Geodetic monitoring methods of landslide-prone regions - application to Rabenov

The article focuses on the geodetic monitoring of the Rabenov landslide territory. The monitored slope is situated in the landscape deteriorated by mining activity in North Bohemia, West of Usti nad Labem, in Chabařovice, a reclaimed brown coal pit. The article presents a general description of the application and accuracy of geodetic methods used to measure on the movement of material in landslides. Also, the history, the problems and the plans for reclamation of the monitored territory are briefly mentioned. The text concentrates on the description of the network of three observed points which are formed by geotechnical instrumentations and on the description of a terrestrial and GNSS measurement in the network of monitored points. The assessment methods and the results from the eight-year phased monitoring process are also discussed. Different methods were tested during the phases. For terrestrial measurements, standard deviations of about 2 mm in position were made and for GNSS standard deviations of about 14 mm. Surveys in a local grid showed that there were continuous movements of observed station points of about 10 mm per year. The paper also discusses the use and assessment of digital terrain models in zones with on-going artificial as well as natural changes. Models indicate elevation changes of about 2-6 m and movement of about 10,000-100,000 m3 of material.51