Publications associées à Sediment mass movement of a particle-laden turbidity current based on ultrasound velocity profiling and the distribution of sediment concentration

Ultrasonic sediment flux profiling with ACVP Technology: application to sediment-laden Boundary Layer flows

Sediment transport in geophysical boundary layer flows has relevance to a broad spectrum of sciences ranging from the physical and chemical, to the biological, ecological and geological. Advances in sediment transport modelling and prediction strongly suff ...

2023

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

Continuous monitoring of morphological changes from sediment augmentation by field measurements and flume experiments

Giovanni De Cesare, Christian Mörtl

In this study, we present results from continuous field monitoring and a flume ex-periment of a sediment augmentation measure in a residual flow reach of the Swiss midlands. A straight morphological channel with fixed bed material was constructed to repres ...

2023

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

Mehrdad Kiani Oshtorjani, Yong Zhang, Zhipeng Li

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

Clogging of riverbed substrates by fine sediment

Romain Maxime Dubuis

Riverbeds represent the habitat of numerous aquatic species. Exchanges between the groundwater, the hyporheic zone and the surface flow are also essential for river ecosystems. Fine sediment transported by rivers deposits inside or on top of the bed and mo ...

EPFL2023

Experimental characterization of root-reinforced riparian sediment deposits in a restored and widened river course

Giovanni De Cesare, Paolo Perona

The Arbogne River is located mainly in the Swiss canton of Fribourg. The River was meandering through the plane at a very low gradient and several exceptional historic floods with large sediment accumulation are mentioned. After important river training wo ...

2023

The clogging of riverbeds: A review of the physical processes

Giovanni De Cesare, Romain Maxime Dubuis

Fine sediment represents an important part of the solid flux of rivers. Due to the size of these particles, they are often transported as suspended load. They gradually fill the pores of the substrate forming the hyporheic zone or cover the substrate by se ...

2023

Laterally unconfined neutral or negative buoyancy inflow into a quiescent ambient over sloping bottom

Haoran Shi

This work studies the nearshore hydrodynamics of a shallow turbulent flow entering a laterally unconfined quiescent ambient with a sloping bottom boundary. Examples of such flow are neutrally buoyant ebb tidal jets and hyperpycnal river plumes entering ope ...

EPFL2023

Reactivation of variably sealed joints and permeability enhancement in geothermal reservoir rocks

Michael Heap, Alexandra Roma Larisa Kushnir

Hydraulic stimulation of enhanced deep geothermal reservoirs commonly targets pre-existing joint networks with the goal of increasing reservoir permeability. Here, we study the permeability and strength of joint-free and jointed Buntsandstein sandstones fr ...

2023

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

Permeability sets the linear path instability of buoyancy-driven disks

François Gallaire, Pier Giuseppe Ledda, Giuseppe Antonio Zampogna, Giovanni Vagnoli

The prediction of trajectories of buoyancy-driven objects immersed in a viscous fluid is a key problem in fluid dynamics. Simple-shaped objects, such as disks, present a great variety of trajectories, ranging from zig-zag to tumbling and chaotic motions. Y ...

Cambridge University Press2023

Visualization and modelling of dynamic flow in fibrous preforms for liquid composite molding

Helena Luisa Teixido Pedarros

Nowadays, Liquid Composite Molding techniques are often used to manufacture high quality fiber reinforced composite parts at a relatively low cost. These involve an infiltration process, in which a liquid resin is forced to ingress into a dry fibrous porou ...

EPFL2023

p Spatio-temporal deposition profile of an experimentally produced turbidity current with a continuous suspension supply

Giovanni De Cesare, Shun Nomura

A turbidity current is a turbulent, particle-laden gravity current that is driven by density differences resulting from the presence of suspended sediment particles. The current travels downslope, bearing a large amount of sediment over a great distance, a ...

2022

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

Do Antidune Trains Undergo Morphological Changes When These Bedforms Migrate Upstream?

Christophe Ancey, Ivan Pascal

Upstream migrating antidunes develop in streams under supercritical flow conditions. These bedforms are often organised in trains (i.e. sequences of well-developed antidunes). In shallow flows over coarse sediments, the dynamics of a single antidune can be ...

Madrid2022

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

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

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

Density currents driven by differential cooling in lakes: occurrence, dynamics and implications for littoral-pelagic exchange

Tomy Doda

Cross-shore flows exchange water laterally in lakes, with ecological implications for the ecosystem. One example is the convective circulation induced by differential cooling, also known as the thermal siphon. This lateral flow forms when the sloping sides ...

EPFL2022

Measurement of the inner structure of turbidity currents by ultrasound velocity profiling

Giovanni De Cesare, Shun Nomura, Jumpei Hitomi

The inner velocity structure and particle concentration profile of opaque turbidity currents were mea- sured simultaneously by ultrasound velocity profilers. Currents consisting of a quartz particle suspension were generated by using the lock-exchange meth ...

2021

Numerical simulation of sediment dynamics with free surface flows

Arwa Mrad

We present a numerical model for the simulation of 3D mono-dispersed sediment dynamics in a Newtonian flow with free surfaces. The physical model is a macroscopic model for the transport of sediment based on a sediment concentration with a single momentum ...

EPFL2021

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