Description du projet
Les rivières déplacent les sédiments et remodèlent les vallées creusées par la glace
Les cycles glaciaires-interglaciaires répétés au cours des 2,6 derniers millions d’années ont considérablement influencé la topographie des chaînes de montagnes du monde entier. L’érosion glaciaire et les glissements de terrain dans les vallées abruptes déglacées génèrent d’énormes volumes de sédiments. Ces sédiments peuvent accélérer le rythme auquel les rivières creusent leurs lits après la déglaciation, si les sédiments agissent comme un outil pour abraser le lit de la rivière, ou peuvent au contraire inhiber l’érosion en blindant le lit. La façon dont les sédiments affectent l’érosion et l’évolution du paysage à travers des oscillations climatiques répétées n’a pas été bien quantifiée. Avec le soutien du programme Actions Marie Skłodowska-Curie, le projet POSTCOLD développera et appliquera un modèle d’évolution du paysage incorporant les effets de la dynamique sédimentaire sur l’incision des rivières. Les connaissances qui en découleront permettront d’évaluer les risques naturels et de gérer les écosystèmes.
Objectif
Repeated glacial-interglacial cycles during the Quaternary have significantly impacted the topography of many mountain ranges around the world. Yet, the response of landscape evolution to repeated climate oscillations has not been well quantified. In recently deglaciated landscapes, the transition from glacial to fluvial/hillslope processes have induced progressive topographic adjustments, and the large amounts of sediments inherited from glacial periods and generated through landsliding of oversteepened glaciated topography may act as a fundamental control on the incision of postglacial rivers. These sediments can enhance fluvial incision rate by providing more tools for erosion, or inhibit incision by armoring the river bed. Characterizing when and where sediment enhances or inhibits fluvial incision in postglacial landscapes is critical for understanding the changes in postglacial landscape evolution rates over time and quantifying the response times of mountain ranges to deglaciation. In this project, I propose to develop a landscape evolution model to account for the complex impact of sediment dynamics on fluvial incision in postglacial landscapes. I will utilize this model to investigate the response of fluvial incision to changes in sediment supply and assess the effects of sediment on postglacial landscape evolution. I will apply the model to quantify response times of the deglaciated European Alp, leveraging the rich observational datasets in this region. The proposed work will provide a quantitative understanding of postglacial fluvial incision histories, which is critical for ecosystem management and natural hazard assessment in recently deglaciated mid-latitude mountain ranges and perhaps in high-latitude mountain ranges where continued climate change may eventually lead to deglaciation.
Champ scientifique
- natural sciencesphysical sciencesastronomyplanetary sciencesplanetary geology
- natural sciencesbiological sciencesecologyecosystems
- social sciencessociologygovernancecrisis management
- natural sciencesearth and related environmental sciencesphysical geographynatural disasters
- natural sciencesearth and related environmental sciencesatmospheric sciencesclimatologyclimatic changes
Programme(s)
- HORIZON.1.2 - Marie Skłodowska-Curie Actions (MSCA) Main Programme
Régime de financement
HORIZON-TMA-MSCA-PF-EF - HORIZON TMA MSCA Postdoctoral Fellowships - European FellowshipsCoordinateur
14473 POTSDAM
Allemagne