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1
Grecchi, Rosana Cristina. "Zoneamento geoambiental da região de Piracicaba - SP, com auxílio de geoprocessamento." Universidade de São Paulo, 1998. http://www.teses.usp.br/teses/disponiveis/18/18132/tde-06102017-110122/.
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O trabalho consiste na realização de um zoneamento geoambiental para a região de Piracicaba-SP, com base na análise de variáveis ambientais, principalmente de atributos do meio físico, tais como: geologia, solos, hidrologia, etc. A área estudada localiza-se na bacia hidrográfica do Rio Piracicaba, uma das mais importantes do estado de São Paulo e que vem apresentando intenso desenvolvimento econômico e consequentemente problemas de degradação ambiental. Este estudo foi realizado seguindo-se os pressupostos da cartografia geoambiental, mas utilizando-se também os procedimentos da cartografia geotécnica tradicional. Incorporou-se ainda ao estudo a utilização de um Sistema de Informações Geográficas (SIG) e do processamento digital de imagens de satélite, que permitiram maior agilidade e confiabilidade no levantamento, análise e tratamento das informações. Para a obtenção da carta de zoneamento geoambiental partiu-se da compartimentação do terreno em \"Landforms\", sendo que estas unidades homogêneas foram então caracterizadas e avaliadas quanto as suas principais aptidões e restrições. A carta obtida apresenta-se dividida em 16 unidades, descritas quanto a aptidões, restrições e conflitos de uso, principalmente em relação a aptidão agrícola, erosão, vulnerabilidade do aqüífero e disposição de rejeitos.<br>This work presents the geoenvironmental mapping of the Piracicaba (SP) region, based on the analysis of environmental attributes, such as: geology, soils and surface and ground waters. This region is located in the Piracicaba river basin, one of the more importance basins in the São Paulo state. It presents serious environmental degradation problems due to intense economic activities. This study has been based on the proposal of the geoenvironmental mapping, but using to the procedures of the traditional Engineering Geological Mapping. A Geographical Information System (IDRISI) and digital image processing were used to permit quickness and confidence on the collect, analysis and handling of the geological-geotechnical informations. The geoenvironmental zoning chart has been based on the terrain landforms division and the characterization of these homogeneous units that were evaluated with respect to the mainly aptitudes and constraints. The region was divided into 16 geoenvironmental units with their advantages and limitations analised in terms of agriculture aptitude, erosion susceptibility, aquifer vulnerability and waste disposal.
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Dilts, Thomas E. "Morphometric characterization of artificial post-mining landforms and natural landforms using a Geographic Information System." abstract and full text PDF (free order & download UNR users only), 2007. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1447595.
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Lauder, Glen A. "Coastal landforms and sediments of the Marlborough Sounds." Thesis, University of Canterbury. Geography, 1987. http://hdl.handle.net/10092/4518.
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This thesis examines coastal form and sediments of the Marlborough
Sounds, New Zealand.
An important aspect of coastal behaviour in this landscape stems from
linkages between catchment and coast. Focus is therefore placed on the manner
in which sediment delivered from catchment sources is redistributed within the
shore and offshore domains.
Coastal response is shown to depend on two factors: the form of the
receiving sites and the mobility of sediments within them. Investigation of coastal
landforms at a range of scales identifies the framework within which
sedimentation takes place. Consideration of landscape sediment redistribution at
Quaternary, Holocene and human timescales establishes the locations in the
coastal landscape in which change has taken place. A key factor in coastal
response relates to the wide size range of sediments delivered.
The fractionation of sediment within the coastal domains is used as an
index by which to identify the controls on coastal sedimentation. A new
conceptual model of coastal behaviour, the Ordered Response Model, is developed
as a framework within which to investigate coastal response. The model is
operationalised in three ways. This is done first with regard to coastal sediments
and their grain-size interpretation, secondly in the context of shoreline form and
sediment redistribution, and thirdly in relation to form and sediment trapping
within coastal embayments.
The patterns of sediment redistribution are seen to reflect trapping
behaviour in the coastal landscape at a range of scales. Sediments are
investigated from the viewpoint of the factors which determine their retention or
accumulation in or rejection from a coastal site.
Shore sites are distinguished on the basis of the extent to which they trap
materials delivered to them from catchment sources. Governing factors are
shoreline gradient and size grade of materials. A primary fractionation of
sediments takes place at the shore and the finer fractions are by-passed to the
nearshore. Sediment fractions that are relatively immobile under prevailing
environmental conditions develop paved lag surfaces at a range of scales.
Sediments that accumulate at the shore are distinctive in their mixed sand and
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gravel composition with a dominant mode in the granule and very coarse sand
grades (-291 to 091).
Sediment deposited on the intertidal surfaces is found to be redistributed
by a distinctive mechanism. Migratory intertidal bedforms defined here as
"clastic waves" are a means by which the low energy shores disperse sediment
which is delivered to them. These waves are a distinctive form of the shoreline of
the Marlborough Sounds, and have attributes different from other shoreline
forms identified in the literature. Clastic waves are shore-parallel, crescentic or
lunate forms with longshore crest dimensions of 0.5 to 30m, length dimension
perpendicular to the crest of up to 20m, and crest heights of 0.05m to 0.5m. Rates
of intermittent migration vary from 1m/day to 10m/year. Key factors in their
development are identified as low wave energy, tidal range, intermediate to low
intertidal gradients (<1:20) and a mixed sand and fine gravel grain-size.
Bathymetric form is found to reflect the varying influence of sub-bottom
morphology, sediment accumulation and hydraulic reworking. Analysis of
sediment thickness identifies a mean thickness over sub-bottom of 7.33m in
Pelorus Sound. Spatial variations in sediment thickness identifY marginal
embayments as significant sediment traps.
Mean sedimentation rates calculated over a 6,000 year timespan give
Pelorus Sound a spatially averaged rate of 1.22mm/yr. Sub-bottom form is shown
to have a stronger role in determining bathymetric form than previously
reported. Due to the constraining effect of shallow sub-bottom form on
sedimentary processes sediment thicknesses in the inner Pelorus Sound are not
greater than those found in channels or embayments in the middle reaches of the
Sound. A mean thickness of 5.75m from sub-bottom seismic profiles in the inner
Pelorus equates to a sedimentation rate of 0.96mm/year over 6,000years, at about
which time the river valleys of the Marlborough Sounds were drowned by postglacial
rising sea-levels.
Analysis of sub-bottom form reveals evidence of previously unreported
drowned terrace remnants, which are correlated to subaerial terrace remnants.
On the basis of both long profile patterns along these remnant surfaces and an
analysis of bathymetric form of marginal bays and channels, an interpretation is
developed of the origin of form in Pelorus Channel and Tory ChanneL
Sediment trapping behaviour is identified as the most distinctive attribute
of this coastal landscape, and shown to operate at a range of nested scales. As a
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consequence of trapping behaviour, the operation of any part of this coastal
landscape must be considered in relation to its operation as a whole.
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Hassan, Wael. "Comparing Geomorphometric Pattern Recognition Methods for Semi-Automated Landform Mapping." Ohio University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou160690391009081.
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George, Chinotu Franklin. "Geometries of surface and subsurface landforms and deposits in the Niger Delta." Thesis, University of Aberdeen, 2014. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=211213.
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This research is focused on mapping the geometries of surface and subsurface landforms and their relationship in the Niger Delta. Landforms on the surface are studied to improve our understanding of the spatial distribution of buried landforms. GIS techniques are applied to high resolution Landsat and SPOT imagery to map surface landforms, a necessary step in order to improve and better constraint subsurface modelling. Also, attributes from three dimensional seismic data are used to map buried landforms. Both techniques are focused on mapping the spatial distribution of landforms and analysis of their shape, size, orientation, connectivity and density. Results on the study of fluvial channels, point bars, braid bars, tidal channels, beach-barrier islands and spits are presented in this thesis. The updated map of the subarial Niger Delta covers an area of 70,000 km2. Tidal channel width increases exponentially toward the coast; in contrast the fluvial channel width decreases linearly downstream. Tidal channels are interconnected within a complex network. The tidal channels are wider in the East and West Flanks while in the centre they are narrower. Here, channel mouths are at a high angle with the coastline because of a combined effect of high sediment flux and longshore drift. Tidal channels are therefore grouped into four distinct zones; the West (Forcados River Zone), the Central (Nun River Zone), the East (Sombreiro River Zone) and the Far-East (Cross River Zone) based on their channel morphology and density. Each lobe is influenced differently by the interaction of fluvial, tidal and wave-related processes. This implies that it is appropriate to look at the Niger Delta as an amalgam of deltas geographically separated into four lobes. The morphology of the beaches also supports the considered reclassification, as they show distinct morphologies within each of the four lobes. Beaches are longer and wider on the eastern and western flanks and thin out towards the central lobe due to high sediment influx and wave reworking. Parallel channels form between scrolls and ridges and are prominent in areas where tidal influence does not extend far into the land. The correlation between the geometries of the surface and subsurface landforms is very strong and indicates that where subsurface details are missing, it is acceptable and reasonable to use surface information to make predictions about the subsurface. The result will help in constraining parameters used in modelling of geometric and dimensional properties of reservoirs and to better manage uncertainties, all elements relevant to the oil and gas industry.
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Vere, D. M. "Depositional characteristics of ice-marginal landforms, Jotunheimen, Southern Norway." Thesis, Coventry University, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.374681.
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Nelson, Timothy L. "Hydrodynamic Controls on the Morphodynamic Evolution of Subaqueous Landforms." ScholarWorks@UNO, 2017. https://scholarworks.uno.edu/td/2425.
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The southern Chandeleur Islands are an ideal setting to study shoal evolution given their history of submergence and re-emergence. Here, numerical models shed light on the attendant processes contributing to shoal recovery/reemergence following a destructive storm event. Simulations of a synthetic winter storm along a cross-shore profile using Xbeach shows that convergence of wave-induced sediment transport associated with repeated passage of cold-fronts initiates aggradation, but does not lead to reemergence. A Delft3d model of the entire island chain shows that as these landforms aggrade alongshore processes driven by incident wave refraction on the shoal platform, backbarrier circulation and resulting transport become increasingly important for continued aggradation and eventual emergence. Aggradation magnitudes are a function of depth ranging from 2 – 10 mm per event (onset to recovery to near mean sea level). In the absence of big storms, this modest aggradation can be more than one meter in a few years.
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Peterson, Gustaf. "The development and relative chronology of landforms at Kongsfjordhallet, Spitsbergen." Thesis, Stockholm University, Department of Physical Geography and Quaternary Geology, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-37061.
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<p>Kongsfjordhallet is situated at 79° N on the North coast of Kongsfjorden, Spitsbergen.The landscape shows a large diversity of landforms and sediments and the aim of thisstudy has been to investigate the spatial distribution and temporal differences betweenthese landforms.The most prominent landform is interpreted as a lateral moraine dividing the area fromsoutheast to northwest. This is probably a sign of a standstill during the deglaciation ofan ice-sheet glacier tongue filling the fjord. The valley-glaciers at Kongsfjordhallet haveadvanced after this event and left end moraines on top of the lateral moraine. Largeamounts of meltwater have eroded parts of the Kongsfjordhallet, creating several fossilmeltwater channels that dissect the landscape. Erratic boulders of mainly gneiss type arescattered all over the landscape, as high up as 500 m a.s.l. In addition to the erraticboulders, a lot of allochthonous material is found incorporated in local material,especially as a diamict interpreted as till that covers large parts of Kongsfjordhallet.The till can likely be correlated to one of the diamict units in the cliff sections at theKongsfjordhallet coast. At present, two large ravines drain the area, moving water fromthe glaciers to the ocean and a beach is developing in the Southeast part of the area dueto ocean transgression. Landforms from two glacial events are found, one regional andone local. An episode of high sea-level as well as fluvial and mass-wasting activity afterthe deglaciation is also recorded. The formation of the landforms in the area is believedto be after the Last Glacial Maximum and into the Holocene, but no absolute dates areavailable.</p><br>SciencePub
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Anderson, Dustin Carl. "How landforms and geology affect the structure of riparian areas." Thesis, Montana State University, 2012. http://etd.lib.montana.edu/etd/2012/anderson/AndersonD0812.pdf.
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Current riparian zone assessments focus on the morphological features of the stream channel and ocular vegetation measurements. This procedure fails to address the hydraulic features responsible for the floristic structure and composition of the riparian zone. We looked at how the geology and landforms function as drivers of groundwater and surface-water exchange. These can mitigate watershed processes via groundwater availability to shape riparian processes; e.g. discharge, seasonality. We hypothesized that groundwater surface-water exchange is a first order process and that it dictates riparian water availability and that the underlying geology and landform can serve as a tool to gain greater understanding of a properly functioning riparian ecosystem. We tracked groundwater surface-water exchange using wells, piezometers, water temperature, conservative tracer injections and solute conductivity on an alluvial fan in the Gallatin valley. Southwestern Montana Conservative tracer injection indicated 3% tracer losses over the 1.5km reach. Through spring and summer 2011 groundwater wells and piezometers indicated flashy transient shallow groundwater. Significant late growing season stream discharge (~300 l/s) and standard riparian monitoring assessments would suggest a larger floristic community than what is present at the site. These metrics together suggest a disconnection between the surface-water and groundwater ultimately limiting the extent of the riparian vegetation community. We further determined that the surface water is disconnected from the local groundwater table. We conclude that the lack of surface water - groundwater connectivity drives the floristic structure and character of the riparian zone. Skewed or inaccurate views of riparian functionality may occur because; the current assessment fails to address surface water - groundwater connectivity.
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Sharpe, David Robert. "Glacial sediments and landforms, southern Victoria Island, Northwest Territories, Canada." Thesis, University of Ottawa (Canada), 1992. http://hdl.handle.net/10393/7846.
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Wollaston Peninsula and most of southern Victoria Island comprise Palaeozoic carbonate lowlands, scarps, and tableland situated between rises and arches of underlying Precambrian sedimentary and igneous rocks. Quaternary sediments are hummocky, thick and ice-cored near escarpments where ice flow resistance, thrusting and meltwater concentrated glacial debris; thinner, streamlined drift occurs in lowlands. Quaternary sediments are mainly Late Wisconsinan in age. Glacial sediments predominate but surficial raised marine and periglacial sediments are noted. Fluvial modification of the landscape is minor. Many of the spectacular glacial landforms on Wollaston Peninsula are streamlined and indicate formation under thick, warm-based (i.e. free subglacial water) glaciers. A set of distinctive landforms, including ground moraine (with small moraines and marginal channels), hummocky moraine, lateral moraines, and streamlined forms, relates to varying flow conditions within one major glacial advance. Stratified drift within moraines indicates the importance of glaciofluvial processes in addition to ice action. Collectively, these landforms record ice-marginal retreat, marginal stagnation following compressional flow, surging, flooding and regional stagnation during deglaciation. Freeze-on and ice stagnation trapped extensive bodies of drift-rich ice in zones of hummocky moraine. Arborescent networks of narrow eskers record subglacial meltwater drainage beneath major ice lobes and long broad eskers record subaerial deposition by meltwater of mainly supraglacial derivation. Late glacial events are dated relative to the incursion of the sea during deglaciation of northwest areas of Wollaston Peninsula by about 12 000 BP. Active ice-marginal conditions existed just before 10 000 BP, during formation of the large Colville moraines. Ice downwasted in the area causing glacier thinning. Prominent ground-ice features include pingos, thermokarst scars, and debris-flow lobes. Ground ice occurs as massive icy bodies, ice-wedge ice, and buried pingo ice. Based on its setting in hummocky moraine, its stratigraphy, debris content, and isotopic composition, the massive ice is likely buried glacial ice. Landscape modification by thermokarst erosion has produced ubiquitous diamictons similar to till, and landforms similar to glacial forms. Thick ground ice bodies exist only above marine limit and the limits of streamlined landforms because permafrost degradation occurred below these limits. Widespread thaw slumps and large-scale thermal contraction cracks also indicate ice-cored terrain.
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Sefton-Nash, Elliot. "Water-altered mineralogy and landforms in equatorial regions of Mars." Thesis, University of Bristol, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.541616.
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James, H. C. L. "Late Quaternary coastal landforms and associated sediments of west Cornwall." Thesis, University of Reading, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239536.
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Al-Garni, Abdullah Mohammed. "Image interpretation for landforms using expert systems and terrain analysis /." The Ohio State University, 1992. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487777170407991.
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Phillips, Zachary Rockford. "Holocene Postglacial Fluvial Processes and Landforms in Low Relief Landscapes." Diss., North Dakota State University, 2020. https://hdl.handle.net/10365/32036.
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Postglacial rivers are part of the relatively young low-relief landscape system left behind by glaciers. Over time, postglacial rivers are susceptible to both minor and major channel planform changes as the Earth and its newly exposed rivers adjust to new isostatic and geomorphic equilibriums. Those planform changes result in topographic features that are well preserved among the largely unaltered landscape and offer opportunities to learn about the processes that create them. This work focuses on those minor and major planform changes and the resulting landforms, with a focus on processes effecting the glaciolacustrine Red River Valley. Here, three studies were conducted, two regarding minor planform changes and one focusing on major planform changes. Studies included in this work regard 1) the spatial distribution of meander cutoffs and meander cutoff relief on the Red River, 2), avulsion timing and length resulting from isostatic tilting and 3) mobile river ice and bank interaction frequency, locations, and erosion in meandering rivers. Results show that rivers develop meander cutoffs that faster in areas where geologic materials are more easily eroded and their relief shows a positive relationship with the rate of river incision. Major channel path changes (avulsions) in the presence of isostatic tilting were found to be most frequent soon after river establishment while rates of isostatic rebound are high enough to outpace channel incision. River ice was found to most frequently interact with the outer banks of channels with long, tight bends and high sinuosity, potentially contributing to the meandering process. From these results it can be interpreted that postglacial rivers were highly dynamic early in their history and have stabilized over time, with most of the changes occurring in areas with more erodible alluvium. Presently, rivers undergo most of their changes during the spring thaw when mobile river ice is impacting the banks, with sinuous river reaches impacted most frequently by mobile river ice.<br>North Dakota Water Recourses Research Institute (ND WRRI) Fellowship Program
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Fontes, Silvana Brandão. "Mapeamento geotécnico com ênfase em erosões no município de Ouro Preto - MG, escala 1:5.000." Universidade de São Paulo, 1999. http://www.teses.usp.br/teses/disponiveis/18/18132/tde-23082018-145637/.
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Este trabalho consiste no estudo sistemático dos fenômenos erosivos em áreas urbanas, tendo como objetivo a avaliação e identificação das causas destes fenômenos no município de Ouro Preto - MG. Como ferramenta principal utilizou-se o mapeamento geotécnico, na escala de detalhe 1:5.000 em uma área de aproximadamente 6 Km2, com o objetivo de fazer uma caracterização geotécnica das feições erosivas existentes na área. Buscou-se também fazer um levantamento de dados geológicos, geomorfológicos e de influência antrópica. Os resultados obtidos através deste mapeamento possibilitaram a elaboração do mapa de susceptibilidade à erosão. Como ferramenta auxiliar utilizou-se a sistemática da Técnica de Compartimentação do Terreno proposta por LOLLO (1995) e o Sistema de Informação Geográfica IDRISI. A compartimentação do terreno baseou-se no estudo das formas de relevo (landforms), que foram divididas a nível de elementos, procurando sempre respeitar os limites naturais do meio físico. O SIG-IDRISI possibilitou a atualização e o tratamento das diversas informações levantadas e analisadas, além da agilidade em se gerar as cartas. Os documentos cartográficos gerados foram: mapa de documentação, modelo digital do terreno, mapa do substrato rochoso, mapa de landforms, carta de declividade e carta de susceptibilidade à erosão.<br>This work presents a systematic study on the erosion processes in urban areas, with the aim of evaluation and identification of its causes in the municipal district of Ouro Preto - MG. As the main tool, the engineering geological mappping procedures have been used, scale 1:5.000, covering on area of about 6 Km2. These procedures were particulary used for the geothecnical characterization of the erosion features present in the area. lt was intended also to get, as much as possible, all the geological, geomorphological and human interference. The results obtained from the mapping procedures have been used as a base for the erosion susceptibility chart. The sistematic of the terrain landforms division, proposed by LOLLO (1995) and the GIS - IDRISI were used as auxiliary tools. These landforms have been divided in elements, obeing environmental constraints. The use of the GIS - IDRISI, has promoted the updating and manilulation of the several information obtained, besides the agility in generating the charts. The chartographycal documents produced were digital terrain model, documentation map, bedrock map, landforms map, declivity chart, erosion susceptibility chart.
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Chandra, Shobhit. "Fluvial landforms and sediments in the north-central Gangetic Plain, India." Thesis, University of Cambridge, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309855.
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Channon, Heather. "Multiscale analysis of the landforms and sediments of palaeo-ice streams." Thesis, Queen Mary, University of London, 2013. http://qmro.qmul.ac.uk/xmlui/handle/123456789/8398.
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Ice streams play a fundamental role in the stability and dynamics of ice sheets. They are defined by their rapid flow and this is enabled by conditions and processes at the icebed interface. A significant limitation to our understanding of this environment is that most studies, of both contemporary and palaeo-ice streams, have focussed on only one or two, discrete spatial scales of analysis and so integration between scales is restricted. This thesis investigates palaeo-ice streams at multiple scales in order to examine their subglacial processes and characteristics, and to assess the links between and the application of different spatial scales of analysis. Seven palaeo-ice streams from the British and Laurentide ice sheets were investigated at the macroscale, which involved geomorphological mapping, spatial analysis of subglacial lineations and examination of bed characteristics. Two ice streams were also investigated at smaller scales, which included sedimentological analysis (mesoscale) and micromorphological analysis (microscale). Macroscale results showed that subglacial lineations display certain spatial characteristics, including: clustering according to elongation ratio; distribution of low elongation ratios throughout the ice streams; and a decrease in maximum elongation ratio towards the ice stream lateral margins. The latter of which is considered to reflect the transverse distribution of ice velocity. In some cases, a decline in subglacial lineation concentration and elongation ratio coincided with topographic obstacles at the ice stream bed. The most common bed characteristics identified were: widespread till, fine grained sedimentary bedrock with a moderate permeability, low relief and a flat topographic curvature. Key subglacial processes identified included deformation, which was observed at all three scales, and high pore water pressures, for which multiple lines of evidence were found at the meso and micro scales. Spatial variability in both strain and pore water pressure was also common. The multiscale approach allowed robust interpretations of fast flow mechanisms, which furthers knowledge of the sediment and landform characteristics that may result from these flow mechanisms. A summary of the processes that can be identified at each of the spatial scales is given.
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Hughes, Anna L. C. "The last British Ice Sheet : a reconstruction based on glacial landforms." Thesis, University of Sheffield, 2008. http://etheses.whiterose.ac.uk/16363/.
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The last British Ice Sheet has been a focus of research for over a century, and yet we have only a generalised picture of its extent and internal geometry. This is a remarkable situation compared to knowledge of the larger former ice sheets of North America and Fennoscandia. The central tenet of this thesis is that the glacial landform record has been neglected as a source of spatial information, hindering our attempts to reconstruct the characteristics of the ice sheet. This motivated systematic mapping of glacial landforms (subglacial bedforms, moraines, eskers, and meltwater channels) for the whole of Britain, yielding the first consistent and countrywide glacial maps. Mapping was achieved primarily using a high resolution (5 m horizontal) digital elevation model to visualise the landscape. Over 60,000 features were identified and mapped, greatly expanding the known distribution and pattern of glacial landforms. Analysis of the landform data permitted a country-wide reconstruction of the pattern of ice sheet retreat. A database of just over 400 dates, compiled from the literature, was used to arrange the pattern of retreat in time. This exercise highlighted various incompatibilities between the presently available dates. Examination of landform patterns enabled the elucidation of some pre-deglacial configurations of ice divides and flow geometry, including ice streams. This revealed the existence of both transient (migrating) and persistent ice divides. In contrast to other and larger palaeo-ice sheets, the majority of flow evidence in Britain exhibits a particularly close association with topography, indicative of an ice sheet thickness comparable with the amplitude of subglacial relief. The retreat pattern, flow geometries and divide configurations that have been identified from this research provide a set of evidence-based constraints at ice sheet scale for future numerical ice sheet modelling experiments.
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von, Holdt Johanna R. C. "Aeolian dust emission dynamics across spatial scales: landforms, controls and characteristics." Doctoral thesis, University of Cape Town, 2018. http://hdl.handle.net/11427/28364.
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Variable erodibility (surface characteristics) and erosivity factors (meteorological conditions) result in dust emission dynamics being complex in both space and time. Accounting for localscale surface variability is critical to our understanding of dust emitting processes. This study identifies mineral dust using remote sensing, establishes emission thresholds through field measurements and identifies particle chemistry for major dust sources in the Central Namib Desert. Examining over 2000 Landsat images over a period from 1972 to 2016, identified 40 days of visually detectable dust, originating from sub-km scale point sources. The observations suggest that dust sources can be identified at the landform scales which particularly include ephemeral river valleys and saline pan surfaces. These persist throughout the 25-year record; however, a gradual shift in source point clusters is noted through time, which can be tentatively attributed to anthropogenic modification of the hydrological systems. A PI-SWERL (Portable In-Situ Wind ERosion Lab) wind tunnel was used to measure the emission potential of the Landsat derived targets. The most emissive sources were paleostockpiles of alluvial silt deposits and associated degraded nebkhas within the Kuiseb River Delta. These had a geometric mean emission flux of 0.076 mg m-2 s -1. In comparison, the active channel had a geometric mean emission flux of 0.008 mg m-2 s -1, undisturbed desert pavement 0.007 mg m-2 s -1, pan surfaces 0.001 mg m-2 s -1 and wadis within the gravel plains 0.030 mg m-2 s -1. The emission thresholds were augmented with site-specific field measurements such gravel cover (%), moisture content (%), particle size (µm), elemental composition (%) and shear and compressive strength (kg cm-2). A Boosted Regression Tree (BRT) machine-learning algorithm identified the most important surface and sediment characteristics determining dust emission from the measured surfaces. The model explained 70.8% of the deviance in the measured dust flux with the top predictor variables and their relative importance (%) as follows: gravel cover, 16%; moisture content, 14%; kurtosis, 13%; very coarse silt, 13%; very fine sand, 11%; fine sand, 8%; compressive strength, 7%, calcium, 7% and magnesium, 6%. Such an analysis can be used to identify critical thresholds for dust emission and standardise testing protocols. Linking landforms with such emission measurements allow for the assessment of two existing dust emission schemes: the Preferential Dust Scheme (PDS; Bullard et al. 2011) and the Sediment Supply Map (SSM; Parajuli et al. 2017). Although these schemes represent a major advance in our representation of dust emission source areas and erodibility, this study shows that these schemes still need to be improved to accurately depict dust emission potential. For the PDS this would include producing a global rasterised output with quantified dust emission potential and for the SSM, a more accurate classification of the highly emissive geomorphic units. Landsat source point sediments were subjected to physical and geochemical analyses and compared to samples obtained from passive collectors such as the Big Spring Number Eight (BSNE) and active PI-SWERL exhaust emissions, using an auto-SEM (QEMSCAN). This provided individual particle mineralogy (>2 µm resolution) for a total of approximately 10000 to 60000 particles per sample which enabled a comparison of particle size, shape and mineralogy. The samples consist of a mixture of minerals reflecting the varied metamorphic geology and consists predominantly of feldspar, quartz, mica, other aluminosilicates such as the alteration products epidote and chlorite and low to medium grade metamorphics such as amphibole and pyroxene, iron oxihydroxides, titanium minerals, carbonates and clay minerals.
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Arnold, Billie J. "A Comparitive Analysis of Glacial Landforms: Skeidararsandur Iceland and Northwestern Pennsylvania." Kent State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=kent1389103411.
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Faivre, Sanja. "Landforms and tectonics of the Velebit mountain rance (Outer Dinarides, Croatia)." Clermont-Ferrand 2, 2000. http://www.theses.fr/2000CLF20005.
Full textAbstract:
Cette étude s'inscrit dans le cadre de la géomorphologie structurale. Le but en est d'apporter une explication à la répartition des formes du relief par rapport aux nouvelles conceptions tectoniques. Pour examiner ce lien, les déformations et les contraintes ont été calculées à partir des dolines des crêtes. L'intérêt de la montagne de Velebit tient à sa grande densité en formes karstiques et à sa dynamique tectonique récente. Ce travail a permis de dégager une nouvelle méthodologie en la matière. 2 méthodes géologiques, la méthode de centre et celle de projection, ont été adaptées aux conditions géomorphologiques. Les contraintes et les déformations ont été calculées à partir de la distribution spatiale des dolines, pour détecter les influences tectoniques récentes, et à partir de la morphologie des crêtes, pour distinguer les différents types d'influences tectoniques récentes et anciennes. Un intérêt particulier a été porté sur les variations spatiales des paramètres mesurés, lesquels sont examinés à travers la méthode des trajectoires. Les résultats acquis dans les 1ères parties ont été utilisés pour l'élaboration de plusieurs modèles numériques. La 1ère serie de modèles utilise les résultats d'analyse morphologique alors que la 2e consiste en la simulation cinématique. Le but en est d'apporter des éléments explicatifs sur les causes principales des distributions de contraintes et de déformations, obtenues précédemment. La comparaison de résultats, issus de méthodes différentes et d'analyses à différentes échelles, a permis d'établir en termes quantitatifs, le lien étroit qui existe entre les deux formes de relief étudiées et la tectonique. Enfin, cette étude met en exergue l'importance de la géomorphologie dans l'étude de la géodynamique et celle de la tectonique dans l'étude des formes du relief
22
Cannon, Charles Matthew. "Landforms along the Lower Columbia River and the Influence of Humans." PDXScholar, 2015. https://pdxscholar.library.pdx.edu/open_access_etds/2231.
Full textAbstract:
River systems, such as the Columbia River in the Pacific Northwest, USA have been influenced by human activities, resulting in changes to the physical processes that drive landform evolution. This work describes an inventory of landforms along the Columbia River estuary between the Pacific Ocean and Bonneville Dam in Oregon and Washington. Groupings of landforms are assigned to formative process regimes that are used to assess historical changes to floodplain features. The estuary was historically a complex system of channels with a floodplain dominated by extensive tidal wetlands in the lower reaches and backswamp lakes and wetlands in upper reaches. Natural levees flank most channels in the upper reaches, locally including areas of ridge and swale topography and crevasse splays that intrude into backswamps. Other Holocene process regimes affecting floodplain morphology have included volcanogenic deltas, tributary fans, dunes, and landslides. Pre-Holocene landforms are locally prominent and include ancient fluvial deposits and bedrock. Historical changes to streamflow regimes, floodplain isolation by flood-control systems, and direct anthropogenic disturbance have resulted in channel narrowing and limited the amount of floodplain that can be shaped by flowing water. Floodplain isolation has caused relative subsidence of tidal floodplains along much of the lower estuary. Most extant landforms are on trajectories controlled by humans and new landforms are mostly created by humans.
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Lo, Edward Limin. "FLUVIAL-LACUSTRINE PROCESSES SHAPING THE LANDFORMS OF THE DISTAL PARAGUAY FLUVIAL MEGAFAN." UKnowledge, 2017. http://uknowledge.uky.edu/ees_etds/54.
Full textAbstract:
Tropical wetlands such as the Pantanal help regulate global biogeochemical cycles, but climate change is modifying these environments. Controls on environmental changes can potentially be assessed from ancient, well-dated lacustrine sedimentary records. An integrated field and laboratory approach was undertaken to study the limnogeology of Lake Uberaba in the northern Pantanal, and test whether the lake has preserved a reliable record of environmental change in its strata. This study was designed to understand how the basin accumulates sediment and to assess its sensitivity to hydroclimatic variability. The data showed that modern Lake Uberaba is a highly dynamic, freshwater fluvial-lacustrine basin. Modern lake floor sediments are largely siliciclastic silts, with limited organic matter content and abundant sponge spicules. This sedimentary composition reflects the lake’s open hydrology and well-mixed water column. Limited data from sediment cores indicates that Lake Uberaba may have formed ~1760 CE, following an abrupt transgression over an oxidized floodplain depositional environment. The stratal contact between lacustrine and floodplain deposits suggests the presence of an erosional unconformity, the timing and duration of which remains unknown. The environmental change favoring lake formation appears to be linked to increased effective precipitation provided by the Intertropical Convergence Zone (ITCZ) in the northern Pantanal.
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Scott, David Alan. "On active layer processes and landforms in western Dronning Maud Land, Antarctica." Thesis, Rhodes University, 2015. http://hdl.handle.net/10962/d1019757.
Full textAbstract:
Permafrost is a variable in Antarctic terrestrial ecosystems, and the role it plays in the cryosphere is not well understood. There is much still to be learnt about the thermal state, physical properties, thickness and age of permafrost in Western Dronning Maud Land (WDML). Active layer dynamics and observed change over time have the potential to improve our knowledge of climate change. Understanding the effects of a warming climate on permafrost can also be of benefit to infrastructure, especially in areas with a large amount of frozen ground such as Scandinavia, Canada and Russia. Active layer and permafrost dynamics of WDML, Antarctica, are presented and discussed using data from six study sites, namely the Robertskollen, Vesleskarvet, Flarjuven, Grunehogna, Slettjfell nunataks and the Troll research station in the Jutulsessen area. Ground and ambient air temperature, as well as ground moisture data were collected for each site. An inventory of active layer and permafrost landforms was compiled, as were the frequency of cycles over the zero-degree isotherm, and the depth of the active layer. Furthermore, 3D models, geo-referenced maps and Digital Elevation Models were created of study areas with the use of an Unmanned Aerial Vehicle (UAV). Polygonal features are the most common landscape feature and are common to most of the study sites. Robertskollen has the deepest active layer at over 66cm and Slettfjell the shallowest at 9cm. A maximum recorded air temperature of 8.76°C (10/11/2014) occurred at Troll with the second highest maximum of 6.77°C (22/12/2010) recorded at Vesleskarvet. Robertskollen has the highest observable biological growth and a maximum recorded ground temperature of 22.84°C (10/01/2014). Troll and Valterkulten, registered the second and third highest ground temperatures respectively. The high ground Temperature observed for Robertskollen may be ascribed to it being the lowest altitude site. The highest number of cycles over the zero-degree isotherm was observed at Troll (11.01%), followed by Robertskollen (10.99%). For relatively warm areas, such as Robertskollen it is recommended that two metre borehole loggers are installed in order to capture a detailed understanding of the active layer. The UAV proved to be a beneficial tool for capturing aerial photographs for post fieldwork analysis and 3D modelling.
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Voelker, Martin [Verfasser]. "Glacial and Fluvial Evolution of Landforms in Hellas Planitia, Mars / Martin Voelker." Berlin : Freie Universität Berlin, 2018. http://d-nb.info/1170877036/34.
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Magri, Rômulo Amaral Faustino. "Análise da suscetibilidade à erosão da região do Médio Rio Grande (MG)." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/18/18132/tde-28082013-091459/.
Full textAbstract:
Este trabalho objetivou analisar a suscetibilidade à erosão linear da região do Médio Rio Grande (MG), que abrange uma área de 9794,12 km², através de documentos cartográficos interpretativos. Utilizando técnicas de geoprocessamento e sensoriamento remoto associadas a levantamentos de campo e ensaios de laboratório, foram produzidos os seguintes documentos cartográficos: Carta de Declividade, Mapa de Landforms, Mapa de Materiais Inconsolidados e Inventário de Feições Erosivas. O produto final do trabalho, a Carta de Suscetibilidade à Erosão em escala 1:100.000, foi elaborada utilizando informações referentes ao substrato rochoso, formas do terreno, materiais inconsolidados e declividade. Cada documento cartográfico utilizado foi analisado de forma individual, para observar a potencialidade de cada um de seus atributos internos (ou classes) em desenvolver processos erosivos, assim, foram atribuídos pesos através do Processo Analítico Hierárquico (AHP). A Carta de Suscetibilidade à Erosão obtida conseguiu retratar bem a suscetibilidade da área, pois dos 78 processos erosivos de grande porte (boçorocas), identificados no inventário, em torno de 80% estão situados nas classes de alta e muito alta suscetibilidade à erosão. Portanto, esta Carta indica quais são as áreas em que se deve ter um controle mais rígido do uso e ocupação do solo para prevenir o desencadeamento de processos erosivos de grande porte, ou seja, auxilia no planejamento ambiental e na definição de medidas a serem tomadas.<br>This study aimed to analyze the susceptibility to linear erosion of the region of the Middle Rio Grande (Minas Gerais - Brazil) that covers an area of 9794.12 km², through interpretive cartographic documents. Using geoprocessing techniques and remote sensing associated with field surveys and laboratory tests, the following cartographic documents were produced: Chart of Slope, Landforms Map, Map of Unconsolidated Material and Inventory of Erosive Features. The final product of this work is the Chart of Erosion Susceptibility in scale 1:100,000. It was prepared using information relating to the bedrock, forms of terrain, unconsolidated materials and slope. Each cartographic document used was analyzed individually in order to observe the potential of each of its internal attributes (or classes) to develop erosive processes, thus were assigned weights using the Analytic Hierarchy Process (AHP). The Chart of Erosion Susceptibility obtained could well portray the susceptibility of the area because analyzing a total of 78 large erosion processes (gully erosion) identified in the inventory, about 80% are located in the classes of high and very high susceptibility to erosion. Therefore, this Chart indicates which areas in which to have a tighter control of the use and occupation of land to prevent large erosion triggering, ie assists in environmental planning and defining actions to be taken.
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White, Shawn K. "Validating Missouri landtype associations using tree species composition, forest structure, and productivity." Diss., Columbia, Mo. : University of Missouri-Columbia, 2005. http://hdl.handle.net/10355/4296.
Full textAbstract:
Thesis (M.S.)--University of Missouri-Columbia, 2005.<br>The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (January 10, 2007) Vita. Includes bibliographical references.
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Hartley, Kelley A. "Stratigraphic anaylsis [sic] of areal discontinuities of late Wisconsinan till sheets near Conneaut Lake, northwestern Pennsylvania." Akron, OH : University of Akron, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=akron1248371875.
Full textAbstract:
Thesis (M.S.)--University of Akron, Dept. of Geology, 2009.<br>"August, 2009." Title from electronic thesis title page (viewed 10/21/2009) Advisor, John P. Szabo; Faculty readers, Linda Barrett, LaVerne Friberg; Department Chair, John P. Szabo; Dean of the College, Chand Midha; Dean of the Graduate School, George R. Newkome. Includes bibliographical references.
29
Gercek, Deniz. "Object-based Classification Of Landforms Based On Their Local Geometry And Geomorphometric Context." Phd thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12611780/index.pdf.
Full textAbstract:
Terrain as a continuum can be categorized into landform units that exhibit common physiological and morphological characteristics which might serve as a boundary condition for a wide range of application domains. However, heterogeneous views, definitions and applications on landforms yield inconsistent and incompatible nomenclature that lack interoperability. Yet, there is still room for developing methods for establishing a formal background for general type of classification models to provide different disciplines with a basis of landscape description that is also commonsense to human insight.
This study proposes a method of landform classification that reveals general geomorphometry of the landscape. Landform classes that are commonsense to human insight and relevant to various disciplines is adopted to generate landforms at the landscape scale. Proposed method integrates local geometry of the surface with geomorphometric context. A set of DTMs at relevant scale are utilized where local geometry is represented with morphometric DTMs, and geomorphometric context is incorporated through relative terrain position and terrain network. &ldquo<br>Object-based image analysis (OBIA)&rdquo<br>tools that have the ability to segment DTMs into more representative terrain objects and connect those objects in a multi-level hierarchy is adopted. A fuzzy classification approach is utilized via semantic descriptions to represent ambiguities both in attribute and geographical space.
Method is applied at different case areas to evaluate the efficiency and stability of the classification. Outcomes portray reasonable amount of consistency where the results can be utilized as general or multi-purpose regarding some ambiguity that is inherent in landforms as well.
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VALLE, BARBARA. "PLANT AND ARTHROPOD COMMUNITIES OF ALPINE ICE-RELATED LANDFORMS: ECOLOGICAL AND BIOGEOGRAPHIC IMPORTANCE." Doctoral thesis, Università degli Studi di Milano, 2022. https://hdl.handle.net/2434/947188.
Full textAbstract:
This PhD thesis is mainly organised as collection of research papers published, submitted, and in preparation.
Chapter 1 outlines the state of the art, the main aims of the PhD project and the approaches used for reaching these objectives on peculiar study areas
Chapter 2, “Vanishing habitats”, presents, as a first result, a scientific call for studying and monitoring glacial and periglacial habitats – refugia for a cold-adapted and threatened biodiversity - because of the lack of knowledge that still affects these habitats (Gobbi et al. 2021). The study points out the urgency in planning this research due to the risk of total disappearance of these habitats in the current scenario of global warming.
Chapter 3, “Glacial and periglacial biodiversity”, is focused in analysing with multiple approaches the glacial and periglacial biodiversity. Studies 3.1-3.2 (Valle et al. 2022a-b) describe plants and arthropod communities of threatened glacial sites (Peirabroc, Clapier and Calderone glaciers) in peripheral mountain chains (Maritime Alps and Apennines, Italy, respectively). In these studies also important environmental parameters (e.g. debris thickness, soil temperatures and chemical parameters) have been correlated with biological communities. Study 3.3 focuses on glacial springtails and regards the description of a new species of ice-dwelling springtail from Calderone glacier (3.3, Valle et al. 2021). Studies 3.4-3.5 (Valle et al. 2020, Ornaghi et al. submitted) analyse the efficacy of cryophilic ground beetles (Carabidae: Nebrini) as ecological indicators of sub-superficial ice presence, through community, demographic (3.5) and morphometric (3.6) approaches. The paragraph 3.6 focuses on the biodiversity hosted by two of the few Dolomitic debris-covered glaciers, Sorapiss glaciers (Bernasconi et al. 2019). The last study (3.7, Fugazza et al. in submission) is a glaciological analysis that lays the foundations for studying in detail how the thickness of the stony debris accumulating on the glaciers influences the distribution of the biological community on debris-covered glacier.
In chapter 4, “Toward a synthesis of glacial ecology”, we move from the detail spatial scale (i.e. the glacier) of the previous chapter to a regional scale (e.g. Alpine), that could be useful for global considerations. The first study (4.1, Valle et al. in preparation) gives a complete overview on taxonomy, ecology and biogeography of ice-dwelling cryphilic springtails from European Alps. The second study (4.2, in preparation) aims to answer the question “what is the fate of cold-adapted species during global warming and glacier retreat?”; in order to do this, a comprehensive database with abundance data of 513 species of plants, ground beetles and spiders sampled in 463 glacial and periglacial plots has been analysed. The second paper (4.3, Hågvar et al. 2020) is a review of ecological studies performed in Europe (Svalbard, Scandinavia and European Alps) and points out the ecological features of young environments close to retreating glaciers: these “virgin” soils are colonised by a pioneer peculiar biological community in which springtails results a key taxon of the early trophic chain and consequently the early successional stages.
In chapter 5 are presented conclusions and perspectives of the research.
Chapter 6 reports the comprehensive Curriculum Vitae of my PhD, including all papers published, in submission and in preparation, congresses, teaching activity, grants, awards, dissemination, education activities and other projects which I joined.
31
Fogwill, Christopher J. "The application of cosmogenic exposure dating to glacial landforms : examples from Antarctica and Patagonia." Thesis, University of Edinburgh, 2003. http://hdl.handle.net/1842/24576.
Full textAbstract:
Through the measurement of the concentrations of the in situ cosmogenic nuclides 1°Be and 26A1 within rock surfaces, this thesis has attempted to solve previously intractable problems regarding the timing and magnitude of glaciation during the last glacial cycle in the vicinity of the Drake Passage. In southernmost Patagonia we have been able to constrain the timing of two major advances of the formerly expanded Patagonian Ice Sheet during the last glacial interglacial transition. In the past these have been in question due to the paucity of radiocarbon dates, in the extremely and conditions prevailing to the east of the southern-most Andes. The timing of deglaciation over 16° of latitude appears to be synchronous, although the magnitude of glaciation differed markedly from latitude to latitude. In southernmost Patagonia maximum ice extent was achieved before 26 ka BP, and deglaciation occurred rapidly at around 17 ka Bp. This is indistinguishable from that of the last glacial period in the Northern Hemisphere. This is interesting as it at a time when insolation was rising to its maximum in the southern hemisphere. The similarity of glacial chronologies from mid-latitudes in both hemispheres indicate that global atmospheric signaling is a major driving mechanism of climate. Results from Antarctica indicate a much more complex picture, with the Antarctic Peninsula and the Shackleton Range Mountains producing very different patterns of deglaciation. These data suggest that glaciation of the Antarctic Peninsula has been forced predominately by eustatic sea level fluctuations, with a complex spread of ages, suggesting ice surface thinning at times of rapid sea level rise. The pattern of deglaciation is very different in the Shackleton Mountains of Antarctica where Quaternary glacial fluctuations have been characterised by extreme stability, with no evidence of substantial ice thickening suggested by some hypotheses. The concentrations of radionuclides demonstrate that these summits have not been covered by ice for significant periods during the Quaternary. The implication is that this periphery of the East Antarctic Ice Sheet has not thickened by more than 400 m in the last 3 million years. Although these are only preliminary results, they place important constraints on glacial modelling studies and research regarding ice thickening of the Filchner Ice Shelf during glacial maxima. In turn these data have implications for ice-sheet controls of the global seawater budget during the last glacial interglacial cycle.
32
Wilmot, Nicola. "Periglacial landforms of the Ahlmannryggen and Jutulsessen areas of western Dronning Maud land, Antarctica." Thesis, Rhodes University, 2018. http://hdl.handle.net/10962/61535.
Full textAbstract:
Periglacial landforms are a common occurrence in Ahlmannryggen and Jutulsessen areas of western Dronning Maud land (WDML). Classification and formation of these landforms were disputed in literature. In Antarctica information on periglacial landforms is limited or confined to a specific landform. Thus a holistic approach was taken when investigating the periglacial landforms found in WDML. An overview of the existing knowledge base on periglacial landforms in WDML was given which was coupled with the analysis of archival data. The landforms found in this area were patterned ground, openwork block deposits (OBD), rock glaciers, terraces, a pronival rampart and lake ice blisters. With patterned ground being the common periglacial landform in WDML, heave monitoring was used where time-lapse videos were used to investigate the formation processes in patterned ground. From consolidating existing knowledge as well as adding new knowledge on the formation of periglacial landforms, it is clear that the landforms in Antarctica should not be compared to other examples, especially examples from the northern hemisphere. Further research in the formation of periglacial landforms is needed and can be further enhanced with more extensive use of the heave monitoring method in future research.
33
Havel, Jaroslav J. "Ecology of the forests of south western Australia in relation to climate and landforms." Murdoch University, 2000. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20060815.114944.
Full textAbstract:
This thesis sets out to test the hypothesis that the vegetational patterns in the forested region of south western Australia are primarily determined by the interaction of climate and landform.
The region is an area of 4.25 million hectares subject to recent agreement between the Commonwealth of '4ustralia and the state of Western Australia regarding long-term
protection and management of forest (Regional Forest Agreement).
The climate of the South Western forest region is warm temperate and summer dry, matching Koeppen's category Cs, usually described as mediterranean.
The dominant geological features of South Western Australia are crystalline and sedimentary plateaus and coastal plains. They are subject to a complex process of
weathering, denudation and re-deposition, which is the key determinant of landforms and soil patterns. Deep but infertile soils are prevalent.
The dominant vegetation formation of the region is open forest, which reduces to woodland in the drier north and east and increases to tall open forest in the moister
south. Floristically the vegetation is very rich, comprising over 3000 vascular plant species. The richness resides in the forest and woodland understorey and in the
shrublands, heathlands and sedgelands of edaphically extreme sites. By comparison, the forest overstorey is very simple, only one or two species being often dominant
over extensive areas.
The validation of the hypothesis that climate and landforms determine the vegetation patterns in South Western Australia is carried out in the following stages:
1) review of past studies of vegetation patterns in relation to the underlying environmental factors, relating them to one another in terms of floristics,
2) conversion of landform and climate maps for the region into vegetation maps by means of toposequences, that is gradients of topography, soils and vegetation within individual landform/climate combinations,
3) production of two sets of vegetation maps, namely six maps of vegetation complexes (1:250,000) and one map of vegetation systems (1:500,000),
4) testing the predictive capability of the resulting maps by comparing the occurrences of individual species of trees, shrubs and herbs predicted by map
legends, with their records in FloraBase, the geographic information system of the Western Australian Herbarium, and
5) using the outcomes of the above studies to assess the validity of the hypothesis.
Because the above hypothesis is so broad, it will be considered under seven headings:
a) nature of the vegetation patterns (continuum or discrete categories),
b) regional effect of climate and local effect of landform,
c) effect of landforms on soil depth, texture and fertility,
d) joint effect of slope, soil depth and texture on water balance,
e) interactive effect of landform and climate on vegetation patterns,
f) response of individual species to climate and landform, and
g) effect of other factors of environment, such as fire, on vegetation patterns.
The subsidiary hypotheses are defined in Chapter 5.
It is concluded that the vegetation of the region forms a lumpy continuum from the wet south west to the dry north east. Within that broad continuum there are localised
continua from waterlogged sites in depressions to drought-prone sites on steep stony slopes. However, the dominant vegetation of the region is open forest on plateau
uplands with deep infertile soils.
Although climate and landforms have a strong effect on vegetation patterns, they do not determine all vegetation patterns directly. Some tree species have ranges of
occurrence that are too broad for that, and others have ranges that are too restricted.
A more probable explanation is that climate and landforms, together with fire, set the stage on which the interplay of species takes place and determines the structure and
composition of the vegetation. An attempt is made to predict the likely effect of climatic changes on vegetation patterns.
The applicability of the methodology developed to the mapping of other regions, especially the adjacent ones, is examined. A review is made of how the products of
the study, in particular the maps, are currently being used, and suggestions are made how they could be used in the future.
34
Hjort, Jan. "Environmental factors affecting the occurrence of periglacial landforms in Finnish Lapland : a numerical approach /." Aachen : Shaker, 2006. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=014835670&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Havel, J. J. "Ecology of the forests of south western Australia in relation to climate and landforms /." Access via Murdoch University Digital Theses Project, 2000. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20060815.114944.
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Drake, Nick A. "Mapping and monitoring surficial materials, processes and landforms in southern Tunisia using remote sensing." Thesis, University of Reading, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333490.
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Sutton, Brian. "Glacial landforms and sedimentology and Late Pleistocene evolution of the Mourne Mountains, Northern Ireland." Thesis, University of Ulster, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267825.
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Van, Dijk Thaienne A. G. P. "Glacier surges as a control on the development of proglacial fluvial landforms and deposits." Thesis, Keele University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.392176.
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Havel, Jaroslav Joseph. "Ecology of the forests of south western Australia in relation to climate and landforms." Thesis, Havel, Jaroslav Joseph (2000) Ecology of the forests of south western Australia in relation to climate and landforms. PhD thesis, Murdoch University, 2000. https://researchrepository.murdoch.edu.au/id/eprint/70/.
Full textAbstract:
This thesis sets out to test the hypothesis that the vegetational patterns in the forested region of south western Australia are primarily determined by the interaction of climate and landform.
The region is an area of 4.25 million hectares subject to recent agreement between the Commonwealth of Australia and the state of Western Australia regarding long-term protection and management of forest (Regional Forest Agreement). The climate of the South Western forest region is warm temperate and summer dry, matching Koeppen's category Cs, usually described as mediterranean. The dominant geological features of South Western Australia are crystalline and sedimentary plateaus and coastal plains. They are subject to a complex process of weathering, denudation and re-deposition, which is the key determinant of landforms and soil patterns. Deep but infertile soils are prevalent. The dominant vegetation formation of the region is open forest, which reduces to woodland in the drier north and east and increases to tall open forest in the moister south. Floristically the vegetation is very rich, comprising over 3000 vascular plant species. The richness resides in the forest and woodland understorey and in the shrublands, heathlands and sedgelands of edaphically extreme sites. By comparison, the forest overstorey is very simple, only one or two species being often dominant over extensive areas.
The validation of the hypothesis that climate and landforms determine the vegetation patterns in South Western Australia is carried out in the following stages:
1) review of past studies of vegetation patterns in relation to the underlying environmental factors, relating them to one another in terms of floristics, 2) conversion of landform and climate maps for the region into vegetation maps by means of toposequences, that is gradients of topography, soils and vegetation within individual landform/climate combinations, 3) production of two sets of vegetation maps, namely six maps of vegetation complexes (1:250,000) and one map of vegetation systems (1:500,000), 4) testing the predictive capability of the resulting maps by comparing the occurrences of individual species of trees, shrubs and herbs predicted by map legends, with their records in FloraBase, the geographic information system of the Western Australian Herbarium, and 5) using the outcomes of the above studies to assess the validity of the hypothesis.
Because the above hypothesis is so broad, it will be considered under seven headings:
a) nature of the vegetation patterns (continuum or discrete categories),
b) regional effect of climate and local effect of landform,
c) effect of landforms on soil depth, texture and fertility,
d) joint effect of slope, soil depth and texture on water balance,
e) interactive effect of landform and climate on vegetation patterns,
f) response of individual species to climate and landform, and
g) effect of other factors of environment, such as fire, on vegetation patterns.
The subsidiary hypotheses are defined in Chapter 5.
It is concluded that the vegetation of the region forms a lumpy continuum from the wet south west to the dry north east. Within that broad continuum there are localised continua from waterlogged sites in depressions to drought-prone sites on steep stony slopes. However, the dominant vegetation of the region is open forest on plateau uplands with deep infertile soils. Although climate and landforms have a strong effect on vegetation patterns, they do not determine all vegetation patterns directly. Some tree species have ranges of occurrence that are too broad for that, and others have ranges that are too restricted. A more probable explanation is that climate and landforms, together with fire, set the stage on which the interplay of species takes place and determines the structure and composition of the vegetation. An attempt is made to predict the likely effect of climatic changes on vegetation patterns. The applicability of the methodology developed to the mapping of other regions, especially the adjacent ones, is examined. A review is made of how the products of the study, in particular the maps, are currently being used, and suggestions are made how they could be used in the future.
40
Jones, Andrew. "Sedimentological record of the late palaeozoic Gondwanan glaciation in Queensland /." St. Lucia, Qld, 2003. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17532.pdf.
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D'Urso, Gary John. "Revised glacial margins and Wisconsin meltwater paleoflood hydrology in Slippery Rock Creek Basin, central western Pennsylvania." Morgantown, W. Va. : [West Virginia University Libraries], 2000. http://etd.wvu.edu/templates/showETD.cfm?recnum=1436.
Full textAbstract:
Thesis (Ph. D.)--West Virginia University, 2000.<br>Title from document title page. Document formatted into pages; contains x, 174 p. : ill. (some col.), maps (some col.) Includes abstract. Includes bibliographical references (p. 171-174).
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Stark, Jonathan Michael. "Use of LIDAR in geomorphic mapping and interpretation of coastal, fluvial, glacial and anthropogenic landforms." The Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=osu1409232439.
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Park, Soojin. "Modelling soil-landform continuum on a three-dimensional hillslope." Thesis, University of Oxford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.670238.
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Lopes, Rita Pereira. "A delimitação de unidades de terra. Caso do concelho de Lourinhã." Master's thesis, ISA/UL, 2015. http://hdl.handle.net/10400.5/9212.
Full textAbstract:
Mestrado em Arquitectura Paisagista - Instituto Superior de Agronomia<br>Land units have become an important mapping tool as they express similar climate, geology, soils,
landforms and vegetation characteristics. They summarize all information that facilitate mapping
development and can be applied at any scale. Land units are used for many purposes, such as
landscape characterization and support for land evaluation processes. Hence it is important to deepen
the knowledge and practice of the delimitation procedures in areas where the required information is
complex and insufficient. In the present study, Lourinhã municipally was opted as a case study,
where land units were mapped through geology, landforms, soils, presence of rocky outcrops and field
observation. The results of 30 land units have shown the main land degradation risks,
essentially associated with climate, erosion risks and flood risks. The land unit survey is therefore a
support for the management needs and conservation of resources that can respond to general matters
related to landscape planning but also provides support of general evaluations in the context of land
capability classification
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Zhang, Fangli. "A particle-set distributed hydrological model for the dynamic simulation of surface runoff." HKBU Institutional Repository, 2017. https://repository.hkbu.edu.hk/etd_oa/472.
Full textAbstract:
1.1\xThis study proposed a particle-set distributed hydrological model for the dynamic simulation of rainfall-runoff process. With the supports of remote sensing, GIS, terrain analysis and distributed computing techniques, a representation-simplified and physically-based high-performance watershed framework has been developed. It simplifies the underlying watershed with a flow path network model, and represents the moving surface flow with independent runoff particles.;1.2\xThe original idea was to investigate a real-time modeling system for the space-time dynamics of increasingly frequent extreme rainfall events. Short-term heavy rains may cause further damages by spawning floods and landslides. It is quite essential to understand how the rainfall water moves across the watershed surface as early as possible. A modelling system with high-performance in simulation efficiency and space-time prediction accuracy would be very desirable.;1.3\xWatershed modeling is the primary way to explore the hydrological cycle at a local scale. Existing models are classified as empirical lumped, conceptual semi-distributed and physically-based distributed models. The first two types of models have focused more on predicting outlet discharges rather than estimating spatiotemporal flow dynamics. The application of physically-based models has always been hampered by some common shortcomings like over-parameterization, inflexibility and computational burden. With the increasing support from terrain analysis and parallel computing techniques, a number of previous studies have made some efforts to improve the performance in dynamic and real-time simulation. However, research gaps still exist in realistic representation, physical description and real-time simulation.;1.4\xThis study, therefore, developed the particle-set modeling system on the basis of flow path network model. This one-dimensional topological structure was created beforehand to represent the three-dimensional watershed, and a series of particle beams were dynamically generated to simulate the surface flow. Under the control of flow velocities, these runoff particles would keep on moving along with the flow paths, which can represent the spatial distributions of surface water in time.;1.5\xTo validate the proposed particle-set framework, a prototype of particle-set system was implemented by programming methods with the assistance of third-party platforms. Three experiments were undertaken to respectively evaluate the performance in prediction accuracy, simulation efficiency and parameter sensitivity. More specifically, a total of 10 rainfall events and up to 128 computer processors were tested. In addition, the influences of underlying spatial scale and source sampling density on hydrological responses were explored with comparative tests.;1.6\xThe accuracy validation comes in two parts, the representation loss in terrain analysis, and the discharge error in hydrological modeling. The experimental results indicate that the TIN-based flow path network has maintained the terrain features at a very high level with much less data storage, and the particle-set framework has achieved quite acceptable predictions of outlet discharges. Besides, the efficiency evaluation concerns with two aspects, parallel portion and parallel efficiency. The speed-up results indicate that about 99% of the computational workloads can be computed in parallel, and the particle-based scheme can achieve almost the ideal parallel efficiency. In addition, the sensitivity test focuses also on two parameters, underlying spatial scale and source sampling density. The preliminary results show that the particle-set model has shown a good reliability and stability as scale gets coarser or density becomes sparser.;1.7\xThis study will contribute to the understanding of short-term rainfall-runoff events at a basin scale. The particle-set distributed hydrological model has been proven to provide real-time spatio-temporal dynamics of surface flow. Further studies would still be required to apply it to real world scenarios.;1.8\xKeywords: terrain analysis, watershed hydrology, rainfall-runoff process, flow path network, particle system, parallel computing
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Hjort, Jan [Verfasser]. "Environmental factors affecting the occurrence of periglacial landforms in Finnish Lapland: a numerical approach / Jan Hjort." Aachen : Shaker, 2006. http://d-nb.info/1170529194/34.
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Peagler, Arriyan L. "Design guidelines for incorporating landforms and sculptural elements into residential treatment centers for at-risk youth." Virtual Press, 2008. http://liblink.bsu.edu/uhtbin/catkey/1397794.
Full textAbstract:
A wide range of individuals, from counselors to psychiatrists, have recognized the value of residential treatment centers for at-risk youth. Many residential treatment centers foster therapeutic interventions indoors. Typically, however, there have been few initiatives taken to enhance the outdoor landscapes of these facilities. In particular, potential supplements to therapeutic practices such as landforms and sculpture have been overlooked. This creative project explores how outdoor settings can be enhanced with landforms to provide at-risk youth with alternative venues to address aggressive and antisocial behaviors. Additionally, group activities are considered that could take place in these spaces, using landforms as educational tools.The purpose of this creative project was to determine ways to utilize sculptural landforms in support of treatment plans at a residential treatment facility. The research process included interviews with employees of the Youth Opportunity Center (YOC) in Muncie, Indiana, site visits to various outdoor public spaces, and reviews of the writings of Clare Cooper Marcus and Marni Barnes. The research phase contributed to the development of a design program, and led to the development of design concepts for the YOC. These concepts are documented in master plan, elevation, and sketch form. The research and design concepts are found in the following document.<br>Department of Landscape Architecture
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Osei, Nana Akwasi. "Large wood in fluvial systems : quantity, structure and landforms, sediment retention, and riparian seed bank development." Thesis, Queen Mary, University of London, 2014. http://qmro.qmul.ac.uk/xmlui/handle/123456789/8813.
Full textAbstract:
This thesis investigates the characteristics and impacts of large wood accumulations within river reaches of different size and style. Four reaches were studied: (i) a wide, braided, headwater reach, characterised by dead wood (Tagliamento River, Italy); (ii) a lower gradient, wide, braided reach, characterised by resprouting wood (Tagliamento River, Italy); (iii) a low gradient, single thread reach with a natural supply of dead wood (Highland Water, UK), and (iv) a low gradient, single thread reach that has been restored by felling trees into the river (River Bure, UK). In each reach, quantities of wood, types of accumulation and their association with sediment retention, landform and propagule bank development were investigated, generating four main findings: 1. There were marked differences in the size and character of large wood accumulations among the four reaches. 2. Retention of fine sediment and organic matter by wood was observed on all four reaches, giving rise to notable spatial heterogeneity in surface sediments. 3. Sediment retention resulted in the development of different landforms among the four reaches. In the two multi-thread reaches, accretion of finer sediment around large wood led to island development. In the naturally-functioning single-thread reach, wood jams spanned the river channel, accumulating sediment and organic matter to produce unvegetated wood jams, and inducing other landforms, notably pools and bars. Such geomorphic heterogeneity was anticipated in the restored reach, but to date this has not significantly occurred. 4. Spatio-temporal variations were observed in propagule abundance and species richness within different wood-related mesohabitats. Higher abundance and species richness were associated with finer, more organic sediments retained within wood accumulations and related mesohabitats. In the restored reach such associations were not statistically significant, further indicating that responses to wood emplacement take longer than the 4 years since restoration. iv Overall, this research has strengthened the evidence concerning the differing nature of wood accumulations in rivers of different size and style, and it has demonstrated the importance of large wood for retaining organic matter and plant propagules, resources essential for riparian vegetation succession and for the success of river restoration efforts.
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Korzeniowska, Karolina [Verfasser], and Oliver [Akademischer Betreuer] Korup. "Object-based image analysis for detecting landforms diagnostic of natural hazards / Karolina Korzeniowska ; Betreuer: Oliver Korup." Potsdam : Universität Potsdam, 2017. http://d-nb.info/1218402792/34.
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Grimm, Günter Albin. "Vegetation succession on glacier forelands in the Jostedalsbreen region and Jotunheimen, south-central Norway." Thesis, University of Oxford, 2000. http://ora.ox.ac.uk/objects/uuid:aedabc31-7022-4666-8121-7379b1bc4998.
Full textAbstract:
In this study four different aspects of primary successions on glacier forelands in South-Central Norway are investigated. First, general vegetation and environment trends, which have been observed by other scientists, were studied on two forelands. It is shown that the two selected forelands (one low- and one high-altitude foreland, Nigardsbreen and Storbreen, respectively) differ in the speed of vegetation cover change and in the overall species richness developed over the last 250 years since deglaciation. This is attributed to differences in the severity of the environment between the two forelands. Some support for an early peak in the number of species was found for the Nigardsbreen foreland, whereas the Storbreen foreland shows no significant trend in the development of species richness. Life-forms and soil-depth change on both forelands in the predicted manner. A novel approach for the use of Ellenberg indicator values for the estimation of pH-values from the existent vegetation shows highly significant correlations between predicted pH values and trends measured for similar terrain ages from a study by Messer (1988). Investigation at two different scales indicated that small-scale disturbances (< 100 m) may influence the mosaic of the environment, which affects the results of the chronosequence approach. By using a strict geometrical sampling design more variable conditions entered the analyses than with the stratified random sampling schemes adopted by others, such as Matthews (1979b). Some loss in the power of analysing the data occurred, but the results are still consistent with hypotheses about primary succession on glacier forelands. Second, new aspects of the temporal development and successional change of plant communities were investigated on the same two forelands. There is some evidence of succession from a pioneer community to the local climax community of the surrounding area for both forelands. There is also support for the correlation of timedependent environmental variables with the successional development of plant communities. A new application of Ellenberg indicator values in ordinations was assessed for its value in estimating average environmental conditions derived from the vegetation. As with the previous analyses, investigation of community development at two different scales supported the importance of sampling scale on the analysis of succession data. Third, spatially explicit analyses of distribution patterns of dominant woody species was developed as a means to investigate processes and formulate hypotheses about primary succession on glacier forelands. The data for this part of the study was collected on five glacier forelands, three low-altitude (Nigardsbreen, Austerdalsbreen and Bødalsbreen) and two high-altitude (Storbreen and Høgvaglbreen). Pattern descriptors including perimeter/area index, autocorrelation measures and fractal dimensions, support the hypothesis of differential colonisation of wind and animaldispersed species. Even more convincing is the result that low- and high-altitude forelands show significant differences in the patterns exhibited by wind and animals dispersed species. This result is thought to be related to the differences in environmental severity affecting the establishment of colonising species. Finally, logit modelling of the distributions of dominant woody species provides insights into the sampling effort needed to gather enough data for meaningful analyses. It also leads to the identification of important factors influencing the distribution of those species.