Dry Means Green. Using ULS- & ALS Dem to Determine the Geomorphological Reaction of A Large, Untrained, European River to Summer Drought (the Vistula, Warsaw, Poland)

Using ALS and UAS LiDAR DEM we study the geomorphology of fluvial islands in the channel of braided river which was affected by summer drought. On the basis of DoD (DEM of difference) method we analyse the dynamics of geomorphological processes in two periods: 2019 to 2020 and 2020 to 2022. Bank erosion is analysed on the basis of difference between DTM. Bank erosion reduces the area of riverine islands. The difference of CHM reveals a process of succession of riparian vegetation (mostly willow shrubs - Salix alba) on sandbars. The riparian succession makes these landforms anchored by newly developed shrubs, what induces accretion of sandbars. The sandbars therefore transform into riverine islands.