Publications de Mário Jorge Rodrigues Pereira Da Franca

Künstliche Hochwasser in Restwasserstrecken unter Berücksichtigung von Geschiebevorkommen, hydromorphologischer und ökologischer Indikatoren

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

Stauanlagen mit großen Speichern beeinflussen oftmals das Abfluss- und Geschieberegime im Gewässerunterlauf. Dadurch kann die natürliche Dynamik, Morphologie und Ökologie von noch verbliebenen Auenlandschaften erheblich beeinträchtigt werden. In der Saane ...

2021

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

The impact of hydrograph variability and frequency on sediment transport dynamics in a gravel-bed flume

Mário Jorge Rodrigues Pereira Da Franca, Carmelo Juez Jiménez

A laboratory study was undertaken to investigate how changes in flow regime and hydrograph shape (number of cycled hydrographs and duration of each hydrograph) together impact bedload transport and resulting bed morphology. Three hydrologic conditions (exp ...

WILEY2020

Sampling sufficiency for determining hydraulic habitat diversity

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

The geometry and hydrodynamics of river reaches are key ecohydraulic descriptors. Statistics of water depth and velocity measurements are usually taken as proxies for habitat suitability in rivers. However, little is known about the sufficiency of data to ...

2018

Continuously-fed gravity currents propagating over a finite porous substrate

Anton Schleiss, Mário Jorge Rodrigues Pereira Da Franca, Sara Venuleo

We present the results of laboratory investigations of continuously-fed density currents that propagate first over a smooth horizontal bed and then over a porous substrate of limited length. Inflow discharge, initial excess density, and substrate porositie ...

2019

Effect of a second layer on the time to failure of compressed riprap as mountain riverbank protection

Anton Schleiss, Mário Jorge Rodrigues Pereira Da Franca, Mona Jafarnejad Chaghooshi, Michael Pfister

Recently, Jafarnejad, Franca, Pfister, and Schleiss [2017. Time-based failure analysis of compressed riverbank riprap. Journal of Hydraulic Research, 55(2), 224–235. doi: 10.1080/00221686.2016.1212940] presented an experimental study on the stability of co ...

Taylor & Francis Ltd2019

Increase of hydraulic habitat diversity downstream of dams with sediment replenishment and artificial flooding

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

Nexus - The Water, Energy & Food Security Platform2019

Sediment replenishment combined with an artificial flood improves river habitats downstream of a dam

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

River reaches downstream dams 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, a two-year return flood was released from an upstream reservoir ...

Nature Research2019

Bottom slope influence on flow and bedload transfer through contractions

Anton Schleiss, Mário Jorge Rodrigues Pereira Da Franca, Sebastian Schwindt

In-stream open check dams are essential for flood protection at mountain rivers that are characterized by steep slopes (>1%) and sediment-laden flood discharges. These structures comprise an opening acting as a lateral or vertical flow contraction to force ...

Taylor & Francis Ltd2019

Floodplain Land Cover and Flow Hydrodynamic Control of Overbank Sedimentation in Compound Channel Flows

Anton Schleiss, Mário Jorge Rodrigues Pereira Da Franca, Carmelo Juez Jiménez, Hannes Jenny

Overbank sedimentation is predominantly due to fine sediments transported under suspension that become trapped and settle in floodplains when high-flow conditions occur in rivers. In a compound channel, the processes of exchanging water and fine sediments ...

2019

Potential erosion capacity of gravity currents created by changing initial conditions

Anton Schleiss, Mário Jorge Rodrigues Pereira Da Franca, Jessica Zordan

We investigate to what extent the initial conditions (in terms of buoyancy and geometry) of saline gravity currents flowing over a horizontal bottom influence their runout and entrainment capacity. In particular, to what extent the effect of the introducti ...

2019

Design of Riverbank Riprap Using Large, Individually Placed Blocks

Anton Schleiss, Mário Jorge Rodrigues Pereira Da Franca, Mona Jafarnejad Chaghooshi, Michael Pfister

The protection of river banks in mountain rivers by riprap requires large blocks with weights typically exceeding 1 t. Thus, the blocks have to be placed individually. Such packed riprap has a relatively small spacing between the blocks. Consequently, the ...

2019

Sediment replenishment as a measure to enhance river habitats in a residual flow reach downstream of a dam

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

Floodplains downstream of a dam, where the natural flow regime is replaced by a constant residual flow discharge, often lack sediment supply and periodic inundation due to the absence of natural flood events. In this study, a flood with a one-year return p ...

Canadian Dam Association2019

Erosion processes of a novel configuration of sediment replenishment during an artificial flood

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

Floodplains downstream of dams with constant residual flow discharge often lack sediment supply and periodic inundation due to the absence of flood events. At the Sarine floodplain in Fribourg, western Switzerland, an artificial flood was released from Ros ...

2019

Experimental results of gravity currents travelling over a fissured bed

Anton Schleiss, Mário Jorge Rodrigues Pereira Da Franca, Sara Venuleo

Gravity currents are geophysical flows having large impact on human life and on the environment. The need to prevent and mitigate their negative consequences justifies the multitude of studies carried out to understand their physics. However little has bee ...

2019

Image processing and laser measurements for determination of the erosion and deposition of fine sediments by a gravity current

Anton Schleiss, Mário Jorge Rodrigues Pereira Da Franca, Jessica Zordan, Carmelo Juez Jiménez

This paper reports a high-resolution, non-intrusive, low-cost technique to measure volumes of erosion and deposition of fine sediments. The combination of two techniques, photography and laser scanning, gives the advantage of simultaneous quantitative esti ...

2018

Teildurchgängige Geschiebesammler für sicheren Rückhalt

Anton Schleiss, Mário Jorge Rodrigues Pereira Da Franca, Sebastian Schwindt

Geschiebesammler halten oft bei kleineren Hochwassern unnötig Geschiebe zurück. Dadurch wird die öko-morphologische Gewässerkontinuität unterbrochen. Beobachtet werden zudem oft gefährliche, selbsttätige Entleerungen. Durch den Einsatz eines Leitgerinnes i ...

2018

Feinsedimentdynamik in revitalisierten Flüssen

Anton Schleiss, Mário Jorge Rodrigues Pereira Da Franca, Carmelo Juez Jiménez, Matthias Thalmann

Im Rahmen von Flussrevitalisierungen werden oftmals seitliche Aufweitungen geschaffen, in denen sich Feinsedimente ablagern können. Insbesondere in Flüssen, die von Schwall und Sunk betroffen sind, stellt sich die Frage, wie der Ablagerungsprozess von Fein ...

2018

Influence of lateral embayments on suspended sediment transport under unsteady flow conditions

Anton Schleiss, Mário Jorge Rodrigues Pereira Da Franca, Carmelo Juez Jiménez, Matthias Thalmann

Local widening in a channelized river is a common practice in restoration projects. The lateral embayments built for this purpose in the river banks are partially filled up by fine sediments. This allows the formation of aquatic habitats with hydraulic and ...

2018

Morphological resilience to flow fluctuations of fine sediment deposits in bank lateral cavities

Anton Schleiss, Mário Jorge Rodrigues Pereira Da Franca, Carmelo Juez Jiménez, Matthias Thalmann

Lateral cavities are built in the banks of rivers for several purposes: to create harbors, to capture sed- iment, to keep a central navigable channel (i.e., Casiers de Girardon in the Rhone river) or to promote the formation of aquatic habitats if a limite ...

2018