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Bandyopadhyay, M. K. "Geomorphological characteristics of the Mayurbhanj upland of Orissa." Thesis, University of North Bengal, 1988. http://hdl.handle.net/123456789/823.
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Matthews, David. "Simulating Martian geomorphology." Thesis, University of Dundee, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.629065.
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The Planetary And Natural scene Generation Utility (P ANGU) , developed at the University of Dundee for the European Space Agency (ESA), successfully generates stochastic Digital Elevation Models (DEMs) of simulated planetary surfaces. P ANGU was developed to allow development and extensive testing of vision-guided navigation software for autonomous planetary landers. PANGU's initial scope was to model airless bodies such as the Moon and Mercury. ESA has outlined the Mars exploration programme for the next few decades as part of its Aurora programme. In this context, "Modelling Martian Geomorphology" looks at extending PANGU's capabilities to allow the modelling of Martian surfaces. A review of available Martian remote sensing data is undertaken and a summary of Martian terrain types is provided. From this, the requirements for a Martian surface model are derived. The development of a stochastic sand dune model was identified as a key addition to allow P ANGU to model Mars. Existing geomorphological sand dune models concentrate on modelling the dynamic processes that generate sand dunes. A dynamic model developed by Werner is implemented in PANGU. Novel aspects of this research are, running the model over existing surfaces and exploration of scale factors for use in a P ANGU hierarchical model. The model though proves to be scale dependent and is not directly suitable for use in PANGU. Research is undertaken into feature extraction from the dynamic model. Dune crests and toe locations are extracted and a geometric model of the dune cross-section is used to reconstruct the dune. This generates a model that can be rendered at a range of scales as required by PANGU. This model suffers from artefacts introduced in the dune reconstruction where dunes overlap. An entirely static model is developed based on the random placement of barchan dunes. Where these overlap, they are merged to produce barchanoid ridge dunes. With high densities of initial barchan dunes, after merging, transverse dune fields are created. This method has been implemented in P ANGU and used in development research by ESA.
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Martin, Yvonne. "Modelling geomorphology in landscape evolution." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape15/PQDD_0030/NQ27198.pdf.
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Sjogren, Elizabeth Claire. "Geomorphology of the Tawatinaw region." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0020/MQ47096.pdf.
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Overby, Steven T., and Daniel G. Neary. "Travertine Geomorphology of Fossil Creek." Arizona-Nevada Academy of Science, 1996. http://hdl.handle.net/10150/296999.
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Lama, Sangita. "Urban geomorphology of Darjeeling town." Thesis, University of North Bengal, 1994. http://hdl.handle.net/123456789/853.
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Finlayson, David P. "The geomorphology of Puget Sound beaches /." Thesis, Connect to this title online; UW restricted, 2006. http://hdl.handle.net/1773/11035.
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Bisht, Deepti. "Structure and geomorphology, southeast Dinarides, Croatia." Thesis, University of Cambridge, 2014. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708060.
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Moore, Edwin Neville. "Glacial geology and geomorphology of Weardale." Thesis, Durham University, 1994. http://etheses.dur.ac.uk/1625/.
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Alsheeb, Ali I. M. "Coastal geomorphology of the Qatar Peninsula." Thesis, Swansea University, 1988. https://cronfa.swan.ac.uk/Record/cronfa43167.
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This study concerns the geomorphology of the coastline of the Qatar Peninsula. In all, the coastline is approximately 750kg long and is dominated by Tertiary and Quaternary limestone rocks. Since little previous work has been carried out into the coastal geomorphology of the Arabian Gulf in general and Qatar in particular, a fundamental task was to undertake a classification of the coastal types. There are: 1) sand dunes and sheets; 2) sabkhas; 3) cliffs; 4) coral reefs; 5) beaches and 6) mangroves. A second task in this study was to investigate the processes responsible for the different coastal types. This was achieved using different field and laboratory techniques. Aerial photo interpretation enabled the nature of forms to be better understood and photos of different dates enabled temporal change to be investigated. Both Abeny level and Dumpy level were used to show the forms of the different coastal types. Particle size analysis was used to differentiate the origin of sediments. Laboratory experiments of salt weathering on rocks of the Qatar shoreline indicated the effectiveness of this process. SEM analysis showed the mix of aeolian and beach transport histories in the coastal sediments. The study shows that the following factors are particularly important in producing the distinctiveness of the Qatar coastline: these are warm sea temperatures leading to rapid chemical weathering; the prevailing NW ('shamal') wind, which influences strongly sand supply at the coast and longshore drift direction; and a low tidal range.
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Gales, Jenny Anne. "The geomorphology of Antarctic submarine slopes." Thesis, University of Manchester, 2013. https://www.research.manchester.ac.uk/portal/en/theses/the-geomorphology-of-antarctic-submarine-slopes(d117ad12-927b-44f1-bf67-d195e2fef51b).html.
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The Antarctic continental margin contains a diverse range of continental slope morphologies, including iceberg keel marks, gullies, channels, mass-wasting features (slides, slumps), ridges, furrows, mounds and trough mouth fans. These features vary significantly in morphology, with bedforms varying in size (width, amplitude and length), shelf incision, sinuosity, branching order, spatial density and cross-sectional shape. The processes which form these features and the environmental controls influencing their morphology are not well documented or well constrained. Understanding the processes operating on the Antarctic continental margin is essential for interpreting seafloor erosion patterns, continental margin evolution, slope instability and sediment core records from the continental slope and rise. Through quantitative analysis of multibeam bathymetric data along >2670 km of the outer shelf and upper-slope of high latitude continental margins, five distinct Antarctic gully types are identified. Gully morphology was found to vary with local slope character (slope geometry, gradient), regional factors (location of cross-shelf troughs, trough mouth fans and drainage basin size), sediment yield and ice-sheet history. Most gullies are likely formed by: (1) flows generated as a result of the release of subglacial meltwater from beneath an ice-sheet grounded to the shelf edge during glacial maxima; (2) turbidity currents initiated by intense iceberg scouring; or (3) small-scale mass-wasting. Erosion by cascading dense water overflow does not form the deeply incised and V-shaped gullies that occur over much of the Antarctic continental margin. A comparison of some Arctic and Antarctic gully morphologies shows that the Antarctic gullies have much deeper mean incision depths and greater shelf-incisions, suggesting that they either formed over significantly longer periods, or by a greater release of meltwater in the areas with greater gully incision depths. The first morphological analysis of the southern Weddell Sea outer shelf and upper slope is presented. Two large and relatively recent submarine slides occur on the Crary Fan, the first Quaternary slides to be documented on an Antarctic trough mouth fan. These slides provide evidence for recent large-scale mass-wasting events on the Antarctic continental margin. The interpretation of bedforms on the outer shelf of the southeastern Weddell Sea provide insight into the timing and extent of past ice and points to grounded ice near to the shelf edge during the Late Quaternary.
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Alqahtani, Faisal A. "3D seismic geomorphology of fluvial systems." Thesis, Imperial College London, 2010. http://hdl.handle.net/10044/1/6180.
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Fluvial sandstones constitute one of the major clastic petroleum reservoir types in many sedimentary basins around the world. This is especially true in the Tertiary basins of Southeast Asia, which display a wide range of fluvial channel reservoir types. This study is based on the analysis of high-resolution, shallow (seabed to ca. 500 m depth) 3D seismic data which provide exceptional imaging of the geometry, dimension and temporal and spatial distribution of fluvial channels. The Malay Basin comprises a thick (>8 km), rift to post-rift Oligo-Miocene to Pliocene basin-fill. The youngest (Miocene to Pliocene), post-rift succession is dominated by a thick (1-5 km), cyclic succession of coastal plain and coastal deposits, which accumulated in a humidtropical climatic setting. This study focuses on the Pleistocene to Recent (ca. 500 m thick) succession, which comprises a range of seismic facies, mainly reflecting changes in fluvial channel style and gross stratigraphic architecture. The succession has been divided into four seismic units (Unit 1-4), bounded by basin-wide stratal surfaces. Units 3 and 4 have been further divided into two sub-units. Two types of boundaries have been identified: 1) a boundary that is defined by a regionally-extensive erosion surface at the base of a prominent incised valley (e.g. Horizons C.1 and D.1); 2) a sequence boundary that is defined by more weakly-incised, straight and low-sinuosity channels which is interpreted as lowstand alluvial bypass channel systems (e.g. Horizons A, B, C, and D). Each unit displays a predictable vertical change of the channel pattern and scale, with wide low-sinuosity channels at the base passing gradationally upwards into narrow high-sinuosity channels at the top. The wide variation in channel style and size is interpreted to be controlled mainly by the sea-level fluctuations on the widely flat and tectonically-quiescent Sundaland Platform.
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Bamberg, Marlene. "Planetary mapping tools applied to floor-fractured craters on Mars." Phd thesis, Universität Potsdam, 2014. http://opus.kobv.de/ubp/volltexte/2014/7210/.
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Planetary research is often user-based and requires considerable skill, time, and effort. Unfortunately, self-defined boundary conditions, definitions, and rules are often not documented or not easy to comprehend due to the complexity of research. This makes a comparison to other studies, or an extension of the already existing research, complicated. Comparisons are often distorted, because results rely on different, not well defined, or even unknown boundary conditions.
The purpose of this research is to develop a standardized analysis method for planetary surfaces, which is adaptable to several research topics. The method provides a consistent quality of results. This also includes achieving reliable and comparable results and reducing the time and effort of conducting such studies. A standardized analysis method is provided by automated analysis tools that focus on statistical parameters. Specific key parameters and boundary conditions are defined for the tool application. The analysis relies on a database in which all key parameters are stored. These databases can be easily updated and adapted to various research questions. This increases the flexibility, reproducibility, and comparability of the research. However, the quality of the database and reliability of definitions directly influence the results. To ensure a high quality of results, the rules and definitions need to be well defined and based on previously conducted case studies. The tools then produce parameters, which are obtained by defined geostatistical techniques (measurements, calculations, classifications).
The idea of an automated statistical analysis is tested to proof benefits but also potential problems of this method. In this study, I adapt automated tools for floor-fractured craters (FFCs) on Mars. These impact craters show a variety of surface features, occurring in different Martian environments, and having different fracturing origins. They provide a complex morphological and geological field of application. 433 FFCs are classified by the analysis tools due to their fracturing process. Spatial data, environmental context, and crater interior data are analyzed to distinguish between the processes involved in floor fracturing.
Related geologic processes, such as glacial and fluvial activity, are too similar to be separately classified by the automated tools. Glacial and fluvial fracturing processes are merged together for the classification. The automated tools provide probability values for each origin model. To guarantee the quality and reliability of the results, classification tools need to achieve an origin probability above 50 %. This analysis method shows that 15 % of the FFCs are fractured by intrusive volcanism, 20 % by tectonic activity, and 43 % by water & ice related processes. In total, 75 % of the FFCs are classified to an origin type. This can be explained by a combination of origin models, superposition or erosion of key parameters, or an unknown fracturing model. Those features have to be manually analyzed in detail. Another possibility would be the improvement of key parameters and rules for the classification.
This research shows that it is possible to conduct an automated statistical analysis of morphologic and geologic features based on analysis tools. Analysis tools provide additional information to the user and are therefore considered assistance systems.Planetenforschung umfasst oft zeitintensive Projekte, bei denen Expertise und Erfahrung eine wesentliche Rolle spielen. Auf Grund äusserst komplexer und sich selten wiederholender Forschungsfragen sind Annahmen, Definitionen und Regeln zur Lösung dieser Fragen nicht leicht nachvollziehbar oder aber nicht eindeutig dokumentiert. Ein Vergleich der Ergebnisse unterschiedlicher Forscher zum selben Thema oder eine Erweiterung der Forschungsfrage macht dies somit nur schwer möglich. Vergleiche liefern oftmals verzerrte Ergebnisse, da die Ausgangslage und Randbedingungen unterschiedlich definiert worden sind. Das Ziel dieser Arbeit ist es eine Standardmethode zur Oberflächenanalyse zu entwickeln, die auf zahlreiche Untersuchungsfragen angewandt werden kann. Eine gleichbleibende Qualität der Ergebnisse muss durch diese Methode gewährleistet sein. Ein weiteres Ziel ist es, dass diese Methode ohne Vorwissen und Expertise angewandt werden kann und die Ergebnisse in kurzer Zeit vorliegen. Ausserdem müssen die Ergebnisse vergleichbar und nachvollziehbar sein. Automatisch operierende Analysewerkzeuge können die zahlreichen Anforderungen erfüllen und als Standardmethode dienen. Statistische Ergebnisse werden durch diese Methode erzielt. Die Werkzeuge basieren auf vordefinierten, geowissenschaftlichen Techniken und umfassen Messungen, Berechnungen und Klassifikationen der zu untersuchenden Oberflächenstrukturen. Für die Anwendung dieser Werkzeuge müssen Schlüsselstrukturen und Randbedingungen definiert werden. Des Weiteren benötigen die Werkzeuge eine Datenbank, in der alle Oberflächenstrukturen, aber auch Informationen zu den Randbedingungen gespeichert sind. Es ist mit geringem Aufwand möglich, Datenbanken zu aktualisieren und sie auf verschiedenste Fragestellungen zu adaptieren. Diese Tatsache steigert die Flexibilität, Reproduzierbarkeit und auch Vergleichbarkeit der Untersuchung. Die vordefinierten Randbedingungen und die Qualität der Datenbank haben jedoch auch direkten Einfluss auf die Qualität der Ergebnisse. Um eine gleichbleibend hohe Qualität der Untersuchung zu gewährleisten muss sichergestellt werden, dass alle vordefinierten Bedingungen eindeutig sind und auf vorheriger Forschung basieren. Die automatisch operierenden Analysewerkzeuge müssen als mögliche Standardmethode getestet werden. Hierbei geht es darum Vorteile, aber auch Nachteile zu identifizieren und zu bewerten. In dieser Arbeit werden die Analysewerkzeuge auf einen bestimmten Einschlagskratertyp auf dem Mars angewandt. Krater mit zerbrochenen Kraterböden (Floor-Fractured Craters) sind in verschiedensten Regionen auf dem Mars zu finden, sie zeigen zahlreiche Oberflächenstrukturen und wurden durch unterschiedliche Prozesse geformt. All diese Fakten machen diesen Kratertyp zu einem interessanten und im geologischen und morphologischen Sinne sehr komplexen Anwendungsgebiet. 433 Krater sind durch die Werkzeuge analysiert und je nach Entstehungsprozess klassifiziert worden. Für diese Analyse sind Position der Krater, Art des Umfeldes und Strukturen im Kraterinneren ausschlaggebend. Die kombinierten Informationen geben somit Auskunft über die Prozesse, welche zum Zerbrechen des Kraterbodens geführt haben. Die entwickelten Analysewerkzeuge können geologische Prozesse, die sehr ähnlich zueinander sind, von einander abhängig sind und zusätzlich auch dieselben Oberflächenstrukturen formen, nicht eindeutig unterscheiden. Aus diesem Grund sind fluviale und glaziale Entstehungsprozesse für den untersuchten Kratertyp zusammengefasst. Die Analysewerkzeuge liefern Wahrscheinlichkeitswerte für drei mögliche Entstehungsarten. Um die Qualität der Ergebnisse zu verbessern muss eine Wahrscheinlichkeit über 50 % erreicht werden. Die Werkzeuge zeigen, dass 15 % der Krater durch Vulkanismus, 20 % durch Tektonik und 43 % durch Wasser- und Eis-bedingte Prozesse gebildet wurden. Insgesamt kann für 75 % des untersuchten Kratertyps ein potentieller Entstehungsprozess zugeordnet werden. Für 25 % der Krater ist eine Klassifizierung nicht möglich. Dies kann durch eine Kombination von geologischen Prozessen, einer Überprägung von wichtigen Schlüsselstrukturen, oder eines bisher nicht berücksichtigten Prozesses erklärt werden. Zusammenfassend ist zu sagen, dass es möglich ist planetare Oberflächenstrukturen quantitativ durch automatisch operierende Analysewerkzeuge zu erfassen und hinsichtlich einer definierten Fragestellung zu klassifizieren. Zusätzliche Informationen können durch die entwickelten Werkzeuge erhalten werden, daher sind sie als Assistenzsystem zu betrachten.
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Thompson, Chris J. Physical Environmental & Mathematical Sciences Australian Defence Force Academy UNSW. "The geomorphology of Southeast Australian mountain streams." Awarded by:University of New South Wales - Australian Defence Force Academy. School of Physical, Environmental and Mathematical Sciences, 2006. http://handle.unsw.edu.au/1959.4/38681.
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This thesis is a study of the morphology and sediment transport dynamics of mountain streams in southeast Australia. Mountain streams represent important geomorphological and ecological systems in Australia which have hitherto been poorly studied. The variability of mountain stream reach morphology was investigated at the regional scale using topographical surveys and sediment sampling techniques. Study sites were stratified by slope and local lithology. Eight channel-morphologies including Bedrock, Cascade, Step-pool, Planebed, Pool-Riffle, Cascade-pool, Riffle-step and Infilled, were identified using an objective statistical approach. Overall, channel types were found to correspond to existing reach-scale mountain stream templates. Five morphologies were associated with a specific lithology type which controlled the size and shape of grains supplied to the channels. Differences in coarse sediment transport processes between morphologies were investigated using stream monitoring techniques and Optically Stimulated Luminescence (OSL) dating. Monitoring results from a 3 year period indicated that channel beds are resistant to entrainment with shear stress thresholds for bedload transport ranging between 64 to 74 N/m2. Transport of reach median grain sizes requires floods that exceed bankfull discharge. Existing competence equations were found to over-predict the hydraulic driving force and consequently, a modified entrainment model was used to account for the regional channel characteristics. OSL dating was investigated as a tool to provide data on long-term sediment transport processes. Minimum age model results from the OSL dates show overall agreement with a selected entrainment model, and indicate differences in sediment transport dynamics between some reach morphology types. A regime model was used to quantify the physical domains of different channel morphologies. Limitations of the model were overcome by modifying the sediment supply surrogate to better reflect the dominant transported bedload size. Morphology types were delineated according to different sediment transport capacity-sediment supply domains. The distribution of channel morphology types within a series of catchments in southeast Australia was modelled within a GIS platform using the diagnostics of reach morphology derived from this study. The model provides a conceptual framework to evaluate the potential link between channel form, potential habitat diversity and aquatic biodiversity within the channel network in mountain streams.
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Kabouris, Ioannis. "A geomorphologic instantaneous unit hydrograph streamflow model." Thesis, Georgia Institute of Technology, 1988. http://hdl.handle.net/1853/20855.
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Elvidge, Elizabeth Mary. "Aspects of glacial geomorphology of northern Scotland." Thesis, University of East Anglia, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261199.
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Redda, Araya. "Quaternary geomorphology of the Vale of Edale." Thesis, University of Sheffield, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.392762.
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Saville, Christopher. "Fluvial and tectonic geomorphology of orogenic plateaux." Thesis, Durham University, 2013. http://etheses.dur.ac.uk/7718/.
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Geomorphology is an expression of processes acting upon an area. The links between driving processes and the resulting geomorphology are far from being fully understood. This thesis investigates controls on the dynamics and behaviour of fluvial systems from the interior of orogenic plateaux to the tectonically active plateaux margins. Orogenic plateaux provide a good study area by juxtaposing different tectonic and climatic settings that are served by the same sediment transport systems, allowing for observation of different variables on the same or similar fluvial systems. This is the first time that rivers draining orogenic plateaux have been extensively investigated. The Turkish-Iranian and Tibetan plateaux are the study areas. Forms of rivers draining from plateaux interiors, through the plateaux margins are analysed, along with alluvial fans within both the plateaux interior and plateaux margins. Plateau draining rivers act as the major route for material leaving the plateau region and a first-order control on erosive processes retarding plateau growth. Alluvial fans redistribute material within the plateau interior, enhancing the low relief topography diagnostic of a plateau. It is found that rivers draining plateaux show a sigmoidal form associated with the edge of the plateaux. High gradients and curvatures occur within the mountain ranges at the plateaux margins, while low values are present within the plateau interiors. Modelling work demonstrates that such forms to be likely responses for all plateau-draining rivers, but are most sensitive to the effects of precipitation upon a river’s ability to incise in-to the underlying sedimentary cover and bedrock lithologies. Alluvial fans in orogenic plateau regions are larger and with a lower surface gradient within the plateau interior than those nearer the active tectonic margins. It is theorised that this is due to the lack of lateral control on the accommodation space of alluvial fans within the plateau interior.
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Mathew, Manoj joseph. "Geomorphology and Morphotectonic Analysis of north Borneo." Thesis, Lorient, 2016. http://www.theses.fr/2016LORIS408/document.
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L’analyse géomorphologique d'une zone d’étude permet d’identifier et de comprendre le rôle des facteurs de contrôle tectonique et climatique sur l’évolution passée, récente et future de la surface topographique. Ce travail de recherche porte sur l’analyse géomorphologique des paysages du secteur de l’état de Sarawak, localisé au nord de l’île de Bornéo en contexte tropical. À travers l'analyse morphotectonique des deux plus grands bassins versants : le bassin versant du Rajang et du Baram, il a été possible de dresser une première évaluation du cadre morpho-tectonique de la région et des conséquences topographiques. Les bassins versants étudiés et situés au centre et au Nord de Sarawak drainent une superficie totale d'environ 75 000 km². L'île de Bornéo présente une couverture végétale dense spécifique aux régions tropicales, et demeurant souvent difficile d’accès. Cette île témoigne de terrains montagneux et accidentés, découpés par de vallées profondes aux flancs abruptes, entraînant des taux de dénudation notables depuis le Miocène. La première contribution est d’identifier les principales failles mineures et majeures ayant par réactivation participées au rajeunissement de la surface topographie à l’échelle régionale. À l’échelle des deux bassins versants, les facteurs géomorphologiques suivants comme l’intégrale hypsométrique, les facteurs d’asymétrie, les anomalies de pente identifiées le long des rivières ont été cartographiées à l’aide des techniques d'autocorrélation spatiale. Les principaux mouvements verticaux identifiés sont accommodés le long des accidents structuraux majeurs et des chevauchements spécifiques de la zone Nord de Bornéo. Parmi les autres résultats, il est également observé des surfaces planes reliques, à haute altitude, n’ayant pas encore réajustées leur surface d’équilibre depuis les 5 derniers Ma malgré de phases rapides de soulèvement connues. Enfin, à l’échelle de la zone d’étude, où les contrastes lithologiques sont absents, la présence de nombreuses ruptures de pente ou knickpoints sont observés le long des principaux profils longitudinaux des rivières. Les ruptures de pente fortes sont dans la majorité corrélables aux principaux accidents structuraux. Des observations de terrain viennent renforcer nos hypothèses par la présence de terrasses fluviatiles soulevées. Ce travail d’analyse d’indices géomorphologiques complétés par des observations de terrain permet alors de proposer un modèle synthétique des principaux facteurs de contrôle responsables du rajeunissement de la surface topographique de l’état de Sarawak jusqu’alors sous-estimé et méconnuGeomorphic assessment of a region is considered to be crucial in understanding the present day landscapeand forces that have acted and is currently acting on the ever evolving topography. This thesis explores the geomorphology of the tropical landscape of Sarawak, north Borneo through morphotectonic analysis of two of the largest drainage basins of the entire Borneo Island: the Rajang and Baram basin; making this work the first systematic tectono-geomorphic evaluation of the region. The island of Borneo is enveloped by thick rainforests, hostile rugged mountainous terrain with deep and steep valleys, and is characterized by high denudation rates since Miocene. The studied drainage basins flow across entire central and north Sarawak and drain a total combined area of ca. 75, 000 km². The first contribution to the field is by conducting a study on the presence of active tectonic forces that modify the topography through rejuvenation of major and minor faults. The analysis using basin-scale hypsometry, asymmetry factor, normalized channel steepness index and spatial autocorrelation techniques showed that the landscape has been rejuvenated and experiences tectonic deformation to present-day in the form of active folding of the fold-thrust orogenic belts of the Interior Highlands which form the backbone of Borneo. From the results, we highlighted the presence of relict surfaces of landscapes which were isolated at high elevations unable to balance a rapid uplift phase experienced after 5 Ma. We extended the study in order to identify the current stage of landscape development by conducting stream profile analysis which displayed an array of knick-zones and knick points devoid of lithological and climatic controls. Deep V-shaped valleys formed in the zones that demonstrated active folding of the highlands also revealed relief anomalies highlighted through topographic analysis. We showed that enhanced orographic precipitation following the rapid creation of relief has supported adjustment of the topography to a state of transience. In the next part of this work, we conducted swath profile analysis, minimum bulk erosion and channel steepness anomaly maps in order to identify the role of rapid incision in exacerbating erosion rates as a response to tectonic and climatic forcing. We show that there exists a coupling between incision rates, precipitation and channel steepness which shows a relation of direct proportionality. Extensive geomorphic and sedimentological field campaigns were carried out in order to substantiate our results and conclusions. The field work revealed the presence of uplifted fluvial terraces, waterfalls and cataracts corresponding to knick-points identified by us. Finally, we combine our results from the geomorphic analysis and stratigraphic field work in order to construct a conceptual model showing the geomorphic evolution of Sarawak, north Borneo
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Borsa, Adrian Antal. "Geomorphology of the salar de Uyuni, Bolivia /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2005. http://wwwlib.umi.com/cr/ucsd/fullcit?p3171116.
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Strick, Robert John Paul. "Floodplain geomorphology and topography in large rivers." Thesis, University of Brighton, 2016. https://research.brighton.ac.uk/en/studentTheses/a61e4805-4874-4cec-a1d8-e019aefd3053.
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Rivers are essential components of the earth surface. The world’s largest rivers have been studied much less than to smaller rivers. They are dominated by meandering channels – whether these are individual km-wide meander bends or ‘accessory’ meandering channels in an anabranching system. Large rivers, specifically ones with laterally migrating bends, can build a variety of floodplain elements that are represented by a complex surface topography, the dynamics and characteristics of which are not yet fully understood. This research brings a greater understanding to, and quantification of, the floodplain topography and geomorphology of large rivers. The project uses remote sensing imagery of the World’s largest rivers, LiDAR datasets of meandering scroll bar topography, and global coverage elevation data. Novel analytical methods are created, involving image manipulation and GIS processing, to quantify these landforms in a way that was not possible until recent technological and computational advancements. A new hierarchical classification schema of meandering floodplain deposits is presented and applied to quantify meandering deposits for two large rivers, the Amazon and the Ob. Both floodplains show similar downstream morphological changes to their floodplains despite their different sizes and locations. The new classification schema works well to describe meandering floodplain deposits. The geomorphology of scroll bars is investigated for the Mississippi River, revealing the heterogeneity of these deposits and that local meander bend conditions are important in determining scroll bar formation and preservation on the floodplain. The periodicity of scroll bars from a range of rivers is investigated and it is shown that scroll bars are intrinsically linked with the width of the adjacent river channel and respond to local planform changes. Floodplains of large rivers have complex overbank sedimentation processes that create spillage sedimentation phenomena. Spillage sedimentation was quantified down a 1700 km reach of the Amazon River and a 1400 km reach for the River Ob, revealing spatial discontinuities in spillage phenomena. Spillage dominance depends on diverse sediment loadings, hydrological sequencing, and morphological opportunity. Understanding spillage dynamics is important in quantifying overbank sedimentation rates and the spatial distribution of fine-grained deposits. The findings of this thesis highlight that despite the incredible complexity and heterogeneity of large river floodplains, order can be inferred via classification schemas and fundamental relationships identified. The thesis uses novel methods and conceptual models to bring a greater understanding and quantification to this complex floodplain geomorphology.
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Belliard, Jean-Philippe. "Bio-physical controls on tidal network geomorphology." Thesis, Queen Mary, University of London, 2014. http://qmro.qmul.ac.uk/xmlui/handle/123456789/7904.
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Looking over a tidal wetland, the tidal network characterised by its intricate system of bifurcating, blind-ended tidal courses clearly stands out from the overall landscape. This tidal landform exerts a fundamental control on the morphology and ecology within the tidal environment. With today’s recognition of the ecological, economical and societal values provided by tidal wetlands, which has been notably reflected in the development of restoration management strategies across Europe and USA, there is a need to fully understand the nature and development of tidal networks as well as their relationships with associated landforms and biotic components (e.g. vegetation), to eventually guarantee the success of current and future restoration practices. Accordingly, this research aims to bring further insights into the bio-physical controls on the geomorphology of tidal networks. To this end, a combination of remote sensing, modelling and field activities was employed. A geo-spatial analysis was performed at Queen Mary, University of London (UK), to address the variability of tidal network patterns. A series of network scale morphometric variables was extracted using airborne LiDAR data among selected tidal networks across the UK depicting different planview morphologies, and supplemented with the collection of corresponding marsh scale environmental variables from published sources. Multivariate statistics were then performed to characterise the variability of tidal network patterns and identify the inherent environmental controls. The analysis has revealed that every network type can be characterised based upon measures of network size and complexity, with each network pattern depicting proper morphometric aspects. Particularly, the stream Strahler order and the median depth of the network main channel have the highest discriminating weight on the patterns investigated. High correlation between the latter variable and network main channel width has revealed that linear, linear-dendritic and dendritic networks followed a transitional gradient in their aspect ratio approximated by a power law and thus are seen to depict similar erosional processes. To the contrary, meandering networks clearly depart from this relationship, and show particular segregation in their aspect ratios with respect to dendritic networks. Globally, differentiation on network morphometric properties has been linked to environmental conditions specific to the marsh physiographic setting within which a tidal network develops. Conceptually, tidal networks seem to adapt to marsh environmental conditions by adopting suitable morphologies to drain their tidal basin effectively. An eco-geomorphic modelling framework was developed at University of Trento (Italy), to address tidal network morphological development. In line with current theories as well as modelling advances and challenges in the field of tidal network ontogeny, emphasis was thus placed on the investigation of tidal channel formation and evolution in progressive marsh accretional context. Under these environmental conditions, tidal network development can be ascribed to the combination of two channel-forming processes: channel initiation results from bottom incisions in regions where topographic depressions occur; channel elaboration results from differential deposition, contributing to the deepening of the tidal channels relative to the adjacent marsh platform. Further evolutionary stages including channel reduction proceed from the horizontal progradation of the marsh platform which may lead eventually to channel infilling. Moreover, both qualitative and quantitative results allude to an acceleration of the morphological development of the synthetic tidal networks with increasing sediment supply. These different observations thus emphasise the prevalence of depositional processes in shaping tidal channels. In a second stage, the investigation was extended to the role of the initial tidal flat morphology as an inherent control on tidal network development, by considering different scenarios of topographic perturbations, which has revealed its legacy on tidal network morphological features. Modelling experiments have also acknowledged salt marsh macrophytes as a potential control on network evolution depending on their biomass distribution within the tidal frame. However, tidal channel morphodynamcis appears to be sensitive to the way biomass growth is mathematically parameterised in the model. In view of the current challenges in transcribing mathematically such a dynamic process and the relevance of bio-physical interactions in driving salt marsh and tidal network evolution, a field survey was conducted in a temperate salt marsh in the Netherlands, as part of the mobility to UNESCO-IHE (Netherlands) in partnership with University of Antwerp (Belgium), to assess vegetation distribution and productivity in the tidal frame. Particularly, emphasis was placed on extending investigations on the possible presence of relationships involving vegetation properties in different climatic and ecological conditions from those characterising these previously documented relationships. Regression analysis has revealed that biomass growth can be expressed as a linear function of marsh relative elevation, providing therefore direct empirical validation for corresponding assumptions reported in the literature and used in the present modelling framework; surprisingly, that increase did not correlate with an increase in species richness and diversity. Analysis of likely associations between vegetation morphometrics and total standing biomass yielded only a single linear relationship linking the latter variable to stem height. In truth, these observations may bear reconsiderations on the global validity of the assumptions used in the formulation of some eco-geomorphic processes which are applied in the study and prediction of wetland resiliency facing climate change.
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Belliard, Jean-Philippe. "Bio-physical controls on tidal network geomorphology." Doctoral thesis, Università degli studi di Trento, 2014. https://hdl.handle.net/11572/368998.
Full textAbstract:
Looking over a tidal wetland, the tidal network characterised by its intricate system of bifurcating, blind-ended tidal courses clearly stands out from the overall landscape. This tidal landform exerts a fundamental control on the morphology and ecology within the tidal environment. With today’s recognition of the ecological, economical and societal values provided by tidal wetlands, which has been notably reflected in the development of restoration management strategies across Europe and USA, there is a need to fully understand the nature and development of tidal networks as well as their relationships with associated landforms and biotic components (e.g. vegetation), to eventually guarantee the success of current and future restoration practices. Accordingly, this research aims to bring further insights into the bio-physical controls on the geomorphology of tidal networks. To this end, a combination of remote sensing, modelling and field activities was employed. A geo-spatial analysis was performed at Queen Mary, University of London (UK), to address the variability of tidal network patterns. A series of network scale morphometric variables was extracted using airborne LiDAR data among selected tidal networks across the UK depicting different planview morphologies, and supplemented with the collection of corresponding marsh scale environmental variables from published sources. Multivariate statistics were then performed to characterise the variability of tidal network patterns and identify the inherent environmental controls. The analysis has revealed that every network type can be characterised based upon measures of network size and complexity, with each network pattern depicting proper morphometric aspects. Particularly, the stream Strahler order and the median depth of the network main channel have the highest discriminating weight on the patterns investigated. High correlation between the latter variable and network main channel width has revealed that linear, linear-dendritic and dendritic networks followed a transitional gradient in their aspect ratio approximated by a power law and thus are seen to depict similar erosional processes. To the contrary, meandering networks clearly depart from this relationship, and show particular segregation in their aspect ratios with respect to dendritic networks. Globally, differentiation on network morphometric properties has been linked to environmental conditions specific to the marsh physiographic setting within which a tidal network develops. Conceptually, tidal networks seem to adapt to marsh environmental conditions by adopting suitable morphologies to drain their tidal basin effectively.An eco-geomorphic modelling framework was developed at University of Trento (Italy), to address tidal network morphological development. In line with current theories as well as modelling advances and challenges in the field of tidal network ontogeny, emphasis was thus placed on the investigation of tidal channel formation and evolution in progressive marsh accretional context. Under these environmental conditions, tidal network development can be ascribed to the combination of two channel-forming processes: channel initiation results from bottom incisions in regions where topographic depressions occur; channel elaboration results from differential deposition, contributing to the deepening of the tidal channels relative to the adjacent marsh platform. Further evolutionary stages including channel reduction proceed from the horizontal progradation of the marsh platform which may lead eventually to channel infilling. Moreover, both qualitative and quantitative results allude to an acceleration of the morphological development of the synthetic tidal networks with increasing sediment supply. These different observations thus emphasise the prevalence of depositional processes in shaping tidal channels. In a second stage, the investigation was extended to the role of the initial tidal flat morphology as an inherent control on tidal network development, by considering different scenarios of topographic perturbations, which has revealed its legacy on tidal network morphological features. Modelling experiments have also acknowledged salt marsh macrophytes as a potential control on network evolution depending on their biomass distribution within the tidal frame. However, tidal channel morphodynamcis appears to be sensitive to the way biomass growth is mathematically parameterised in the model. In view of the current challenges in transcribing mathematically such a dynamic process and the relevance of bio-physical interactions in driving salt marsh and tidal network evolution, a field survey was conducted in a temperate salt marsh in the Netherlands, as part of the mobility to UNESCO-IHE (Netherlands) in partnership with University of Antwerp (Belgium), to assess vegetation distribution and productivity in the tidal frame. Particularly, emphasis was placed on extending investigations on the possible presence of relationships involving vegetation properties in different climatic and ecological conditions from those characterising these previously documented relationships. Regression analysis has revealed that biomass growth can be expressed as a linear function of marsh relative elevation, providing therefore direct empirical validation for corresponding assumptions reported in the literature and used in the present modelling framework; surprisingly, that increase did not correlate with an increase in species richness and diversity. Analysis of likely associations between vegetation morphometrics and total standing biomass yielded only a single linear relationship linking the latter variable to stem height. In truth, these observations may bear reconsiderations on the global validity of the assumptions used in the formulation of some eco-geomorphic processes which are applied in the study and prediction of wetland resiliency facing climate change.
24
Belliard, Jean-Philippe. "Bio-physical controls on tidal network geomorphology." Doctoral thesis, University of Trento, 2014. http://eprints-phd.biblio.unitn.it/1383/1/belliard_phd_thesis.pdf.
Full textAbstract:
Looking over a tidal wetland, the tidal network characterised by its intricate system of bifurcating, blind-ended tidal courses clearly stands out from the overall landscape. This tidal landform exerts a fundamental control on the morphology and ecology within the tidal environment. With today’s recognition of the ecological, economical and societal values provided by tidal wetlands, which has been notably reflected in the development of restoration management strategies across Europe and USA, there is a need to fully understand the nature and development of tidal networks as well as their relationships with associated landforms and biotic components (e.g. vegetation), to eventually guarantee the success of current and future restoration practices. Accordingly, this research aims to bring further insights into the bio-physical controls on the geomorphology of tidal networks. To this end, a combination of remote sensing, modelling and field activities was employed. A geo-spatial analysis was performed at Queen Mary, University of London (UK), to address the variability of tidal network patterns. A series of network scale morphometric variables was extracted using airborne LiDAR data among selected tidal networks across the UK depicting different planview morphologies, and supplemented with the collection of corresponding marsh scale environmental variables from published sources. Multivariate statistics were then performed to characterise the variability of tidal network patterns and identify the inherent environmental controls. The analysis has revealed that every network type can be characterised based upon measures of network size and complexity, with each network pattern depicting proper morphometric aspects. Particularly, the stream Strahler order and the median depth of the network main channel have the highest discriminating weight on the patterns investigated. High correlation between the latter variable and network main channel width has revealed that linear, linear-dendritic and dendritic networks followed a transitional gradient in their aspect ratio approximated by a power law and thus are seen to depict similar erosional processes. To the contrary, meandering networks clearly depart from this relationship, and show particular segregation in their aspect ratios with respect to dendritic networks. Globally, differentiation on network morphometric properties has been linked to environmental conditions specific to the marsh physiographic setting within which a tidal network develops. Conceptually, tidal networks seem to adapt to marsh environmental conditions by adopting suitable morphologies to drain their tidal basin effectively.An eco-geomorphic modelling framework was developed at University of Trento (Italy), to address tidal network morphological development. In line with current theories as well as modelling advances and challenges in the field of tidal network ontogeny, emphasis was thus placed on the investigation of tidal channel formation and evolution in progressive marsh accretional context. Under these environmental conditions, tidal network development can be ascribed to the combination of two channel-forming processes: channel initiation results from bottom incisions in regions where topographic depressions occur; channel elaboration results from differential deposition, contributing to the deepening of the tidal channels relative to the adjacent marsh platform. Further evolutionary stages including channel reduction proceed from the horizontal progradation of the marsh platform which may lead eventually to channel infilling. Moreover, both qualitative and quantitative results allude to an acceleration of the morphological development of the synthetic tidal networks with increasing sediment supply. These different observations thus emphasise the prevalence of depositional processes in shaping tidal channels. In a second stage, the investigation was extended to the role of the initial tidal flat morphology as an inherent control on tidal network development, by considering different scenarios of topographic perturbations, which has revealed its legacy on tidal network morphological features. Modelling experiments have also acknowledged salt marsh macrophytes as a potential control on network evolution depending on their biomass distribution within the tidal frame. However, tidal channel morphodynamcis appears to be sensitive to the way biomass growth is mathematically parameterised in the model. In view of the current challenges in transcribing mathematically such a dynamic process and the relevance of bio-physical interactions in driving salt marsh and tidal network evolution, a field survey was conducted in a temperate salt marsh in the Netherlands, as part of the mobility to UNESCO-IHE (Netherlands) in partnership with University of Antwerp (Belgium), to assess vegetation distribution and productivity in the tidal frame. Particularly, emphasis was placed on extending investigations on the possible presence of relationships involving vegetation properties in different climatic and ecological conditions from those characterising these previously documented relationships. Regression analysis has revealed that biomass growth can be expressed as a linear function of marsh relative elevation, providing therefore direct empirical validation for corresponding assumptions reported in the literature and used in the present modelling framework; surprisingly, that increase did not correlate with an increase in species richness and diversity. Analysis of likely associations between vegetation morphometrics and total standing biomass yielded only a single linear relationship linking the latter variable to stem height. In truth, these observations may bear reconsiderations on the global validity of the assumptions used in the formulation of some eco-geomorphic processes which are applied in the study and prediction of wetland resiliency facing climate change.
25
Eltner, Anette. "Photogrammetric techniques for across-scale soil erosion assessment." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-212516.
Full textAbstract:
Soil erosion is a complex geomorphological process with varying influences of different impacts at different spatio-temporal scales. To date, measurement of soil erosion is predominantly realisable at specific scales, thereby detecting separate processes, e.g. interrill erosion contrary to rill erosion. It is difficult to survey soil surface changes at larger areal coverage such as field scale with high spatial resolution. Either net changes at the system outlet or remaining traces after the erosional event are usually measured. Thus, either quasi-point measurements are extrapolated to the corresponding area without knowing the actual sediment source as well as sediment storage behaviour on the plot or erosion rates are estimated disrupting the area of investigation during the data acquisition impeding multi-temporal assessment. Furthermore, established methods of soil erosion detection and quantification are typically only reliable for large event magnitudes, very labour and time intense, or inflexible.
To better observe soil erosion processes at field scale and under natural conditions, the development of a method is necessary, which identifies and quantifies sediment sources and sinks at the hillslope with high spatial resolution and captures single precipitation events as well as allows for longer observation periods. Therefore, an approach is introduced, which measures soil surface changes for multi-spatio-temporal scales without disturbing the area of interest. Recent advances regarding techniques to capture high resolution topography (HiRT) data led to several promising tools for soil erosion measurement with corresponding advantages but also disadvantages. The necessity exists to evaluate those methods because they have been rarely utilised in soil surface studies.
On the one hand, there is terrestrial laser scanning (TLS), which comprises high error reliability and retrieves 3D information directly. And on the other hand, there is unmanned aerial vehicle (UAV) technology in combination with structure from motion (SfM) algorithms resulting in UAV photogrammetry, which is very flexible in the field and depicts a beneficial perspective. Evaluation of the TLS feasibility reveals that this method implies a systematic error that is distance-related and temporal constant for the investigated device and can be corrected transferring calibration values retrieved from an estimated lookup table. However, TLS still reaches its application limits quickly due to an unfavourable (almost horizontal) scanning view at the soil surface resulting in a fast decrease of point density and increase of noise with increasing distance from the device. UAV photogrammetry allows for a better perspective (birds-eye view) onto the area of interest, but possesses more complex error behaviour, especially in regard to the systematic error of a DEM dome, which depends on the method for 3D reconstruction from 2D images (i.e. options for additional implementation of observations) and on the image network configuration (i.e. parallel-axes and control point configuration). Therefore, a procedure is developed that enables flexible usage of different cameras and software tools without the need of additional information or specific camera orientations and yet avoiding this dome error. Furthermore, the accuracy potential of UAV photogrammetry describing rough soil surfaces is assessed because so far corresponding data is missing.
Both HiRT methods are used for multi-temporal measurement of soil erosion processes resulting in surface changes of low magnitudes, i.e. rill and especially interrill erosion. Thus, a reference with high accuracy and stability is a requirement. A local reference system with sub-cm and at its best 1 mm accuracy is setup and confirmed by control surveys. TLS and UAV photogrammetry data registration with these targets ensures that errors due to referencing are of minimal impact. Analysis of the multi-temporal performance of both HiRT methods affirms TLS to be suitable for the detection of erosion forms of larger magnitudes because of a level of detection (LoD) of 1.5 cm. UAV photogrammetry enables the quantification of even lower magnitude changes (LoD of 1 cm) and a reliable observation of the change of surface roughness, which is important for runoff processes, at field plots due to high spatial resolution (1 cm²). Synergetic data fusion as a subsequent post-processing step is necessary to exploit the advantages of both HiRT methods and potentially further increase the LoD.
The unprecedented high level of information entails the need for automatic geomorphic feature extraction due to the large amount of novel content. Therefore, a method is developed, which allows for accurate rill extraction and rill parameter calculation with high resolution enabling new perspectives onto rill erosion that has not been possible before due to labour and area access limits. Erosion volume and cross sections are calculated for each rill revealing a dominant rill deepening. Furthermore, rill shifting in dependence of the rill orientation towards the dominant wind direction is revealed.
Two field plots are installed at erosion prone positions in the Mediterranean (1,000 m²) and in the European loess belt (600 m²) to ensure the detection of surface changes, permitting the evaluation of the feasibility, potential and limits of TLS and UAV photogrammetry in soil erosion studies. Observations are made regarding sediment connectivity at the hillslope scale. Both HiRT methods enable the identification of local sediment sources and sinks, but still exhibiting some degree of uncertainty due to the comparable high LoD in regard to laminar accumulation and interrill erosion processes. At both field sites wheel tracks and erosion rills increase hydrological and sedimentological connectivity. However, at the Mediterranean field plot especially dis-connectivity is obvious. At the European loess belt case study a triggering event could be captured, which led to high erosion rates due to high soil moisture contents and yet further erosion increase due to rill amplification after rill incision. Estimated soil erosion rates range between 2.6 tha-1 and 121.5 tha-1 for single precipitation events and illustrate a large variability due to very different site specifications, although both case studies are located in fragile landscapes. However, the susceptibility to soil erosion has different primary causes, i.e. torrential precipitation at the Mediterranean site and high soil erodibility at the European loess belt site.
The future capability of the HiRT methods is their potential to be applicable at yet larger scales. Hence, investigations of the importance of gullys for sediment connectivity between hillslopes and channels are possible as well as the possible explanation of different erosion rates observed at hillslope and at catchment scales because local sediment sink and sources can be quantified. In addition, HiRT data can be a great tool for calibrating, validating and enhancing soil erosion models due to the unprecedented level of detail and the flexible multi-spatio-temporal application.
26
Luz, Rodolfo Alves da. "Geomorfologia da planície fluvial do rio Pinheiros entre os bairros de Pinheiros, Butantã e Cidade Jardim, São Paulo (SP)." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/8/8135/tde-03112010-093445/.
Full textAbstract:
Na presente pesquisa investiga-se a geomorfologia da planície fluvial do rio Pinheiros entre os bairros de Pinheiros, Butantã e Cidade Jardim, na cidade de São Paulo. Para tal, propõe-se uma carta geomorfológica de detalhe deste setor da planície na escala de 1:20.000, confeccionada a partir de pesquisa arquivística prévia e, principalmente, de fotografias aéreas e de mapas antigos. A análise da carta e a sua correlação com informações sedimentológicas e estratigráficas encontradas, principalmente, em recentes relatórios de engenharia para a construção do Metrô de São Paulo, permitem a caracterização do sistema fluvial deste setor do rio Pinheiros, bem como de parte da morfodinâmica atuante no sistema antes da perturbação antrópica de alto impacto decorrente da urbanização que ali se instalou a partir da década de 1930. A pesquisa permitiu também a interpretação de uma provável sequência de eventos geomorfológicos atuantes no setor estudado durante o Pleistoceno Superior e o Holoceno. Parâmetros morfométricos tais como índice de sinuosidade de canais e paleocanais e largura da planície no trecho estudado evidenciaram aspectos da influência da estrutura geológica em sua evolução. O reconhecimento de sistemas geomorfológicos em seu estágio préperturbação antrópica é essencial para a compreensão dos processos atuais, principalmente em meios intensamente modificados como as áreas urbanas. A pesquisa apresenta então este tipo de reconhecimento, colaborando assim na compreensão dos processos antecedentes às grandes rupturas que se instalam no sistema a partir das ações antrópicas na superfície.This research investigates the geomorphology of part of Pinheiros River fluvial plain in São Paulo city. This study main result is a detailed geomorphologic map - 1:20,000 - that used ancient aerial photographs and maps obtained from formal archival surveys. The descriptions of floodplain units were associated to stratigraphic and sedimentologic data obtained from recent engineering projects reports of São Paulo underground (such as subway). This association allows the understanding of part of Pinheiros River fluvial system and morphodynamic before urbanization. The research also allowed offering a sequence of geomorphological events related to the floodplain and channel systems over the Holocene. Morphometric parameters, such as width and sinuosity index of channels and paleo-channels of floodplain meandering system, appear as an evidence of the structural influence in geomorphological evolution of this system. The recognition of geomorphologic systems in pre-disturbance stage is essential for understanding the current processes, mainly in environments greatly modified by human actions, such as urban areas. This research presents this kind of recognition and contributes to the understanding of processes in the system before human actions in the surface.
27
Warwick, Gail L. "The geomorphology and sedimentology of terminal fluvial systems." Thesis, University of Aberdeen, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.487421.
Full textAbstract:
The geomorphology and sedimentology of terminal fluvial systems. Fluvial systems operating within drylands commonly experience downstream discharge reduction due to infiltration, evaporation and limited tributary inputs. Sediment bodies developed within the distal zones of rivers that do not drain into the sea or a lake (terminal fluvial systems) are currently represented by the terminal fan facies model. This model summarises the development of a distally thinning and fining sedimentary wedge from a coeval network of low sinuosity distributary channels as induced by the sub aerial termination ofchannelised flow under a dryland climate regime.. Extensive review of sediment fan bodies located within modern drylands highlights pronounced disequilibrium between planform character and present ephemeral flow conditions. Out of eighty documented fluvial systems no convincing examples fit the terminal fan model, including two commonly cited analogues used to support this model. In order to fully evaluate the terminal fan concept and redress the current imbalance in modern analogue studies, field work was undertaken to characterise sub aerial fluvial system termination within a single physiographic province - the Basin and Range rift complex of the southwestern U.S.A. Documentation of the potential range in fluvial style and character within this modern dryland environment is provided by the detailed study of seven terminal fluvial systems. Basin and Range terminal fluvial systems demonstrate strong geomorphic form inheritance. Fan landforms observed within medial and distal reaches of these systems predominantly represent relic Late Pleistocene highstand delta bodies into which the modern system is inset. Active terminal reaches operate within basin centre playa environments where shallo~ gradients induce frequent avulsion and the generation of composite lowstand fan bodies located downstream of lateral system confinement. These terminal features record non-coeval channel activity and the dominance of sinuous channel forms. Morphometric trends distinguish a general downstream reduction in channel scale characterised by the development of progressively narrower and shallower channel forms. Channelised flow is maintained within proximal and medial reaches but does not dominate distal reaches where sheetflow discharge is readily attained. Concomitant reductions in channel capacity and competence control the volume and calibre of fluvial material supplied to basinal environments. Progressive downstream thinning is associated with selective deposition and general basinwards sediment fining and sorting. Terminal reaches transport negligible bedload material and display a comparable depositional record to that generated by background playa sedimentation. Identified similarities with the terminal fan model include downstream loss of channel definition, sediment thinning, fining and improved sorting. Conversely, coeval distributive flow is not observed, constituent channels record moderate to high sinuosity and negligible fluvial material reaches basin centre locations. Basin and Range systems are principally responding to streampower reduction controlled primarily by gradient and enhanced by discharge attenuation. Sub aerial termination dominates due to the absence of basin centre lacustrine bodies; a condition forced by limited discharge supply from catchment reaches, compounded by transmission losses and maintained by excessive evaporation from extensive, low elevation flat playa surfaces. In conclusion, fluvial fan landforms generated exclusively from discharge attenuation do not characterise modern dryland environments. Selection of modern analogue systems for use in the interpretation and prediction of ancient fluvial successions must acknowledge the influence of high frequency and high magnitude climate fluctuations upon modern fluvial geomorphology. Key to this is an appreciation of modern processform disequilibrium and the identification of inherited planform characteristics.
28
Smith, Brent. "An examination of desert geomorphology throughout geologic time /." Connect to resource, 1998. http://hdl.handle.net/1811/28576.
Full text
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Spence, James B. "Habitat analysis by hierarchical scheme and stream geomorphology." Huntington, WV : [Marshall University Libraries], 2005. http://www.marshall.edu/etd/descript.asp?ref=555.
Full textAbstract:
Theses (M.S.)--Marshall University, 2005.Title from document title page. Includes abstract. Document formatted into pages: contains ix, 139 p. including illustrations and map. Bibliography: p. 83-89.
30
Abuodha, Joseph Zedekia Odhiambo. "Geomorphology of the Malindi Bay coastal sand dunes." [S.l. : Amsterdam : s.n.] ; Universiteit van Amsterdam [Host], 2000. http://dare.uva.nl/document/55857.
Full text
31
Wilson, David William. "On the problem of indeterminacy in fluvial geomorphology." Thesis, University of Southampton, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246883.
Full text
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Huppert, Kimberly Lynn. "Climatic and geodynamic influences on ocean island geomorphology." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/108915.
Full textAbstract:
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2017.Cataloged from PDF version of thesis.
Includes bibliographical references.
With homogeneous bedrock, dramatic rainfall gradients, and remnant surfaces that constrain their age, initial topography, and vertical motions relative to sea level, volcanic ocean islands provide an exceptional natural experiment in landscape evolution. Analyses traversing gradients in island climate and bedrock age have the potential to advance our understanding of landscape evolution in a diverse range of continental settings. Yet, islands are initially conic, net subsiding, boundary-dominated, and initially permeable landmasses, in many ways dissimilar to most continental landscapes. This thesis examines unique aspects of island landscape evolution, and it exploits steep climate gradients and variations in bedrock age on volcanic ocean islands to understand controls on rates and patterns of erosion and the contribution of lithosphere and mantle processes to surface deformation at hotspots. Through physically-based modeling, analysis of remote sensing and geochronologic data, and field measurements, this thesis examines (1) the dominant mechanisms of vertical motion in the Hawaiian Islands, (2) the influence of wave power on cliff retreat rates in the Hawaiian Island over geologic timescales, (3) the control of rainfall rates on the efficiency of bedrock river incision on the Hawaiian Island of Kaua'i, (4) the evolution of erosion rates over the course of landscape development on Kaua'i and other volcanic ocean islands, and (5) the mechanisms that cause volcanic ocean islands to ultimately subside below sea level to form atolls and guyots. These analyses provide empirical evidence for climatic control on erosion processes and they constrain the dynamics of plume-plate interactions at oceanic hotspots.
by Kimberly Lynn Huppert.
Ph. D.
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Costigan, Katie Helen. "Hydrology and geomorphology of select Great Plains rivers." Diss., Kansas State University, 2013. http://hdl.handle.net/2097/15761.
Full textAbstract:
Doctor of PhilosophyDepartment of Geography
Melinda Daniels
Great Plains rivers are unique systems that vary from large, continental scale, to small intermittent streams with grain sizes that range from bedrock to cobbles to silt. These rivers have been subject to widespread hydrologic alteration both within the channel and the watershed, which has resulted in an alteration in their hydrologic and geomorphic regimes. Although there is an acknowledgement of this alteration, to date there has not been a synthesis of the hydrology of Great Plains rivers or of their longitudinal morphologies. Chapters in this dissertation provide, to my knowledge, the first comprehensive analyses of the hydrology and morphology of Great Plains rivers over a range of spatial and temporal scales. In the first study, I found that there was no uniform pattern of hydrologic alteration throughout the Great Plains, which is likely attributable to variable system-specific reservoir management objectives, land use changes, and climatic regimes over the large area the Great Plains encompass. Results of this study are the first to quantify the widespread hydrologic alteration of Great Plains rivers following impoundment. In the second study, I found an apparent decoupling between local moisture conditions and streamflow in intermittent prairie streams. Results of this study used statistical models to identify relationships between flow intermittence, mean annual flow, and flood flow characteristics with moisture to characterize flow in an intermittent prairie stream. In the final study, I found that the downstream trends in hydraulic geometry and substrate characteristics of the Ninnescah River were consistent with the expected trends proposed by hydraulic geometry and substrate theories. However, there were points that deviated from the expected trends, most notably where a substantially large tributary enters the Ninnescah River and as the Ninnescah River approaches the Arkansas River, and causal explanations for these deviations were explored. Results of this study are, to my knowledge, the first of its kind to assess the longitudinal hydraulic geometry and substrate characteristics of a large sand-bed river over a large spatial scale. To our knowledge, there have been no comparable studies exist that attempted to describe hydrologic and geomorphic characteristics of prairie streams.
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Beeslaar, Salome. "Geomorphology of a portion of Mariepskop, South Africa." Diss., University of Pretoria, 2013. http://hdl.handle.net/2263/40238.
Full textAbstract:
Hillslopes usually have high heterogeneity in terms of landscape processes. Interactions
occur between geology, geomorphological processes, and vegetation distribution on a hillslope. This
study was undertaken to assess the processes and interactions of geology, regolith production,
geomorphological processes, channel formation and how these are influenced by the vegetation on a
portion of Mariepskop. Mariepskop forms part of the Drakensberg Escarpment, but is a separate
hillslope within the Mpumalanga Province. A north-eastern portion of the Mariepskop forms the study
site, with a drainage line located within the site. Deciduous bush covers most of the study site, and
grassland patches occur on the southern parts of the study site. Quartz-feldspar-biotite gneiss
dominates most of the area with the cliff and higher parts consisting of feldspar-rich schist. Three site
visits were undertaken where bedrock geology, weathering, soil formation, erosion, mass movement
processes and the drainage channel were assessed. Maps of these processes as well as slope
profiling and plan forms were compiled. According to the results, Mariepskop shows heterogeneous
processes both laterally and vertically, with various degrees of interactions taking place. Underlying
geology, mass movements on higher altitudes, and soil creep on lower altitudes occur on both the
northern and southern parts. Processes mainly occurring on the northern part are rockfall from
drainage channel incision, weathering, rill erosion and fluvial erosion within the drainage channel.
Main processes on the southern part are mass movement in term form of slumping/debris flow, and
erosion, in particular rainsplash and overland flow. Soil is deeper on northern part than on southern
part of the study site. Geomorphological processes interact with the vegetation distribution over the
study area. Grassland patches on the southern part of the study site are mainly due to
slumping/debris flow, rainsplash erosion, convexity of the plan form (therefore no valleys) and oxidic
soils occurrence. Similar geomorphological processes will probably influence grassland patches over
the rest of Mariepskop.Dissertation (MSc)--University of Pretoria, 2013.
gm2014
Geography, Geoinformatics and Meteorology
unrestricted
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Phillips, William Morton. "Applications of noble gas cosmogenic nuclides to geomorphology." Diss., The University of Arizona, 1997. http://hdl.handle.net/10150/282369.
Full textAbstract:
The buildup of the cosmogenic nuclides ³He and ²¹Ne in surficial rocks permit exposure ages and erosion rates to be estimated. This dissertation extends the cosmogenic exposure technique to garnets, plagioclase with significant nonspallation ²¹Ne components, and alluvial fill terraces. Garnets from Nanga Parbat, Pakistan have low nucleogenic ³He and moderate radiogenic ⁴He concentrations. ³He exposure ages from garnets in glacial erratics indicate glacial advances at Nanga Parbat at about 16 ka and 55 ka. 3He in alluvial garnets suggests that denudation in small unglaciated basins proceeds 5 to 7 times slower than glacial erosion, and 10 to nearly 100 times slower than regional rock exhumation and surface uplift. Rocks older than several million years possess nucleogenic and mugenic ²¹Ne and ³He components that must be resolved for accurate exposure ages. These nonspallation components in plagioclase and clinopyroxene from the Miocene Columbia River Basalt Group are best isolated with shielded samples. Analyses of ⁴He, U, Th, and Li systematically underpredict the amount of nonspallation ²¹Ne and ³He present in shielded samples, probably because of mugenic production. Step heating experiments suggest that ²¹Ne diffusive loss from plagioclase is possible, but most samples do not exhibit such ²¹Ne loss. The ratio of ²¹Ne in plagioclase and ³He in clinopyroxene is generally constant after correction for the nonspallation component, indicating that little or no ²¹Ne loss has occurred. The last highly erosive floods at Grand Coulee occurred at about 21 ka, early in the cycle of Missoula flooding. Nuclide inheritance must be resolved for accurate exposure ages of stream fill terraces. Depth profiles of cosmogenic ²¹Ne in quartz from terraces on the Pajarito Plateau, northern New Mexico resolve nuclide inheritance. Three patterns of depth profiles are recognized: (1) downward decreasing; (2) downward increasing; and (3) uniform; types 2 and 3 are associated with cumulate deposits and bioturbation, respectively. Inheritance corrected exposure ages for the terraces agree with independent radiocarbon and soil development ages. Denudation rates estimated from the profiles are higher for fill terraces than for straths.
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McCarthy, Forrest G. "Landcover change in Arctic Alaska observations through repeat photography /." Laramie, Wyo. : University of Wyoming, 2008. http://proquest.umi.com/pqdweb?did=1594501471&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.
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Erlingsson, Ulf. "Geomorphological development of the bottoms off Österlen, southernmost Sweden." Uppsala, Sweden : Uppsala University, Dept. of Physical Geography, 1990. http://catalog.hathitrust.org/api/volumes/oclc/22874540.html.
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Bookhagen, Bodo. "Late quaternary climate changes and landscape evolution in the Northwest Himalaya geomorphologic processes in the Indian summer monsoon domain /." Phd thesis, [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=974115487.
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Hesselink, Annika W. "History makes a river : morphological changes and human interference in the river Rhine, the Netherlands /." Utrecht : Koninklijk Nederlands Aardrijkskundig Genootschap : Faculteit Ruimtelijke Wetenschappen, Universiteit Utrecht, 2002. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=010018442&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Landgraf, Angela. "Fault interaction at different time- and length scales : the North Tehran thrust and Mosha-Fasham fault (Alborz mountains, Iran)." Phd thesis, Universität Potsdam, 2010. http://opus.kobv.de/ubp/volltexte/2011/5080/.
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The seismically active Alborz mountains of northern Iran are an integral part of the Arabia-Eurasia collision. Linked strike-slip and thrust/reverse-fault systems in this mountain belt are characterized by slow loading rates, and large earthquakes are highly disparate in space and time. Similar to other intracontinental deformation zones such a pattern of tectonic activity is still insufficiently understood, because recurrence intervals between seismic events may be on the order of thousands of years, and are thus beyond the resolution of short term measurements based on GPS or instrumentally recorded seismicity. This study bridges the gap of deformation processes on different time scales. In particular, my investigation focuses on deformation on the Quaternary time scale, beyond present-day deformation rates, and it uses present-day and paleotectonic characteristics to model fault behavior. The study includes data based on structural and geomorphic mapping, faultkinematic analysis, DEM-based morphometry, and numerical fault-interaction modeling. In order to better understand the long- to short term behavior of such complex fault systems, I used geomorphic surfaces as strain markers and dated fluvial and alluvial surfaces using terrestrial cosmogenic nuclides (TCN, 10Be, 26Al, 36Cl) and optically stimulated luminescence (OSL). My investigation focuses on the seismically active Mosha-Fasham fault (MFF) and the seismically virtually inactive North Tehran Thrust (NTT), adjacent to the Tehran metropolitan area. Fault-kinematic data reveal an early mechanical linkage of the NTT and MFF during an earlier dextral transpressional stage, when the shortening direction was oriented northwest. This regime was superseded by Pliocene to Recent NE-oriented shortening, which caused thrusting and sinistral strike-slip faulting. In the course of this kinematic changeover, the NTT and MFF were reactivated and incorporated into a nascent transpressional duplex, which has significantly affected landscape evolution in this part of the range. Two of three distinctive features which characterize topography and relief in the study area can be directly related to their location inside the duplex array and are thus linked to interaction between eastern MFF and NTT, and between western MFF and Taleghan fault, respectively. To account for inferred inherited topography from the previous dextral-transpression regime, a new concept of tectonic landscape characterization has been used. Accordingly, I define simple landscapes as those environments, which have developed during the influence of a sustained tectonic regime. In contrast, composite landscapes contain topographic elements inherited from previous tectonic conditions that are inconsistent with the regional present-day stress field and kinematic style. Using numerical fault-interaction modeling with different tectonic boundary conditions, I calculated synoptic snapshots of artificial topography to compare it with the real topographic metrics. However, in the Alborz mountains, E-W faults are favorably oriented to accommodate the entire range of NW- to NE-directed compression. These faults show the highest total displacement which might indicate sustained faulting under changing boundary conditions. In contrast to the fault system within and at the flanks of the Alborz mountains, Quaternary deformation in the adjacent Tehran plain is characterized by oblique motion and thrust and strike-slip fault systems. In this morphotectonic province fault-propagation folding along major faults, limited strike-slip motion, and en-échelon arrays of second-order upper plate thrusts are typical. While the Tehran plain is characterized by young deformation phenomena, the majority of faulting took place in the early stages of the Quaternary and during late Pliocene time. TCN-dating, which was performed for the first time on geomorphic surfaces in the Tehran plain, revealed that the oldest two phases of alluviation (units A and B) must be older than late Pleistocene. While urban development in Tehran increasingly covers and obliterates the active fault traces, the present-day kinematic style, the vestiges of formerly undeformed Quaternary landforms, and paleo earthquake indicators from the last millennia attest to the threat that these faults and their related structures pose for the megacity.Das seismisch aktive Elburs Gebirge im Nordiran ist Bestandteil der Arabisch-Eurasischen Kollisionszone. Gekoppelte Blattverschiebungs- und Überschiebungssysteme dieses Gebirges zeichnen sich durch geringe Spannungsaufbauraten aus. Dementsprechend treten große Erdbeben räumlich und zeitlich weit verteilt voneinander auf und Wiederkehrperioden solcher Erdbeben können tausende von Jahren dauern und wurden noch nicht von kurzzeitigen Messmethoden, wie GPS oder instrumenteller Seismologie erfasst. Diese Arbeit überbrückt verschiedene Zeitskalen. Diese Studie beinhaltet insbesondere Auswertungen struktureller und geomorphologischer Kartierungen, störungskinematische Analysen, auf digitalen Höhenmodellen basierende Morphometrie und numerische Modellierung von Störungsinteraktion. Um das lang- und kurzfristige Verhalten solcher komplexen Schwächezonen besser zu verstehen, benutze ich geomorphologische Oberflächen als Deformationsmarker und datiere alluviale und fluviatile Oberflächen mittels kosmogener Nuklide (TCN, 10Be, 26Al, 36Cl) und optisch stimulierter Lumineszenz (OSL). Mein Untersuchungsgebiet umfasst die seismisch aktive Mosha-Fasham Störung (MFF) und die als seismisch quasi inaktiv geltende Nordteheranstörung (NTT), die sich in unmittelbarer Nähe zum Teheraner Ballungsgebiet befinden. Die Ergebnisse zeigen, dass sich das Deformationfeld mit der Zeit verändert hat. Die störungskinematischen Daten haben ergeben, dass NTT und MFF bereits seit einer früheren dextral-transpressionalen Phase unter NW-gerichteter Einengung mechanisch gekoppelt sind. Dieses System wurde von pliozäner und bis heute andauernder NE-gerichteter Einengung ersetzt, woraufhin sich Überschiebungen und linkslaterale Blattverschiebungen herausbildeten. Während dieses kinematischen Wechsels wurden NTT und MFF reaktiviert und in ein beginnendes transpressionales Duplexsystem eingebunden, welches die Landschaftentwicklung in diesem Teil des Gebirges signifikant beeinflusst hat. Zwei von drei ausgeprägten topographischen Besonderheiten des Untersuchungsgebietes können direkt mit deren Lage in der Duplexanordnung in Verbindung gebracht werden und spiegeln Interaktion zwischen den östlichen Segmenten von NTT und MFF, bzw., zwischen dem westlichen Segment der MFF und der parallelen Taleghan Schwächezone wider. Um diejenige Topographie auszuweisen, die möglicherweise aus der vorhergehenden Phase vererbt wurde, wurde ein neues Konzept tektonischer Landschaftscharakterisierung benutzt. Einfache Landschaften sind unter dem Einfluß gleichbleibender tektonischer Randbedingungen entstanden. Dagegen enthalten zusammengesetzte Landschaften vererbte Elemente vergangener tektonischer Randbedingungen, die mit dem heutigen Spannungsfeld und kinematischen Stil unvereinbar sind. Mittels numerischer Störungsinteraktionsmodellierungen teste ich verschiedene Randbedingungen und berechne synoptische Momentaufnahmen künstlicher Topographie um sie mit reellen topographischen Maßen zu vergleichen. Im Elburs Gebirge treten allerdings auch E-W streichende Schwächezonen auf, die so günstig orientiert sind, dass sie Verformung unter der gesamten Einengungsspanne von Nordwest nach Nordost zeigen. Diese weisen den höchsten totalen Versatz auf. Hier tritt das Grundgebirge zutage und wird versetzt, was, wie die Modellierungen vermuten lassen, auf langanhaltende Verformung unter sich ändernden Randbedingungen hinweisen kann. Quartäre Deformation in der benachbarten Teheran Ebene ist durch Schrägbewegungen, Überschiebungen und Blattverschiebungssyteme gekennzeichnet, die typischerweise in Auffaltungen entlang von Hauptstörungen, vereinzelten Blattverschiebungen und en-échelon Anordnungen untergeordneter oberflächlicher Überschiebungen resultieren. Junge Deformation tritt auf, die Hauptbewegungen fanden allerdings im frühen Quartär und wahrscheinlich späten Pliozän statt. TCN-Datierungen, die erstmalig an geomorphologischen Oberflächen in der Teheran Ebene durchgeführt wurden, ergeben dass die beiden älteren Sedimentationsphasen (Einheiten A und B) älter sind als spätes Pleistozän. Obwohl die urbane Entwicklung im Teheraner Ballungsraum die aktiven Störungslinien zunehmend verdeckt und ausradiert, zeugen der heutige kinematische Stil, die Überreste ehemals unverstellter Quartärer Landschaftsformen und Hinweise auf Paläoerdbeben während der letzten Jahrtausende von der Gefahr, die diese Schwächezonen für die Megastadt bedeuten.
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Clement, David T. "Fluvial geomorphology of the Yukon River, Yukon Flats, Alaska." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape9/PQDD_0015/MQ47994.pdf.
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McGuinness, Michaella. "The geomorphology of the Campbell Uplift, Northwest Territories, Canada." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape9/PQDD_0019/MQ48400.pdf.
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Merrill, MaximilIan Atlas. "The Effects of Culverts and Bridges on Stream Geomorphology." NCSU, 2005. http://www.lib.ncsu.edu/theses/available/etd-11302005-175258/.
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Culverts and bridges are necessary in order to cross waterways during road construction. However, these structures have detrimental affects on the hydrology and ecology of the streams they cross. The objective of this study was to investigate how these bridges and culverts alter stream hydrology and geomorphology by determining the effects on the upstream and downstream reaches of a road crossing on the cross sectional area, the hyporheic depth, on riffle habitat, and substrate types. Three types of culverts (arch, box, and pipe) and small bridges were evaluated. All four types of stream crossings were determined to increase the cross sectional area downstream of the structure. Crossing structures also affected hyporheic zone depths by decreasing average depths downstream of the structure. Finally, most mussels seemed to occur in substrates that were dominated by relatively large particles (gravel and cobble) that were less movable by sheer stress during higher flows. Each of the problems discovered with these structures is a result of the channel restriction and the increased flow velocity and turbulence scour that it creates. These detrimental conditions can be mitigated by providing for floodplain access for higher flows. It is recommended that culverts be designed for low flows and high flows. Oversizing culverts, compared to current design criteria will allow floodplain access and build bankfull benches in the extra openings to restrict low flows to a few openings. The use of bridges that span across the valley limiting fill and allowing floodplain access may even be more beneficial. When valley fill is necessary, then side culverts in the floodplain may alleviate degradation and allow more natural floodplain hydrology.
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Walker, Andrew Curtis. "A morphometric analysis of the geomorphology of Florida's springs." [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001679.
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Gore, Shannon. "Beach geomorphology and management in the British Virgin Islands." Thesis, University of Ulster, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.589521.
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The geomorphology of tropical island beaches has received little attention in literature compared to their temperate equivalents. This is particularly true of studies of the spatial and temporal variability of carbonate beaches. The British Virgin Islands (BVI), a small archipelago located in the north-eastern Caribbean contains numerous beaches in a wide variety of settings within a small geographical area. Over 100 beaches across 60+ high volcanic and reef islands were selected for study. Through the analysis of benthic habitat maps, aerial photographs, sedimentary characteristics, and ground-truthing, beach distribution and form are interpreted in terms of their geologic, oceanographic and ecologic setting. The Atlantic-facing beaches exhibit modally high energy waves which drive carbonate-rich sediment onshore from extensive reef systems and a carbonate bank. In contrast, Caribbean-facing beaches, primarily those of coral rubble, are dominated by modally low energy waves punctuated by very high energy events (i.e. hurricanes) and contain a lower proportion of fine-grained carbonate sands. While some of these high energy events have significant short-term impact, many beaches exhibit long-term stability. There has, however, been a general narrowing of beaches over the past 50 years which is tentatively attributed to sand mining in the past. In contrast to the high volcanic islands, Anegada is an emergent reef island comprising a lithified Pleistocene reef core and a sequence of Holocene deposits (beach ridges, lagoons, and mangroves). The form and distribution of the island's contemporary sedimentary environment reveal four distinctive coastlines. Three of these coastlines have shown relative stability over the past 149 years while one coastline has morphologically adjusted to surrounding environmental conditions by rotating in a counter clockwise motion. All the beaches are subject to a variety of human impacts and require a formal coastal management response, however, this has not yet been realised. Despite an existing statutory framework for beach management, environmental degradation from uncontrolled coastal development and space-use conflicts caused by unmanaged mass tourism continues. A current case study reveals the management plan requires implementation via a co-management regime between the local beach community and stakeholders with support from the local government. A simple framework is presented that provides thirteen environmental, socio-cultural, economic and governance goals which define the context in which the management plan operates. This framework ensures not only a clear understanding of what constitutes sustainable beach management, but also sustainable development specifically within the BVI.
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Saleem, Shihadah M. "Geomorphology of Submarine Spring West of Fort Myers, Florida." Scholar Commons, 2007. http://scholarcommons.usf.edu/etd/3836.
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In March of 2000, March of 2001, and April of 2002, multibeam bathymetry and backscatter data were collected, which revealed several low-temperature hydrothermal submarine springs in the Mudhole Submarine Springs (MHSS) area that were investigated by SCUBA divers. High-resolution multibeam sonar provides a precise way of defining the geomorphology of the seafloor. The bathymetry data were used to understand (1) vent geomorphology and how it varied from vent to vent; (2) spatial patterns of active vents compared to extinct vents and known land springs identified by Kohout (1977) and Breland (1980); and (3) potential correlations between geochemical and geomorphological characteristics of the vents in the study area. SCUBA observations show that MHSS, Spring #3, New Spring, Northern Rusty, Rusty, and Near Rusty are active springs, while Dormant Spring and Sinister Spring were extinct or inactive at the time of the March 2001 cruise.During the April 2002 cruise the locations of Rusty Spring, New Spring and MHSS were confirmed. Two submarine springs, Creature Hole and Sparky Lee were also confirmed. Spring #3 is the deepest spring and Dormant Spring is the shallowest.
There appears to be a rough spatial correlation between vents located on land and the vents on the seafloor, in which all known vents are either to the west or north of Lake Okeechobee. Vent distribution in the MHSS study area appears to correlate with the structural pattern of the local seafloor. Backscatter data and SCUBA observations show that fine to medium grain siliciclastic sediment bands overlie limestone hardbottom in a NE-SW orientation. Although vent geomorphologies are generally distinctive, vent activities generally correlate with the steepness of vent depressions.Most active vents had slopes of 6 degrees or greater, with the exception of Rusty Spring and Near Rusty Spring whose slopes ranged from 2.5 degrees and 6 degrees; whereas all the inactive vents had slopes of 5 degrees or less. Most active vents have "V"-shaped profiles versus the "U"-shaped profiles of most of the inactive vents. The inactive springs have shallower maximum depths and shallower ambient seafloor depths than the active vents.
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Rosser, Nicholas John. "The geomorphology of coarse clastic surfaces in arid environments." Thesis, Durham University, 2002. http://etheses.dur.ac.uk/3745/.
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This study explores the linkages between slope form and slope process in arid environments. In doing so, questions of the development of slopes in arid environments are examined. The age of many arid environment surfaces, combined with the sporadic nature of formative events, means that long-term surface and slope development remains an elusive question in geomorphology. Deserts have inspired many of the most enduring theories of landscape evolution and continue to provide a test-bed for new and emerging ideas in geomorphology. The clast-mantled surface of the northeast Jordan Badia presents an ideal opportunity to study the links between surface character and slope processes in arid environments. The northeast Badia also provides an opportunity to explore theories of slope development and the behaviour of earth surface systems. The nature of the clast covered ground surface has been assessed using a new digital aerial photography and image analysis technique. A field study of surface processes has been used to explore links between surface form and slope process. Additionally, a computer based simulation of long-term modification of the spatial distribution of surface clast has been undertaken. Given the subtle variation in earth surface form between disparate locations, a new semi-quantitative method of locating sample sites has been developed. The characterization of surface form has identified statistically significant relationships between ground surface character and two-dimensional slope form. Systematic variations in ground surface configuration, both within and between basalt flows, are found to be indicative of the action of slope processes. The first study of ground surface hydrology in the north eastern Badia has been undertaken. The results from a series of rain-storm simulation experiments show subtle but significant links between the action of surface processes and variations in ground surface form. The controls on surface process are diverse and vary in significance with position in the landscape. A combination of ground surface characterization and process studies has identified several interesting geomorphological phenomena The surfaces exhibit systematic variations in structure and organization. Homeostatic links between form and process are clearly apparent, which suggests that surface form influences and is influenced by process action via a process of positive feedbacks. Given the sporadic and infrequent recurrence of formative events in arid environments, a modelling approach has been developed to understand the long-term, spatial dynamics of the ground surface. The model has been used to simulate structure in the surface clast arrangement and the sensitivity of surface organization to physically constrained variations in model parameters. The model also allows the surfaces to be considered as self-organizing earth surface systems. The model results provide new insights into the process-form linkages in operation on clast-mantled arid surfaces. The model results provide new ways of examining and understanding the dynamics of clast mantled arid surfaces and have implications for the application of self-organization in geomorphology.
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Hodskinson, Andrew. "Flow structure and geomorphology of non-classical river bends." Thesis, University of Sheffield, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360484.
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Contreras, Daniel Alexander. "Sociopolitical and geomorphologic dynamics ar Chavín de Huántar, Peru /." May be available electronically:, 2007. http://proquest.umi.com/login?COPT=REJTPTU1MTUmSU5UPTAmVkVSPTI=&clientId=12498.
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McGuinness, Michaella (Michaella Kathleen) Carleton University Dissertation Geography. "The Geomorphology of the Campbell Uplift, Northwest Territories, Canada." Ottawa, 1999.
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