Esta tese é uma compilação de diversos estudos que relatam as características e as mudanças encontradas nas praias do Rio Grande do Sul (RS). Destaca os princípios da gestão integrada dos ambientes costeiros e as práticas utilizadas em praias e dunas, auxiliando neste tema interdisciplinar, e colaborando desta forma com um caminho que conduza esta região a um desenvolvimento econômico e social com a manutenção das características naturais. As praias do RS têm atraído as pessoas para a costa há mais de um século, assim como um grande número de visitantes aos balneários e áreas turísticas, durante períodos de férias e lazer. A utilização deste ambiente tem sido de importância crescente para a economia dos municípios litorâneos, sendo que a gestão destas áreas tornou-se necessária para lidar com uma variedade de problemas. Exemplos destes problemas e da preocupação das pessoas que buscam a costa estão relacionados aos processos de erosão, que diminuem a beleza do ambiente, o espaço disponível para o lazer, e expõe a população a riscos de inundação; além disso, a presença de resíduos sólidos (lixo) e de efluentes domésticos a céu aberto traz preocupação com a saúde dos frequentadores. Esta tese inclui uma análise das causas da degradação da praia de Xangrilá, e oferece técnicas e respostas sobre como lidar com a reconstrução do ambiente erodido, principalmente o sistema de dunas, assim como os problemas enfrentados durante este processo, como resultado de efeitos adversos. Nos últimos anos estas práticas tornaram-se amplamente utilizadas no mundo, como um meio de manter ou melhorar as funções naturais de proteção das infra-instrutoras posicionadas próximas deste ambiente. Considerando que a gestão de praias e dunas será mais eficaz se os interessados (gestores, moradores e frequentadores) entenderem a sua funcionalidade ambiental, a importância na proteção da costa, e as alterações que estão ocorrendo, são relatados nos diversos artigos desta tese questões referentes às problemáticas da presença de resíduos sólidos, a dispersão de espécies exóticas, assim como as ferramentas disponíveis aos gestores costeiros para desenvolver suas políticas, voltadas especificamente para esta região, e sugestões de dinâmicas para estimular a percepção e o entendimento do ambiente. / This thesis is a compilation of several papers that include the features and changes found on the beaches of Rio Grande do Sul (RS). It focuses on the principles of integrated management of coastal environments and practices on beaches and dunes, collaborating in this way on a path leading to an economic and social development keeping the natural features. The beaches of RS have attracted people to the coast for more than two centuries, and a large number of people visit the beaches along the seaside each year for holidays and leisure. Beach utilization has been of increasing importance to the economies of these towns, and the beach management has become necessary to deal with a variety of problems that have appeared. Examples of these problems and concerns are related to beach erosion, which reduces the beauty of the environment, the space available for beach recreation as well as the exposure of people to risks of flooding; and the presence of solid waste (garbage) and open sewers, which brings concerns about the health of the regulars. The thesis includes an analysis of the causes of beach erosion in the city of Xangri-lá, and offers techniques and answers about how to deal with the reconstruction of the environment eroded, especially the dune system, as well as the problems faced during this process as a result of adverse effects. In recent years, these practices have become widely used worldwide as a means of keeping or improving the natural functions of protecting infrastructure placed near this environment. Whereas the management of beaches and dunes will be more effective if the stakeholders (managers, residents and regulars) understand its functionality, importance, and the changes that are occurring, in various articles of this thesis problematic issues concerning the presence of solid waste are reported, the spread of exotic species, as well as the tools available to coastal managers to develop their policies, fitted specifically to this region, as well as suggestions to stimulate dynamic awareness and understanding of the environment.

Esta tese é uma compilação de diversos estudos que relatam as características e as mudanças encontradas nas praias do Rio Grande do Sul (RS). Destaca os princípios da gestão integrada dos ambientes costeiros e as práticas utilizadas em praias e dunas, auxiliando neste tema interdisciplinar, e colaborando desta forma com um caminho que conduza esta região a um desenvolvimento econômico e social com a manutenção das características naturais. As praias do RS têm atraído as pessoas para a costa há mais de um século, assim como um grande número de visitantes aos balneários e áreas turísticas, durante períodos de férias e lazer. A utilização deste ambiente tem sido de importância crescente para a economia dos municípios litorâneos, sendo que a gestão destas áreas tornou-se necessária para lidar com uma variedade de problemas. Exemplos destes problemas e da preocupação das pessoas que buscam a costa estão relacionados aos processos de erosão, que diminuem a beleza do ambiente, o espaço disponível para o lazer, e expõe a população a riscos de inundação; além disso, a presença de resíduos sólidos (lixo) e de efluentes domésticos a céu aberto traz preocupação com a saúde dos frequentadores. Esta tese inclui uma análise das causas da degradação da praia de Xangrilá, e oferece técnicas e respostas sobre como lidar com a reconstrução do ambiente erodido, principalmente o sistema de dunas, assim como os problemas enfrentados durante este processo, como resultado de efeitos adversos. Nos últimos anos estas práticas tornaram-se amplamente utilizadas no mundo, como um meio de manter ou melhorar as funções naturais de proteção das infra-instrutoras posicionadas próximas deste ambiente. Considerando que a gestão de praias e dunas será mais eficaz se os interessados (gestores, moradores e frequentadores) entenderem a sua funcionalidade ambiental, a importância na proteção da costa, e as alterações que estão ocorrendo, são relatados nos diversos artigos desta tese questões referentes às problemáticas da presença de resíduos sólidos, a dispersão de espécies exóticas, assim como as ferramentas disponíveis aos gestores costeiros para desenvolver suas políticas, voltadas especificamente para esta região, e sugestões de dinâmicas para estimular a percepção e o entendimento do ambiente. / This thesis is a compilation of several papers that include the features and changes found on the beaches of Rio Grande do Sul (RS). It focuses on the principles of integrated management of coastal environments and practices on beaches and dunes, collaborating in this way on a path leading to an economic and social development keeping the natural features. The beaches of RS have attracted people to the coast for more than two centuries, and a large number of people visit the beaches along the seaside each year for holidays and leisure. Beach utilization has been of increasing importance to the economies of these towns, and the beach management has become necessary to deal with a variety of problems that have appeared. Examples of these problems and concerns are related to beach erosion, which reduces the beauty of the environment, the space available for beach recreation as well as the exposure of people to risks of flooding; and the presence of solid waste (garbage) and open sewers, which brings concerns about the health of the regulars. The thesis includes an analysis of the causes of beach erosion in the city of Xangri-lá, and offers techniques and answers about how to deal with the reconstruction of the environment eroded, especially the dune system, as well as the problems faced during this process as a result of adverse effects. In recent years, these practices have become widely used worldwide as a means of keeping or improving the natural functions of protecting infrastructure placed near this environment. Whereas the management of beaches and dunes will be more effective if the stakeholders (managers, residents and regulars) understand its functionality, importance, and the changes that are occurring, in various articles of this thesis problematic issues concerning the presence of solid waste are reported, the spread of exotic species, as well as the tools available to coastal managers to develop their policies, fitted specifically to this region, as well as suggestions to stimulate dynamic awareness and understanding of the environment.

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / O litoral cearense convive hoje com um dos maiores ensamentos litorÃneos brasileiro, isso ocorre porque, nas Ãltimas dÃcadas, a ocupaÃÃo das Ãreas litorÃneas para o turismo e habitaÃÃo tem se intensificado gradativamente. AtravÃs do estudo das dunas do municÃpio de Aquiraz pretendeu-se apreender a dinÃmica presente nesse setor litorÃneo e obter apÃs uma anÃlise detalhada um diagnostico ambiental, o qual propiciou a elaboraÃÃo de propostas de gestÃo para toda Ãrea estudada. Mas, a principal finalidade da pesquisa foi compreender a estrutura e funcionamento das dunas de maneira integrada. E entender como essas unidades naturais se comportam e interagem dentro do sistema litorÃneo. A Ãrea em que se desenvolvem as avaliaÃÃes situa-se no setor leste costeiro desse municÃpio e o campo de duna presente nesse setor sÃo umas das maiores expressÃes espaciais desse tipo de feiÃÃes no litoral nordestino brasileiro. A compreensÃo dos processos pretÃritos e presentes que contribuÃram na formaÃÃo dessas dunas, a identificaÃÃo das suas diferentes tipologias, a classificaÃÃo de acordo com o seu estado dinÃmico e individualizaÃÃo das suas geraÃÃes foi o nosso principal objetivo. A pesquisa encontra-se alicerÃado na Teoria GeossitÃmica e dentro dos procedimentos tÃcnicos e metodolÃgicos aplicados buscou-se a anÃlise espaÃo-temporal atravÃs da interpretaÃÃo de produtos cartogrÃficos de diferentes perÃodos, em uma faixa tempo de quase cinqÃenta anos. Diante do contexto a revisÃo bibliogrÃfica, anÃlise cartogrÃfica e etapa de campo foram cruciais para um maior conhecimento da Ãrea e para a concretizaÃÃo do trabalho. De acordo com os critÃrios adotados foram identificadas duas geraÃÃes de dunas e vÃrios tipos de morfologia, alÃm de alguns setores com formas de uso e ocupaÃÃo indevidas que estÃo provocando a degradaÃÃo das dunas e alterando a dinÃmica natural da Ãrea. Entretanto, o trecho estudado tem a maior parte das suas dunas ainda conservadas, em virtude de grande partes delas estarem sob proteÃÃo da LegislaÃÃo Federal. Ao final foi evidenciada a necessidade da implantaÃÃo de medidas de manejo ambiental capazes de minimizar os impactos ambientais nos trechos com ocupaÃÃes e de monitoramento, para que os setores de dunas mais conservados, nÃo se transformem em futuras de Ãreas de degradaÃÃo ambiental. / Ceara coast possesses one of the largest occupations of the coast Brazilian coast, this happens because, in the last decades, the occupation of the coastal areas for the tourism and house has if intensified gradually. Thr ough the study of the dunes of the municipal district of Aquiraz it intended to apprehend the present dynamics in that coastal areas and to obtain after a detailed analysis an environmental diagnose, which propitiated the elaboration of management proposals for every studied area. But, the main purpose of the research was to understand the structure and operation of the dunes in an integrated way. And to understand about those natural units behaves and they interact inside of the coastal system. The area that if was developed the evaluations locates in the coastal east of that municipal district and the field of present dune in that section are some of the largest space expressions of that type of features in the coast Brazilian Northeast. The understanding of the past and present processes that contributed in the formation of those dunes, the identification of their different typologies, the classification in agreement with their dynamic state and individualization of their generations was our main objective. The research is based in the Geosystem theory and inside of the technical and methodological procedures applied the analysis in a space of time was looked for through the interpretation of cartographic products of different periods, almost fifty year old. Before the context the bibliographical rev ision, cartographic analysis and field stage were crucial for a larger knowledge of the area and for the materialization of the research. In agreement with the adopted criteria they were identified in two generations of dunes and several morphology types, besides some areas with use and occupation forms that are provoking the degradation of the dunes and altering the natural dynamics of the area. However, the studied area has most of their dunes conserved still, because great parts of them to be under protection of the Federal Legislation. At the end the need of the implantation of environmental measures handling was evidenced capable to minimize the environmental impacts in the areas with occupations and of accompaniment, so that the dunes more conserved, don't change in the future in areas of environmental degrad ation.

Background: Tropical sand dunes are ideal systems for understanding drivers of community assembly as dunes are subject to both deterministic and stochastic processes. However, studies that evaluate the factors that mediate plant community assembly in these ecosystems are few. Aims: We evaluated phylogenetic community structure to elucidate the role of deterministic and stochastic processes in mediating the assembly of plant communities along the north of the Yucatan Peninsula, Mexico. Methods: We used plastid genetic markers to evaluate phylogenetic relationships in 16 sand-dune communities. To evaluate the role of climate in shaping plant community structure we carried out linear regressions between climatic variables and mean phylogenetic distance. We estimated the Net Relatedness Index and Nearest Taxon Index to identify ecological processes mediating community assembly. Results: Observed phylogenetic structure was not different from random, suggesting that stochastic processes are the major determinants of community assembly. Climate was slightly correlated with phylogenetic diversity suggesting that abiotic environment plays a minimal role in community assembly. Conclusions: Random assembly appears to be the primary factor structuring the studied sand dune plant communities. Environmental filters may represent a secondary factor contributing to the observed phylogenetic structure. Thus, both processes may act simultaneously to mediate the assembly of sand-dune plant communities.

Artificial beach nourishment, the most common method to mitigate coastal erosion in the United States, is also considered the most ecologically friendly alternative for shoreline stabilization. However, this habitat alteration has the potential to impact nesting marine turtles and developing hatchlings. The first objective of this study was to determine how nourishing beaches with two different design templates affects loggerhead (Caretta caretta) and green turtle (Chelonia mydas) nesting success, the ratio of nests to the total number of nests and non-nesting emergences, and reproductive success, the ratio of hatched and emerged hatchlings to the total number of eggs deposited. Two types of restoration designs exist along the southern Brevard County, FL coastline, which supports some of the highest density loggerhead and green turtle nesting worldwide. Since 2005, approximately 35 kilometers of beach have undergone 1) fullscale restoration (typically called nourishment), where sand was added above and below the mean high tide line (2005, 2010) or 2) dune restoration, where sand was placed on the dune (2005, 2006, 2008, 2009). To quantify the effects of these restoration types, we used a Before-After-ControlImpact-Paired Series (BACIPS) model, which tests for significance between the difference in nesting success rates at the impact (engineered) and control sites (natural beach) before and after restoration ( ). For loggerheads, there was a significant difference in after dune restoration during the years of construction (2005, 2006, 2008, and 2009; p

When considering the large amount of work done on dune ecology, and that a number of the classical ecological theories originate from work on dunes, it is apparent that there remains a need for physiological and mechanistic explanations of dune plant phenomena. This thesis demonstrated that in the extreme coastal environment dune plants must survive both high rates of burial (disturbance), and low nutrient availability (stress). The ability of four species to respond to these two factors corresponded with their position in a vegetation gradient on the dunes. A low stem tissue density was shown to enhance the potential stem elongation rate of buried plants, but reduced the maximum height to which a plant could grow. Such a tradeoff implies that tall light-competitive plants are able to survive only in stable areas, while burial responsive mobile-dune plants are limited to areas of low vegetation height. This stem tissue density tradeoff was suggested as the mechanism determining the zonation that species show within the dune vegetation gradient present at various sites in South Africa. Finally, detailed investigations of dune plant ecophysiology found that: 1) The resources used in the response to burial derive from external sources of carbon and nitrogen, as well as simple physiological and physical mechanisms of resource allocation. 2) The leaves of dune plants were found to be operating at one extreme of the photosynthetic continuum; viz efficient use of leaf nitrogen at the expense of water loss. 3) Contrary to other ecosystems, the environmental characteristics of dunes may allow plants to occupy a high disturbance, high stress niche, through the maintenance of lowered competition. 4) At least two mobile-dune species form steep dunes, and are able to optimise growth, on steeper dunes, such that they have to grow less in response to burial than plants that form more shallow dunes. In this thesis, it was shown that the link between the carbon and nitrogen economies of dune plants was pivotal in determining species distributions and survival under extreme environmental conditions. As vast areas of the world’s surface are covered by sand dunes these observations are not just of passing interest.

Biological invasions provide a unique opportunity to study the mechanisms that regulate community composition and ecosystem function. Invasive species that are also ecosystem engineers can substantially alter physical features in an environment, and this can lead to cascading effects on the biological community. Aquatic-terrestrial interface ecosystems are excellent systems to study the interactions among invasive ecosystem engineers, physical features, and biological communities, because interactions among vegetation, sediment, and fluids within biophysical feedbacks create and modify distinct physical features. Further, these systems provide important ecosystem services including coastal protection afforded by their natural features. In this dissertation, I investigate the interactions and feedbacks among sand-binding beach grass species (a native, Elymus mollis (Trin.), and two non-natives, Ammophila arenaria (L.) Link and A. breviligulata Fernald), sediment supply, and dune shape along the U.S. Pacific Northwest coast. Dunes dominated by A. arenaria tend to be taller and narrower compared to the shorter, wider dunes dominated by A. breviligulata. These patterns suggest an ecological control on dune shape, and thus, coastal vulnerability to overtopping waves. I investigate the causes and consequences of these patterns with experiments, field observations, and modeling. Specifically, I investigate the relative roles of vegetation and sediment supply in shaping coastal dunes over inter-annual and multi-decadal time scales (Chapter 2), characterize a biophysical feedback between beach grass species growth habit and sediment supply (Chapter 3), uncover the mechanisms leading to beach grass coexistence and whether A. breviligulata can invade and dominate new sections of coastline (Chapter 4), and examine the non-target effects resulting from management actions that remove Ammophila for the recovery of the threatened Western Snowy plover (Charadrius alexandrinus nivosus) (Chapter 5). I found that vegetation and sediment supply play important roles in dune shape changes across inter-annual and multi-decadal time scales (Chapter 2). I determined that a biophysical feedback between the beach grass growth habits and sediment supply results in species-specific differences in sand capture ability, and thus, is a likely explanation for differences in dune shape (Chapter 3). I found that all three beach grass species can coexist across different sediment deposition rates, and that this coexistence is largely mediated by positive direct and indirect species interactions. I further determined that A. breviligulata is capable of invading and dominating the beach grass community in regions where it is currently absent (Chapter 4). Combined, these findings indicate that A. breviligulata is an inferior dune building species as compared to A. arenaria, and suggest that in combination with sediment supply gradients, these species differences ultimately lead to differences in dune shape. Potential further invasions of A. breviligulata into southern regions of the Pacific Northwest may diminish the coastal protection ability of dunes currently dominated by A. arenaria, but this effect could be moderated by the predicted near co-dominance of A. arenaria in these lower sediment supply conditions. Finally, I found that the techniques used to remove Ammophila for plover recovery have unintended consequences for the native and endemic dune plant communities, and disrupt the natural disturbance regime of shifting sand. A whole-ecosystem restoration focus would be an improvement over the target-species approach, as it would promote the return of the natural disturbance regime, which in turn, would help recover the native biological community. The findings from this dissertation research provide a robust knowledge base that can guide further investigations of biological and physical changes to the coastal dunes, can help improve the management of dune ecosystem services and the restoration of native communities, and can help anticipate the impacts of future beach grass invasions and climate change induced changes to the coast. / Graduation date: 2012 / Access restricted to the OSU Community at author's request from Sept. 22, 2011 - March 22, 2012

Call number: LD2668 .T4 1985 M666 / Master of Landscape Architecture

Thesis (MScEng)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: An accurate description of the atmospheric boundary layer (ABL) is a prerequisite for computational fluid dynamic (CFD) wind studies. This includes taking into account the thermal stability of the atmosphere, which can be stable, neutral or unstable, depending on the nature of the surface fluxes of momentum and heat. The diurnal variation between stable and unstable conditions in the Namib Desert interdune was measured and quantified using the wind velocity and temperature profiles that describe the thermally stratified atmosphere, as derived by Monin- Obukhov similarity theory. The implementation of this thermally stratified atmosphere into CFD has been examined in this study by using Reynoldsaveraged Navier-Stokes (RANS) turbulence models. The maintenance of the temperature, velocity and turbulence profiles along an extensive computational domain length was required, while simultaneously allowing for full variation in pressure and density through the ideal gas law. This included the implementation of zero heat transfer from the surface, through the boundary layer, under neutral conditions so that the adiabatic lapse rate could be sustained. Buoyancy effects were included by adding weight to the fluid, leading to the emergence of the hydrostatic pressure field and the resultant density changes expected in the real atmosphere. The CFD model was validated against measured data, from literature, for the flow over a cosine hill in a wind tunnel. The standard k-ε and SST k-ω turbulence models, modified for gravity effects, represented the data most accurately. The flow over an idealised transverse dune immersed in the thermally stratified ABL was also investigated. It was found that the flow recovery was enhanced and re-attachment occurred earlier in unstable conditions, while flow recovery and re-attachment took longer in stable conditions. It was also found that flow acceleration over the crest of the dune was greater under unstable conditions. The effect of the dune on the flow higher up in the atmosphere was also felt at much higher distances for unstable conditions, through enhanced vertical velocities. Under stable conditions, vertical velocities were reduced, and the influence on the flow higher up in the atmosphere was much less than for unstable or neutral conditions. This showed that the assumption of neutral conditions could lead to an incomplete picture of the flow conditions that influence any particular case of interest. / AFRIKAANSE OPSOMMING: 'n Akkurate beskrywing van die atmosferiese grenslaag (ABL) is 'n voorvereiste vir wind studies met berekenings-vloeimeganika (CFD). Dit sluit in die inagneming van die termiese stabiliteit van die atmosfeer, wat stabiel, neutraal of onstabiel kan wees, afhangende van die aard van die oppervlak vloed van momentum en warmte. Die daaglikse variasie tussen stabiele en onstabiele toestande in die Namib Woestyn interduin is gemeet en gekwantifiseer deur gebruik te maak van die wind snelheid en temperatuur profiele wat die termies gestratifiseerde atmosfeer, soos afgelei deur Monin-Obukhov teorie, beskryf. Die implementering van hierdie termies gestratifiseerde atmosfeer in CFD is in hierdie studie aangespreek deur gebruik te maak van RANS turbulensie modelle. Die handhawing van die temperatuur, snelheid en turbulensie profiele in die lengte van 'n uitgebreide berekenings domein is nodig, en terselfdertyd moet toegelaat word vir volledige variasie in die druk en digtheid, deur die ideale gaswet. Dit sluit in die implementering van zero hitte-oordrag vanaf die grond onder neutrale toestande sodat die adiabatiese vervaltempo volgehou kan word. Drykrag effekte is ingesluit deur die toevoeging van gewig na die vloeistof, wat lei tot die ontwikkeling van die hidrostatiese druk veld, en die gevolglike digtheid veranderinge, wat in die werklike atmosfeer verwag word. Die CFD-model is gevalideer teen gemete data, vanaf die literatuur, vir die vloei oor 'n kosinus heuwel in 'n windtonnel. Die standaard k-ε en SST k-ω turbulensie modelle, met veranderinge vir swaartekrag effekte, het die data mees akkuraat voorgestel. Die vloei oor 'n geïdealiseerde transversale duin gedompel in die termies gestratifiseerde ABL is ook ondersoek. Daar is bevind dat die vloei herstel is versterk en terug-aanhegging het vroeër plaasgevind in onstabiele toestande, terwyl vloei herstel en terug-aanhegging langer gevat het in stabiele toestande. Daar is ook bevind dat vloei versnelling oor die kruin van die duin groter was onder onstabiele toestande. Die effek van die duin op die vloei hoër op in die atmosfeer is ook op hoër afstande onder onstabiele toestande gevoel, deur middel van verhoogte vertikale snelhede. Onder stabiele toestande, is vertikale snelhede verminder, en die invloed op die vloei hoër op in die atmosfeer was veel minder as vir onstabiel of neutrale toestande. Dit het getoon dat die aanname van neutrale toestande kan lei tot 'n onvolledige beeld van die vloei toestande wat 'n invloed op 'n bepaalde geval kan hê.

Shelby Hearon's four novels--Armadillo in the Grass, The Second Dune, Hannah's House, and Now and Another Time--are unified by the common elements of the vital female character and her quest for selfawareness, self-integration, and fulfillment. This study examines the four novels chronologically in order to understand the development of this character and the themes which are common to all four. The concluding chapter offers an assessment of Hearon as a novelist whose work is both universally lasting and relevant.