Detection and spatial prediction of rockfalls by means of terrestrial laser scanner monitoring

A rock face affected by small rockfalls has been monitored using a ground-based remote sensing apparatus: Terrestrial Laser Scanner (TLS). The pilot study area corresponds to the main scarp of the 1881 Puigcercَs landslide (Pallars Jussà, Catalonia, Spain). Four datasets of the slope were acquired from September 2007 to July 2008 in an ongoing project. The geomorphological evolution of the rock face in terms of volume and frequency of rockfall was studied by the comparison of sequential datasets. In addition to the detection of past events, this study deals with the spatial prediction of rockfalls through the detection of pre-failure deformation as a precursory indicator. The high resolution and accuracy and the maximum range of the TLS offer interesting prospects for both spatial location and prediction of rockfall.