[H-TT14] HIGH-DEFINITION TOPOGRAPHIC SURFACE DATA FOR CONNECTIVITY IN THE ANTHROPOCENE

[HTT14-P08] High-Resolution UAV Photogrammetry and Laser-Scanning Combined with Ground Penetrating Radar to assess the complex interaction of the Tottori Sand-dune and the Vegetation

*Christopher A Gomez¹, Jiaqi Liu², Jing Wu² (1.Kobe University Faculty of Maritime Sciences Volcanic Risk at Sea Research Group, 2.Tottori University, Dry Land Research Centre, Japan)

Keywords:coast, sand dune, Tottori, Ground Penetrating Radar, High-Resolution Topography

The coastal sand dune of Tottori has been the object of sand-control management early in the 20th Century, which has remained in different forms until now. Seasonal sand-blowout covers existing vegetation while limiting re-transportation at the same time. However aerial mapping of the vegetation and understanding its temporal dynamic is hampered by this very same process.
In order to quantify the amount of vegetation buried by the sand transport, the authors have combined a high-resolution topographic survey with Ground Penetrating Radar (GPR) -based subsurface data acquisition and analysis. The drone data was calibrated using ground targets recorded using an RTK-GNSS, while the GPR data was acquired using a Mala Pro-Ex mounted with an 800 MHz antenna, which can resolve signal structure at the centimeter scale in a sandy environment.
The results have shown that vegetation mapping from aerial data was grossly underestimated as 20 m to 30 m wide strips of sand were hiding vegetation a few centimeters underneath the surface, in turn modifying the sand transport on the dune. For conservation purposes, regular assessment of the subsurface is thus essential, if the mobile part of the sand dune is to be preserved.