Publications de Christophe Ancey

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A longstanding problem in the study of sediment transport in gravel-bed rivers is related to the physical mechanisms governing bed resistance and particle motion. To study this problem, we investigated the motion of coarse spherical glass beads entrained b ...

For the prediction of landslide-generated waves, previous studies have developed numerous empirical equations to express the maximums of wave characteristics as functions of slide parameters upon impact. In this study, we built the temporal relationship be ...

We investigated the dam-break problem for Herschel-Bulkley fluids: a fixed volume of a viscoplastic material (a polymeric gel called Carbopol ultrez 10) was released and flowed down an inclined flume. Using Particle Image Velocimetry techniques, we measure ...

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 ...

Experimental studies of impulse-wave formation have mostly used rigid blocks or granular materials to mimic landslides at the laboratory scale. These studies have deduced that material deformability plays a key part in wave formation: the more rigid the sl ...

In order to simulate a simple entraining geophysical flow, a viscous Newtonian gravity current is released from a reservoir by a dam-break and flows along a rigid horizontal bed until it meets a layer of entrainable material of finite depth, identical to t ...

Gravity-driven flows can erode the bed along which they descend and increase their mass by a factor of 10 or more. This process is called "basal entrainment." Although documented by field observations and laboratory experiments, it remains poorly understoo ...

Describing bedload transport as a stochastic process is an idea that emerged in the 1930s with the pioneering work of Einstein. For a long time, the stochastic approach attracted marginal attention, but the situation has radically changed over the last dec ...

We conducted a series of laboratory experiments to investigate the impact of vegetation on bedload transport rates depending on submergence. In the experiments, we used aluminum rods to simulate rigid vegetation, with vegetation submergence ratios (i.e., t ...

A simple theoretical model, the Kulikovskiy–Sveshnikova–Beghin (KSB) model, is outlined, describing the motion of a particle cloud moving down an incline. This model includes both the entrainment of surrounding ambient fluid and the entrainment of particle ...

Bedload sediment transport of two-size coarse spherical particle mixtures in a turbulent supercritical flow was analyzed with image and particle tracking velocimetry algorithms in a two-dimensional flume. The image processing procedure is entirely presente ...

This article examines the spatial {dynamics of bed load particles} in water. We focus particularly on the fluctuations of particle activity, which is defined as the number of moving particles per unit bed {length}. Based on a stochastic model recently prop ...

The advection diffusion equation is one of the most widespread equations in physics. It arises quite often in the context of sediment transport, e.g., for describing time and space variations in the particle activity (the solid volume of particles in motio ...

This paper shows how a conveyor belt setup can be used to study the dynamics of stationary granular flows. To visualise the flow within the granular bulk and, in particular, determine its composition and the velocity field, we used the refractive index mat ...

Investigating the stability of river bedforms is essential for understanding their occurrence and evolution over time. Whereas the formation of ripples and dunes has been extensively studied [1, 2], little is known about antidune stability in the early sta ...

Bed-load transport rate in gravel-bed rivers shows large non-Gaussian fluctuations, even under steady flow conditions. The development of high-resolution measurement techniques during the last two decades creates research opportunities to study the intermi ...

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 ...

Even under flow equilibrium conditions, river bed topography continuously evolves with time, producing trains of irregular bed forms. The idea has recently emerged that the variability in the bed form geometry results from some randomness in sediment flux. ...

Mountain rivers exhibit sediment transport rate fluctuations that often cover more than two orders of magnitude. Bedform migration is often cited as the key process that causes giant fluctuations in the sediment transport rate. To quantify the effect of be ...

In this paper, we seek similarity solutions to the shallow water (Saint-Venant) equations for describing the motion of a non-Boussinesq, gravity-driven current in an inertial regime. The current is supplied in fluid by a source placed at the inlet of a hor ...

Christophe Ancey

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Statistical description of sediment transport experiments

Temporal Prediction of Landslide-Generated Waves Using a Theoretical-Statistical Combined Method

Viscoplastic dambreak waves: review of simple computational approaches and comparison with experiments

The dam-break problem for eroding viscoplastic fluids

The effects of slide cohesion on impulse-wave formation

Visualization of the internal flow properties and the material exchange interface in an entraining viscous Newtonian gravity current

Basal entrainment by Newtonian gravity-driven flows

Stochastic bedload transport in mountain streams

Vegetation Submergence Effects on Bedload Transport Rate

The Kulikovskiy-Sveshnikova-Beghin Model of Powder Snow Avalanches: Development and Application

Image processing for the study of bedload transport of two-size spherical particles in a supercritical flow

Spatial correlations in bed load transport: Evidence, importance, and modeling

Stochastic interpretation of the advection diffusion equation and its relevance to bed load transport

A conveyor belt experimental setup to study the internal dynamics of granular avalanches

Instability of Antidune Incipience under Low Submergence Conditions

Continuous Monitoring of Bed-Load Transport in a Laboratory Flume Using an Impact Sensor

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

Stochastic modeling in sediment dynamics: Exner equation for planar bed incipient bed load transport conditions

Bar dynamics and sediment transport pulses in gravel-bed channels

Front dynamics of supercritical non-Boussinesq gravity currents