Publications associées à Digue

Morphometry of Tidal Meander Cutoffs Indicates Similarity to Fluvial Morphodynamics

Sinuous channels wandering through coastal wetlands have been thought to lack lateral-migration features like meander cutoffs and oxbows, spurring the broad interpretation that tidal and fluvial meanders differ morphodynamically. Motivated by recent work s ...

Amer Geophysical Union2024

Insights Into the Dynamics of Vegetated Alternate Bars by Means of Flume Experiments

Giulio Calvani

Alternate bars are bedforms recognizable in straight or weakly curved channels as a result of riverbed instability. The length and height of alternate bars scale with the river width and the water depth, respectively. During low water stages, alternate bar ...

American Geophysical Union2023

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

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

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

Upstream Erosion and Sediment Passage at Piano Key Weirs

Anton Schleiss, Michael Pfister, Ivan Stojnic

Piano key weirs (PKWs) are a weir type characterized by an effective rating curve. Accordingly, this control structure is primarily applied at dams to increase the spillway capacity. In recent years, PKWs also have been implemented in rivers combined with ...

2019

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

Artificial floods in residual flow reaches – How do they affect hydraulic habitats

Severin Stähly

Floodplains in hydropower-controlled rivers, where a constant residual flow discharge is imposed, often lack sediment supply and periodic inundation due to the absence of natural flood events. In this study we compare two residual flow systems. The first r ...

2019

The dam-break problem for eroding viscoplastic fluids

Christophe Ancey, Belinda Margaret Bates

Natural gravity-driven flows can increase in volume by eroding the bed on which they descend. This process is called basal entrainment and is thought to play a key role in the bulk dynamics of geophysical flows. Although its study is difficult using field ...

Elsevier2017

A multiscale model for sediment impact erosion simulation using the finite volume particle method

François Avellan, Ebrahim Jahanbakhsh, Siamak Alimirzazadeh, Audrey Paulette Solange Maertens, Sebastián Camilo Leguizamón Sarmiento

The erosion of a surface by a sediment-laden flow is an inherently multiscale phenomenon which includes physical interactions covering many orders of magnitude in both length and time scales. Conforming to the nature of the problem, we propose a novel mult ...

2017

The role of mass-transport deposits and turbidites in shaping modern lacustrine deepwater channels

Nicolas Le Dantec

Subaquatic canyons are an important pathway for sediment transport into oceanic and lacustrine basins. Understanding the mechanisms governing their geomorphological evolution is a key to predict the sediment distribution patterns through these sediment con ...

Elsevier2016

Reactivation of Klingnau reservoir sidearm: Numerical simulation of sediment release downstream

Anton Schleiss, Giovanni De Cesare, Azin Amini, Philippe Heller

The Klingnau reservoir, situated in north Switzerland, suffers from sedimentation in its left enlargement. The dam is placed in the Aare River about 1 km upstream of its confluence with the Rhine. Due to natural conservation and flood protection reasons, i ...

CRC Press/Balkema2014

Sediment dynamics in the subaquatic channel of the Rhone delta (Lake Geneva, France/Switzerland)

Nicolas Le Dantec

With its smaller size, well-known boundary conditions, and the availability of detailed bathymetric data, Lake Geneva's subaquatic canyon in the Rhone Delta is an excellent analogue to understand sedimentary processes in deep-water submarine channels. A mu ...

Springer Verlag2014

Design of a bed load and driftwood filtering dam, analysis of the phenomena and hydraulic design

Giovanni De Cesare

Flood protection often calls on to the realization of retention works for bed load as well as wood and debris flow. Certain relatively recent arrangements did not perform according to their intended function, what shows the complexity of the design and the ...

CRC Press/Balkema2014

Reservoir sedimentation management at Gebidem Dam (Switzerland)

Tobias Meile

The Gebidem Dam located on the Massa River intercepts annually around 400’000 m3 of solid material. These sediments must be evacuated by annual flushing of the reservoir over 4 to 7 days. A trend for silting in the flushing channel was observed during the ...

CRC Press/Balkema2014

Advancing catchment hydrology to deal with predictions under change

Steven Vincent Weijs

Throughout its historical development, hydrology as an earth science, but especially as a problem-centred engineering discipline has largely relied (quite successfully) on the assumption of stationarity. This includes assuming time invariance of boundary c ...

Copernicus Gesellschaft Mbh2014

Experimental assessment of riverbed sediment reinforcement by vegetation roots

Paolo Perona

Vegetation roots are known to increase soil stability on hillslopes, crops and river banks, thus reducing slide hazards, surface erosion and general processes affecting lateral channel migration. Many studies have tackled this classical engineering problem ...

Crc Press-Taylor & Francis Group2014

Active flood management in Alpine catchment areas equipped with storage hydropower schemes

Anton Schleiss, Martin Peter Bieri, Frédéric Jordan

The simulation of runoff in Alpine catchment areas is essential for the optimal operation of high-head storage hydropower plants (HPP) under normal flow conditions, but also in case of flood events. A semi-distributed conceptual numerical approach has been ...

Crc Press-Taylor & Francis Group2013

Influence of in- and outflow sequences on flow patterns and suspended sediment behavior in reservoirs

Michael Müller

Reservoir sedimentation and the resulting storage losses impact reliability, efficiency, safety and thus the sustainability of the hydropower schemes. Beside traditional storage hydropower plants, also pumped-storage facilities are affected. Flexible turbi ...

EPFL2012

Influence of Tributary Widening on Confluence Morphodynamics

Marcelo Leite Ribeiro

In alpine regions of Europe, river training works were typically the reason for the transformation of wide and braided rivers into linear river systems with a lack of structural diversity, i.e. gravel banks, islands, woody debris, riffles or pools. These i ...

EPFL2011