Landslide Monitoring Based On Geodetically Derived Distance Changes

Abstract

Analysis of an exceptionally long and homogeneous geodetic monitoring record of a deep-seated, slow (15cm/year) moving landslide indicates that changes in the distance between a survey point lying on stable ground and several control points lying on slipping ground have effectively and accurately detected and recorded dislocations of the control points exceeding the value of a few millimeters; a result confirmed by independent, submillimeter-accuracy spirit leveling data. Landslide monitoring based on radial length changes permits estimation of the velocity and of the acceleration of the landslide movement, and is free of various disadvantages characterizing other geodetic techniques (delayed results, high cost, need for accessibility of control points, etc.). This method can therefore be used to provide near-real time, efficient, low cost, and reliable monitoring for many landslides and other deforming bodies at a few millimeter accuracy. It may also be combined with modern telemetric or robotic survey systems to provide real-time and automated deformation monitoring.