The future of Gâvres Peninsula: towards a sustainable and integrated adaptation strategy to climate change (FUGASCIA)

Gâvres, Morbihan – France

Dates : 2019-2022

 

Project leaders : Université de Bretagne Sud : Laboratoire Géoscience Océan, Observatoire Citoyen du Littoral Morbihannais

Classification

Risks

Solutions

Actors

Costs

Summary

For the last decades, the Gâvres peninsula (Brittany region) has been increasingly impacted by coastal erosion and floods. Faced with the challenges coming with the shrinking isthmus – the only remaining access to the city of Gâvres – the Urban Community of Lorient launched a series of construction work to prevent marine flood and coastal erosion risks on the “Great Beach” of Gâvres; in consultation with the University of Bretagne Sud’s Laboratoire Géosciences Océan (LGO). 

These works aim to confront the existing buildings and upkeep the dune through eco-engineering solutions (timber logs, fence, dune elevation, etc.). In addition, as part of the Observatoire Citoyen du Littoral Morbihannais, the project seeks to deploy voluntary monitoring undertook by citizens. The latter would allow citizens to regularly report any significant evolution of the beach works. In this respect, this project guides the reflection of Gâvres’ population on the management of the coastline and on some issues such as erosion, dune preservation and planning through the interactions between citizens, planners, elected officials and scientists.

Actions

The work carried out by Lorient Agglomération consists in elaborating a global redevelopment plan to optimize the pre-existing developments of the large beach of Gâvres carried out in 2012 (wooden groins, recharging). The new works carried out in 2020-2021 consist in :

  • reducing the length of existing structures (wooden groynes)
  • installing three new wooden groynes to maintain the sand while allowing the passage of users between the logs;
  • Installing alignments of baskets and wooden fence at the top of the beach;
  • Raising the dune area at the end of a promenade dike

Finally, by setting up a voluntary monitoring system, the project can follow the evolution of the sediment and the vegetation on the beach and within these installations and can measure their effects.

Participatory-science activities: volunteer citizens carry out autonomous field measurements based on a simple protocol developed by the LGO (monitoring of the layout, monitoring of coastal sedimentation and the evolution of the dune vegetation). This participatory science approach makes citizens aware of their responsibilities by improving their knowledge and understanding of natural phenomena related to the coastline and the functioning of its ecosystems. In parallel to the OCLM protocol, CoastSnap stations are installed on the beach, allowing anyone to follow the evolution of the coastline by taking a simple photo with their smartphone. 

Workshops (2021-2022): The organization of public meetings and participatory workshops will require the collaboration of the inhabitants and will gather the main stakeholders to debate on coastal management and coastal risks. These workshop-debates will organize a dialogue between researchers, inhabitants and local actors and address the following themes “Coastal management and adaptation strategies: what vision for the coast of Gâvres in 50 years; The memory of the past, revealing the challenges of the territory and the impacts of climate change”. 

Field trip on the beach for educational purposes (2021-2022)  

Questionnaires/surveys to evaluate users’ perceptions (inhabitants, local actors) on coastal risks and the adaptation techniques installed. 

Mobile application (2021-2022): Information and awareness tool on the coastal issues of Gâvres 

Communication via OCLM’s social networks

Regular surveys carried out by the volunteers involved in the Gâvres’ Grande plage management enhance the scientific knowledge and understanding of the site. Thus, data collection can support managers’ comprehension of the site’s functioning and guide their policies towards further sustainability, especially regarding exceptional meteorological phenomena and climate change-related events (e.g. sea-level rise).

The LGO may propose Lorient Agglomération expertise on the existing facilities. However, at this stage of the project, it is still complex to make an initial assessment for the Grande plage de Gâvres site, as citizen surveys began in August 2020.

Outcomes

In the long run, the project coordinators expect: 

  • Enhanced scientific knowledge of the natural dynamics of the Gâvres site (databases) 
  • A better understanding of natural phenomena and eco-engineering solutions among citizens and stakeholders
  • Stronger social cohesion and collective reflection
  • The establishment of a new integrated, adapted and sustainable management method on the site of Gâvres 
  • The implementation and perpetuation of high-frequency monitoring (OCLM monitoring) via participatory science 
  • Communication and regular restitution 
  • An increase in the number of volunteer observers.

At this stage of the project, project coordinators have already achieved and implemented: 

  • Discussions between citizens, elected officials, managers, and scientists on the issue of the coastline of Gâvres 
  • Activities of participative sciences related to the physical evolution of the coastline (citizen monitoring)
  • The creation of simple protocols based on scientific methods for coastline monitoring 
  • Training and knowledge sharing
  • The launch of a database to better understand the area in the face of climate change
  • Raising awareness on coastal issues and involving citizens in coastline management. Citizens are not only spectators but actors of their coastal zone.
  • Public and high-frequency restitution of results and data to scientists, managers and volunteers.  
  • Regular discussions

Communication is necessary (e.g. social networks) to make the project known, to rouse volunteers’ interest and to keep them enthusiastic about participatory science activities. Yet, participatory science actions can take time to be launched. 

Due to the pandemic, some actions have been delayed or postponed. Meetings scheduled for 2020 were cancelled through municipal decrees prohibiting public meetings. Eventually, the work on the development of the large beach has also been delayed, preventing the beginning of participatory science activities.

Partners

Technical partners: LGO-UBS, Association RIEM, Lorient Agglomération, Municipality of  Gâvres, Associations Les Peuples des Dunes et les Enfants des Marais, Citizens-volunteers, Institut Archipel de l’UBS, Fondation de France

Financial partners: Fondation de France, Lorient Agglomération

Resources