Publications associées à Delta (hydrologie)

Morphological processes and potential for lacustrine delta restoration

Giovanni De Cesare, Stéphanie Joëlle André, Alexandre Philippe Louis Antoine Fourrier

Most lacustrine deltas are nowadays highly anthropized systems. River training works during past centuries considered rivers mainly as vectors of water and sediments from a point source to a sink. However, numerous problems have been identified by resident ...

2024

Reducing transport via extreme flux-surface triangularity

Stefano Coda, Justin Richard Ball

Based on a gyrokinetic analysis of and extrapolation from TCV discharges with large negative and positive triangularity delta, the potential of extreme | delta | in reducing turbulent transport is assessed. Linearly, both positive and negative delta can ex ...

IOP Publishing Ltd2024

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

Mehrdad Kiani Oshtorjani

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

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

Fulfilling Riverscape – a creative interdisciplinary approach

Giovanni De Cesare, Paolo Perona, Sylvie Tram Nguyen

Hydrological, water technological, managerial and human induced processes affect aquatic, amphibian and terrestrial organisms and their habitats, far beyond the main channel of a river. This Riverscape includes diverse riparian habitats which vary in space ...

2023

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

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

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

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

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

Ecosystem engineering by periphyton in Alpine proglacial streams

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

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

Controlling factors of phytoplankton distribution in the river–lake transition zone of a large lake

David Andrew Barry, Frédéric Charles Soulignac, Matthieu Fallet

River–lake transition zones have been identified as major drivers of phytoplankton growth. With climate change reducing the frequency of complete lake overturns, it is expected that the Rhône River, the main tributary to Lake Geneva (France/Switzerland), w ...

2023

Unconfined Plunging of a Hyperpycnal River Plume Over a Sloping Bed and Its Lateral Spreading: Laboratory Experiments and Numerical Modeling

David Andrew Barry, Ulrich Lemmin, Koen Blanckaert, Haoran Shi

Hyperpycnal (negatively buoyant) river inflow into lakes and oceans often develops three-dimensional (3D) plunging flow patterns when laterally unconfined. To determine the 3D flow pattern characteristics, laboratory experiments of laterally unconfined plu ...

American Geophysical Union2022

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

Unexpectedly minor nitrous oxide emissions from fluvial networks draining permafrost catchments of the East Qinghai-Tibet Plateau

Tom Ian Battin, Sibo Zhang

Streams and rivers emit substantial amounts of nitrous oxide (N2O) and are therefore an essential component of global nitrogen (N) cycle. Permafrost soils store a large reservoir of dormant N that, upon thawing, can enter fluvial networks and partly degrad ...

Nature Research2022

Decadal shoreline erosion and recovery of beaches in modified and natural estuaries

Vincent Henri De Staercke

Sandy beaches in estuaries and bays (BEBs) are common landforms on the coasts of many major cities. They exist under a wide range of settings and their morphology is controlled by their distance from the estuary/bay entrance, exposure to different types of ...

ELSEVIER2021

The Metabolic Regimes at the Scale of an Entire Stream Network Unveiled Through Sensor Data and Machine Learning

Enrico Bertuzzo, Tom Ian Battin, Pier Luigi Segatto

Streams and rivers form dense networks that drain the terrestrial landscape and are relevant for biodiversity dynamics, ecosystem functioning, and transport and transformation of carbon. Yet, resolving in both space and time gross primary production (GPP), ...

2021

Towards an improved understanding of biogeochemical processes across surface-groundwater interactions in intermittent rivers and ephemeral streams

Luis Gómez Gener, Oleksandra Shumilova

Surface-groundwater interactions in intermittent rivers and ephemeral streams (IRES), waterways which do not flow year-round, are spatially and temporally dynamic because of alternations between flowing, non-flowing and dry hydrological states. Interaction ...

2021

Missing water from the Qiangtang Basin on the Tibetan Plateau

David Andrew Barry, Tao Wang, Jiaqi Chen

The Qiangtang Basin is a large endorheic basin in the inner part of the Tibetan Plateau and has been thought to be a dry region in contrast with its wet surrounding outer region that feeds all the major Asian rivers. Combining surface hydrological data wit ...

2021

A Novel Method for River Bank Detection from Landsat Satellite Data: A Case Study in the Vietnamese Mekong Delta

Giovanni De Cesare, Sameh Ahmad Kantoush

River bank (RB) erosion is a global issue aecting livelihoods and properties of millions of people. However, it has not received enough attention in the Vietnamese Mekong Delta (VMD), i.e., the world’s third largest delta, compared to salinity intrusion an ...

2020