The influence of Holocene climatic changes on landslide occurrence in Europe

The paper deals at first with the problems and the sources of uncertainty to be considered while setting up an outline of the temporal occurrence of landslides with respect to climate changes. Actually, while the reconstruction of climate fluctuations is by now largely assessed, only a relatively small number of landslides has been dated and only in few cases statistical correlations between climatic changes and landslide oc-currence have been proposed. Nevertheless, the data so far achieved show periods of increasing landslide fre-quency since the retreat of the LGM glaciers which might be reasonably referred to climate changes. The paper then focuses on problems in detecting triggering factors of past landslides and on the limitations given by different persistence of landforms in landscape related to the magnitude/frequency of these events. Moreo-ver, difficulties linked to the dating techniques adopted (including sampling, calibration and correlation of re-sults) are shown. From this point of view, an in-depth knowledge of the principles and limitations of each technique applied and of the geomorphological context in which the instability occurred are of basical im-portance in order to obtain reliable chronostratigraphic data. However, even when all of these items are taken into account, it is still difficult to assess a straightforward relationship between climate changes and landslide occurrence. This is mainly caused by the natural variability of climate in space and time and by the different responses to climatic changes given by the slopes (“slope sensitivity”). Finally, the state of the art on the rela-tionship between landslides and climatic changes in Europe during the Holocene, with particular reference to the most relevant papers dealing with this topic, is described.