EGU24-12585, updated on 09 Mar 2024
EGU General Assembly 2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Modeling seasonal sediment dynamics and landscape evolution in a marly badland catchment, Draix-Bléone Critical Zone Observatory, SE France

Caroline Le Bouteiller1, Coline Ariagno2,1, Peter van der Beek3, Sebastien Klotz1, Gregory Tucker4,5, and Benjamin Campforts6,7
Caroline Le Bouteiller et al.
  • 1INRAE, UR ETNA, Saint-Martin d'Heres, France (
  • 2Univ. Rennes, CNRS, Géosciences Rennes, UMR 6118, 35000 Rennes, France
  • 32 Institut für Geowissenschaften, Universität Potsdam, Potsdam, Germany
  • 4Department of Geological sciences, University of Colorado Boulder, Boulder, CO, USA
  • 5Cooperative institute for research in Environmental Sciences (CIRES). University of Colorado Boulder, Boulder, CO, USA.
  • 6Department of Earth Sciences, VU University Amsterdam, Amsterdam, 1081HV, the Netherlands
  • 7Institute of Artic and Alpine Research, University of Colorado, Boulder, CO, USA

Badlands are particularly sensitive components of the critical zone where weathering, erosion and transport processes can be observed on human time-scales. Within the Draix-Bléone Critical Zone Observatory (CZO), SE France, water and sediment (both bedload and suspended load) fluxes and climatic drivers have been recorded since more than 35 years, making it an ideal natural laboratory to develop a landscape-evolution model (LEM) for badland evolution calibrated with field data. Based on these records and existing knowledge on the sediment dynamics of these marly catchments, the aim of this study is to develop a LEM that is able to reproduce the observed intra-annual sediment-flux variability, in particular the transition from transport-limited to supply-limited conditions that occurs during summer. Our model predicts soil thickness and sediment export at monthly timescales, thereby providing potential links between “classical” LEM that run at long time scales and event-scale models, and simulating the physical processes driving the sediment dynamics in these catchments at their relevant timescale. We use the annual hysteresis cycle between rainfall and sediment export recorded in the Draix catchments as a quantitative indicator of the adequacy of the model. First, we model the supply-limited regime observed in the second half of the year in the badlands, illustrated by an clockwise loop in the annual hysteresis pattern, using depth-dependent hillslope regolith production and erosion laws. Next, we express the impact of rainfall intensity, identified as the main trigger of sediment motion both on hillslopes and in the drainage network, in order to reproduce the observed non-linear relation between sediment export and rainfall during the first part of the year (illustrated by an initial anti-clockwise loop in the hysteresis cycle). Parameter calibration is performed using average annual sediment export and soil depth in specific compartments of the catchment. The model successfully reproduce the hysteresis pattern but further work is needed on the calibration to obtain consistent magnitudes of sediment export. This new landscape evolution model appears to be a relevant tool to model observed annual morphology changes in badlands and to predict badland evolution in a context of climate change. 


How to cite: Le Bouteiller, C., Ariagno, C., van der Beek, P., Klotz, S., Tucker, G., and Campforts, B.: Modeling seasonal sediment dynamics and landscape evolution in a marly badland catchment, Draix-Bléone Critical Zone Observatory, SE France, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-12585,, 2024.