Using UAV and Structure-From-Motion Photogrammetry for the Detection of Boulder Movement by Storms on a Rocky Shore Platform in Laghdira, Northwest Morocco

The detachment and mobilization of boulders from rocky shore platforms by waves involves complex geomorphic hydrodynamic processes. Understanding these processes requires precise information on the rates patterns movement megaclasts scaled against wave conditions that generate boulder mobility. Repeat photogrammetry structure-from-motion (SfM) models commonly used in analyses are an interesting option for monitoring dynamics. In this study, we unmanned aerial vehicle (UAV)-based digital SfM differential to identify recent movements over a platform Laghdira, Morocco. Combining results with data storm occurrence study area allowed us as unique driver dislodged mobilized boulders. identified event had significant height 5.2 m. UAV were built imagery captured September December 2019 using DJI MAVIC PRO PLATINUM, QGIS produce 2D 3D model outputs. exploitation differentials appreciate response determine volumetric changes and, therefore, valuable determining mode transport Mobility included sliding, overturning no further mobility, rotation saltation, well breakup. Storm did not have preferential impact any particular shape, size category, or position at outer edge platform. These highlight utility combining surveys events, which much more frequent than tsunamis, observed initiation