Transfer of fine sediments in an alpine gravel bed river

The river scale approach will enable to extend observations from local and bar/reach scales to better understand the long-term dynamics of fine sediments (mechanisms of transfer/deposition/erosion) in alpine gravel bed rivers (Figure 6). Field monitoring and remote sensing data processing will provide a spatial and temporal database of the river and gravel bar characteristics, needed both to comprehensively portray the river morphodynamics and to be used as input and calibration reference in the numerical model. Indeed, through the development and application of 1D modelling, a large part of the work will deal with the initial conditions (roughness, fine stocks) and the boundary conditions (sediment concentration and characteristics) feeding the 1D model, as well as their uncertainties. Uncertainty analysis of the sediment inputs will be performed as the sediment yield from upstream catchments is out of the scope of the present project.

This workpackage is divided into 3 subtasks:

3.1. Evolution of the stock of fine sediments and of the vegetation cover along the river system

3.2. Uncertainty analyses on the fine sediment fluxes

3.3. 1D modelling