UAV aerial photogrammetry offers a powerful and cheap methodology to reconstruct the terrain geomorphology. The purpose of this study is the application of a generic Structure-from-Motion workflow to properly elaborate different set of images from multitemporal surveys in order to perform a surface and volume change detection by meaning of a cloud-to-cloud comparison. The complex geomorphology of the site of interest, characterized by niches, asperities, flat rock walls with different orientation, debris deposits and isolated rock blocks, challenges the accurate reprojection of the points into a 3D space. The chronological comparison of the point cloud offers a qualitative and quantitative estimation of distances and volume change between sequential models.