• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • 2
  • 1
  • Tagged with
  • 7
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Sedimentary processes and deposits associated with a coastal headland : Portland Bill, Southern UK

Bastos, Alex C. January 2002 (has links)
No description available.
2

Influence of hydrological seasonality on sandbank benthos: algal biomass and shrimp abundance in a large neotropical river

Montoya Ceballos, Jose Vicente 15 May 2009 (has links)
In this study, I examined the influence of hydrological seasonality on spatiotemporal variation of algal biomass and shrimp abundance on sandbanks of the Cinaruco River in southwestern Venezuela. Seasonal variations of abiotic and biotic variables in the Cinaruco were driven by the hydrological regime. During the highwater periods, river sites in the main channel and lagoon sites were similar in water physicochemical variables and algal biomass. In contrast, physicochemical variables and algal biomass differed between river and lagoon sites during the low-water period. The absence of flow in lagoons and consistently low algal biomass on river sandbanks were the most important features of the spatial variability between main-channel and lagoon sandbanks during low-water phases. Benthic algal biomass was highly uniform at small spatial scales and significantly heterogeneous at large spatial scales. In the second major part of this dissertation, I found a relatively species-rich shrimp assemblage with seven species inhabiting the sandbanks of the Cinaruco. I also observed clear patterns of temporal and spatial variation in shrimp abundance on the Cinaruco sandbanks. Abundance of shrimp on the sandbanks presented remarkable diel variation, showing almost exclusive use of this habitat at nights. Seasonally, shrimp were more abundant during rising- and falling-water periods, when rapid changes of environmental conditions occur. Shrimp abundance was high on those sandbanks with absence of troughs and presence of submerged vegetation. These environmental features presumably promote colonization/establishment and survival/persistence of shrimp in the sandbanks. In a patch-dynamic view of communities, a mobility control model seems to apply to shrimp of the sandbanks in the Cinaruco during the period of rapid changes in hydrology and habitat structure. During low-water periods, when habitat structure of sandbanks is relatively constant, low shrimp abundance appears to be heavily controlled by high fish predation. The annual flood regime of the Cinaruco, which drives the concentrations of dissolved materials, affects material interchanges between aquatic and terrestrial systems, and modifies aquatic habitat structural complexity, is responsible for creating strong patterns of seasonal and spatial variation in benthic algal crops and shrimp abundance on the sandbanks of this large floodplain river.
3

Cultural planning as an instrument for locating Ontario provincial parks within the valuable landscape of a community: A case study of Sandbanks Provincial Park in Prince Edward County, Ontario

Fitzpatrick, Anne January 2009 (has links)
The purpose of this research was to determine if the relationship between a community and the nearby provincial park can be enhanced through the use of the cultural planning process. To address the research question a qualitative approach was used which included a case study, a document analysis, a questionnaire and a series of interviews. The subject of the case study was Sandbanks Provincial Park in Prince Edward County, Ontario. The findings illustrated that there are elements and applications of the cultural planning process that can assist a community in efforts to improve or work towards establishing a relationship with its local provincial park. The cultural planning process emphasizes the use of a broad definition of culture and encourages a community to produce an inventory of its cultural resources. This helps to illustrate the value a provincial park contributes to the landscape of an area. The cultural planning process also emphasizes the importance and potential for interaction and communication between different sectors of a community, including the provincial parks. Although Prince Edward County is a leader in cultural planning, it does not yet have a perfectly interactive relationship with its local provincial park. However, the plans, policies, forums and atmosphere produced by the cultural planning have established an environment that is conducive to improving the relationship between Sandbanks and the County. Based on the findings of this research, recommendations have been made to the County, Sandbanks Provincial Park and the Ontario Parks organization. This research will contribute to the literature that exists regarding cultural planning, valuable landscape models and relationships between a community and the nearby provincial park.
4

Cultural planning as an instrument for locating Ontario provincial parks within the valuable landscape of a community: A case study of Sandbanks Provincial Park in Prince Edward County, Ontario

Fitzpatrick, Anne January 2009 (has links)
The purpose of this research was to determine if the relationship between a community and the nearby provincial park can be enhanced through the use of the cultural planning process. To address the research question a qualitative approach was used which included a case study, a document analysis, a questionnaire and a series of interviews. The subject of the case study was Sandbanks Provincial Park in Prince Edward County, Ontario. The findings illustrated that there are elements and applications of the cultural planning process that can assist a community in efforts to improve or work towards establishing a relationship with its local provincial park. The cultural planning process emphasizes the use of a broad definition of culture and encourages a community to produce an inventory of its cultural resources. This helps to illustrate the value a provincial park contributes to the landscape of an area. The cultural planning process also emphasizes the importance and potential for interaction and communication between different sectors of a community, including the provincial parks. Although Prince Edward County is a leader in cultural planning, it does not yet have a perfectly interactive relationship with its local provincial park. However, the plans, policies, forums and atmosphere produced by the cultural planning have established an environment that is conducive to improving the relationship between Sandbanks and the County. Based on the findings of this research, recommendations have been made to the County, Sandbanks Provincial Park and the Ontario Parks organization. This research will contribute to the literature that exists regarding cultural planning, valuable landscape models and relationships between a community and the nearby provincial park.
5

Variação Morfológica e Parasitismo em Cnemidophorus ocellifer (Sauria: Teiidae) de áreas de restinga da Ilha do Maranhão, Brasil. / Morphological variation and parasitism Ocellifer Cnemidophorus (Sauria: Teiidae) from areas sandbank of the island of Maranhao, Brazil.

Lopes, Gildevan Nolasco 31 March 2009 (has links)
Made available in DSpace on 2016-08-17T15:00:42Z (GMT). No. of bitstreams: 1 Gildevan Nolasco Lopes.pdf: 963789 bytes, checksum: d73e668c2731927697f98bf14d6ea427 (MD5) Previous issue date: 2009-03-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study compared the morphological variation among different populations of Cnemidophorus ocellifer in areas of restinga, and investigated the pattern of sexual dimorphism for this species in this region. Therefore, 130 specimens were collected from four independent areas of restinga in Maranhão Island (Panaquatira, Raposa, Araçagy, and São Marcos Beaches), and measured in the laboratory. Significant morphological differences occurred both for populations and sexes. The populations differed in both body size and shape. The lizards from Raposa showed larger sizes. And the lizards from Panaquatira had more morphological variation, showing shorter limbs and longer trunks. The males of C. ocellifer showed larger body and head, while females had more elongation of the body. The morphological differences were attributed to ecological processes suffered by different groups. / Este estudo comparou a variação morfológica entre populações de Cnemidophorus ocellifer presentes em áreas de restinga, e investigou o padrão de dimorfismo sexual para esta espécie nesta região. Para isso foram coletados 130 espécimes em quatro áreas independentes de restinga na Ilha do Maranhão (Praias de Panaquatira, Raposa, Araçagy e São Marcos) e mensurados em laboratório. Diferenças morfológicas significantes ocorreram tanto para as populações quanto para os sexos. As populações divergiram tanto no tamanho do corpo quanto na forma. Os lagartos da Raposa apresentaram maiores tamanhos. E os lagartos de Panaquatira tiveram maior variação morfológica, apresentando menor comprimento dos membros locomotores e maior alongamento do meio do corpo. Os machos de C. ocellifer apresentaram maior tamanho do corpo e da cabeça, enquanto que as fêmeas apresentaram maior alongamento do corpo. As divergências morfológicas encontradas foram atribuídas a processos ecológicos diferenciados sofridos pelos grupos.
6

Morphodynamics of sand mounds in shallow flows

Garcia-Hermosa, M. Isabel January 2008 (has links)
Large-scale bed features are often encountered in coastal waters, and include sandbanks and spoil heaps. The morphodynamic development of such features involves complicated nonlinear interactions between the flow hydrodynamics, sediment transport, and bed profile. Numerical modelling of the morphodynamic evolution and migration of large-scale bed features is necessary in order to understand their long-term behaviour in response to changing environmental conditions. This thesis describes detailed measurements of the morphodynamics of sand mounds in unidirectional and oscillatory (tidal) flows, undertaken at the U.K. Coastal Research Facility (UKCRF). High quality data were collected, including water velocities, water levels and overhead images. The parameters tested are: three types of mound shape (circular and elliptical in plan shape, and Gaussian, cosine and triangular in cross-section); underlying fixed or mobile bed conditions; and initial crest height (submerged, surface-touching and surface-piercing). Peak flow velocities are about 0.5 m/s, the sand median grain size is 0.454 mm, and transport occurring mostly as bedload. When analysing the data, the bed contours are determined by digitising the shoreline at different water levels. From these plots, the volume, height, and centroid position of the mound are calculated. A large-scale fit method, based on a Gaussian function has been used to separate small-scale ripples from the large-scale bed structure during the evolution of an isolated sand mound or spoil heap. The bed profile after the ripples are removed is comparable to typical predictions by shallow-flow numerical solvers. The UKCRF experiments investigated the morphodynamic response of a bed mound to hydrodynamic forcing: shape changes, migration rates, volume decay and sediment transport rates. The measured migration rate and decay of a submerged sand mound in the UKCRF are found to be in satisfactory agreement with results from various theoretical models, such as the analytical solution derived by De Vriend. Numerical predictions of mound evolution by a commercial code, PISCES, are also presented for a fully submerged sand mound; the bed evolution is reasonably similar to that observed in the UKCRF. The data provided as a result of the research reported in this thesis provide insight into the behaviour of sand mounds in steady and unsteady flows at laboratory scale, and should also be useful for benchmark (validation) purposes to numerical modellers of large-scale morphodynamics.
7

Transformações ambientais das restingas da planície costeira sergipana

Costa, Jailton de Jesus 17 June 2013 (has links)
Man-nature relationship and that one of social groups among themselves, as well as the form of natural resources ownership, are determinant factors of the environment current state and of society life quality. This thesis aimed at analyzing Sergipe coastal plain sandbank landscape environmental changes. The spatial area of this analysis was Sergipe coastal plain, located in nine coastal counties bordering sea, namely: Brejo Grande, Pacatuba, Pirambu, Barra dos Coqueiros, Itaporanga D Ajuda, Estância, Santa Luzia do Itanhy e Indiaroba, grouped into three coast sectors (north, center and south). This study methodology is set upon four stages: documentary fieldwork, laboratory and synthesis. The theoretical-methodological model is the GTP (Geosystem, Territory, Landscape). Bertrand (2007), as this corroborates the idea of having an integral holistic vision, in opposition to the compartmentalized analysis, merely descriptive. Doing environmental research, from a method involving the intrinsic relationship between society and nature, is the innovative challenge of Geography. Among the obtained results, there was a concept that sandbank, in geographical sense, is part of the coastal plain, except for beach, dunes, tômbolos, among other sub-environments, covered or not by vegetation, and especially occupied or not by man, having as internal boundary the coastal plains (Barreiras Group). The study of the landscape physiology allowed one to visualize that landscape transformation by man represents one of the main elements in its formation. It was also possible to apply GTP in the study area. A geosystem (Coastal Plain) with seven territories and two landscape classifications with five major subdivisions was visualized. One reaches the conclusion that Bertrand s model enabled a better understanding of the area, for the integrated analysis, from the socio-environmental perspective that comes from such model, allowed one to see and analyze all spatial area phenomena, enabling a better understanding of Sergipe coastal plain sandbank landscape environmental changes. The presence of Hancornia speciosa Gomes in Sergipe is linked to environmental conditions required by this species, which is found in the study area and also to the reasons expressed in the Refuges Theory from AB Sáber. Currently, sandbanks have been the target of such explosive real estate speculation, which has transformed the natural landscape into a mosaic landscape, meaning, into a disturbed and fragmented landscape, in short term, where the climatic variability produce significant environmental changes when compared to the intensity of human actions. / A relação homem-natureza e dos grupos sociais entre si, bem como a forma de apropriação dos recursos naturais, são fatores determinantes do estado atual do meio ambiente e da qualidade de vida da sociedade. Esta tese objetivou analisar as transformações ambientais da paisagem de restinga da planície costeira sergipana. O recorte espacial desta análise foi a planície costeira sergipana, assentada em nove municípios costeiros defrontantes com o mar, a saber: Brejo Grande, Pacatuba, Pirambu, Barra dos Coqueiros, Aracaju, Itaporanga D Ajuda, Estância, sendo dois estuarinos: Santa Luzia do Itanhy e Indiaroba, agrupados em três setores do litoral (norte, centro e sul). A metodologia deste estudo está configurada em quatro etapas: documental, trabalho de campo, laboratório e síntese. O modelo teórico-metodológico é o GTP (Geossistema, Território, Paisagem) de Bertrand (2007), pois este corrobora com a ideia de se ter uma visão holística integralizada, contrapondo-se à análise compartimentada, meramente descritiva. Fazer pesquisa ambiental, a partir de um método que envolva a intrínseca relação sociedade e natureza, é o desafio inovador da Geografia. Dentre os resultados alcançados, chegou-se a um conceito de restinga que, na acepção geográfica, é a parte da planície costeira, com exceção da praia, dunas, tômbolos, entre outros sub-ambientes, coberta ou não por vegetação e, principalmente, ocupada ou não pelo homem, tendo como limite interno os tabuleiros costeiros (Grupo Barreiras). O estudo da fisiologia da paisagem permitiu visualizar que a transformação da paisagem pelo homem representa um dos elementos principais na sua formação. Foi possível também aplicar o GTP na área de estudo. Visualizou-se um Geossistema (Planície Costeira), sete territórios e duas classificações de paisagem com quatro subdivisões principais. Conclui-se que o modelo de Bertrand possibilitou um maior entendimento da área, pois a análise integrada, a partir da perspectiva socioambiental que dele se extrai, permitiu enxergar e analisar a maioria dos fenômenos do recorte espacial, possibilitando compreender melhor a realidade das transformações das restingas da planície costeira sergipana. A presença da Hancornia speciosa Gomes em Sergipe está ligada às condições edafoclimáticas exigidas por essa espécie, a qual é encontrada na área de estudo e também aos motivos expressos na Teoria dos Refúgios de AB Sáber. Atualmente, as restingas têm sido alvo de uma explosiva especulação imobiliária, que tem transformado o ambiente natural numa paisagem de mosaicos, ou seja, numa paisagem antropizada e fragmentada, onde a variabilidade climática produz alterações ambientais significativas quando comparada com a intensidade das ações humanas.

Page generated in 0.0435 seconds