In the riverbed

In the riverbed

How is sediment transported in the Sélune? How is the morphology of the river changing?

The riverbed is not set in stone; it evolves according to a complex dynamic. The banks are eroded and then stabilised by the action of the water and the vegetation that covers them. Particles are carried downstream and deposited depending on the slope and the strength of the current, creating a variety of aquatic habitats. This ongoing dynamic is being monitored to understand what tomorrow's river will look like.

Various methods are used to achieve this, including:

  • Sediment traps set up along the river to observe changes in sand size before and after the removal of the dams.
  • Marking pebbles with Pit tags (active transponders) to track their movement in the watercourse. This monitoring is carried out using a mobile antenna that is moved manually along the river and detects the precise location of the marked pebbles.
Pebbles fitted with pit-tags, tracking pebbles with an antenna in the watercourse, recovery of a sediment trap (Photos: P.Vrchovsky and F.Meric)

Modification date : 08 August 2023 | Publication date : 31 July 2023 | Redactor : Selune Team