Kinematic behaviour of a large earthflow defined by surface displacement monitoring, DEM differencing, and ERT imaging

摘要

Large earthflow-type landslides are destructive mass movement phenomena with highly unpredictable behaviour. Knowledge of earthflow kinematics is essential for understanding the mechanisms that control its movements. The present paper characterises the kinematic behaviour of a large earthflow near the village of tubietova in Central Slovakia over a period of 35 years following its most recent reactivation in 1977. For this purpose, multi-temporal spatial data acquired by point-based in-situ monitoring and optical remote sensing methods have been used. Quantitative data analyses including strain modelling and DEM differencing techniques have enabled us to: (ⅰ) calculate the annual landslide movement rates; (ⅱ) detect the trend of surface displacements; (ⅲ) characterise spatial variability of movement rates; (ⅳ) measure changes in the surface topography on a decadal scale; and (ⅴ) define areas with distinct kinematic behaviour. The results also integrate the qualitative characteristics of surface topography, in particular the distribution of surface structures as defined by a high-resolution DEM, and the landslide subsurface structure, as revealed by 2D resistivity imaging. Then, the ground surface kinematics of the landslide is evaluated with respect to the specific conditions encountered in the study area including slope morphology, landslide subsurface structure, and local geological and hydrometeoro-logical conditions. Finally, the broader implications of the presented research are discussed with particular focus on the role that strain-related structures play in landslide kinematic behaviour.