Publications associées à The hydro-morphological index of diversity: a tool for describing habitat heterogeneity in river engineering projects

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

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

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

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

Enhancing Flood Resilience: Sediment Management in Le Bez Torrent

Giovanni De Cesare, Azin Amini, Romain Nathan Hippolyte Merlin Van Mol

In the canton of Bern, Switzerland, the “Le Bez” torrent is known for its flash floods, causing sediment and wood debris buildup in Villeret village settled on the alluvial fan. To mitigate this issue, a sediment/wood trap system is being implemented upstr ...

Swiss Academy of Sciences (SCNAT)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

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

Giovanni De Cesare, David Hurther

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

Exploring the efficacy of reservoir fine sediment management measures through numerical simulations

Giovanni De Cesare, Azin Amini, Samuel Luke Vorlet, Montana Marshall

Reservoir sedimentation is one of the main challenges in the sustainable operation of large reservoirs because it causes volume loss, affecting hydropower production capacity, dam safety, and flood management. To ensure the sustainability of deep reservoir ...

CRC Press/Balkema2023

Ecosystem engineering by periphyton in Alpine proglacial streams

Matteo Roncoroni, Tom Ian Battin, Marc Aguet, Adrijan Selitaj, Davide Mancini

Stream periphytons are candidate ecosystem engineers in proglacial margins. Here, we quantify the extent to which they are engineers for the case of hillslope-fed tributaries in the terrace zones of proglacial margin alluvial plains. Candidate ecosystem en ...

WILEY2023

Effect of blocked driftwood on the hydraulic performance of a gated standard weir

Giovanni De Cesare, Michael Pfister, Loïc Bénet

Driftwood belongs to riverine ecosystems and is stored and transported in every natural stream. Hydraulic structures built in streams typically alter the flow characteristics and might consequently get in conflict with driftwood. The latter can get trapped ...

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

Untersuchung der ökomorphologischen Wirksamkeit von Sedimentzugaben unterhalb von Talsperren [Assessment of the eco-morphological effectiveness of sediment augmentation downstream of dams]

Giovanni De Cesare, Christian Mörtl

The regulation of discharge and the retention of sediments in reservoirs disturb the natural water dynamics in residual flow stretches below reservoirs. However, a dynamic river morphology as well as near-natural hydrological hydrographs are fundamental ...

ETH2021

Experimental and Numerical Study on Scour-Protection Methods in a Stilling Basin: Case Study of Chancy-Pougny Dam

Giovanni De Cesare, Erik Bollaert, Anton Schleiss, Sabine Chamoun, Davide Wüthrich

Chancy-Pougny is a run-of-river dam on the Swiss–French border constructed in the early 1920s. Since its commissioning, the operation of the four spillway gates has been responsible for a progressive erosion of the stilling basin. The future scour potentia ...

2021

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

Assessing Subaquatic Mass Movement Hazards: an Integrated Observational and Hydrodynamic Modelling Approach

Alfred Johny Wüest, Damien Bouffard, Nathalie Dubois, Carl Love Mikael Råman Vinnå

High-resolution lake and reservoir bathymetric surveys can pinpoint locations that may experience underwater landslides (subaquatic sedimentary mass movements). These can pose a risk to underwater and shoreline infrastructure. This paper outlines an approa ...

2020

Evaluation of a Dynamic Transfer Matrix for a Hydraulic Turbine

François Avellan, Andres Müller, Keita Yamamoto

It is well known that hydraulic machines experience various types of flow instabilities causing a negative influence on the system under off-design operations. The transfer matrix method correlating the flow properties in upstream and downstream of hydraul ...

2020

Continuously-fed density currents over impermeable and porous substrates

Sara Venuleo

Gravity currents are buoyancy-driven flows having a significant impact on the environment and human life. They can be observed in a vast range of natural and anthropogenic scenarios, such as seawater and freshwater, the atmosphere, or industrial processes. ...

EPFL2020

Erosion, transport and deposition of a sediment replenishment under flood conditions

Anton Schleiss, Mário Jorge Rodrigues Pereira Da Franca, Christopher Robinson, Severin Stähly

River reaches downstream of dams with constant residual discharge often lack sediment supply and periodic high flows due to dam sediment retention and flow regulation, respectively. To test a novel multi-deposit methodology for defining environmental flows ...

2020

Modeling turbulent stream flows over rough permeable beds

Christophe Ancey, Gauthier Paul Daniel Marie Rousseau, Ivan Pascal

In steep streams, turbulent flows run over coarse sediments that are similar in size to flow depth. Under these conditions, a significant part of the flow may seep through the permeable bed. Based on experimental data, this paper presents a model able to r ...

CRC Press2020

Hydraulic-morphological habitat assessment in rivers considering residual flow, sediment replenishment and artificial flood events

Severin Stähly

Dams store water and trap sediment in their reservoirs. Downstream river segments, hence, are affected by a limited sediment dynamics. This becomes obvious by river bed incision, limited geomorphological variability and depletion of hydraulic habitats for ...

EPFL2019