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Concept

Pente (topographie)

Publications associées (19)

The variability of antidune morphodynamics on steep slopes

Christophe Ancey, Ivan Pascal

Steep streams on rough beds are generally characterised by supercritical flow conditions under which antidunes can develop and migrate over time. In this paper, we present flume experiments that we conducted to investigate the variability of antidune geome ...

2021

Management of turbidity current venting in reservoirs under different bed slopes

Anton Schleiss, Giovanni De Cesare, Sabine Chamoun

The lifetime and efficiency of dams is endangered by the process of sedimentation. To ensure the sustainable use of reservoirs, many sediment management techniques exist, among which venting of turbidity currents. Nevertheless, a number of practical questi ...

Elsevier2017

Snow fracture in relation to slab avalanche release: critical state for the onset of crack propagation

Johan Alexandre Philippe Gaume, Nander Wever

The failure of a weak snow layer buried below cohesive slab layers is a necessary, but insufficient, condition for the release of a dry-snow slab avalanche. The size of the crack in the weak layer must also exceed a critical length to propagate across a sl ...

Copernicus GmbH2017

The dam-break problem for eroding viscoplastic fluids

Christophe Ancey, Belinda Margaret Bates

Natural gravity-driven flows can increase in volume by eroding the bed on which they descend. This process is called basal entrainment and is thought to play a key role in the bulk dynamics of geophysical flows. Although its study is difficult using field ...

Elsevier2017

Buoyant Turbulent Kinetic Energy Production in Steep-Slope Katabatic Flow

Marc Parlange, Eric Richard Pardyjak, Chad Higgins, Holly Jayne Oldroyd

We develop several critical concepts that should be considered when interpreting, modelling and designing future experiments for flows over sloping terrain. Vertical buoyancy fluxes in katabatic flows can be positive and a source of turbulent kinetic energ ...

Springer Verlag2016

Adapting tilt corrections and the governing flow equations for steep, fully three-dimensional, mountainous terrain

Marc Parlange, Wolf Hendrik Huwald, Eric Richard Pardyjak, Holly Jayne Oldroyd

In recent studies of atmospheric turbulent surface exchange in complex terrain, questions arise concerning velocity-sensor tilt corrections and the governing flow equations for coordinate systems aligned with steep slopes. The standard planar-fit method, a ...

2016

Theoretical and numerical studies of atmospheric boundary-layer flows over complex terrain

Marco Giovanni Giometto

Atmospheric boundary-layer (ABL) flows over complex terrain have been the focus of active research, given their impact on weather and climate variability. Surface complexity is understood in a broad sense and includes variation in roughness properties, inc ...

EPFL2016

Air Entrainment in Skimming Flow on Stepped Spillways: the Effect of an Abrupt Slope Change

Anton Schleiss, Michael Pfister, José Pedro Gamito de Saldanha Calado Matos, Mohammad Javad Ostad Mirza

Numerous stepped spillways were built during the last decades. In particular, a stepped spillway may be integrated economically into the downstream face of a RCC gravity dam, or on valley flanks besides embankment or rockfill dams, where slope changes may ...

2015

Quantifying snowfall and avalanche release synchronization: a case study

Paolo Perona, Benoît Crouzy, Betty Sovilla

We quantify the synchronization between snowfall and natural avalanches in relation to terrain properties at the detachment zone. We analyze field statistics of 549 avalanche events in terms of slope, aspect, timing, coordinate, and release area, identifie ...

Wiley-Blackwell2015

Air entrainment and pressure development in skimming flow on an abrupt slope change on stepped spillways

Anton Schleiss, Michael Pfister, José Pedro Gamito de Saldanha Calado Matos, Mohammad Javad Ostad Mirza

Numerous stepped spillways were built to date, namely on RCC gravity dams or on valley flanks besides embankment or rockfill dams, while some others are currently under design or construction. In some cases, slope changes may be required on stepped chutes, ...

2015

Turbulent Transport in Complex, Alpine Environments

Holly Jayne Oldroyd

Turbulent exchanges between the atmosphere and the underlying surface transport heat, moisture, momentum and pollutants, and thus understanding them is crucial to water resource management, meteorological predictions, climate modeling, wind energy producti ...

EPFL2015

Modeling the Onset of Shallow Landslides in Partially Saturated Slopes Subjected to Rain Infiltration

Lyesse Laloui, Mathieu Nuth, John Eichenberger

Heavy rainfall can lead to shallow slips on slopes which are often initially in a state of partial water saturation. A multiphysics approach and advanced constitutive modeling are necessary to take into account the physical key processes in partially satur ...

ASCE2011

Hydromechanically coupled analysis of transient phenomena in a rainfall-induced landslide

Lyesse Laloui, Mathieu Nuth, John Eichenberger

Heavy rainfall can lead to shallow slips in slopes that are initially in a state of partial water saturation. Multiphysics numerical modelling approaches taking into account the involved physical key processes in variably saturated soils during rainfall ev ...

International Center for Computational Engineering (IC2E)2011

Atmospheric Boundary Layer Dynamics of Transitional Flows over Complex Terrain

Daniel Nadeau

Recent advances in boundary-layer meteorology are beginning to allow the study of atmospheric flow phenomena that have previously been poorly understood. In this dissertation, we study the effects of complex terrain and unsteady regimes on the atmospheric ...

EPFL2011

Half-scale experimental study of rockfall impacts on sandy slopes

Vincent Labiouse, Barbara Heidenreich

In the framework of rockfall trajectory modelling, the bouncing phenomenon occurring when a rock block impacts with the slope surface is the most difficult to predict, owing to its complexity and its very limited understanding. To date, the rebound is comm ...

2009

The dam-break problem for Herschel-Bulkley viscoplastic fluids down steep flumes

Christophe Ancey, Steve Cochard

In this paper we investigate the dam-break problem for viscoplastic (Herschel- Bulkley) fluids down a sloping flume: a fixed volume of fluid initially contained in a reservoir is released onto a slope and flows driven by gravitational forces until these fo ...

2009

The dam-break problem for viscous fluids in the high-capillary-number limit

Christophe Ancey, Steve Cochard, Nicolas Andreini

Experiments were undertaken to investigate dam-break flows where a finite volume of highly viscous fluid (glucose with viscosity μ ≈ 350 Pa s) maintained behind a lock gate was released into a horizontal or inclined flume. The resulting sequence of flow-de ...

Cambridge University Press2009

An exact solution for ideal dam-break floods on steep slopes

Christophe Ancey, Martin Rentschler

Dam-break floods on steep slopes occur in diverse settings. They may result from failure of either natural or man-made dams, and they have been responsible for the loss of thousands of lives [Costa, 1988]. Recent disasters resulting from dam-break floods o ...

American Geophysical Union2008

Dry rock avalanche propagation : unconstrained flow experiments with granular materials and blocks at small scale

Irene Manzella

Rock avalanches are catastrophic phenomena which are not yet exhaustively understood. They consist of rock mass movements of more than one million cubic metres, involving a great amount of energy and travelling farther than expected with a normal sliding f ...

EPFL2008