HIGH-RESOLUTION DEBRIS FLOW VOLUME MAPPING WITH UNMANNED AERIAL SYSTEMS (UAS) AND PHOTOGRAMMETRIC TECHNIQUES

We performed an analysis on semi-automatically mapped shallow landslide scarps and forest cover in the Sellrain valley, Tyrol (Austria), to investigate how the morphology and topographic profiles of landslides are affected by the forest. The results show that landslides located in dense forest cover occurred on steeper slopes and were deeper than others. The results also show that the use of forest stand density parameters, such as tree spacing, enhanced the found differences in the study area.

The manuscript describes airborne, dual-polarised X and Ku band synthetic aperture radar (SAR) data collected over several campaigns over snow-covered terrain in Finland, Austria and Canada. Colocated snow and meteorological observations are also presented. The data are meant for science users interested in investigating X/Ku band radar signatures from natural environments in winter conditions.

We map the distribution of snow depth at two alpine test sites with unmanned aerial system (UAS) data by applying structure-from-motion photogrammetry. In comparison with manual snow depth measurements, we find high accuracies of 7 to 15 cm for the snow depth values. We can prove that photogrammetric measurements on snow-covered terrain are possible. Underlaying vegetation such as bushes and grass leads to an underestimation of snow depth in the range of 10 to 50 cm.