Adaption of the cost benefit analysis for torrent and avalanche control

The Forest Technical Service for Torrent and Avalanche Control (WLV) applies cost / benefit analysis (CBA) to evaluate the economic efficiency of planned protection concepts. The corresponding directives contrast the occurring construction costs and the prospective damages. In the frame of these investigation so called event – and reduction factors are used, that should enable to consider the intensity and the return period of future events. But concerning the assessment of the intended effects as well as concerning the mentioned factors improvements are desirable that allow a more comprehensible and modern valuation. Therefore an adaptation of the currently applied directives is scheduled into two steps. The first one obtains the examination and evaluation of already finished CBA and the collection of available data and literature for secondary investigations. In a second step occured damages of former events are analysed to prove the validity of the present evaluation process, to gain the mentioned reduction factors and to enable to make suggestions for improvements.