Landslide mapping and volume estimation using UAV-based point clouds, GIS and geophysical techniques

Mass movements and therefore rockfalls are common natural hazards that require the development of new methodologies and techniques for an effective research, which could help governments, communities or policy makers in the adoption of the most appropriate practices. In that context different remote sensing data have been used and several methodologies have been tested. In the present study, we initially map a rockfall occurred on the settlement Myloi, which is located near the village of Andritsaina in Western Greece, while later we estimated the volume of rock fragments. The data sets consist of repeated GNSS measurements, laser scanning surveys and UAV campaigns over the study area. The precise mapping of the rockfall was carried out through the processing of GNSS measurements. However, mapping was also performed using orthophotos derived from UAV data and 3D images of laser scanning campaigns. Regarding the volume estimation, three methodologies were applied -two of them were photogrammetric and one was geophysical- using ArcGIS, Cloud Compare and Oasis Montaj from Geosoft respectively. The selection of different types of data and processing methodologies took place within the framework of the comparison of their results in terms of accuracy as well as the achievement of their synergy in the direction of a more detailed research.