Application and reliability of techniques for landslide site investigation, monitoring and early warning – outcomes from a questionnaire study

The presented questionnaire study summarizes an evaluation of approaches, techniques and parameters of slope-instability investigation and monitoring of their occurrence, reliability and the applicability of the monitoring techniques for early warning. The study is based on information collected from 86 monitored landslides in 14 European and Asian countries. Based on the responses, lidar ALS (airborne laser scanners), geophysical logging, aerial photographs, resistivity surveying, GB InSAR (ground-based synthetic aperture radar interferometer) and the refraction seismic were considered the most reliable methods for investigation of structure and character of landslides. Especially lidar ALS and geophysical logging were ranked high despite their application at relatively few landslides. Precipitation amount, pore-water pressure and displacement monitored by wire extensometers, dGPS and total stations, followed by air temperature and EM-emissions monitoring and displacement monitored by the TM 71 crack gauge were considered the most promising parameters for early warning

Slope deformations and pseudocarst

The proceedings presents thematicaly organized presentations from the conference, which deal with landslides and pseudo-carst

Slope deformations and pseudocarst

The proceedings presents thematicaly organized presentations from the conference, which deal with landslides and pseudo-carst

Geomorphological aspects of deep-seated slope deformations in the Vsetín Region

A complex geomorphic research has been carried out at three deep-seated slope failures in the flysch mountain area near Vsetín (E Moravia, Czech Republic). Main landforms, e. g. rotated bedrock blocks, shallow landslides in colluvial material, pressure ridges or pseudokarstic forms were distinguished and mapped

Slope instability hazard evaluation and landslide sites monitoring in the western Flysch Carpathians (Czech Republic)

W lipcu 1997 roku obfite deszcze spowodowały ruchy zboczowe, zwłaszcza utworów fliszowych, w północno-wschodnich Czechach. Kompleksy mezozoiczne i trzeciorzędowe Zachodnich Karpat fliszowych charakteryzują się wysoczyznami i rzeźbą górską, głównie o charakterze erozyjnym i strukturalno-denudacyjnym. Obecnie jest realizowany projekt badawczy, podsumowujący dotychczasowe obserwacje, mający na celu ocenę wpływu morfologii i mechanizmów uruchamiających zjawiska osuwiskowe na obszarach modelowych. Każde lokalne osuwisko, poza oddziaływaniami przyrodniczymi, było także poddane działalności ludzkiej. Do badań wykorzystano kartografię geomorfologiczną, wiercenia rdzeniowe oraz badania geofizyczne. Wiek osuwisk określono na podstawie datowania metodą 14C oraz badaniami palinologicznymi, paleomagnetycznymi i archeologicznymi. W wyniku przeprowadzonych badań ustalono geometrię, mechanizmy oraz możliwy rozwój różnego typu osunięć zboczy. Rejestrację osuwisk prowadzono elektronicznie, duże tereny osuwiskowe dokładnie badano, a wyniki tych badań nanoszono na mapy w skali 1:10 000. Obszary te zostały sklasyfikowane w zależności od stopnia zagrożenia oraz intensywności występowania osuwisk. Mapy prezentujące warunki stabilności terenu stanowią podstawę do tworzenia map zagrożeń osuwiskami. Ocena stabilności terenu, morfologii, warunków geologicznych i hydrogeologicznych pozwala na wyznaczanie quasi-jednorodnych stref o określonym stopniu zagrożenia osuwiskami. Mapy takie wykorzystują władze administracyjne przy tworzeniu planów regionalnych i miejskich

Investigation of recent catastrophic landslides in the flysch belt of Outer Western Carpathians (Czech Republic): progress towards better hazard assessment

Rapid snow melting and intense precipitation triggered and reactivated tens of mostly shallow landslides in the eastern part of the Czech Republic at the turn of March and April 2006. This area is build up by highly fractured flysch rock units with variable content of sandstones and claystones. The landslide complex at Hluboče (Brumov-Bylnice town) is composed of shallow translational (up to 10 m thick) as well as deep-seated (up to 20 m thick) rotational landslides, which generated a catastrophic earthflow at their toe. This earthflow destroyed three buildings, the access road and caused total loss of about 350 000 EUR. Detailed field investigation, review of the archive sources and interviewing of local inhabitants allowed brief description of slope movement history prior the catastrophic event as well as detailed reconstruction of slope failure mechanisms during the main movement activity (3–4 April 2006). This information, along with the detailed description of the passive as well as active causative factors (structural and morphologic settings) can contribute towards better identification of potentially dangerous slope failures in the study region

Airborne geophysical mapping as an innovative methodology for landslide investigation: evaluation of results from the Gschliefgraben landslide, Austria

In September 2009, a complex airborne geophysical survey was performed in the large landslide affected area of the Gschliefgraben valley, Upper Austria, in order to evaluate the applicability of this method for landslide detection and mapping. An evaluation of the results, including different remote-sensing and ground-based methods, proved that airborne geophysics, especially the airborne electromagnetic method, has a high potential for landslide investigation. This is due to its sensitivity to fluid and clay content and porosity, which are parameters showing characteristic values in landslide prone structures. Resistivity distributions in different depth levels as well as depth slices along selected profiles are presented and compared with ground geoelectrical profiles for the test area of Gschliefgraben. <br><br> Further interesting results can be derived from the radiometric survey, whereas the naturally occurring radioisotopes ⁴⁰K and ²³²Th, as well as the man-made nuclide ¹³⁷Cs have been considered. While the content of potassium and thorium in the shallow subsurface layer is expressively related to the lithological composition, the distribution of caesium is mainly determined by mass wasting processes