Application of Terrestrial Laser Scanner to the Assessment of the Evolution of Diachronic Landslides

During the diachronic evolution of landslides, slope-morphology changes may be detected and assessed by using high-resolution digital models. Slope deformation is detected by scanning sequences over a given time period. This paper presents the results found combining TLS digital models and Global Navigation Satellite Systems in the detection and assessment of reactivations and differential displacements of two slides located at the SW of Sierra Nevada (Spain) between 2008 and 2010. In the first landslide a maximum downward movement of 1.2 m at the top was measured, whereas below the middle part of the mass, 1.3 m of maximum advance was established with a maximum displacement gradient of 1.04 m/year. In the second landslide, downward displacements with gradients between 0.32 m and 0.56 m/year were found, corresponding to rupture movements in incipient to initial stages of evolution. The combined use of TLS and GNSS enabled a quantification and mapping of complementary terrain features which are considered useful in forecasting further activity and slope evolution of these landslides. The high resolution and accuracy of the techniques applied offer broad possibilities in the spatial location of the slope movement and also in forecasting its diachronic activity.