Meteorological triggers of landslide activity and hazard analysed from tree rings (Central Sudetes, Southern Poland)

Abstract

The aim of this study is to check which type of precipitation control the activity of Garbatka landslide (southern Poland, Central Sudeten Mts) from a decadal perspective. In order to achieve aforesaid goal dendrochronological methods of reconstructing landslide activity have been applied. The study has revealed dendrochronology to be an efficient method for determining triggering factors of landslide activity as the method provides long data sets on past landslide activity which are suitable for statistical analyses and comparisons with precipitation record. In case of the Garbatka landslide the oldest dated landslide activity event is 1942. Dendrochronological record has been compared with precipitation record from the nearest gauging station which is available since 1951. Correlation of data on landslide activity and precipitation data has shown that the landslide under study is sensitive to high short-term precipitation totals (up to 5-days) and to extremely long-term precipitation totals (60-days and 90-days). The main factor driving the activity of the landslide under study is total annual precipitation which is characterized by the highest level of correlation coefficient. However, the nature of the relation between precipitation and landsliding is complex.