Mixed sand-gravel beaches act as an efficient natural sea defence and are increasingly managed by beach recharge, which can alter the sediment size composition of such beaches and their profile response. This creates an urgent need for better information about the behaviour of mixed sand and gravel beaches after recharge. UAS promise to be a promising novel tool in this context. To test their suitability for routine surveying, we aligned an experimental UAS survey along the standard monitoring schedule that was in operation for a mixed beach in East Sussex, UK. High wind speeds at the time of deployment significantly affected the data collection, but it was possible to generate (i) a surface model using Structure-from-Motion-based photogrammetry and (ii) an image mosaic that clearly identifies the spatial patterns of the sand-gravel mix of the beach. This indicates that UAS offer substantial potential for beach monitoring. However, an unclear legal framework acts and the sensitivity of platforms to high winds sets clear limits for UAS to serve as a stand-alone monitoring tool for beach environments at the present time.
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