Publications associées à Abrasion (géologie)

Stochastic Simulations and Machine Learning Modeling to Predict Bedload Transport and Bed Topography

In computational hydraulics models, predicting bed topography and bedload transport with sufficient accuracy remains a significant challenge. An accurate assessment of a river's sediment transport rate necessitates a prior understanding of its bed topograp ...

EPFL2024

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

Influence of channel geomorphic units on bedload transport and river morphology during low‐magnitude bed‐forming floods coupled with sediment augmentation

Giovanni De Cesare, Severin Stähly, Christian Mörtl, Robin Schroff

In this study, we map different types of channel geomorphic units in a sediment-starved, residual-flow reach before and after an artificial flood. Bedload particles of a previous sediment augmentation measure are tracked with passive integrated transponder ...

2023

Dynamics of Dual-Mode Bedload Transport With Three-Dimensional Alternate Bars Migration in Subcritical Flow: Experiments and Model Analysis

Mehrdad Kiani Oshtorjani, Zhipeng Li, Yong Zhang

Bedload transport often exhibits dual-mode behavior due to interactions of spatiotemporal controlling factors with the migrating three-dimensional bedforms (characterized by the fully developed patterns in the bed, such as alternate bars, pools, and cluste ...

AMER GEOPHYSICAL UNION2023

Experimental Study on Bedload Transport and Bedforms: Behaviour and Interplay in Steep Turbulent Streams

Ivan Pascal

In mountain regions, steep streams play an important role in water and sediment connectivity. In these highly dynamic systems, water flow features, sediment fluxes and stream morphologies are tightly interlinked over a broad range of temporal and spatial s ...

EPFL2022

In situ observations of the Swiss periglacial environment using GNSS instruments

Alessandro Cicoira, Matthias Meyer, Hugo Raetzo

Monitoring of the periglacial environment is relevant for many disciplines including glaciology, natural hazard management, geomorphology, and geodesy. Since October 2022, Rock Glacier Velocity (RGV) is a new Essential Climate Variable (ECV) product within ...

COPERNICUS GESELLSCHAFT MBH2022

The Biogeochemical Legacy of Arctic Subglacial Sediments Exposed by Glacier Retreat

Tyler Joe Kohler

During past periods of advance, Arctic glaciers and ice sheets overrode soil, sediments, and vegetation and buried significant stores of organic matter (OM); these glaciers are now shrinking rapidly due to climate warming. Little is known about the biogeoc ...

2022

Benthic Biofilms in Glacier-Fed Streams from Scandinavia to the Himalayas Host Distinct Bacterial Communities Compared with the Streamwater

Tom Ian Battin, Hannes Markus Peter, Susheel Bhanu Busi, Grégoire Marie Octave Edouard Michoud, Leïla Ezzat, Massimo Bourquin, Matteo Tolosano, Emmy Marie Oppliger, Jade Brandani, Paraskevi Pramateftaki, Virginia Tadei, Vincent Henri De Staercke, Tyler Joe Kohler, Michail Styllas, Stylianos Fodelianakis, Martina Andrea Schön

Microbial life in glacier-fed streams (GFSs) is dominated by benthic biofilms which fulfill critical ecosystem processes. However, it remains unclear how the bacterial communities of these biofilms assemble in stream ecosystems characterized by rapid turno ...

AMER SOC MICROBIOLOGY2022

Bedload transport assessment on a physical model of a large river widening using ultrasonic Doppler velocity measurements

Giovanni De Cesare, Azin Amini, Jean-Noël Saugy

The 3rd correction of the Rhône River is the largest flood protection project in Switzerland so far. Covering a length of 162 km, it aims to protect some 100,000 people and prevent flood damages, which could raise up to 10 billion Swiss francs for major ev ...

ETH Zurich, Laboratory of Food Process Engineering2021

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

Bedload transport: a walk between randomness and determinism. Part 1. The state of the art

Christophe Ancey

This paper outlines the various approaches used to calculate bedload transport. As bedload transport exhibits considerable spatial and temporalvariations, computing the bedload transport rates and morphological changes experienced by streambeds is difficul ...

Taylor & Francis Ltd2020

Estimating Mean Bedload Transport Rates and Their Uncertainty

Christophe Ancey, Ivan Pascal

Measuring bedload transport rates usually involves measuring the flux of sediment or collecting sediment during a certain interval of time Δt. Because bedload transport rates exhibit significant non‐Gaussian fluctuations, their time‐averaged rates depend a ...

2020

Bedload transport: a walk between randomness and determinism. Part 2. Challenges and prospects

Christophe Ancey

By the late nineteenth century, the scientific study of bedload transport had emerged as an offshoot of hydraulics and geomorphology. Since then, computing bedload transport rates has attracted considerable attention, but whereas other environmental scienc ...

Taylor & Francis Ltd2020

Study of Aerodynamic Grain Entrainment in Aeolian Transport

Aeolian transport controls landform formations on Earth and other planets and crucially affects the atmospheric system. With elaborate wind tunnel measurements, we find that the aerodynamic entrainment rate follows a yet unreported exponential increase in ...

2020

The impact of hydrograph variability and frequency on sediment transport dynamics in a gravel-bed flume

Mário Jorge Rodrigues Pereira Da Franca, Carmelo Juez Jiménez

A laboratory study was undertaken to investigate how changes in flow regime and hydrograph shape (number of cycled hydrographs and duration of each hydrograph) together impact bedload transport and resulting bed morphology. Three hydrologic conditions (exp ...

WILEY2020

Catchment drainage network scaling laws found experimentally in overland flow morphologies

David Andrew Barry, Andrea Rinaldo, Paolo Perona, Mohsen Cheraghi

The scaling relation between the drainage area and stream length (Hack’s law), along with exceedance probabilities of drainage area, discharge and upstream flow network length are well known for channelized fluvial regions. We report here on a laboratory e ...

2018

Stochastic bedload transport in mountain streams

Christophe Ancey

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 ...

EDP Sciences2018

Design optimization of permeable sediment traps for fluvial bed load transport

Anton Schleiss, Sebastian Schwindt, Mona Jafarnejad Chaghooshi, Anita Hélène Roth

Sediment traps are crucial elements for flood protection in mountain rivers with high sediment transport capacity. Existing structures often interrupt the channel connectivity. Ideally, a sediment trap should be permeable for bed load during non-hazardous ...

2018

Breaking size-segregation waves and mobility feedback in dense granular avalanches

Christophe Ancey, Kasper van der Vaart

Through experiments and discrete particle method (DPM) simulations we present evidence for the existence of a recirculating structure, that exists near the front of dense granular avalanches, and is known as a breaking size-segregation (BSS) wave. This is ...

2018

Is the Thorpe and Mason model valid for drifting and blowing snow?

Varun Sharma, Michael Lehning, Francesco Comola

Sublimation of drifting and blowing snow has been recognized as an important component of the surface mass budget of polar and alpine regions. The Thorpe and Mason (TM) model is the basis of all existing small and largescale estimates of drifting snow sub ...

Copernicus2018