Publications associées à Gravier (granulat)

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

Hydromorphological assessment of sediment augmentation measures in gravel-bed rivers

Christian Mörtl

In the riverine environment, the riverscape, sediment and flow regime are essential drivers for natural habitat dynamics. Today, most water courses in Europe are regulated, and their natural dynamics are impaired. Flood releases coupled with the artificial ...

EPFL2023

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

Effects of water releases and sediment supply on a residual flow reach

Giovanni De Cesare, Robin Schroff, Camille Blanck

An artificial floods program has been implemented on the Sarine residual flow reach, downstream of the Rossens dam. Two artificial floods were released in 2016 (coupled with sediment augmentation) and in 2020. A natural flood occurred in 2021. The indicato ...

CRC Press/Balkema2023

Reduction of riverbed clogging related to sediment flushing

Giovanni De Cesare, Romain Maxime Dubuis

The ecological effects of dams on sediment and river flow have been subject to an increasing attention, leading to the implementation of mitigation measures such as environmental flow release and sediment replenishment. However, fine sediment dynamics have ...

CRC Press/Balkema2023

GALET: A deep learning image segmentation model for drone-based grain size analysis of gravel bars

Giovanni De Cesare, Christian Mörtl

In this study, we present the deep learning image segmentation model for drone-based grain size analysis of gravel bars called GALET. The objectives are to quantify the performance of the code and to test its applicability in river research and management. ...

International Association for Hydro-Environment Engineering and Research (IAHR)2022

Influence of depositional fabric on mechanical properties of naturally deposited sands

Gioacchino Viggiani, Edward Carlo Giorgio Andò

Fabric characteristics and shear deformation behaviour were analysed in four intact small-scale samples, including two disturbed and two undisturbed samples of naturally deposited sand from a shoal in the San Francisco Bay. Triaxial compression tests were ...

ICE PUBLISHING2022

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

Antidunes on steep slopes: variability of wave geometry and migration celerity

Christophe Ancey, Ivan Pascal

As a result of interactions between streamflow andsediment, riverbeds are seldom smooth, but depending onhydraulic and sediment transport conditions, they exhibitbedforms, which grow and migrate over time (upstreamor downstream). Morphology migration may e ...

Heide Friedrich and Karin Bryan2019

How bar generate sediment transport pulses in gravel-bed channels

Christophe Ancey, Ivan Pascal, Blaise Etienne Marceau Dhont

We ran flume experiments with constant water dis- charge and sediment feed rate at the inlet. Experi- ments were conducted over long times (typically 600 h). The bars migrated downstream intermittently, producing the most important pulses. When the bar pos ...

IAHR2018