CLIFF COLLAPSE HAZARD FROM REPEATED MULTICOPTER UAV ACQUISITIONS: RETURN ON EXPERIENCE

Volcanic edifices result from successive construction and dismantling phases. Thus, the geological units forming volcanoes display complex geometries. We show that such geometries can be reconstructed thanks to aerial views, topographic surveys and photogrammetric models. In our case study of the Samperre cliff (Martinique, Lesser Antilles), it allows us to link destabilizations from a rocky cliff to the existence of a filled paleo-valley and estimate a potentially unstable volume.

Coastal erosion is of major concern for society. Our study focused on rocky coasts, where coastal evolution remains poorly understood. We utilized the increasing number of erosion-related data and compiled them to better understand how and to what degree rocky coasts erode. We found that rock resistance primarily explained erosion rates, whilst the influence of the climate and sea was secondary. Weak rock coasts lose a median of 23 meters per century, about ten times more than hard rock coasts.

This article uses summary statistics of spatial point process theory to study the spatio-temporal pattern of a rockfall inventory recorded with repeated terrestrial laser scanning surveys at a chalk coastal cliff site in Normandy, France. This allows testing and quantifying the significance of geomorphological observations. From a spatial distribution perspective, behaviours of small and large scars cannot be considered equivalent, suggesting that erosion processes and triggering factors differ.