Author(s): Thomas Gil; Azin Amini; Giovanni De Cesare

Linked Author(s):

Keywords: Bird island; Tombolo; Sediment transport; Hydrodynamic modelling; Ecological management

Abstract: Since its construction in 2002, the bird island in Préverenges has been recognized as an ornithological hotspot on Lake Geneva, particularly for migratory species. However, the progressive formation of a tombolo connecting the island to the shore has compromised its isolation and ecological function. The present study analyses the site's morphological evolution and evaluates the potential of various engineering solutions to restore its isolation. Wave hydrodynamic modelling was conducted using SWAN software and was supported by sediment analysis and wave climate data. The results indicate that only solutions involving a substantial opening of the rock structure, or the construction of a groyne, could address the issue of sediment transport dynamics around the island. However, none of the tested configurations can ensure the long -term viability of these measures, given the intricacy of the processes involved and the limitations of the simulations. This work emphasizes the need for an integrated management strategy and long-term monitoring to achieve the site's sustainable conservation.

DOI: https://doi.org/10.64697/iahr.proc.ise2026.abs.214

Year: 2026