Publications de Christian Mörtl

Hydromorphological assessment of sediment augmentation measures in gravel-bed rivers

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

Influence of channel geomorphic units on bedload transport and river morphology during low‐magnitude bed‐forming floods coupled with sediment augmentation

Giovanni De Cesare, Severin Stähly, Christian Mörtl, Robin Schroff

In this study, we map different types of channel geomorphic units in a sediment-starved, residual-flow reach before and after an artificial flood. Bedload particles of a previous sediment augmentation measure are tracked with passive integrated transponder ...

2023

Assessment of the hydromorphological effectiveness of sediment augmentation measures downstream of dams

Giovanni De Cesare, Christian Mörtl

This article presents assessment methods for the hydromorphological effectiveness of sediment augmentation measures downstream of dams. First, we describe different ways of quantifying hydromorphological effectiveness based on typical objectives of sedimen ...

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

Plunge pool scour and bank erosion: assessment of protection measures for Ilarion dam by physical and numerical modelling

Giovanni De Cesare, Anton Schleiss, Azin Amini, Romain Nathan Hippolyte Merlin Van Mol, Christian Mörtl

The 130 m high Ilarion Dam is built on the Aliakmon River in northern Greece. Its two spillways are equipped with ski jumps to deflect high-velocity jets towards the centre of the plunge pool. Significant scouring occurred in the pool during two major floo ...

2022

Dataset for a flume experiment on sediment augmentation

Christian Mörtl

Dataset for the paper "Influence of hydrograph shape and sediment augmentation repetition frequency on sediment transport dynamics and bed morphology evolution". It includes coordinates of the defined areas of interest and digital elevation models from the ...

EPFL2022

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

Impacts et enjeux de charriage d’une crue artificielle – Exemple de la Petite Sarine 2020 ||| Wirkung und Geschiebeproblematik eines künstlichen Hochwassers – Beispiel der Kleinen Saane 2020

Giovanni De Cesare, Christian Mörtl, Robin Schroff

En octobre 2020, une crue artificielle d’essai a été relâchée dans la Sarine en aval du barrage de Rossens, dans le canton de Fribourg. L’objectif était de redynamiser le tronçon à débit résiduel de 13 km de long, surnommé la « Petite Sarine ». Manquant de ...

2022

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

Wirkungskontrolle einer Sedimentzugabe: Habitatvielfalt und Kolmation

Giovanni De Cesare, Christian Mörtl, Robin Schroff

In einer Restwasserstrecke der Saane wurde 2016 zur Sanierung der kolmatierten Gewässersohle und zur Aufwertung der Lebensräume ein künstliches Hochwasser ausgelöst und mit einer Sedimentzugabe gekoppelt. Die mittelfristigen Wirkungen der Sedimentzugabe wu ...

2021

Ultrasonic Doppler flow velocity measurements as a co-indicator for the eco-morphological assessment in a residual flow reach

Giovanni De Cesare, Christian Mörtl, Robin Schroff

It is a complex task to evaluate the effects of a river rehabilitation measure on the riverscape’s habitat mosaic. This study investigated the medium term effects of a rehabilitation measure in a residual flow reach downstream of a hydroelectric dam. The r ...

ETH2021

Sediment Augmentation for River Rehabilitation and Management—A Review

Giovanni De Cesare, Christian Mörtl

Sediment management is an important part of river rehabilitation and management. Global case studies provide a growing number of examples of successful sediment augmentation measures that can counter the adverse effects of disturbed sediment regimes. The i ...

2021

The sediment challenge of Swiss river corridors interrupted by man-made reservoirs

Giovanni De Cesare, Pedro Filipe De Almeida Manso, Samuel Luke Vorlet, Christian Mörtl

Depending on their characteristics and management, man-made reservoirs can have a significant impact on the natural sediment continuity of rivers. We classify different reservoir types and describe potential risks for the dam and downstream river reach. Ou ...

CRC Press2020