Dynamics of evolution of coastal blowout (Vistula Spit, South-Eastern Baltic)

The findings of a 12-year study of dune complex element development on the Vistula Spit of the Baltic Sea are hereby presented. The focal point of this study is an intensively developing blowout basin in the context of anthropogenic impact. The assessment of landform development over time was conducted by determining geomorphologic changes using digital elevation models (DEMs). These DEMs were obtained by means of topographic terrestrial laserscanning (TLS) measurements or aerial triangulation with a ground control point, accompanied by GPS-RTK measurements. The findings indicated that the rate of desertification was contingent on the composition of plant communities and was sustained by pulse sand supply, facilitated by a network of channels. Grassy areas were the most actively assimilated, exhibiting low roughness, while tree and shrub vegetation, in contrast, exerted a force that directed the wind-sand flow, thereby accumulating a thickness in front of it. The activity of the basin was observed at its peak at the point of connection with the beach. A decline in activity was noted as the basin reached a critical width, at which point the Venturi effect ceased to be effective under the prevailing wind climate.