Statistische Untersuchungen von Rutschungen im Nordbayerischen Deckgebirge

Summary

The North-Bavarian cover rock area is a cuesta landscape in the south of Germany consisting of land-, clay- and limestones of mesozoic age (fig. 1 and 2). Every year it is haunted by a great number of land slides.The claystones of the Triassic and the Jurassic are of a special significance in relation to these slides (table 1). The Statistical evaluation of the landslides which were recorded during the past 30 years indicates that most of the slides are exposed to the south or east (fig. 3). This is partly the consequence of an eastward oriented inclination of the layers, but also of the intensive exposure to sunlight which results in a faster weathering of the layers in the ground. Most of the slides were found at the margin of the Frankenalb (fig. 2) or in regions with higher frequency of tectonical faults. The slides are restricted to only a few stratigraphic units. It is noticeable that the majority of the landslides is bound to reactivated sliding planes which were created during the Pleistocene. Neglecting the cohesion, a comparison of characteristics from back-calculations and laboratory tests on slip-surface-material (table 2) indicates a rather good agreement. The examination of climatic and human influences indicated among others, that many slides were found at slopes where man had changed the morphology or the Vegetation for example by the construction of roads or by the clearing of forests.