Sylvio Demers

• Université du Québec à Rimouski UQAR

The consensus around the need for a shift in river management approaches to include more natural processes is steadily growing amongst scientists, practitioners, and governmental agencies. The freedom space for rivers concept promotes the delineation of a single space that integrates multiple fluvial dynamics such as floods, lateral migration, chan...

River systems are increasingly under stress and pressure from agriculture and urbanization in riparian zones, resulting in frequent engineering interventions such as bank stabilization or flood protection. This study provides guidelines for a more sustainable approach to river management based on hydrogeomorphology concepts applied to three contras...

L'hydrogéomorphologie est une approche en développement au Québec afin d'apporter un cadre d'analyse complémentaire aux pratiques de gestion des systèmes fluviaux. À travers l'étude de cas de la rivière Matane, cet article propose des méthodes cartographiques appliquées pour la gestion de l'aléa d'inondation de rivières situées en climat tempéré fr...

Hydro-geomorphological assessments are an essential component for riverine management plans. They usually require costly and time-consuming field surveys to characterize the spatial variability of key variables such as flow depth, width, discharge, water surface slope, grain size and unit stream power throughout the river corridor. The objective of...

The aim of this work is to compare macroturbulent coherent structures (MCS) geometry and organization between ice covered and open channel flow conditions. Velocity profiles were obtained using a Pulse‐Coherent Acoustic Doppler Profiler in both open channel and ice‐covered conditions. The friction imposed by the ice cover results in parabolic shape...

Turbulence organizes river flows and contributes to fluvial dynamics. Key methodologies and classical measures that are used to document the structure of turbulent flows and the presence of coherent flow structures are presented. The progress made in characterizing the nature of turbulent flows in rivers has led to a better understanding of the ori...

Understanding the hydrogeomorphological trajectory of a river allows us to document the impact of environmental changes on the river, but also to determine sustainable management solutions in the cases of a non-equilibrium river system. The hydrogeomorphological trajectory is obtained through the quantification of morphological and hydrological cha...

The investigation of the flow field with a pulse-coherent acoustic Doppler profiler has led to new high resolution observations of the secondary flow pattern occurring in a natural ice-covered meander reach. Surveys were conducted during two successive winter periods with different ice conditions. Massive frazil ice accumulation was present during...

L’hydrogéomorphologie fluviale est peu reconnue dans les politiques de gestion et d’aménagement du territoire québécois. Une meilleure reconnaissance permettrait pourtant une gestion plus éclairée des cours d’eau par une intégration de leur dimension dynamique. Cette étude teste l’applicabilité d’une méthode de sectorisation de cours d’eau en unité...

Cet article examine l’effet des barrages sur le synchronisme des crues du fleuve Moulouya (Maroc) ainsi que les incidences sur l’ajustement morphologique de ses tributaires intermittents. Une analyse comparative des débits mensuels moyens enregistrés de part et d’autre des infrastructures de retenue montre une diminution du débit moyen de 52 % et u...

This paper looks at the effect of dam impoundments on the flood synchronicity of the Moulouya River (Morocco) and its consequences on the morphological adjustments of its ephemeral tributaries. The comparative analysis of monthly discharges measured upstream and downstream of the dams shows a diminution of 52% of mean discharges and a diminution of...

In cold climate environments, rivers have an ice cover that can persist for a significant period of time. The addition of an ice cover on an open channel creates a flow in which two distinctive boundary layers develop and contribute to turbulence production. It is still unclear how turbulent coherent flow structures rising from both boundaries inte...