bevorder en die potensiaal vir uitskuring verminder. Aanbeveling vir verdere studies sluit die studie van die effekte van verskillende draai radiusse en die sediment-grootte in, sowel as verskillende kanaalbreedtes, vloeie en rivierhellings. Die gebruik van 'n drie-dimensionele hidrodinamiese model sal ook voordelig wees om die betrokke vloei- en uitskuringspatrone rakende verskillende ontwerpe beter te verstaan.