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Literatura académica sobre el tema "Topographic flow"

Autor: Grafiati

Publicado: 25 de mayo de 2024

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Artículos de revistas sobre el tema "Topographic flow"

Sinha, Surbhi y Vinay Kumar Rai. "Topographical Characteristics of Lower Barakar Basin: A Geospatial Approach". National Geographical Journal of India 66, n.º 1 (31 de marzo de 2020): 12–19. http://dx.doi.org/10.48008/ngji.1725.

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The evolution and development of a drainage network largely depends upon the surface topography of a landscape. Even topographic attributes such as overland flow, sub-surface flow, stream flow etc. are highly determined by the relief and slope aspects of the basin area. Topography influences evolution of landforms, soil development, vegetation growth, types of settlement, agricultural pattern etc. So it becomes very important to quantify different topographical parameters so that proper watershed management can be done. This work is an attempt to evaluate existing topography of study area using topographical sheets and SRTM DEM data. For calculation and analysis of data MS Excel is used while Geographical Information System (GIS) is used for mapping purpose. Present work provides better understanding of surface and relief aspects of landforms in Lower Barakar basin.

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Casas, A., S. N. Lane, D. Yu y G. Benito. "A method for parameterising roughness and topographic sub-grid scale effects in hydraulic modelling from LiDAR data". Hydrology and Earth System Sciences Discussions 7, n.º 2 (12 de abril de 2010): 2261–99. http://dx.doi.org/10.5194/hessd-7-2261-2010.

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Abstract. High resolution airborne laser data provide new ways to explore the role of topographic complexity in hydraulic modelling parameterisation, taking into account the scale-dependency between roughness and topography. In this paper, a complex topography from LiDAR is processed using a spatially and temporally distributed method at a fine resolution. The surface topographic parameterisation considers the sub-grid LiDAR data points above and below a reference DEM, hereafter named as topographic content. A method for roughness parameterisation is developed based on the topographic content included in the topographic DEM. Five subscale parameterisation schemes are generated (topographic contents at 0, ±5, ±10, ±25 and ±50 cm) and roughness values are calculated using an equation based on the mixing layer theory (Katul et al., 2002), resulting in a co-varied relationship between roughness height and topographic content. Variations in simulated flow across spatial subscales show that the sub grid-scale behaviour of the 2-D model is not well-reflected in the topographic content of the DEM and that subscale parameterisation must be modelled through a spatially distributed roughness parameterisation. Variations in flow predictions are related to variations in the roughness parameter. Flow depth-derived results do not change systematically with variation in roughness height or topographic content but they respond to their interaction. Finally, subscale parameterisation modifies primarily the spatial structure (level of organisation) of simulated 2-D flow linearly with the additional complexity of subscale parameterisation.

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Casas, A., S. N. Lane, D. Yu y G. Benito. "A method for parameterising roughness and topographic sub-grid scale effects in hydraulic modelling from LiDAR data". Hydrology and Earth System Sciences 14, n.º 8 (17 de agosto de 2010): 1567–79. http://dx.doi.org/10.5194/hess-14-1567-2010.

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Chu, Xuefeng, Xinhua Jia y Yang Liu. "Quantification of wetting front movement under the influence of surface topography". Soil Research 56, n.º 4 (2018): 382. http://dx.doi.org/10.1071/sr17071.

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Soil surface topography affects fundamental hydrologic processes, such as infiltration and soil water percolation. Topographic variations potentially alter both the magnitude and directions of unsaturated flow. The objective of this study is to evaluate the effects of surface topography on wetting front moving patterns under different rainfall and soil conditions through combined experimental and numerical modelling studies. Specifically, laboratory-scale infiltration and unsaturated flow experiments and HYDRUS-2D modelling were conducted for different topographic surfaces, rainfall intensities, and soil types. The simulated and observed wetting front distributions were compared and evaluated. Two different stages were observed: topography-dominated two-dimensional flow and uniform one-dimensional flow. A uniformly distributed wetting front was eventually achieved although soil surfaces had dissimilar topographic characteristics. However, the timing or duration to reach such a uniform flat wetting front varied, mainly depending on surface topography, rainfall characteristics, and soil hydraulic properties. The findings from this study are important to better understand the mechanism of topography-controlled unsaturated flow, wetting front movement, and overland flow generation, and to further improve modelling of soil water flow and transport processes under such complex conditions across different scales.

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Shakespeare, Callum J., Brian K. Arbic y Andrew McC. Hogg. "The Drag on the Barotropic Tide due to the Generation of Baroclinic Motion". Journal of Physical Oceanography 50, n.º 12 (diciembre de 2020): 3467–81. http://dx.doi.org/10.1175/jpo-d-19-0167.1.

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AbstractThe interaction of a barotropic flow with topography generates baroclinic motion that exerts a stress on the barotropic flow. Here, explicit solutions are calculated for the spatial-mean flow (i.e., the barotropic tide) resulting from a spatially uniform but time-varying body force (i.e., astronomical forcing) acting over rough topography. This approach of prescribing the force contrasts with that of previous authors who have prescribed the barotropic flow. It is found that the topographic stress, and thus the impact on the spatial-mean flow, depend on the nature of the baroclinic motion that is generated. Two types of stress are identified: (i) a “wave drag” force associated with propagating wave motion, which extracts energy from the spatial-mean flow, and (ii) a topographic “spring” force associated with standing motion at the seafloor, including bottom-trapped internal tides and propagating low-mode internal tides, which significantly damps the time-mean kinetic energy of the spatial-mean flow but extracts no energy in the time-mean. The topographic spring force is shown to be analogous to the force exerted by a mechanical spring in a forced-dissipative harmonic oscillator. Expressions for the topographic stresses appropriate for implementation as baroclinic drag parameterizations in global models are presented.

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Richter, Nicole, Massimiliano Favalli, Elske de Zeeuw-van Dalfsen, Alessandro Fornaciai, Rui Manuel da Silva Fernandes, Nemesio M. Pérez, Judith Levy, Sónia Silva Victória y Thomas R. Walter. "Lava flow hazard at Fogo Volcano, Cabo Verde, before and after the 2014–2015 eruption". Natural Hazards and Earth System Sciences 16, n.º 8 (17 de agosto de 2016): 1925–51. http://dx.doi.org/10.5194/nhess-16-1925-2016.

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Abstract. Lava flow simulations help to better understand volcanic hazards and may assist emergency preparedness at active volcanoes. We demonstrate that at Fogo Volcano, Cabo Verde, such simulations can explain the 2014–2015 lava flow crisis and therefore provide a valuable base to better prepare for the next inevitable eruption. We conducted topographic mapping in the field and a satellite-based remote sensing analysis. We produced the first topographic model of the 2014–2015 lava flow from combined terrestrial laser scanner (TLS) and photogrammetric data. This high-resolution topographic information facilitates lava flow volume estimates of 43.7 ± 5.2 × 106 m3 from the vertical difference between pre- and posteruptive topographies. Both the pre-eruptive and updated digital elevation models (DEMs) serve as the fundamental input data for lava flow simulations using the well-established DOWNFLOW algorithm. Based on thousands of simulations, we assess the lava flow hazard before and after the 2014–2015 eruption. We find that, although the lava flow hazard has changed significantly, it remains high at the locations of two villages that were destroyed during this eruption. This result is of particular importance as villagers have already started to rebuild the settlements. We also analysed satellite radar imagery acquired by the German TerraSAR-X (TSX) satellite to map lava flow emplacement over time. We obtain the lava flow boundaries every 6 to 11 days during the eruption, which assists the interpretation and evaluation of the lava flow model performance. Our results highlight the fact that lava flow hazards change as a result of modifications of the local topography due to lava flow emplacement. This implies the need for up-to-date topographic information in order to assess lava flow hazards. We also emphasize that areas that were once overrun by lava flows are not necessarily safer, even if local lava flow thicknesses exceed the average lava flow thickness. Our observations will be important for the next eruption of Fogo Volcano and have implications for future lava flow crises and disaster response efforts at basaltic volcanoes elsewhere in the world.

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Kumhálová, J., F. Kumhála, P. Novák y Š. Matějková. "Airborne laser scanning data as a source of field topographical characteristics ". Plant, Soil and Environment 59, No. 9 (5 de septiembre de 2013): 423–31. http://dx.doi.org/10.17221/188/2013-pse.

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One of the factors frequently affecting yields is topography. Topographic data can be obtained from various sources with different precision. This work evaluates suitability of airborne laser scanning data for use as another source of topographical characteristics creation in a smaller scale in regards to precision agriculture needs. Simple models of elevation, slope and flow accumulation were created and the correlation between yield and topography was determined over a seven-year period in relation to precipitations and temperature. The suitability of airborne laser scanning data was proved with certain limitations. Flow accumulation model derived from original airborne laser scanning data indicated the right trend of flow accumulation but not as clearly compared to other models. In drier years the correlation coefficients between flow accumulation and yield reached up to 60–70%.

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Harmon, Brendan Alexander, Helena Mitasova, Anna Petrasova y Vaclav Petras. "r.sim.terrain 1.0: a landscape evolution model with dynamic hydrology". Geoscientific Model Development 12, n.º 7 (11 de julio de 2019): 2837–54. http://dx.doi.org/10.5194/gmd-12-2837-2019.

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Abstract. While there are numerical landscape evolution models that simulate how steady-state flows of water and sediment reshape topography over long periods of time, r.sim.terrain is the first to simulate short-term topographic change for both steady-state and dynamic flow regimes across a range of spatial scales. This free and open-source Geographic Information Systems (GIS)-based topographic evolution model uses empirical models for soil erosion and a physics-based model for shallow overland water flow and soil erosion to compute short-term topographic change. This model uses either a steady-state or unsteady representation of overland flow to simulate how overland sediment mass flows reshape topography for a range of hydrologic soil erosion regimes based on topographic, land cover, soil, and rainfall parameters. As demonstrated by a case study for the Patterson Branch subwatershed on the Fort Bragg military installation in North Carolina, r.sim.terrain simulates the development of fine-scale morphological features including ephemeral gullies, rills, and hillslopes. Applications include land management, erosion control, landscape planning, and landscape restoration.

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SANSÓN, L. ZAVALA, A. GONZÁLEZ-VILLANUEVA y L. M. FLORES. "Evolution and decay of a rotating flow over random topography". Journal of Fluid Mechanics 642 (4 de diciembre de 2009): 159–80. http://dx.doi.org/10.1017/s0022112009991777.

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The evolution and decay of a homogeneous flow over random topography in a rotating system is studied by means of numerical simulations and theoretical considerations. The analysis is based on a quasi-two-dimensional shallow-water approximation, in which the horizontal divergence is explicitly different from zero, and topographic variations are not restricted to be much smaller than the mean depth, as in quasi-geostrophic dynamics. The results are examined by comparing the evolution of a turbulent flow over different random bottom topographies characterized by a specific horizontal scale, or equivalently, a given mean slope. As in two-dimensional turbulence, the energy of the flow is transferred towards larger scales of motion; after some rotation periods, however, the process is halted as the flow pattern becomes aligned along the topographic contours with shallow water to the right. The quasi-steady state reached by the flow is characterized by a nearly linear relationship between potential vorticity and transport function in most parts of the domain, which is justified in terms of minimum-enstrophy arguments. It is found that global energy decays faster for topographies with shorter horizontal length scales due to more effective viscous dissipation. In addition, some comparisons between simulations based on the shallow-water and quasi-geostrophic formulations are carried out. The role of solid boundaries is also examined: it is shown that vorticity production at no-slip walls contributes for a slight disorganization of the flow.

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Constantinou, Navid C. "A Barotropic Model of Eddy Saturation". Journal of Physical Oceanography 48, n.º 2 (febrero de 2018): 397–411. http://dx.doi.org/10.1175/jpo-d-17-0182.1.

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AbstractEddy saturation refers to a regime in which the total volume transport of an oceanic current is insensitive to the wind stress strength. Baroclinicity is currently believed to be the key to the development of an eddy-saturated state. In this paper, it is shown that eddy saturation can also occur in a purely barotropic flow over topography, without baroclinicity. Thus, eddy saturation is a fundamental property of barotropic dynamics above topography. It is demonstrated that the main factor controlling the appearance or not of eddy-saturated states in the barotropic setting is the structure of geostrophic contours, that is, the contours of f/H (the ratio of the Coriolis parameter to the ocean’s depth). Eddy-saturated states occur when the geostrophic contours are open, that is, when the geostrophic contours span the whole zonal extent of the domain. This minimal requirement for eddy-saturated states is demonstrated using numerical integrations of a single-layer quasigeostrophic flow over two different topographies characterized by either open or closed geostrophic contours with parameter values loosely inspired by the Southern Ocean. In this setting, transient eddies are produced through a barotropic–topographic instability that occurs because of the interaction of the large-scale zonal flow with the topography. By studying this barotropic–topographic instability insight is gained on how eddy-saturated states are established.

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Tesis sobre el tema "Topographic flow"

Marklund, Lars. "Topographic Control of Groundwater Flow". Doctoral thesis, KTH, Mark- och vattenteknik, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-11153.

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Gravity is the main driving force for groundwater flow, and both landscape topography and geology distribute the effects of gravity on groundwater flow. The groundwater table defines the distribution of the potential energy of the water. In humid regions where the bedrock permeability is relatively low and the soil depth is sufficiently shallow, the groundwater table closely follows the landscape topography and, thus, the topography controls the groundwater circulation in these regions. In this thesis, I investigate multi-scale topography-controlled groundwater flow, with the goal of systematizing the spatial distribution of groundwater flow and assessing geological parameters of importance for groundwater circulation. Both exact solutions and numerical models are utilized for analyzing topography-controlled groundwater flow. The more complex numerical models are used to explore the importance of various simplifications of the exact solutions. The exact solutions are based on spectral representation of the topography and superpositioning of unit solutions to the groundwater flow field. This approach is an efficient way to analyze multi-scaled topography-controlled groundwater flow because the impact of individual topographic scales on the groundwater flow can be analyzed separately. The results presented here indicate that topography is fractal and affects groundwater flow cells at wide range of spatial scales. We show that the fractal nature of the land surface produces fractal distributions of the subsurface flow patterns. This underlying similarity in hydrological processes also yields a single scale-independent distribution of subsurface water residence times which have been found in distributions of solute efflux from watersheds. Geological trends modify the topographic control of the groundwater circulation pattern and this thesis presents exact solutions explaining the impact of geological layering, depth-decaying and anisotropic hydraulic conductivity on the groundwater flow field. For instance, layers of Quaternary deposits and decaying permeability with depth both increase the importance of smaller topographic scales and creates groundwater flow fields where a larger portion of the water occupies smaller and shallower circulation cells, in comparison to homogeneous systems.
Gravitationen är den mest betydelsefulla drivkraften för grundvattenströmning. Topografin och geologin fördelar vattnets potentiella energi i landskapet. Grundvattenytans läge definierar vattnets potentiella energi, vilket är ett randvillkor för grundvattnets strömningsfält. I humida områden med en relativt tät berggrund och tillräckligt tunna jordlager, följer grundvattenytan landskapets topografi. Därav följer att grundvattenströmningen är styrd av topografin i dessa områden. I denna avhandling belyser jag den flerskaliga topografistyrda grundvattenströmningen. Min målsättning har varit att kvantitativt bestämma grundvattenströmningens rumsliga fördelning samt att undersöka hur olika geologiska parametrar påverkar grundvattencirkulationen. Jag har använt såväl numeriska modeller som analytiska lösningar, för att undersöka hur topografin styr grundvattenströmningen. De numeriska modellerna är mer komplexa än de analytiska lösningarna och kan därför användas för att undersöka betydelserna av olika förenklingar som finns i de analytiska lösningarna. De analytiska lösningarna är baserade på spektralanalys av topografin, samt superponering av enhetslösningar, där varje enhetslösning beskriver hur en specifik topografisk skala påverkar grundvattnets strömningsfält. Detta är ett effektivt tillvägagångssätt för att undersöka flerskaliga effekter av topografin, eftersom påverkan av varje enskild topografisk skala kan studeras separat. Resultaten som presenteras indikerar att topografin är fraktal och att den ger upphov till cirkulationsceller av varierande storlek som även dessa är av en fraktal natur. Denna grundläggande fördelning i grundvattnets strömningsfält ger upphov till att grundvattnets uppehållstid i marken följer ett självlikformigt mönster och kan förklara uppmätta tidsvariationer av lösta ämnens koncentrationer i vattendrag efter regn. Geologiska trender påverkar hur grundvattenströmningen styrs av topografin. De exakta lösningar som presenteras här, beskriver hur geologiska lager samt djupavtagande och anisotropisk hydraulisk konduktivitet påvekar grundvattnets strömning. Exempelvis är betydelsen av mindre topografiska skalor viktigare i områden med kvartära avlagringar och en berggrund med djupavtagande konduktivitet, än i områden med homogen bergrund utan kvartära avlagringar. Dessutom är en större andel strömmande vatten belägen närmare markytan i de förstnämnda områdena.
QC 20100802

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Holt, Jason Tempest. "Topographic influences on Kelvin-Helmholtz instability". Thesis, University of Southampton, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295515.

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Marks, Kathryn Jean. "Enhanced flood hydraulic modelling using topographic remote sensing". Thesis, University of Bristol, 2001. http://hdl.handle.net/1983/e9866673-d6aa-49b5-964c-ed984940801c.

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Wichura, Henry. "Topographic evolution of the East African Plateau : a combined study on lava-flow modeling and paleo-topography". Phd thesis, Universität Potsdam, 2011. http://opus.kobv.de/ubp/volltexte/2011/5236/.

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The East African Plateau provides a spectacular example of geodynamic plateau uplift, active continental rifting, and associated climatic forcing. It is an integral part of the East African Rift System and has an average elevation of approximately 1,000 m. Its location coincides with a negative Bouguer gravity anomaly with a semi-circular shape, closely related to a mantle plume, which influences the Cenozoic crustal development since its impingement in Eocene-Oligocene time. The uplift of the East African Plateau, preceding volcanism, and rifting formed an important orographic barrier and tectonically controlled environment, which is profoundly influenced by climate driven processes. Its location within the equatorial realm supports recently proposed hypotheses, that topographic changes in this region must be considered as the dominant forcing factor influencing atmospheric circulation patterns and rainfall distribution. The uplift of this region has therefore often been associated with fundamental climatic and environmental changes in East Africa and adjacent regions. While the far-reaching influence of the plateau uplift is widely accepted, the timing and the magnitude of the uplift are ambiguous and are still subject to ongoing discussion. This dilemma stems from the lack of datable, geomorphically meaningful reference horizons that could record surface uplift. In order to quantify the amount of plateau uplift and to find evidence for the existence of significant relief along the East African Plateau prior to rifting, I analyzed and modeled one of the longest terrestrial lava flows; the 300-km-long Yatta phonolite flow in Kenya. This lava flow is 13.5 Ma old and originated in the region that now corresponds to the eastern rift shoulders. The phonolitic flow utilized an old riverbed that once drained the eastern flank of the plateau. Due to differential erosion this lava flow now forms a positive relief above the parallel-flowing Athi River, which is mimicking the course of the paleo-river. My approach is a lava-flow modeling, based on an improved composition and temperature dependent method to parameterize the flow of an arbitrary lava in a rectangular-shaped channel. The essential growth pattern is described by a one-dimensional model, in which Newtonian rheological flow advance is governed by the development of viscosity and/or velocity in the internal parts of the lava-flow front. Comparing assessments of different magma compositions reveal that length-dominated, channelized lava flows are characterized by high effusion rates, rapid emplacement under approximately isothermal conditions, and laminar flow. By integrating the Yatta lava flow dimensions and the covered paleo-topography (slope angle) into the model, I was able to determine the pre-rift topography of the East African Plateau. The modeling results yield a pre-rift slope of at least 0.2°, suggesting that the lava flow must have originated at a minimum elevation of 1,400 m. Hence, high topography in the region of the present-day Kenya Rift must have existed by at least 13.5 Ma. This inferred mid-Miocene uplift coincides with the two-step expansion of grasslands, as well as important radiation and speciation events in tropical Africa. Accordingly, the combination of my results regarding the Yatta lava flow emplacement history, its location, and its morphologic character, validates it as a suitable “paleo-tiltmeter” and has thus to be considered as an important topographic and volcanic feature for the topographic evolution in East Africa.
Das Ostafrikanische Plateau ist ein eindrucksvolles Beispiel für aktive, kontinentale Grabenbildung, aber auch für geodynamische Hochebenenbildung mit weitreichendem klimatischen Einfluss auf die gesamte Region. Als integraler Bestandteil des Ostafrikanischen Grabensystems beläuft sich die mittlere Höhe des Plateaus auf durchschnittlich 1000 m ü.NN. Seine Lage korreliert gut mit der Präsenz einer halbkreisförmigen negativen Bouguer-Schwereanomalie, die an den Aufstieg eines Manteldiapirs im Untergrund gekoppelt ist. Dieser prägte die känozoische Krustenentwicklung seit seinem Aufstieg im Eozän-Oligozän. Die Hebungsgeschichte und topographische Entwicklung des Hochlandes steht seither in enger Beziehung zum einsetzenden Vulkanismus, der Bildung erster Abschiebungssysteme und führte schließlich zur Entwicklung des heutigen Vollgrabensystems. Neueste Hypothesen lassen den Schluss zu, dass topographische Veränderungen als dominierende Einflussgrößen atmosphärischer Zirkulationsmuster sowie der regionalen Niederschlagsverbreitung anzusehen sind. Zusätzlich werden diese Prozesse durch die äquatoriale Lage des Ostafrikanischen Plateaus verstärkt und die Hebung dieser Region oft mit wichtigen Klima- und Umweltveränderungen in Ostafrika und angrenzende Gebiete in Verbindung gebracht. Während der weitreichende klimatische Einfluss des Hochlandes größtenteils akzeptiert ist, sind Zeitpunkt und Ausmaß seiner Heraushebung nicht eindeutig bestimmt und daher noch immer Grundlage bestehender Diskussionen. Diese Zwangslage hat ihre Ursache im Fehlen aussagekräftiger und datierbarer Referenzhorizonte. Um den Hebungsbetrag zu quantifizieren und Beweise signifikanten Reliefs vor der Entwicklung des Grabensystems entlang des Ostafrikanischen Hochlandes zu erbringen, analysierte und modellierte ich einen der längsten terrestrischen Lavaströme. Dieser vor 13,5 Ma abgelagerte Yatta-Lavastrom hat mit 300 km Länge seinen Ursprung in der Region der heutigen östlichen Grabenschulter des zentralen Kenia-Rifts. Die phonolitische Lava ergoss sich entlang eines Flussbettes, das einst die östliche Flanke des Hochlandes entwässerte. Aufgrund unterschiedlicher Erosionspotentiale bildet der Lavastrom gegenwärtig ein positives Relief und befindet sich oberhalb des Athi Flusses, der parallel zum Paläofluß, und somit versetzt zu seinen früheren Verlauf, strömt. Mein Ansatz der Lavastrom-Modellierung basiert auf einer Methode, die das Fließverhalten einer beliebigen Lava in Abhängigkeit von Temperatur und Magmenzusammensetzung in einem rechtwinkligen Kanal berechnet. Die wesentlichen Wachstumsmuster des Lavastroms sind durch ein eindimensionales Modell beschrieben, wobei Newtonsches Fließverhalten im Innern hinter der Lavastromfront von der zeitlichen Entwicklung der Viskosität und/oder der Fließgeschwindigkeit bestimmt wird. Vergleiche meiner Resultate mit verschiedenen Magmenzusammensetzungen zeigen, dass sich lange, kanalisierte Lavaströme mit hohen Ergussraten und schneller Platznahme bilden können. Dies geschieht unter annähernd isothermalen Bedingungen und erfordert laminares Fließen. Die Integration der Yatta- Lavastrom-Dimensionen und der bedeckten Paläotopographie (Neigungswinkel) in das Modell, erlaubte es mir die Topographie des Ostafrikanischen Hochlandes vor der Grabenbildung zu modellieren. Das Ergebnis der Modellierung ergibt einen Neigungswinkel von mindestens 0,2° und impliziert, dass der Lavastrom seinen Ursprung in einer Höhe von mindestens 1400 m ü.NN gehabt haben muss. Somit existierte bereits vor 13,5 Ma hohe Topographie in der heutigen Region des zentralen Kenia-Rifts. Diese abgeleitete regionale Hebungsgeschichte im mittleren Miozän korreliert mit der zweistufigen Ausbreitung der Graslandschaften, sowie dem Aufkommen neuer Arten im tropischen Afrika. Die Kombination aus Fließverhalten, Entstehungsort und morphologischer Eigenschaften macht den Yatta-Lavastrom zu einem “Paläoneigungsmesser” und wichtigen vulkanischen Untersuchungsobjekt für die topographische Entwicklung in Ostafrika.

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Milne, Fraser Dalton. "Topographic and material controls on the Scottish debris flow geohazard". Thesis, University of Dundee, 2008. https://discovery.dundee.ac.uk/en/studentTheses/eb4a6b03-8024-4818-8e92-ce1fd3c77209.

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Debris flows can be considered the most significant geological hazard in areas of high relief in Scotland having impacted upon slope foot infrastructure several times in recent years. The potency of this geohazard is anticipated to increase over the coming decades due to a climatologically enforced upturn in debris flow frequency. In thisresearch material and topographic controls on debris flow activity are investigated using a combination of field and laboratory based analysis of debris flows at six study sites across upland Scotland. Centrifuge modelling is also used to simulate theinitiation of debris flows in soils with varying particle size distributions.Spatial densities of debris flow measured in the field indicate that hillslopes underlain by sandstone and granitic bedrocks, which tend to be mantled by coarser sand rich soils, have a greater frequency of flows than those underlain by schist andextrusive lava bedrocks. Higher debris flow densities on slopes underlain by sandstone and granite lithologies are facilitated by high permeability in overlying regolith matrixes allowing more rapid increase in pore water pressures duringrainstorms although this is likely to be further influenced by packing and organic content. Centrifuge modelling of hillslope debris flows also demonstrate that sandier soils are generally geotechnically more susceptible to slope failure.The susceptibility of a hillslope to debris flow is strongly influenced by slope geometry and morphology. Hillslopes with persistently steep slopes and a high incidence of concavities, gullies and couloirs are topographically more predisposed todebris flow activity due to greater shear stresses and morphologically controlled, gravity induced concentrations of hillslope hydrology. The majority of material in channelised debris flows is entrained during the gully propagation stage of the massmovement. Consequently, such events can be considered accumulative channelised debris flows. Longer and steeper gullies with greater sediment capacities are more likely to yield larger flow mass movements. Coupling between open hillslopes andbedrock gullies is shown to be an essential component for conceptualisation of the debris flow geohazard.Due to the role they play in amplifying debris flow magnitude, hazard management should be focussed around bedrock gullies and stream channels. Highesthazard rankings should be assigned to slope foot infrastructure in proximity to gullied stream channels with high sediment capacities and long, steep profiles conducive to large accumulative channelised debris flows. To avoid detrimental aesthetic impact, hazard management should be strongly geared towards utilisation of lower impactexposure reduction techniques and less visually intrusive engineering approaches such as increasing culvert capacity to accommodate debris flows. During realignment or the planning of future transport infrastructure, culverts with capacities significantly exceeding those required for purely hydrodynamic considerations should be placed straight on to stream channels avoiding proximal gully bends.

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Rizo, Steven R. "Quantifying the Effect of Topographic Slope on Lava Flow Thickness: A First Step to Improve Lava Flow Volume Estimation Methods". Scholar Commons, 2018. http://scholarcommons.usf.edu/etd/7222.

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The volume of lava flows provide important information on the magnitude of volcanic eruptions, and accurate volumes are necessary to produce reliable models of lava flow emplacement or constrain the internal structure of volcanoes. The most accurate lava flow volumes are obtainable when the topography before and after an eruption are both known, but information for the topography before lava flow emplacement is absent in non-historic lava flows. To calculate the volume of non-historic lava flows, this pre-emplacement topography needs to be reconstructed. Common methods for this include using inverse distance-weighted averages or global polynomial interpolation methods, but these can still underestimate the volume of the flow, and the surface of the flow itself is not considered in these interpolations. A new calculation method seems necessary to better constrain the volume of lava flows, and including the lava flow surface in the volume calculation, given that it is generally excluded during interpolation of pre-emplacement topography, may be the solution to improving lava flow volume calculation for flows where the base surface is unknown. The 2012-2013 Tolbachik lava flow is used to look at potential relationships due to the availability of elevation data before and after the eruption. A quantitative analysis on the relationships between the slope of topography before and after lava flow emplacement and on the relationship between the slope and thickness of lava flows is performed. In addition to this, the slope of the topography calculated over local and regional scales is used as a new interpolation method, and the calculated thickness from the interpolated surface is compared to the known thickness for the lava flow.

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CUCCHIARO, SARA. "Assessing sediment dynamics and check dams efficiency in a debris-flow catchment using multi-temporal topographic surveys". Doctoral thesis, Università degli Studi di Trieste, 2019. http://hdl.handle.net/11368/2962385.

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Torrent control works have always been a fundamental tool for preventing torrential hazard in mountain catchments, where the sediment transport phenomena as debris flows are one of the most dangerous geomorphic processes affecting small steep basins. The linkages between sediment source areas on the hillslopes and channel network, along with the temporal and spatial distributions of channel storage, are key controls of debris-flow occurrence and magnitude. Consequently, the prevention of natural hazards related to debris-flows requires a better understanding of sediment dynamic. Among the hydraulic engineering structures, grade control dams and sediment retention dams are the most effective and common technique to manage debris flows and debris floods hazard. These structures could have important effects on sediment dynamic. Therefore, an integrated approach that analyses the debris-flow dynamic and its interactions with torrent control works, is needed to assess the efficiency of the realized structures and to improve the long-term hazard management at catchment scale. In spite of the widespread presence of such hydraulic structures in steep mountain streams worldwide, very little researches considered the role of check dams on sediment dynamics in debris-flow environments over time to enhance the planning of the torrent control works. The monitoring of debris-flow events, the estimation of debris-flow magnitude and frequency, and the analysis of spatial patterns in terms of eroded and deposited volumes, are fundamental to improve the sediment dynamic understanding. In the last two decades, High-Resolution Topography (HRT) has provided new opportunities to characterize debris-flow activity at different scales. Between these, the application of Structure from Motion (SfM) photogrammetry paired with Multi-View Stereo (MVS) algorithms has become a low-cost method to collect HRT at multiple temporal and spatial scales, also in rugged or inaccessible environments like those observed in debris-flow catchments. SfM allows carrying out HRT with high frequency; nevertheless, the SfM technique is limited at broad spatial scales. Therefore, other technologies as LiDAR surveys could be used to assess the sediment dynamic also at catchment scale. However, the use of HRT required the design of appropriate workflows for data post-processing and uncertainty assessment to compare multi-temporal surveys, especially in a topographically complex environment. In this research, the effects of torrent control works on debris-flow dynamics were investigated by means of multi-temporal SfM and LiDAR surveys in the Moscardo torrent (eastern Italian Alps) where several check dams have been built over time. Methodological workflows enabled the realization of multi-temporal Digital Elevation Models (DEMs) which were compared (i.e., DoD) to quantify the debris mobilized and the time evolution of erosion and deposition patterns in debris-flow channels equipped with check dams. The DoDs data were integrated with a sediment connectivity analysis to have a whole assessment of debris-flow dynamic. The results show that the check dams considerably modified debris-flow dynamics in the studied channel but their performance cannot be considered satisfactory. They temporary stored volumes of debris just after their construction, but soon when the structures were filled the check dams acted as sediment sources that increased debris-flow magnitude. Moreover, the sediment paths flowed around some check dams. These processes triggered the slope foot erosion and activated shallow landslides, further sediment source areas for debris-flow process. The analysis proposed in this work could help to improve design approaches and to obtain more realistic cost-benefit ratios of the adopted strategies and, in this way, select the best solutions.

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Nasser, Antoine-Alexis. "Advancing the representation of flows along topography in z-coordinate ocean models". Electronic Thesis or Diss., Sorbonne université, 2023. http://www.theses.fr/2023SORUS446.

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Les fonds marins exercent un contrôle majeur sur la circulation océanique. La représentation discrète de la topographie dans les modèles de circulation générale océanique (OGCM) géopotentiels crée des marches artificielles qui produisent des effets néfastes pour la simulation des courants. Cette thèse vise à établir des solutions adaptées pour résoudre les effets adverses des marches dans les OGCM. A partir de configurations idéalisées et en explorant le potentiel de la méthode de Pénalisation des Volumes de Brinkman (BVP), nous étudions la sensibilité des courants simulé aux frontières en marche d'escalier. Il est montré comment résoudre le 'spurious form drag' latéral (ou le 'staircase problem') mis en évidence par Adcroft et Marshall (1998). Les côtes (ainsi que les isobathes) représentées par des séries de marche deviennent lisses lorsqu'une condition miroir (glissement) est exactement appliquée sur l'écoulement à la côte. La formulation de la condition de glissement dans l'advection exprimé en 'flux-form' ou dans le tenseur visqueux symétrique produit dans le modèle du 'non-glissement' sur une topographie en marche d'escalier. Il est montré que la condition limite visqueuse doit changer le long des contours afin de simuler la rétroflexion du courants à un cape. Afin devenir insensible à la topographie en marche d'escalier, les modèles numériques devraient idéalement être physiquement convergés (c'est-à-dire que les caractéristiques principales de l'écoulement ne sont pas affectées par l'augmentation de la résolution spatiale en conservant les paramètres de viscosité et de friction constants). Il est montré que cette convergence peut être atteinte à une résolution plus faible en résolvant l'advection discrète des moments à l'aide de schémas utilisant un stencil élargi. On montre dans un overflow idéalisée l'impact de la résolution discrète de la quantité de mouvement sur la précision des écoulements le long des pentes en marche d'escalier. La méthode de BVP permet d'étaler l'interface terre-océan en définissant des cellules poreuses qui sont à moitié terre et à moitié océan. Étaler ainsi l'interface lisse les courants et réduit considérablement la diffusion numérique pendant la descente. Il est montré que la stabilité numérique de la méthode BVP peut être assurée en étalant suffisamment la frontière poreuse, et en ajustant de manière cohérente la perméabilité (friction dans les cellules poreuses). Les résultats soulignent le potentiel de la méthode BVP pour la meilleure représentation des courants le long des topographies dans les OGCM
The seafloor exerts a major control on ocean circulation. The discrete representation of marine topography in geopotential Ocean General Circulation Models (OGCMs) creates artificial steps that have adverse effects on the simulated circulation. This thesis aims at finding suitable ways to address the adverse effects of stepped topography in z-coordinate OGCMs. Using idealized configurations and exploring the potential of the Brinkman Volume Penalisation (BVP) method, we investigate the sensitivity of modelled currents to the presence of artificial steps along model boundaries. We first address the spurious lateral form drag (or textit{staircase problem}) highlighted by Adcroft and Marshall (1998). We show that staircase-like coastlines (and isobaths) behave as smooth boundaries when applying a textit{true} mirror condition on the boundary flow. The discrete implementation of free-slip using flux-form advection and a symmetric viscous stress tensor actually corresponds to no-slip along stepped topography. The choice of viscous boundary condition should vary with location to capture the retroflection of boundary currents at capes. To become insensitive to stepped topography, numerical models should ideally achieve physical convergence (i.e. the main characteristics of the flow are not affected by increasing spatial resolution while keeping viscous and frictional parameters constant). This convergence can be attained at lower resolution with a careful treatment of discrete momentum advection involving a large stencil. We highlight the impact of momentum advection schemes on the fidelity of simulated downslope currents within an idealised overflow configuration. The BVP method allows to spread the land-ocean interface, by introducing porous cells that are half-land half-ocean. We find that this spreading allows to smooth bottom currents and to reduce spurious mixing during downslope flow. The numerical stability of the BVP can be guaranteed by sufficient spreading of the boundary and by defining permeability (friction within porous cells) in a consistent way. The results underscore the potential of the BVP method to better represent flows along topography in OGCMs

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Raja, Keshav Jayakrishnan. "Internal waves and mean flow in the presence of topography". Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAU006/document.

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Les ondes internes jouent un rôle important dans de nombreux processus dans les océans.L’interaction entre les vagues internes et la topographie océanique a longtemps été un champ de recherche actif. Pourtant, il reste beaucoup de questions sur le sujet. Dans cette thèse, deux processus principaux sont examinés, à savoir la réflexion de faisceaux d’ondes internes sur une pente, et la génération d’ondes sous le vent sur un obstacle tridimensionnel, en utilisant des expériences de laboratoire et des simulations numériques.La réflexion non linéaire d’un faisceau d’onde interne sur une pente uniforme est étudiée à l’aide de la théorie des invisques bidimensionnels et de simulations numériques. Les interactions triadiques résonnantes entre les faisceaux d’ondes incidentes, réfléchies et de deuxième harmonique sont étudiées en développant la théorie existante et en les vérifiant avec des résultats pour des simulations numériques.Dans le cas de la réflexion de faisceaux d’ondes internes tridimensionnels, un fort flux horizontal moyen est induit par le faisceau d’onde, qui perturbe le champ d’onde et affaiblit les secondes harmoniques. La génération de ce flux moyen induit par les vagues est examinée à l’aide des résultats d’expériences et de simulations numériques tridimensionnelles. De plus,les effets de la rotation de fond sur le débit moyen induit par les vagues sont également étudiés à l’aide de simulations numériques.Le courant circumpolaire antarctique est considéré comme l’une des principales sources de mélange dans les océans. La modélisation en laboratoire du courant circumpolaire antarctique a été réalisée sur la plate-forme de Coriolis à LEGI pour étudier la traînée induite par la topographie sur le courant. L’expérience et ses résultats sont également présentés
Internal waves play an important role in many processes in oceans. The interaction be-tween internal waves and ocean topography has been an active field of research for long. Yetthere are many questions remaining on the topic. In this thesis, two main processes are ex-amined namely, the reflection of internal wave beams on a slope, and generation of lee wavesover a three-dimensional obstacle, using laboratory experiments and numerical simulations.The nonlinear reflection of an internal wave beam on a uniform slope is studied using two-dimensional inviscid theory and numerical simulations. The resonant triadic interactionsamong the incident, reflected and second harmonic wave beams are investigated developingon existing theory and verifying them with results for numerical simulations.In the case of reflection of three-dimensional internal wave beams, a strong mean horizon-tal flow is found to be induced by the wave beam, which perturbs the wave field and weakensthe second harmonics. The generation of this wave-induced mean flow is examined usingresults from experiments and three-dimensional numerical simulations. Furthermore, theeffects of background rotation on the wave induced mean flow are also studied using numer-ical simulations.The Antarctic Circumpolar Current is considered as one of the main sources of mixing inoceans. Laboratory modelling of the Antarctic Circumpolar Current was done in the Coriolisplatform at LEGI to study the topography induced drag on the current. The experiment andits results are also presented

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Skopovi, Ivan 1976. "The role of background flow variations in stratified flows over topography". Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/35632.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2006.
Includes bibliographical references (leaves 89-91).
As the atmosphere and oceans feature density variations with depth, the flow of a density-stratified fluid over topography is central to various geophysical and meteorological applications and has been studied extensively. For reasons of convenience and mathematical tractability, the majority of theoretical treatments of stratified flow over a finite-amplitude obstacle assume idealized background flow conditions, namely constant free-stream velocity and either a homogeneous or two-layer buoyancy-frequency profile. In this work, a numerical model is developed that accounts for general variations in the buoyancy-frequency profile far upstream and the presence of unsteadiness in the free-stream velocity. The model employs a second-order projection method for solving the Euler equations for stratified flow over locally confined topography in a horizontally and vertically unbounded domain - the flow configuration most pertinent to atmospheric applications - combined with absorbing viscous layers at the upper and lateral boundaries of the computational domain. Using this model, a study is first made of the effect of variations in the buoyancy frequency on the generation of mountain gravity waves.
(cont.) Balloon measurements reveal that, apart from a sharp increase (roughly by a factor of 2) at the so-called tropopause, atmospheric buoyancy-frequency profiles often feature appreciable oscillations (typical wavelength 1-2 kni). It is found that such short-scale oscillatory variations can have a profound effect on mountain waves owing to a resonance mechanism that comes into play at certain wind speeds depending on the oscillation length scale. A simple linear model assuming small sinusoidal buoyancy-frequency oscillations suggests, and numerical simulations for more realistic flow conditions confirm, that the induced gravity-wave activity under resonant conditions is significantly increased above and upstream of the mountain, causing transient wave breaking (overturning), similarly to resonant flow of finite depth over topography. The effect of temporal variations in the free-stream velocity is then explored for a range of amplitudes and periods typical of those encountered in the field. The simulations reveal that transient disturbances resulting from such variations can be significant, particularly in the nonlinear regime, and steady states predicted on the assumption of uniform wind may not be attainable.
by Ivan Skopovi.
Ph.D.

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Libros sobre el tema "Topographic flow"

Baines, Peter G. Topographic effects in stratified flows. Cambridge: Cambridge University Press, 1995.

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Thompson, LuAnne. Flow over finite isolated topography. Woods Hole, Mass: Woods Hole Oceanographic Institution, 1990.

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Rennick, Mary Alice. Air flow over large scale topography. Monterey, Calif: Naval Postgraduate School, 1989.

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Luca, Ioana, Yih-Chin Tai y Chih-Yu Kuo. Shallow Geophysical Mass Flows down Arbitrary Topography. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-02627-5.

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Carl, Freeman D. y Intermountain Research Station (Ogden, Utah), eds. Influence of topography on cumulative pollen flow of fourwing saltbush. Ogden, UT (324 25th St., Ogden 84401): U.S. Dept. of Agriculture, Forest Service, Intermountain Research Station, 1993.

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Petroliagis, Thomas I. Studies of barotropic flow over topography using a Galerkin Finite Element model. Monterey, California: Naval Postgraduate School, 1988.

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Skupniewicz, C. E. Vandenberg Boundary Layer Survey (VBLS): Final report - results. Monterey, Calif: Naval Postgraduate School, 1990.

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Rao, Desiraju B. A method of calculating the total flow from a given sea surface topography. Greenbelt, Md: Goddard Space Flight Center, 1987.

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P, Castro I., Rockliff N. J y Institute of Mathematics and Its Applications., eds. Stably stratified flows: Flow and dispersion over topography : based on the proceedings of the Fourth Conference on Stably Stratified Flows, organized by the Institute of Mathematics and Its Applications and held at the University of Surrey in September, 1992. Oxford: Clarendon Press, 1994.

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Batchelor, G. K., Peter G. Baines, L. B. Freud, S. Leibovich y V. Tvergaard. Topographic Effects in Stratified Flows. Cambridge University Press, 1997.

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Capítulos de libros sobre el tema "Topographic flow"

Sodnik, Jošt, Tomaž Podobnikar, Urška Petje y Matjaž Mikoš. "Topographic Data and Numerical Debris-Flow Modeling". En Landslide Science and Practice, 573–78. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-31325-7_75.

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Sodnik, Jošt y Matjaž Mikoš. "TXT-tool 3.386-1.1: Two-Dimensional Debris-Flow Modelling and Topographic Data". En Landslide Dynamics: ISDR-ICL Landslide Interactive Teaching Tools, 235–50. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-57777-7_11.

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Lay, Usman Salihu y Biswajeet Pradhan. "Identification of Debris Flow Initiation Zones Using Topographic Model and Airborne Laser Scanning Data". En GCEC 2017, 915–40. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-10-8016-6_65.

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Grimshaw, R. "Resonant Flow over Topography". En Nonlinear Evolution Equations and Dynamical Systems, 209–11. Berlin, Heidelberg: Springer Berlin Heidelberg, 1990. http://dx.doi.org/10.1007/978-3-642-84039-5_41.

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Oki, S., Y. Katoh, K. Kurisu, T. Nakahara, T. Uozumi, Y. Tokuda, K. Emoto y S. Nishimura. "Effects of Glycerol on Brain Function in Normal Volunteers — Study on Regional Cerebral Blood Flow, Average Topographic EEG and Significance Probability Mapping". En Intracranial Pressure VII, 911–14. Berlin, Heidelberg: Springer Berlin Heidelberg, 1989. http://dx.doi.org/10.1007/978-3-642-73987-3_237.

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Nosoko, T., T. Nagata, T. Shinzato y M. Fang. "The Refracted Image Moire Topography for Measuring Liquid Film Profiles". En Flow Visualization VI, 682–86. Berlin, Heidelberg: Springer Berlin Heidelberg, 1992. http://dx.doi.org/10.1007/978-3-642-84824-7_121.

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Holloway, Greg, Ken Brink y Dale Haidvogel. "Topographic Stress in Coastal Circulation Dynamics". En Poleward Flows Along Eastern Ocean Boundaries, 315–30. New York, NY: Springer New York, 1989. http://dx.doi.org/10.1007/978-1-4613-8963-7_20.

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Wang, Nairu, Suning Huang, Shuang Cao, Hongyu Zhang y Taotao Zhang. "Analysis on the Characteristics of Channel Scour and Deposition in the Nanjing Reach of the Yangtze River After Impoundment of the Three Gorges Reservoir". En Lecture Notes in Civil Engineering, 1460–70. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-19-6138-0_129.

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AbstractThe construction and operation of the Three Gorges reservoir (TGR) alters the water and sediment conditions in the downstream channels, rendering the sediment transport capacity of water flow in these downstream channels at an unsaturated state, subsequently leading to scour and affecting flood prevention. Therefore, this study statistically analyzed the variations of channel scour and deposition in the Nanjing reach since the operation of the TGR, using the measured hydrologic and channel topographic data. The results showed that, the scour in the Nanjing reach was weak during 2001–2006, but prominently intensified during 2006–2020, with the multi-year average bankfull channel scour amount being 745.5 × 104 m3/a for the entire Nanjing reach. For the period of 2020.11–2021.03 after the basin-scale big flood in 2020, the scour was further intensified, with the total bankfull channel scour amount reaching 2677 × 104 m3. Since 2006, the Nanjing reach demonstrated an overall trend of “scour in both main channel and floodplain”, and bankfull channel scour was dominant, with the scour amount being 85% of that of the flood channel scour amount. Furthermore, scour was more intense on the left bank than on the right bank. The left branch of Xinjizhou reach and its downstream reaches were all erosional, demonstrating a pattern of scour amount being larger in the upper reach and smaller in the lower reach. Also, the multi-year average scour amount was the greatest at the Longtan and Yizheng reach, while the multi-year average scour intensity was the strongest at the main reach upstream the Meizizhou bifurcated reach.

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Mejia-Alvarez, Ricardo, Julio M. Barros y Kenneth T. Christensen. "Structural Attributes of Turbulent Flow Over a Complex Topography". En Coherent Flow Structures at Earth's Surface, 25–41. Chichester, UK: John Wiley & Sons, Ltd, 2013. http://dx.doi.org/10.1002/9781118527221.ch3.

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Nelson, Jonathan M. y J. Dungan Smith. "Flow in meandering channels with natural topography". En Water Resources Monograph, 69–102. Washington, D. C.: American Geophysical Union, 1989. http://dx.doi.org/10.1029/wm012p0069.

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Actas de conferencias sobre el tema "Topographic flow"

Santos, R. y R. Menéndez Duarte. "Topographic signature of debris flow dominated channels: implications for hazard assessment". En DEBRIS FLOW 2006. Southampton, UK: WIT Press, 2006. http://dx.doi.org/10.2495/deb060291.

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Noack, M., G. Schmid, M. Thom y S. Wieprecht. "Testing ‘Structure-from-Motion’ photogrammetry for high-resolution topographic surveys in hydraulic laboratories". En The International Conference On Fluvial Hydraulics (River Flow 2016). Taylor & Francis Group, 6000 Broken Sound Parkway NW, Suite 300, Boca Raton, FL 33487-2742: CRC Press, 2016. http://dx.doi.org/10.1201/9781315644479-100.

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Humphreys, Eugene. "WALLOWA BATHOLITH ROOT FOUNDERING, REGIONAL CRUSTAL FLOW AND TOPOGRAPHIC EVOLUTION". En GSA Connects 2022 meeting in Denver, Colorado. Geological Society of America, 2022. http://dx.doi.org/10.1130/abs/2022am-380003.

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Homoud, A. A., M. Ayub y E. Mohammed. "Integrated Topographic Multiphase Flow Modeling in Surface Pipelines - A Case Study". En SPE Kingdom of Saudi Arabia Annual Technical Symposium and Exhibition. Society of Petroleum Engineers, 2017. http://dx.doi.org/10.2118/188117-ms.

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Cattafesta, III, Louis y Jay Moore. "Review and application of non-topographic photogrammetry to quantitative flow visualization". En Advanced Measurement and Ground Testing Conference. Reston, Virigina: American Institute of Aeronautics and Astronautics, 1996. http://dx.doi.org/10.2514/6.1996-2180.

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Survila, Kornelijus, Ahmet Artu Yιldιrιm, Ting Li, Yan Y. Liu, David G. Tarboton y Shaowen Wang. "A Scalable High-performance Topographic Flow Direction Algorithm for Hydrological Information Analysis". En XSEDE16: Diversity, Big Data, and Science at Scale. New York, NY, USA: ACM, 2016. http://dx.doi.org/10.1145/2949550.2949571.

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Bobrow, Taylor L. y Nicholas J. Durr. "An adaptive-coherence light source for hyperspectral, topographic, and flow-contrast imaging". En Multimodal Biomedical Imaging XIV, editado por Fred S. Azar, Xavier Intes y Qianqian Fang. SPIE, 2019. http://dx.doi.org/10.1117/12.2510632.

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Yan, B. W., Q. S. Li, Y. C. He y P. W. Chan. "Numerical Simulation of Topographic Effects on Wind Flow Fields Over Complex Terrain". En Eighth Asia-Pacific Conference on Wind Engineering. Singapore: Research Publishing Services, 2013. http://dx.doi.org/10.3850/978-981-07-8012-8_083.

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Gervais, Felix, Giorgio Ranalli y Sophie Jannin. "IS TOPOGRAPHIC GRADIENT THE ONLY DRIVING FORCE FOR CHANNEL FLOW IN LARGE-HOT OROGENS?" En 53rd Annual GSA Northeastern Section Meeting - 2018. Geological Society of America, 2018. http://dx.doi.org/10.1130/abs/2018ne-310711.

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Wang, Chao, Jesus D. Gomez-Velez y John L. Wilson. "The importance of capturing topographic variability for modeling flow and transport in mountainous terrains". En 2016 New Mexico Geological Society Annual Spring Meeting. Socorro, NM: New Mexico Geological Society, 2016. http://dx.doi.org/10.56577/sm-2016.445.

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Informes sobre el tema "Topographic flow"

Carnevale, George F. Stratified Flow, Wave Packet Reflection and Topographic Currents. Fort Belvoir, VA: Defense Technical Information Center, septiembre de 2001. http://dx.doi.org/10.21236/ada624782.

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Kerr, D. E. Reconnaissance surficial geology, Sloan River, Northwest Territories-Nunavut, NTS 86-K. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/329452.

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The glaciated landscape of the Sloan River map area records evidence of old southwestward ice flow, followed by younger dominant northwestward flow in northernmost areas, and westward to west-southwestward flow in central and southern regions. Glacially and meltwater-scoured bedrock dominates the map area, with various till deposits discontinuously covering northern regions. Eskers and other glaciofluvial sediments define a poorly developed meltwater system, ranging in orientation from westward to northwestward. Meltwater channels show broader ranges of paleoflow directions in topographic highs. During deglaciation, which began about 10.5 ka BP, discontinuous north-south-trending recessional moraines were formed, defining a former margin of stagnating ice. Moraines in the northeast may represent the northern extension of the Forcier Moraine. Glaciolacustrine sediments associated with glacial Lake McConnell occur in the west, up to 300 m elevation. Other unrelated, isolated glaciolacustrine deltas, including those in the Coppermine River valley, occur further east up to 425 m elevation.

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Kerr, D. E. Reconnaissance surficial geology, Bloody River, Northwest Territories-Nunavut, NTS 96-P. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/329457.

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Preliminary surficial geology, based on airphoto interpretation and limited legacy field data of Bloody River map area, records a dynamic Late Wisconsin glacial landscape. Streamlined till and bedrock landforms, relating to Laurentide ice originating east of the map region, indicate regional westward flow diverged northwestward and southwestward at the eastern end of two topographic highs. Ice then converged between and south of these two highs, then diverged at the western end of these highlands. During deglaciation, ice stagnated in northwestern and central highland regions, forming extensive hummocky moraine, large kames, recessional moraines, and kame moraines. In other parts of the map area, hummocky till, small moraines, and undifferentiated till ridges, were deposited over fluted till. Outwash plains, eskers, and meltwater corridors record northwestward to southwestward meltwater flow. Glaciolacustrine sediments associated with glacial Lake McConnell occur in the southeast, up to 280 m elevation. Other unrelated, isolated glaciolacustrine deltas indicate small ice-marginal lakes between 400 and 460 m elevation.

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Goff, Fraser, Jamie N. Gardner, Steven L. Reneau, Shari A. Kelley, Kirt A. Kempter y John R. Lawrence. Geologic map of the Valles Caldera, Jemez Mountains, New Mexico. New Mexico Bureau of Geology and Mineral Resources, 2011. http://dx.doi.org/10.58799/gm-79.

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The Valles caldera, located in the heart of the Jemez Mountains in north-central New Mexico, is the world's premier example of a resurgent caldera, a giant circular volcano with an uplifted central floor and a near-perfect ring of roughly 15 postcaldera lava dome and flow eruptions.This new Valles caldera map and cross sections represent the cumulative research efforts of countless geologists over the past 40 years, and several state and federal agencies. GM-79 compiles detailed geologic mapping completed in the past eight years from parts of the nine 7.5-min USGS topographic quadrangles that encompass the caldera. More than 150 map units are described in detail. Also incorporated are new geochronologic data and recent refinements to nomenclature.

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Johnston, T. M. Flow Encountering Abrupt Topography. Fort Belvoir, VA: Defense Technical Information Center, septiembre de 2013. http://dx.doi.org/10.21236/ada598658.

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Armi, Laurence. Topographic Effects on Stratified Flows. Fort Belvoir, VA: Defense Technical Information Center, agosto de 2002. http://dx.doi.org/10.21236/ada626454.

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Winters, Kraig B. Modeling Non-Hydrostatic Flow Over Topography. Fort Belvoir, VA: Defense Technical Information Center, agosto de 2002. http://dx.doi.org/10.21236/ada629083.

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Gregg, Michael C. y Parker MacCready. Stratified Flow over Rough, Sloping Topography. Fort Belvoir, VA: Defense Technical Information Center, septiembre de 1999. http://dx.doi.org/10.21236/ada629721.

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Miller, Peter. Internal Gravity Waves at Abrupt Topography. ARI: Flow Over Abrupt Topography. Fort Belvoir, VA: Defense Technical Information Center, enero de 1990. http://dx.doi.org/10.21236/ada231756.

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MacCready, Parker. Drag Mechanisms in Flow Over Rough Topography. Fort Belvoir, VA: Defense Technical Information Center, septiembre de 2001. http://dx.doi.org/10.21236/ada624680.

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