Publications de Christophe Ancey

Automated grain sizing from uncrewed aerial vehicles imagery of a gravel-bed river: Benchmarking of three object-based methods

Christophe Ancey, Ivan Pascal, Raphaël Miazza

Measuring grain sizes in gravel-bed rivers is crucial when studying river dynamics and sediment transport. Automated methodologies have been developed in recent years for detecting individual grains and measuring their size on digital imagery. These object ...

2024

Refractive Index Matched (RIM) PIV in Free Surface Flows of Particle-Laden Yield Stress Fluids

Christophe Ancey, Yanan Chen

Flow of lava, avalanches, mudslides, and many geophysical and planetary flow systems are examples of free-surface flows of Yield Stress Fluids (YSFs). This category of fluids is known for its dual behavior below- and above a yielding threshold for the appl ...

2024

Probabilistic Modeling of Sediment Dynamics in Braided River Systems

Christophe Ancey

Understanding the relationship between bedload transport and morphological changes is crucial in braided river systems, particularly those on steep slopes. Despite significant research efforts in recent decades, unraveling this interplay remains a complex ...

2024

Segregation of sediments in meandering river channels

Christophe Ancey, Yanan Chen

Particle segregation is widespread in river channels and significantly influences bed grain size distribution. To date, most studies have investigated particle size segregation in straight river channels. Less studied is the case where particles segregate ...

2024

Particle segregation in an annular shear cell

Christophe Ancey, Yanan Chen

Particle segregation is a widespread process that affects particle composition in granular materials. Particles tend to segregate into distinct regions according to their size, density, and shape. To date, most studies investigate particles segregating in ...

2024

Vegetation Submergence Effects on Bedload Transport Rate

Christophe Ancey

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 ...

2024

Instability of Antidune Incipience under Low Submergence Conditions

Christophe Ancey, Ivan Pascal

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 ...

2024

Bed Topography Inference from Velocity Field Using Deep Learning

Christophe Ancey, Mehrdad Kiani Oshtorjani

Measuring bathymetry has always been a major scientific and technological challenge. In this work, we used a deep learning technique for inferring bathymetry from the depth-averaged velocity field. The training of the neural network is based on 5742 labora ...

2023

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

Christophe Ancey, Zhenzhu Meng, Yating Hu

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 ...

MDPI2023

Scaling behavior of bedload transport: what if Bagnold was right?

Christophe Ancey

There is a paradox in the relationship between bedload transport rates and flow variables: laboratory and field studies have reported on how bedload transport rates depend on flow variables through a power law, but none of the empirical laws fitted to the ...

2023