CALIBRATING VEGETATIVE REGENERATION WITHIN A LANDSLIDE DENUDED ZONE USING CONSUMER GRADE DRONE PHOTOGRAMMETRY TECHNIQUES

Washington State is one of the nation’s foremost landslide zones. Regions dominated by glacial sediments are especially at risk as evidenced by the 2014 Oso slide at Steelhead Haven. In many instances, communities within hazard zones are frequently not aware of the risks associated with potential mass wasting events. LiDAR data can be cost prohibitive for hazard monitoring at short timescales. Consumer-grade small unmanned aerial systems (sUAS) present a viable alternative for risk assessment and hazard monitoring. Available for a fraction of the cost of LiDAR sensors, the combination of sUAS based imagery and Structure-from-Motion photogrammetry is much more practical for budget minded townships and agencies. Imagery from sUAS provides high spatial and temporal resolution datasets that are ideal for assessing surface changes and vegetative re-growth in slide areas. Most published studies focusing on vegetative regeneration after slides are set in tropical regions. We aim to extend this approach to the Pacific Northwest. We mapped a new landslide deposit (<1 y.o.) within the Carbon River Valley near Orting, WA to establish a baseline for surface morphology and vegetation presence immediately following a mass- wasting event. After determining these baseline measurements, future work will quantify surface morphology changes and vegetative re-growth to help develop a calibrated landslide evolution model for the Western Cascades region, based on cost-effective sUAS data.