Measuring Complex Beach-Dune Morphology and Nearshore Process using UAVs
We examined various applications of widely available and low-cost Unoccupied Aerial Vehicles (UAVs) in measuring beach morphodynamics and hydrodynamics. With adequate ground control points, UAVs demonstrate promising potential for capturing highly 3-dimensional beach/dune morphology with cm-scale accuracy and mm-scale resolution. Model accuracy and resolution are also controlled by flight altitude, with lower altitude yielding higher accuracy and resolution but at the expense of less spatial coverage. The time-series of UAV images and DEMs provide a valuable tool to document morphology changes of irregularly shaped coastal features, vegetation coverage and spatial distribution of sediment sizes. The efficiency of UAV data collection allows regional scale pre- and post-storm surveys to quantify storm-induced beach/dune changes. The overhead videos from the reasonably stable platform allow measurements of dynamic surf-zone parameters including incident breaking and non-breaking wave angles, limits of uprush and downrush, swash velocities and longshore current velocity. UAVs prove to be a promising addition to the traditional methods for measuring beach morphodynamics and hydrodynamics.