Analysis of Post-flood Recruitment Patterns in Braided-Channel Rivers at Multiple Scales Based on an Image Series Collected by Unmanned Aerial Vehicles, Ultra-light Aerial Vehicles, and Satellites

This paper uses imagery captured by ultra-light and unmanned aerial vehicles (ULAVs) in combination with satellite remote sensing to explore vegetation development on braided reaches in the Southern and Eastern French Alps. Findings demonstrate that while asexual reproduction processes dominate, sexual reproduction through seed dissemination and wind transport play a significant role during periods of low flow following large floods. This progressive vegetation establishment leads to a general trend of river corridor narrowing. Key climatic conditions lead some years to be critical to initial vegetation development. Sensitivity to encroachment depends on local controls, such as rainfall conditions, distance to water table, local topography, seed availability, summer temperature, and dryness.