Author(s): Giulio Calvani; Paolo Perona

Linked Author(s): Paolo PERONA

Keywords: Riparian vegetation; Stochastic process; Plant uprooting; Renewal process

Abstract: Riparian vegetation exerts fundamental ecological functions within fluvial corridors, acting as a river engineer by promoting soil and bank stability and by enhancing biodiversity. However, during high-flow events, riparian plants are subjected to mechanical stress due to the combined action of flow drag and scouring processes, eventually leading to plant uprooting. This removal mechanism, namely Type II uprooting, results from the gradual weakening of the root anchoring resistance before uprooting takes place. Several models have been proposed in the literature, both from deterministic and stochastic approaches. In this work, we investigate the dynamics of riparian vegetation with particular focus on the occurrence of stochastic erosion events, using a continuous-time stochastic modeling framework for the river regime. Accordingly, the magnitude of scouring events above a specific threshold is calculated based on the theory of the mean hydrograph shape previously developed by the authors. By accounting for the combination of scouring (occurring during flood events and reducing the root anchoring depth) and low-flow periods when plants can recover their root apparatus, we determine the expected average lifetime of vegetation. Specific attention will be given to the dimensionless ratio between the species-dependent root growth rate and the average magnitude and occurrence of scouring events (flow regime), which we expect to provide information on the resilience of riparian plants.

DOI: https://doi.org/10.64697/iahr.proc.ise2026.abs.325

Year: 2026