Flysch and landslides in Switzerland

The flysch sequences are widespread in the Swiss Prealps, The term ''flysch'' was used in the past by the swiss-german people to describe rocks susceptible to sliding. In the framework of the swiss national programme of scientific research, PNR 31, a project called ''Flysch and landslides'' was developped to analyze the behaviour of slopes in flysch terranes in response to past, present and future climatic changes. Sedimentological studies and extensive mapping have provided a very good knowledge of these flysch series and their structural settings, For the detection of landslide-prone areas in flysch terranes, several investigation methods were applied such as geophysical soundings (seismic high resolution, VLF-EM), geodetic measurements, borehole inclinometers, hazard mapping techniques, dendrochronology! C-14 datation and geographical information systems. Based on case studies, the types of movement, the state of activity and the landslide geometry in different flysch terranes can be used now to improve the regional planning in landslide-prone areas.