Publications associées à Cold intrusions in Lake Baikal: Direct observational evidence for deep-water renewal

Spatiotemporal Dynamics of Flow and Hydrochemistry in Drainage Networks

Despite their high ecological value, non-perennial streams have received less attention than their perennial counterparts. This doctoral thesis addresses this disparity by advancing knowledge on the dynamics of the drainage density and hydrologic processes ...

EPFL2024

Technical note: Two-component electrical-conductivity-based hydrograph separation employing an exponential mixing model (EXPECT) provides reliable high-temporal-resolution young water fraction estimates in three small Swiss catchments

Davide Canone, Jana Freiin von Freyberg

The young water fraction represents the portion of water molecules in a stream that have entered the catchment relatively recently, typically within 2-3 months. It can be reliably estimated in spatially heterogeneous and nonstationary catchments from the a ...

Copernicus Gesellschaft Mbh2024

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

Experimental modeling of fine sediment routing: SEDMIX device with thrusters

Giovanni De Cesare, Azin Amini, Montana Marshall

Reservoir sedimentation is a key challenge for storage sustainability because it causes volume loss, affecting hydropower production capacity, dam safety, and flood management. A preliminary EPFL study proposed and studied an innovative device (called SEDM ...

CRC Press/Balkema2023

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

Chimney‐Like Intense Pelagic Upwelling in the Center of Basin‐Scale Cyclonic Gyres in Large Lake Geneva

Ulrich Lemmin, David Andrew Barry, Rafael Sebastian Reiss, Mehrshad Foroughan, Seyed Mahmood Hamze Ziabari

Basin-scale quasi-geostrophic gyres are common features of large lakes subject to Coriolis force. Cyclonic gyres are often characterized by dome-shaped thermoclines that form due to pelagic upwelling that takes place in their center. At present, the dynami ...

2023

Characterization of Thruster-Induced Turbulence for Fine Sediment Suspension

Giovanni De Cesare, Azin Amini, Montana Marshall, Andre Luis Stakowian

Reservoir sedimentation is a key challenge for storage sustainability because it causes volume loss, affecting hydropower production capacity, dam safety, and flood management. A preliminary EPFL study proposed and studied an innovative device (called SEDM ...

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

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

Unraveling submesoscale processes associated with meso- and basin-scale gyres in Lake Geneva

Seyed Mahmood Hamze Ziabari

In large lakes, basin-scale gyres and submesoscale eddies, i.e., rotating coherent water masses, play a key role in spreading biochemical materials and energy throughout the basin, thereby significantly impacting water quality. Due to their transient and s ...

EPFL2023

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

Natural slicks on Lake Geneva: From small-scale effects to large-scale formation and distribution

Mehrshad Foroughan

Low wind speeds (< 4 m/s) are ubiquitous in many water bodies, yet the physical processes occurring at the air-water interface in this range are poorly understood. A notable example is smooth patches on the water surface, known as natural slicks, formed wh ...

EPFL2023

Impact of substrate clogging on vertical connectivity

Giovanni De Cesare, Romain Maxime Dubuis, Robin Schroff

Connectivity between the hyporheic zone and the flow is essential for the development of benthos and the reproductive success of spawning fish. The infiltration of fine sediment leads to clogging of the riverbed, reducing porosity and vertical water exchan ...

2023

Uptake without inactivation of human adenovirus type 2 by Tetrahymena pyriformis ciliates

Tamar Kohn, Margot Ninon Lauren Olive

Human adenoviruses are ubiquitous contaminants of surface water. Indigenous protists may interact with adenoviruses and contribute to their removal from the water column, though the associated kinetics and mechanisms differ between protist species. In this ...

2023

Impacts of climate change on Swiss alluvial aquifers - A quantitative forecast focused on natural and artificial groundwater recharge by surface water infiltration

Carl Love Mikael Råman Vinnå, Sebastiano Piccolroaz

The sensitivity of future groundwater recharge and temperature development was investigated for three alluvial aquifers in the urban agglomeration of the city of Basel, Switzerland. For selected climate projections groundwater recharge and the associated t ...

ELSEVIER2022

Basin-scale gyres and mesoscale eddies in large lakes: A novel procedure for their detection and characterization, assessed in Lake Geneva

Ulrich Lemmin, David Andrew Barry, Mehrshad Foroughan, Frédéric Charles Soulignac, Seyed Mahmood Hamze Ziabari

In large lakes subject to the Coriolis force, basin-scale gyres and mesoscale eddies, i.e. rotating coherent water masses, play a key role in spreading biochemical materials and energy throughout the lake. In order to assess the spatial and temporal extent ...

2022

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

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

Toward biocontrol of waterborne pathogens: contributions of protists to virus removal and associated mechanisms

Margot Ninon Lauren Olive

Human viruses are widespread in the water environment and pose a risk to human health. Wastewater effluents represent the main source of viruses discharge in the environment, leading to contamination of aquatic ecosystems. Viral pathogens can persist on th ...

EPFL2022

Synthesizing the impacts of baseflow contribution on concentration-discharge (C-Q) relationships across Australia using a Bayesian hierarchical model

Camille Roland Marie Minaudo

Understanding concentration-discharge (C - Q) relationships can inform catchment solute and particulate export processes. Previous studies have shown that the extent to which baseflow contributes to streamflow can affect C-Q relationships in some catchment ...

COPERNICUS GESELLSCHAFT MBH2022