Pascale M. Biron

• Doctor of Philosophy
• Professor at Concordia University

Salmonid fishes are one of the best studied fish taxa, but little is known about their biomass distribution. We created a dataset using published material for over 1000 rivers with estimated salmonid biomass, covering 27 countries, and 11 species. The distribution of salmonid biomass and production across streams was skewed to the right with a mean...

Integrating hydrogeomorphological (HGM) principles into the restoration of degraded rivers can achieve sustainable results and provide various human benefits. HGM principles mainly involve understanding the context and processes that shape a fluvial system before any intervention, in order to support its dynamism and to align with its potential fun...

Salmonid fishes are arguably one of the most studied fish taxa on Earth, but little is known about their biomass range in many parts of the world. We created a dataset of estimated salmonid biomass using published material of over 1000 rivers, covering 27 countries and 11 species. The dataset, spanning 84 years of data, is the largest known compila...

Fluvial hazards of river mobility and flooding are often problematic for road infrastructure and need to be considered in the planning process. The extent of river and road infrastructure networks and their tendency to be close to each other creates a need to be able to identify the most dangerous areas quickly and cost‐effectively. In this study,...

L’objectif global du projet était d’appuyer les efforts de la coalition d’intervenants du bassin versant dans leurs démarches visant la restauration de la frayère à éperlan située à l’embouchure de la rivière Boyer. La réalisation du projet s’est centrée sur deux sous-objectifs : 1. Décrire et comprendre les processus hydrologiques et hydrogéomorph...

Habitat degradation is one of the major reasons for freshwater species decline. Hydrogeomorphological processes (such as sediment transport, bank erosion, and flooding) operate at the catchment scale and determine habitat features in river reaches. However, habitat quality indices and restoration for freshwater fish species are often implemented at...

Résumé L'hydrogéomorphologie étudie la dynamique des rivières en se concentrant sur les interactions liant la structure des écoulements, la mobilisation et le transport des sédiments et les morphologies qui caractérisent les cours d'eau et leur bassin‐versant. Elle offre un cadre d'analyse et des outils pour une meilleure intégration des connaissan...

Small differences in the densities of a river confluence's tributaries (i.e. 0.5 kg m $^{-3}$ ) have been proposed to cause coherent streamwise-oriented vortices (SOVs) in its mixing interface. These secondary flow structures are thought to result from density-driven gravity currents being laterally confined between the converging flows. However, e...

Published paper: http://dx.doi.org/10.1002/rra.4304 Integrating hydrogeomorphological principles into the restoration of degraded rivers can achieve sustainable results for a variety of objectives and human benefits that are consistent with the potential functioning of rivers as well as their uses. Despite recent management approaches inspired by...

Fluvial hazards of river mobility and flooding are often problematic for road infrastructure and need to be considered in the planning process. The extent of river and road infrastructure networks and their tendency to be close to each other creates a need to be able to identify the most dangerous areas quickly and cost-effectively. In this study w...

Integrating hydrogeomorphological principles in the restoration of degraded rivers can allow achieving sustainable results to a variety of objectives and benefits that are consistent with potential functioning of rivers as well as their uses. Despite recent management approaches inspired by these principles (e.g. freedom space for rivers), they are...

L’hydrogéomorphologie étudie la dynamique des rivières en se concentrant sur les interactions liant la structure des écoulements, la mobilisation et le transport des sédiments et les morphologies qui caractérisent les cours d’eau et leur bassin-versant. Elle offre un cadre d’analyse et des outils pour une meilleure intégration des connaissances sur...

Le canal Saint-Georges est un cours d’eau d’origine anthropique construit en 1898 lors de l’installation d’Henri Menier sur l’île d’Anticosti. Depuis, il a été aménagé pour l’adapter à différents usages. À partir de la fin des années 1970, les processus fluviaux ont graduellement façonné le cours d’eau, entraînant une morphologie plus naturelle. Un...

Measuring freshwater submerged aquatic vegetation (SAV) biomass at large spatial scales is challenging, and no single technique can cost effectively accomplish this while maintaining accuracy. We propose to combine and intercalibrate accurate quadrat-scuba diver technique, fast rake sampling, and large-scale echosounding. We found that the overall...

La restauration des cours d’eau s’est imposée dans les dernières décennies comme une composante centrale de la gestion des cours d’eau au Québec. Il existe toutefois une certaine confusion dans la distinction entre la restauration et l’aménagement des cours d’eau, ainsi que dans les bonnes pratiques à appliquer pour une restauration durable des cor...

Large rivers can retain a substantial amount of nitrogen (N), particularly in submerged aquatic vegetation (SAV) meadows that may act as disproportionate control points for N retention. However, the temporal variation of N retention in large rivers remains unknown since past measurements were snapshots in time. Using high‐frequency plants and NO3⁻...

A small gradient in the densities (Δρ) of two rivers in Canada was recently shown to develop coherent streamwise orientated vortices (SOVs) in their confluence. Here we use eddy‐resolved numerical modeling to examine how the magnitude and direction of Δρ affect these secondary flow structures. At equal density, lone anticlockwise SOVs are predicted...

When rivers collide, complex three‐dimensional coherent flow structures are generated along the confluence's mixing interface. These structures mix streamborne pollutants and suspended sediment and have considerable bearing on the morphology and habitat quality of the postconfluent reach. A particular structure of interest—streamwise orientated vor...

It is essential for river restoration to integrate hydrogeomorphological principles and human benefits. They can allow achieving a variety of objectives that are consistent with potential functioning of rivers as well as their uses. However, due to some operational limitations, the projects carried out in the province of Quebec still take little ac...

In agricultural watersheds, human interventions such as channel straightening have disrupted the hydrologic connectivity between headwater streams and their riparian environment and have thus undermined the ecological services provided by these small streams. Knowledge of the hydrologic connectivity between these streams and their immediate environ...

A small gradient in the densities of two rivers was recently shown to develop coherent streamwise orientated vortices (SOVs) in the mixing interface of their confluence. We further investigate this phenomenon at the Coaticook and Massawippi confluence (Quebec, Canada) using eddy-resolved numerical modelling to examine how the magnitude and directio...

Le canal Saint-Georges est un cours d’eau d’origine anthropique situé au centre de Port- Menier et construit en 1898 lors de l’installation de Henri Menier sur l’île d’Anticosti. Depuis sa construction, il a traversé trois périodes distinctes en termes d’usages et d’aménagement, qui ont chacune influencé de différentes manières la dynamique et la m...

Il est nécessaire d’intégrer les principes de l’hydrogéomorphologie et les bénéfices humains dans la restauration des cours d’eau. Ils peuvent permettre d’atteindre une diversité d’objectifs cohérents au fonctionnement potentiel des cours d’eau ainsi qu’à leurs usages. Toutefois, dû à certaines limites opérationnelles, les projets réalisés au Québe...

Preuve de concept d'un indice automatisé pour évaluer l'état hydrogéomorphologique des cours d'eau du Québec (livrable 5) Réalisé dans le cadre du projet de Développement et adaptation d'un indice de l'état hydrogéomorphologique des cours d'eau pour le Québec méridional.

Hi Everyone, This preprint presents direct aerial observations of streamwise orientated vortices (SOVs) at a river confluence. The vortices are visible because of a stark turbidity contrast between the turbid high discharge tributary and the clear low discharge channel. The vortices are strongly coupled to large-scale lateral episodic pulses prese...

Stream assessment indices have become increasingly important in quantifying the overall status of river networks to define specific targets for restoration initiatives. Such an assessment is particularly needed in degraded environments, such as agricultural streams. Some of these evaluation tools, for instance the Qualitative Habitat Evaluation Ind...

Confluences are sites of intense turbulent mixing in fluvial systems. The large‐scale turbulent structures largely responsible for this mixing have been proposed to fall into three main classes: vertically orientated (Kelvin‐Helmholtz) vortices, secondary flow helical cells and smaller, strongly coherent streamwise orientated vortices. Little is kn...

Floods are among natural disasters that increasingly threaten society, especially with current and future climate change trends. Several tools have been developed to help planners manage the risks associated to flooding, including the mapping of flood-prone areas, but one of the major challenges is still the availability of detailed data, particula...

Large-scale flood modelling approaches designed for regional to continental scales usually rely on relatively simple assumptions to represent the potentially highly complex river bathymetry at the watershed scale based on digital elevation models (DEMs) with a resolution in the range of 25–30 m. Here, high-resolution (1 m) LiDAR DEMs are employed t...

Owing to declines in salmonid populations, in-stream restoration structures have been used for over 80 years to increase abundance of fish. However, the relative effectiveness of these structures remains unclear for some species or regions, partly due to contrasting conclusions from two previous meta-analyses. To update and reconcile these previous...

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...

Confluences are key nodes of river systems that have the potential of disrupting downstream longitudinal trends in the main river through inputs of water, sediment, wood or ice delivered from tributaries. From a geomorphological perspective, confluence zones are particularly active and thus susceptible to increased flooding and bed instability, whi...

River confluences are characterized by a complex mixing zone with three‐dimensional (3D) turbulent structures which have been described as both streamwise‐oriented structures and Kelvin‐Helmholtz (KH) vertical‐oriented structures. The latter are visible where there is a turbidity difference between the two tributaries, whereas the former are usuall...

Aquatic plants (macrophytes) are known to affect flow dynamics, contributing to flow resistance. Most studies on flow‐vegetation interactions are performed in laboratory flumes and focus on the flow field around plants, with little research at the level of vegetation patches in large aquatic ecosystems. In most hydrodynamic models, increased drag d...

Les techniques de génie végétal pour la stabilisation des berges de cours d'eau restent encore peu utilisées au Québec. Alternatives au génie civil, elles offrent pourtant de nombreux avantages structurels, environnementaux et récréatifs. Alors comment expliquer ce frein et favoriser le développement de ces techniques ? Cet article fait un point su...

Despite a widespread acknowledgment that river restoration projects sometimes fail due to a poor understanding of geomorphology and hydrology, there are relatively few published case studies reporting failures, particularly for nonsalmonid species such as Lake Sturgeon Acipencer fulvescens. We used a three‐dimensional hydrodynamic model to retroact...

Amongst the fluvial models used to examine hydraulics and sediment transport in river channels, most ignore floodplain elements. In comparison, bank retreat and channel planform predictions for an environment with a cohesive soils require the consideration of mass movements, and ideally, of riparian vegetation effects. In this context, a simple mor...

Morphodynamic models of river meandering patterns and dynamics are based on the premise that the integration of biophysical processes matching those operating in natural rivers should result in a better fit with observations. Only a few morphodynamic models have been applied to natural rivers, typically along short reaches, and the relative importa...

Presentation of a research project funded by Environment Canada. The goal of the project is the determine criterias for riparian wetland habitats in agricultural setting having the best potential to restore their ecological functions. Three channelized streams, including their abandoned meander bends, located in the Saint-Lawrence lowland (Quebec p...

In many areas of the world, flood risk assessment is either out of date or completely lacking. In Quebec (Canada), one of the challenges to map flood risk is the very large territory combined with very few datasets on river bathymetry, which are required to run hydraulic models. The objective of this study is to assess the precision and accuracy of...

River confluences are characterized by a complex mixing zone with three-dimensional turbulent structures, which can be affected by the presence of an ice cover during the winter. The objective of this study is to characterize the flow structure in the mixing zone at a medium-size (~ 40 m) river confluence with and without an ice cover. Detailed vel...

In order to promote community accountability for flood risks, the involvement of non-governmental actors and citizens is increasingly valued. The emergence of participatory approaches is consolidated by optimism about the possibility of improving the quality and scope of decisions, managing conflicts, facilitating the implementation of non-structur...

Depuis les dernières décennies, la science de la restauration des cours d’eau a subi de profonds changements. En particulier, l’importance de bien tenir en compte la nature des processus fluviaux à l’échelle du bassin versant fait maintenant consensus, surtout en ce qui a trait au rôle de l’érosion des berges, de la mobilité des chenaux et des débr...

There is growing support amongst scientists worldwide about the need for a shift in river management approaches to include hydrogeomorphic processes. However, the degree to which these concepts are transferred to governmental agencies and practitioners varies widely. In Quebec, for example, many stream restoration projects are based on the (incorre...

The loss of spawning habitat has been identified as a limiting factor to population growth for lake sturgeon, Acipenser fulvescens, the most widely distributed species of the family in North America. While local information exists about lake sturgeon spawning habitat, a synthesis of all available data is needed across its range. Our study used meta...

Meandering river channels are often associated with cohesive banks. Yet only a few river modelling packages include geotechnical and plant effects. Existing packages are solely compatible with single-threaded channels, require a specific mesh structure, derive lateral migration rates from hydraulic properties, determine stability based on friction...

Riverbank stabilization using rock riprap is commonly used for protecting road and bridge structures from fluvial erosion. However, little is known about how streams adjust to such perturbation or how this can affect fish habitat in different fluvial environments, particularly for non-salmonid species in small streams. The objective of this study i...

Alternative management approaches for agricultural streams based on hydrogeomorphological principles such as a two-stage channel are promising, but need to be further tested in contexts other than the Midwestern United States. In Quebec (Canada), the presence of many deep drain outlets may limit their applicability. The objectives of this research...

There is great interest worldwide to reconnect floodplain wetlands to their rivers. Whilst the surface water connection between rivers and wetlands is fairly well understood, the linkages via groundwater are not well known. In this study, it is hypothesized that the significance of the groundwater pathways between rivers and wetlands is largely det...

Morphodynamic models are used by river practitioners and scientists to simulate geomorphic change in natural and artificial river channels. It has long been recognized that these models are sensitive to the choice of parameter values, and proper calibration is now common practice. This paper investigates the less recognized impact of the choice of...

Numerical models are increasingly being employed to examine the morphodynamics of meandering river channels. Although sinuous channels are typically associated with cohesive soils and vegetated floodplains, few models formally include these two elements. Furthermore, certain models reproduce the meandering planform and migration patterns observed i...

Human interventions that limit channel mobility such as bank stabilization are frequent in riparian zones in urban or agricultural environments. This is potentially problematic because channel mobility is an important geomorphological and ecological agent that structures natural instream and riparian ecosystems. This study aims to (1) quantify the...

Poster

Amongst the most widely used computational fluid dynamics models, some include a sediment transport module that enables the examination of river channel dynamics. However, most ignore two families of processes influencing lateral erosion rates, and thus channel evolution mechanisms: lateral transport of sediment through mass wasting along river ban...

Amongst the most widely used computational fluid dynamics models, some include a sediment transport module that enables the examination of river channel dynamics. However, most ignore two families of processes influencing lateral erosion rates, and thus channel evolution mechanisms: lateral transport of sediment through mass wasting along river ban...

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...

Despite significant knowledge developed through the examination of river meandering processes in computer models, a number of limitations remains with respect to the simulation of lateral channel adjustments. In addition, the explanations related to the irregularity of meandering planforms and to the interaction between river channel dynamics and f...

Anthropic riparian land use often leads to human interventions that limit channel mobility, such as bank stabilization. However, channel mobility is an important geomorphological and ecological agent that structures natural in-steam and riparian ecosystems, with migration of meanders being a patch-dynamic process responsible for the maintenance of...

Riprap is a form of riverbank stabilization that is commonly used to protect road and bridge infrastructures from fluvial erosion. However, little is known about how riprap can alter local hydro-geomorphology and how this can affect fish habitat. The objective of this study is therefore to assess potential impacts of riprap on fish habitat quantity...

Despite significant progress made in the research conducted to understand the morphodynamics of meandering rivers using computer models, a number of challenges and limitations remain with respect to simulating lateral river channel adjustments. In particular, some biophysical processes critical to bank erosion (e.g. related to soil and vegetation)...

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...

Despite decades of research on the morphological evolution of rivers, the mechanisms by which meandering rivers form and evolve are not well understood. Nonetheless, a common feature of natural and experimental meandering channels is that they develop in vegetated, cohesive soils. Although the effects of cohesion on river bank stability have been a...

Research projects in geomorphology often require the detection of morphological changes at a fine resolution. This is notably the case in river-related studies where changes in bank morphology are often subtle and difficult to detect. Accurate elevation models can be generated from devices such as terrestrial LIDAR and differential GPS units, but t...

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...

Few studies have examined sediment transport patterns around in-stream structures used to enhance fish habitat despite the importance of this variable in the successful design of stream restoration schemes. The objective of this study is to examine interactions between the (excavated) pool morphology, flow and sediment transport in a restored reach...

Morphodynamics models are increasingly being used in river engineering applications and fluvial geomorphology to assess the security of installed or projected hydraulic structures and to understand linkages between flow patterns, channel morphologies, substrate properties and aquatic communities. These models have a great potential to help determin...

Les collisions routières impliquant l'orignal se produisent souvent à proximité des mares d'eau stagnante où se concentre le sel de déglaçage qui a une forte teneur en sodium, un élément qui attire les orignaux. Cette étude vise à évaluer l'eca-cité du drainage de ces mares salines et de l'implantation de mares salines compensatoires comme mesure d...

Sharp open channel bend flows are highly three-dimensional because of the combined effects of secondary flow, large free-surface variations, and flow separation along the inner bend wall. A comprehensive analysis was performed to determine the best modeling parameters to study the open channel sharp bend flow. Comparisons of the simulation results...

Gravel-Bed Rivers: Processes, Tools, Environments presents a definitive review of current knowledge of gravel-bed rivers, derived from the 7th International Gravel-bed Rivers Workshop, the 5-yearly meeting of the world's leading authorities in the field. Each chapter in the book has been specifically commissioned to represent areas in which recent...

Deflector structures used in many fish habitat rehabilitation schemes are frequently overtopped, yet few studies have examined the scour patterns created around submerged models. Furthermore, laboratory studies typically test smooth-surfaced structures, whereas those installed in natural rivers are generally made of logs or boulders. This study use...

More frequent extreme flood events are likely to occur in many areas in the twenty-first century due to climate change. The impacts of these changes on sediment transport are examined at the event scale using a 1D morphodynamic model (SEDROUT4-M) for three tributaries of the Saint-Lawrence River (Québec, Canada) using daily discharge series generat...

Moose-vehicle collisions are a frequent traffic-safety issue, particularly in northern regions where moose are attracted to the near-road areas because they can consume sodium from de-icing salts that accumulate in pools at snowmelt. Moose that find salt pools near roads tend to remember their location and to re-visit them to get the sodium they ne...

Flow around a sharp open-channel bend is highly three-dimensional (3D) due to the combined effects of secondary flow, a large free surface variation and flow separation along the inner wall. Continuous vanes often used in closed curved conduits to generate a more uniform downstream flow were tested in the open channel using a 3D finite-volume model...

Sharp open-channel bends are commonly encountered in hydraulic engineering design. Disturbances such as secondary flows and flow separation caused by the bend may persist for considerable distances in the downstream channel. A simple way of reducing these disturbances is through the insertion of vertical vanes in the bend section. A laser Doppler a...

Despite a growing consensus that in-stream structures used in fish habitat restoration schemes should be nested within the larger catchment context, they may, nevertheless, provide rapid results, which are often required when fish habitat is urgently needed. However, the design, location, and placement of many of these instream structures are often...

Rural channels in Québec, and across Canada, have historically been heavily modified as a result of agricultural management practices, including straightening, widening and deepening. Although straightening has now largely ceased, dredging remains the leading strategy to maintain the resulting modified channel morphology. However, there is a growin...

The impacts of climate-induced changes in discharge and base level in three tributaries of the Saint-Lawrence River, Québec, Canada, are modelled for the period 2010–2099 using a one-dimensional morphodynamic model. Changes in channel stability and bed-material delivery to the Saint-Lawrence River over this period are simulated for all combinations...

Le redressement et le dragage des cours d’eau agricoles ont été intensivement utilisés lors du 20ième siècle pour drainer les terres argileuses et faciliter la maintenance des cultures. Ces interventions ont déstabilisé les cours d’eau en plus d’affecter la qualité et la diversité des habitats écologiques. La présente étude examine les effets géomo...

Despite the widespread use of stream restoration structures to improve fish habitat, few quantitative studies have evaluated their effectiveness. This study uses a meta-analysis approach to test the effectiveness of five types of in-stream restoration structures (weirs, deflectors, cover structures, boulder placement, and large woody debris) on bot...

Few studies have examined sediment transport patterns around instream structures used to enhance fish habitat despite the importance of this variable in the successful design of stream restoration schemes. This paper presents results from a field experiment on particle movement around flow deflectors during a series of floods in a restored reach of...

"Between 1990 and 2002, more than 200 moose–vehicle collisions occurred each year in Quebec, including about 50/yr in the Laurentides Wildlife Reserve. One cause is the presence of roadside salt pools that attract moose near roads in the spring and summer. Using the computer simulation technique of agent-based modeling, this study investigated whet...