Multi-RIsk assessment on Coastal territory in a global CHange context – RICOCHET

Ricochet project is characterized by the use and development of tools and creative methods to monitor the coastal dynamics (physical processes and planning). These are complementary tools which provide multi-temporal, multi-scale, and multi-sensor data. A multi-sectoral economic analysis, as well as territorial development proposals will provide the transfer of the scientific advances towards the public services to enhance the adopted strategies for the risk reduction / adjustment. This knowledge transfer will also be effective by the provision of a diagnostic tool that could be directly integrated in the State services schemes:
- Multi-temporal, multi-scale, and multi-sensor data acquisition systems: continuous field data acquisition (Optical-fiber, camera, accelerometers ...), photogrammetry using cameras on drones, lasergrammetry using TLS Terrestrial Laser Scanner), MLS (Mobile Laser Scanning) and airborne LiDAR and InfraRed images. For UAV (drones), the areas of innovation are mainly in (i) the integration of new sensors on the same drone in order to detect changes of certain physical parameters of the coastal slopes, and (ii) the capability to operate a fleet of drones equipped with different and complementary sensors and acquiring data at are solution adapted to allow regular surveys for coastal risk management run by local authorities.
- Production of decision-aid maps either for local authorities, public services or private companies producing expertise on coastal risk management. The scientific developments (stability models, mass movement processes, hazard and risk mapping) produced by RICOCHET and formalized in the CMP, will be integrated into a QGIS toolbox able to compute different risk maps from the data already available or recorded by the developed monitoring systems. This toolbox will be disseminated at no charge to end-users for their own use, which will strongly contribute to the impact and transfer of the project results.

Six major and complementary main results are expected from this project:
Identification and quantification of the key parameters controlling current and future hazards with definition of hazard triggering thresholds and return periods;
Definition of sediment sources and stocks location and quantification of sediment supply contributing to the reduction of the current and future coastal flooding risk/storm surge.
Identification of sensitive areas, hotspots subject to relay, combination or superposition of processes taking into account the Global Change.
Identification of risks expected from climate change at a local scale based on a Multi-Risk platform under GIS environment. Multi-hazard maps will be combined with different information and identification and characterization of current vulnerability to provide risk maps based on different scenarios of global change.
Improvement of methodologies to ensure the transfer between the scientific knowledge of the environment dynamics, vulnerability and risk assessment (scientific results and culture of risk) into an adequate strategy of management.
Strengthening of collaboration between scientists and local to national decision-makers and stakeholders on risk reduction in a context of climate change. Through this collaborative and co-constructive work, RICOCHET will provide practical and realistic proposals to improve current policies for management strategies and urban planning.

Deriving a methodological guideline and a «decision support tool« to facilitate the choice of decision makers and stakeholders for planning decision and implementation of sustainable management strategies of coastal areas. This decision tool will be grounded on historical management and discussion between scientists and local authorities.

M. Medjkane, O. Maquaire, S. Costa, Th. Roulland, P. Letortu, C. Fauchard, R. Antoine, R. Davidson. High-resolution monitoring of complex coastal morphology changes: cross-efficiency of SfM and TLS-based survey (Vaches-Noires cliffs, Normandy, France). Landslides (2018) 15: 1097–1108, DOI 10.1007/s10346-017-0942-4.
P. Letortu, M. Jaud, Ph. Grandjean, J. Ammann, S. Costa, O. Maquaire, R. Davidson, N. Le Dantec, & C. Delacourt. Examining high resolution survey methods for monitoring cliff erosion at an operational scale. GIScience and Remote Sensing, December 2017. doi: 10.1080/15481603.2017.1408931

RICOCHET addresses both basic/fundamental scientific questions and their societal applications. The financing instrument (PRCE: Research projects collaborative – Enterprise) supporting the project RICOCHET should allow us to develop and strengthen collaborations between the academic research and the socio-economic worlds. RICOCHET addresses the management of coastal territories that are highly exposed to CC related hazards because of their geographical position, between land and ocean. Along this particular domain, hazards come from coastal erosion and submersion as well as from flooding, flash floods, and landslides. More specifically, due to global/local environmental and societal changes, the project also considers environments issues requiring population relocation. RICOCHET involves both territory/risk managers working on societal needs and scientists, for improving the understanding of coastal dynamics from a global point of view. For this purpose, coastal areas sensitive to cliff recession and to continental flooding but also to demographic pressures are analysed. The project has 3 main objectives: 1) Understanding the present-day Land/Sea continuum dynamics (beach/cliff/hinterland) and assessment of the sedimentary balance along-shore and from continental; 2) Definition of multi-sectorial impact induced by GC (climate, environmental and social/economic changes), e.g., impacts of the increase of storms frequency and SLR on the cliff-beach system functioning. 3) Supporting the stakeholders and politics in their apprehension and questioning about the impacts of GC on coastal territories to provide them with tools to adopt sustainable coastal management strategies.

Highly based on interactions of continental and coastal processes, our approach will consist in developing an integrated risk assessment (multi-hazard and multi-risk analysis). Results will provide risk communication tools, and decision/management tools for the risk management of seashore cliffs environments. Project is remarkable in 2 respects. Firstly, the originality and the particularity of the project consist in the choice of a specific type of coast (coastal cliffs and slopes subjected to fast retreat). Indeed, these territories require more than other type of coast, to consider the interactions of continental and marine processes. Secondly, the project will consider the cascade effects and chains of impacts for a global risk assessment. Because, these processes affect several sectors (agricultural areas, industrial structures, individual houses and tourism infrastructures…), an economic analysis will be conducted to analyse acceptable and sustainable management strategies for a better management and risk prevention in coastal areas.

Methodological and technological innovations of RICOCHET come from the use and development of novel methods to monitor the coastal dynamics (physical processes and planning) and tools to evaluate and manage impacts. These are complementary aspects which should provide multi-temporal, multi-scale, and multi-sensor data for a better risk management. A multi-sectoral economic analysis, as well as territorial development proposals will provide the transfer of the scientific advances towards the public services to enhance the adopted strategies for the risk reduction/adjustment. This knowledge transfer will also be effective by the delivery of a diagnostic tool that could be directly integrated in the State services systems. This tool will be designed in order to be exploitable to other regions affected by these concerns. Valorisation of the results will also be done following these 2 axes: academic valorisation through publications (International Refereed Journals with high impact factors) and communications in congress, and technical and industrial valorisation, thanks to the knowledge transfer that will allow the enterprises to be more active on new markets and new products related to decision support systems and guidelines.