Rockfall, forest and humain interactions in the European Alps

How much is a tree or a forest worth? There are many answers, depending on whom you ask. One of the valuable services a forest in the Alps provides is protection against natural hazards such as rockfall. Adequate management of a mountain forest that protects downslope areas against impacts of rockfall requires insight into the dynamics of the environment of the hillslope as a whole. Therefore, a combined approach, using field and modelling techniques, was applied to assess the determining factors for rockfall source areas, rockfall tracks and rockfall runout zones. The first question of this study was why rockfall occurs in the first place in the investigated area. The second question was if the knowledge obtained in the field could be translated into a model that simulates rockfall dynamics on a forested slope realistically and satisfactorily (i.e. with sufficient predictive power). The third question was how hillslope characteristics, forest stands and rockfall are interacting and what the role of humans herein is. This paper will answer these three questions. By doing so, it shows that a combined field and modelling research as applied in this study helps to understand the dynamics of rockfall in a protection forest and helps to gain knowledge for managing these forests.