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Caracterização do meio físico em bacias hidrográficas com suportes de sensoriamento remoto e geoprocessamento /Leite, Bruno Souza. January 2013 (has links)
Orientador: Sergio dos Anjos Ferreira Pinto / Banca: Roberto Wagner Lourenço / Banca: Sergio Luis Antonello / Resumo: O presente trabalho buscou caracterizar o meio físico da sub-bacia do Ribeirão das Águas Claras, situado no estado de São Paulo, através da utilização de técnicas de Sensoriamento Remoto e Sistemas de Informações Geográficas (SIG). Para isso foram realizados trabalhos de gabinete e estudos de campo, onde ocorreu a coleta de dados primários; análise de bases cartográficas da região, com escalas de 1:50.000 e 1:10.000; análise de imagens de satélite, CBERS do ano de 2010; levantamentos de campo e mapeamento do uso e ocupação do solo e geração de mapas temáticos. Os resultados se materializaram na confecção de mapas temáticos que abarcaram a caracterização da geologia; geomorfologia; pedologia; declividade; pré-disposição aos processos riscos de erosão hídrica; perda do solo; uso e ocupação do solo; áreas de preservação permanente; além de caracterização da hidrografia local. Como conclusão, sugere-se a integração de técnicas de sensoriamento remoto e geoprocessamento como ferramentas importantes para a gestão do meio físico / Abstract: This paper aims to characterize the physical environment of the Ribeirão das Águas Claras watershed, located at São Paulo state, through the use of Remote Sensing and Geographic Information Systems (GIS) techniques. For this aim it has been done office and field studies, where it occur secondary data collection; region cartography bases analysis, with 1:50.000 and 1:10.000 scales; satellite images analysis, from 2010 CBERS collection; field surveys and mapping of the field use and occupation and thematic maps creation. The results materializes in the production of thematic maps which covered the characterization of geology; geomorphology; pedology; slope; predisposition to erosion, soil loss, soil use and occupation; permanent preservation areas, as well as hydrograph characterization. The conclusion is suggest the integration of remote sensing techniques and geoprocessing as an important tools trough the sustainable management of the physical environment / Mestre
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Risk för TBE (Tick BorneEncephalitis) – för vem, var, när, hur och varför? : En metodkritisk studieHellblom, Ellen January 2018 (has links)
Det finns olika sätt att förstå innebörden av fenomenet ’risk för TBE’ och hur den kan presenteras. Denna uppsats problematiserar den befintliga förståelsen och tolkning av fenomenet inom vårdinstanser och forskning. Metoden och empirin som den nuvarande kunskapsbild bygger på, analyseras metodiskt genom en synergi mellan två tolkningsmetoder. Tillvägagångssättets mål är att visa att en annan metodansats behövs för att nå en vidareutveckling av förståelsen inom ämnet. Grundad teori används för att nå slutsatser om vilken kunskap som ska presenteras som relevant empiri och utifrån empirin, genereras teorin att risk för TBE innefattar mer än incidens och att nuvarande sätt att se på risk för TBE har sina tillkortakommanden. / There are a variety of ways to understand the meaning of the phenomenon 'risk for TBE' and how it can be presented. This paper problematises the existing understanding and interpretation of the phenomena by health services and research. The method and empirical knowledge of the present understanding is analysed methodically by a synergy between two interpretation methods. The aim is to show that another methodological approach is needed to achieve further development of the understanding of the subject. Grounded theory is used to reach conclusions about what knowledge could be presented as relevant empirical material for further studies. The empirical material, in turn, generates the theory that risk for TBE covers more than incidence and that the current way of looking at risk of TBE has its shortcomings.
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An examination of the effects of geological and glacigenic controls on the engineering properties of till using a domain based approachFerley, Simon Julius John January 2014 (has links)
Glacial deposits as a whole are some of the most widespread near surface soils in the northern hemisphere, covering large areas of Canada and the United States, eastern and northern Europe and Asia. In Britain during the final Devensian glaciation, significant accretions of stationary ice developed over most upland areas. The resulting materials derived from the attritional action of the base of the moving ice were deposited as till over approximately 60% of the UK. These soils are generally heterogeneous and unsorted, containing varying proportions of clay to boulder size material. This variation in composition has a commensurate effect on the engineering properties of tills. Commercial investigation data from seven sites in Cumbria overlying different bedrock geology were examined in detail using a variety of statistical and graphical techniques to determine whether differences occurred due to bedrock and glacigenic origin. The results of the data analysis confirm the thesis that the bedrock geology, the history of glacigenic deposition and the post glacial history all affect the geotechnical properties of the resulting till. As a corollary, the commonly used empirical relationship between SPT and shear strength used in deriving undrained shear strength was found not to hold for Cumbrian tills.
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A field, petrological and geochemical study of the Masirah Ophiolite, OmanAbbotts, Ian Lloyd January 1979 (has links)
A reconnaissance survey of the 1000 Km\(^2\) of Masirah Island, Oman, has revealed a fully-developed ophiolite complex which is believed to represent a fragment of Cretaceous ocean crust and upper mantle generated at a constructive plate margin. The complex consists of mantle serpentinites, plutonic rocks ranging from dunite to trondhjemite, a sheeted dyke complex and pillow lava-sediment sequences, all of which have been chemically and petrographically analysed. Several belts of serpentinite occur within the ophiolite associated with major fault-lines. The serpentinites are clearly derived from depleted harzburgitic mantle and their field relations suggest that some were emplaced in the oceanic environment. The chemistry of the plutonic rocks suggests that they are products of dominantly open-system fractional crystallisation of tholeiitic liquid(s), possibly in several discrete magma chambers. Modelling of trace and RE elements suggests that moderate degrees of mantle peridotite melting were involved in production of the magma chamber parental liquid(s). At a higher crustal level sheeted dyke-massive gabbro relationships are interpreted in a model of roof underplating, which causes a decreasing frequency of dyke injection. Metamorphism of the sheeted dykes and lavas is interpreted as sub-sea floor in origin and its effect on whole-rock chemistry is assessed. The dykes and lavas have a chemistry largely typical of present-day ocean tholeiites and the relative contributions of the processes of partial melting and fractional crystallisation to that chemistry are evaluated. Two localised volcanic groups were identified, which appear to have enriched chemistries compatible with origin at off -axis oceanic islands. A major tectonic zone cross-cuts the ophiolite units and has features reminiscent of the modern oceanic transform faults. The importance of this structure, both in the oceanic environment and during the process of ophiolite emplacement, is assessed. Intrusive into the ophiolite is a granite whose trace and RE element chemistry is alien to the oceanic environment and suggests melting of continental crust Finally, a synthesized model of the former constructive margin is produced and an attempt is made to define the type of spreading centre represented. Comparison of the Masirah Ophiolite with the Semail Ophiolite of the Oman Mountains suggests that their former correlation may be ill founded. An assessment of late Mesozoic -early Tertiary plate motions indicates an origin during Cretaceous sea-floor spreading of an early Indian Ocean. Several features may indicate a slow-spreading, much-faulted, constructive margin.
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Water quality dynamics in a lowland tropical catchment : the Kinabatangan river, Sabah, MalaysiaHarun, Sahana January 2013 (has links)
Spatial and temporal trends of dissolved organic matter (DOM) were investigated in the Lower Kinabatangan River, Sabah, Malaysia over the period 2008-2012. The objectives were to: i. quantify DOM in areas of the catchment dominated by oil palm plantations; ii. characterise DOM quantity and quality in waters draining three contrasting land use types (oil palm plantations, secondary forests and coastal swamps); iii. characterise and interpret DOM quantity and quality in the main stem of the Kinabatangan river according to depth; and iv. infer differences in water movement through the catchment. Optical parameters, including fluorescence excitation-emission matrices (EEMs) and ultraviolet absorbance spectroscopy (UV-vis); and Parallel Factor Analysis were used throughout the investigation. The research comprised a preliminary catchment-wide study (225 samples) and concentrated fieldwork campaigns (510 samples). The results indicated the dominance of peaks C and M in waters from the oil palm plantations and coastal swamps respectively. The relative loss of terrestrial derived peaks could indicate progressive DOM degradation from the upper reaches towards the estuary. Results also showed DOM was transported back to the main river, as dominated by fluorescence index peak A/peak C, particularly in the coastal swamps. DOM characterisation with depth in the river, showed the dominance of peaks C and M (relative to terrestrial and microbial and/or photo-degradation processes) in waters near the riverbed.
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Cohesive sediment transport on an estuarine intertidal zoneFreeman, David P. January 1994 (has links)
A field study of cohesive sediment movements on a muddy intertidal zone (ITZ) at Portishead, Severn Estuary is presented. Five deployments of 1-3 days have been made to improve the understanding of temporal and spatial variations in suspended and bed sediments at a site which is found to be wave dominated. Pressure transducers, electro-magnetic current meters, optical turbidity meters and ultra-sonic bed level transducers are used to monitor the hydro/sediment dynamics in the bottom metre of the water column at two points on the ITZ. A one-dimensional (vertical) k-ϵ turbulence model has been modified to include bed sediment exchange and density stratification to enable further interpretation of field data. Modelling results show that the weak current on the ITZ would simply provide a mechanism for diffusing suspended sediment into the upper part of the flow, and does not enhance the wave boundary layer by its presence and cannot actively support suspended sediment. Hence near bed (wave generated) turbulence controls the vertical SSC distribution. A bed model based on bed sediment exchange via critical erosional and depositional shear stresses only predicts high near bed concentrations for some of the hydrodynamic conditions reflected in field data, suggesting hindered settling is an important factor in their formation. The introduction of density stratification reduces near surface SSC creating steeper SSC gradients in the upper half of the flow, for a weak current with waves.
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Regional modelling to forecast the transient chlorinated solvent risk to groundwater for water supply securityBarry, Christopher James January 2018 (has links)
The UK has an environmental legacy of chlorinated solvent contamination from historic industrial activity. Groundwater in Permo-Triassic Sandstone aquifers has been widely impacted. Future use of this resource requires methods to forecast regional-scale chlorinated solvent risk to groundwater assets. Current methods do not adequately represent chlorinated solvent dense non-aqueous phase liquid (DNAPL) source term behaviour and transient contaminant transport. This research investigates the hypothesis that improvements for regional contamination forecasting methods are possible and necessary. Experimentation with particle-based transport solutions shows that neglect of spatial dispersion is over-simplistic, especially where there are complex interactions between capture zones of different receptors. A fully dispersing Lagrangian solution, dynamic random walk (DRW), is developed that accurately models contaminant migration even with coarse-gridded flow models. For representation of the source term, a review of research into DNAPL behaviour is conducted. It is not feasible to derive a generic model for DNAPL dissolution into groundwater based on readily derived metrics at the regional scale. Therefore, a source term framework is developed that tests multiple conceptual models of DNAPL behaviour and therefore gives a holistic uncertainty analysis. Two case studies, based in historically industrial catchments in Birmingham and Stourbridge, validate the combined use of the DNAPL source term framework and the DRW transport solution. Chlorinated solvent sources are persistent, but careful asset planning informed by these regional risk modelling tools- DRW and the DNAPL source term framework -could allow continued use of solvent-impacted groundwater bodies.
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Seasonal hydrological prediction in Great Britain – an assessmentLavers, David Anthony January 2011 (has links)
This thesis assesses seasonal hydrological prediction in Great Britain. Firstly, the study evaluates river flow prediction using climate model output to drive a rainfall-runoff model in the Dyfi basin, Wales. Results show that climate model precipitation can not skilfully simulate Dyfi discharge. When a downscaling process is employed to generate precipitation time series, river flow forecast skill improves, but historical river flows still provide superior forecasts. Secondly, large-scale climatic control on British precipitation/discharge and European precipitation is investigated by correlation analysis. Results show spatiotemporal hydroclimatological variation, with western regions generally having stronger empirical relationships. River flow has weaker associations because of basin controls and evapotranspiration. The dynamic nature of precipitation/discharge generating mechanisms is not captured by the North Atlantic Oscillation Index. Thirdly, seasonal climate model forecast skill is evaluated. Limited skill exists over land and over all extratropical regions for forecasts beyond month-1; precipitation has lower skill than 2-metre air temperature and mean sea level pressure. Seasonal climate models exhibit higher idealised predictive skill indicating potential for future increases in actual predictive skill. In conclusion, seasonal hydrological prediction using a climate-to-river modelling chain could be improved through consideration of the uncovered spatiotemporal hydroclimatological variability and through seasonal climate modelling improvements.
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Late Triassic to early Jurassic microfossils and palaeoenvironments of the Waterloo Mudstone FormationAzmi, Azrin January 2018 (has links)
Northern Ireland Waterloo Mudstone Formation has received relatively little attention due to the scarcity of exposures and poor availability of subsurface records. The recent recovery of latest Triassic to Early Jurassic strata from boreholes permits further study of biostratigraphical and palaeoenvironmental using foraminifera and ostracods. The samples are from boreholes (Ballinlea-1, Magilligan and Carnduff-1) and exposures (White Park Bay, Tircrevan Burn, Larne, Ballygalley, Ballintoy and Kinbane Head). The age of the sections, established using foraminiferal biozonation ranges from latest Triassic (Rhaetian) to earliest Pliensbachian (JF9a). The assemblages recovered broadly similar to those elsewhere in NW Europe; European Boreal Atlantic Realm. The latest Rhaetian to earliest Sinemurian low diverse microfossil assemblages dominant by metacopid ostracods with occasional influx of opportunist foraminifera but gradually, foraminiferal abundances exceed the ostracods in the Early Sinemurian onwards with their highest diversity in the Late Sinemurian. The foraminiferal assemblages are dominated by foraminifera of the Lagenida, other groups include the Miliolida, Buliminida and Robertinida. Based on the microfossils, the sediments are considered to represent confined inner shelf environment in latest Rhaetian to Hettangian then gradually recovered to well-oxgenated, open marine deposits of outermost inner shelf to middle shelf in Early Sinemurian to Early Pliensbachian.
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The response of stone columns under the cyclic loadingAshour, Samir January 2016 (has links)
Soft clay soils in railway track can be problematic as, unless they are treated, they can result in increased deformation of track. This will inheritably mean lower track speed. A number of techniques including stone columns are available for improving strength of weak soils. The use of stone columns, for improving both bearing capacity and settlement is well rehearsed for static loading; little is understood about their response, when subjected to cyclic loading. This study is focused on investigating the behaviour of stone columns when subjected to cyclic loading as in railway tracks based on a laboratory scale investigation. A series of monotonic and cyclic loading conditions were undertaken on two laboratory models undrained triaxial and large scale model. Tests were conducted on both soft soils (no column) and soil/ stone column composite (reinforced with 28 mm diameter stone columns). All tests were performed on normally consolidated specimens of soft clay (c\(_u\) ≈ 12 kPa). The effect of both cyclic stresses and loading frequency on the permanent deformation, soils stiffness and pore water pressure generation were investigated. It was found that threshold dynamic stress of soil for cyclic loading increased from 50 kPa for soil only to 60 kPa for soil with stone column. This is equivalent to CSR of 0.7. Changes in frequencies tested did not significantly influence the permanent strain of reinforced soil, but these changes do affect the stiffness. Stone columns also helped reduce pore water pressure build up under cyclic loading by providing a drainage path.
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