Study of bank mobility issues in the St. Lawrence river section

As part of measure 2.6 of the 2013-2020 Action Plan on Climate Change, and in the wake of the project “[Characterization of the banks of the fluvial part of the St. Lawrence and analysis of the evolution of hydro-climatic factors influencing erosion and flooding hazards] (https://www.donneesquebec.ca/recherche/dataset/caracterisation-des-berges-et-analyse-de-l-evolution-des-facteurs-hydro-climatiques)” ()”, the MELCCFP mandated the team of the **Laboratoire de Géomorphology Terre-Mer du Département de Géomorphology de l'Université Laval ** in order to conduct a study on the mobility issues of banks in the fluvial section of the St. Lawrence. The selection of the six issues, spread over ten sites of interest, was based on the previous shoreline characterization project, which made it possible to locate significant problems related to shoreline mobility.

The six issues addressed correspond to:

1. The archipelagos of the fluvial St. Lawrence and the seaway (sites of Île Marie, Île de Grace and Île des Barques)

2. Land use planning and delta formation in Lake Saint-Pierre (Yamachiche Point site)

3. The degradation of the sloping walls between Sainte-Marthe-du-Cap and Champlain (Pointe-au-Vent and Champlain sites)

4. The rapid dynamics of high soft cliffs (Cap Lévrard site)

5. The effects of docks on sedimentary transit in the fluvial estuary (Portneuf and Pointe-Platon sites)

6. The management of urban beaches in Quebec (site of Plage-Jacques-Cartier, Anse-Tibbits and Beauport Bay beach)

This new study has thus made it possible to provide scientific knowledge adapted to the specificities of this densely populated sector of the river, in order to (1) better understand the hydrogeomorphological trajectory of this large fluvial system, and (2) to guide management practices towards better respect for its mobility space and the integrity of its ecosystems. The development of a multi-scale monitoring approach, combining geomorphological and geohistorical components, has proven to be very effective in documenting the implications of the highly artificial nature of the fluvial St. Lawrence and in better defining the influence of natural processes.

The project was made possible thanks to the creation of a vast geospatial database, collected and processed by the research team. In a process of sharing and disseminating, the team makes available all the deliverables and geospatial data* produced during this study, in particular:

A comprehensive report detailing the context of the study, the methodology, the results in the form of six extensively illustrated Mobility-Trajectory sheets, as well as a summary accompanied by a discussion on the impacts of land use planning along the fluvial St. Lawrence.

Self-supported version of the six Mobility-Trajectory portrait sheets.

Geospatial data associated with the historical mapping of coastline features (CTs) and their migration rates, as well as products derived from drone imagery, such as numerical surface models (MNS) and orthomosaics.

*Higher spatial and temporal resolution data are available upon request.

This third party metadata element was translated using an automated translation tool (Amazon Translate).