|Coline Ariagno (2019-2022)|
|PhD student on watershed erosion
|Supervisor: Caroline Le Bouteiller (Irstea Grenoble)
| Doctoral school :TUE (Terre Univers Environnement), Grenoble
Monitoring and modeling physical weathering of Draix marls and its effect on erosion
The objective of the project is to study the effect of rock physical
weathering on erosion. The study will be based on Draix-Bleone critical zone observatory, which is located on a very erodible marly substrate. A variety of physical processes are responsible for the weathering of marl resulting in the formation of a layer of fragments, called regolith, which can later be mobilized for erosion. The first approach will consist in monitoring at a local scale the characteristic of the regolithe (thickness, grain-size distribution, porosity) and the possible controlling factors (soil
temperature and moisture). These measurements will be used to create a 1D model of the seasonal dynamics of regolith. The second approach will be to spatialize and implement this description into a landscape evolution model (Landlab) to simulate the effect of regolith dynamics on catchment-scale erosion. This model will be calibrated based on sediment flux data from Draix observatory then used to test the effect of climatic hypotheses on erosion.