Threshold Conditions for the Shift Between Vegetated and Barebed Rivers

Vegetation plays a fundamental role in riverine environments, by affecting both hydrodynamics and morphodynamics. At the same time, flow velocity sediment scouring influence decay of plants uprooting. The balance among such interactions defines whether or not rivers are colonized submerged emergent vegetation. Previous studies focused on shift between vegetated barebed conditions through flume experiments numerical simulations. Herein, we derive analytical formulations for threshold terms Froude number, accounting submergence. Both predict lower thresholds vegetation than plants. characteristics regime variability play major controlling thresholds. comparison proposed relationships to available data shows good agreement. These results have important implications understand bio-morphological changes induced natural human factors, as well design effective river restoration projects.