Abstrakt
Snow avalanches occur not only in alpine areas but also in mid-mountains such as the High Sudetes (Czech Republic / Poland). They represent important feature with implications in ecology, forestry, geomorphology and natural risk prevention.
The information about avalanche activity (i. e. magnitude and frequency) is necessary to understand the above mentioned consequences. The presented poster deals with dating of avalanche events using dendrochronological methods in 12 avalanche paths located in both western (i.e. the Krkonoše Mts.) and eastern (i.e. the Hrubý Jeseník Mts.
And the Králický Sněžník Mts.) parts of the High Sudetes Mts. Total of 501 trees (Picea abies (L.) Karst.) located within the avalanche paths and on their borders were sampled and analysed by standard field and laboratory methods.
Following markers of disturbances were taken into account: dead wood, scars, traumatic resin ducts, abrupt growth changes, eccentricity and reaction wood. In the western part the results of dendrochronological approach were validated by the avalanche catalogue gathering information about observed avalanche events since the second half of the 20th century.
Moreover, meteorological data and evidence about avalanche events in different paths were used for the validation in the Eastern High Sudetes because of absence of avalanche catalogue in this area. The occurrence and frequency of avalanches in the Eastern High Sudetes is lower than in the western part of the High Sudetes and and there is high variability in avalanche frequency among avalanche paths.
The results show good ability of dendrochronological methods to reconstruct strong avalanche events because 55 % of such observed events were correctly dated. This indicates suitability of dendrochronological approach for use in areas for which information about avalanche activity is lacking.