Author(s): Romain Van Mol; Giovanni De Cesare

Linked Author(s):

Keywords: River transition; Connectivity; Morphology; Stream restauration

Abstract: Restoration of channelized rivers through local river widenings is an increasingly common measure. The widened areas cause sediment deposition, promoting geomorphic heterogeneity and habitats essential for various species. However, transition zones between channelized and widened sections pose challenges due to flow variations leading to scouring and aggradation. Solid stabilizing structures in these zones can hinder fish migration, so alternative solutions such as block cluster ramps are proposed. These ramps, made of dispersed blocks on the riverbed, increase energy dissipation and reduce flow velocity, benefiting fish migration. Yet, they require gentler slopes, resulting in longer structures and potential issues during low flow when the channel may fall dry. A study using a recirculating flume was conducted to simulate these widening transitions, calibrate a numerical model, and conclude on unfavorable configurations for connectivity.

DOI: https://doi.org/10.64697/iahr.proc.ise2026.abs.299

Year: 2026