Das neue NaiS-Anforderungsprofil Steinschlag

Abstract

The new NaiS target profile for rockfall Due to new findings on the protective function of forests against rockfall, the Federal Office for the Environment started in 2008 with a revision of the Swiss target profiles for rockfall protection forests. Until now, fall velocity of rocks, rock mass, as well as the forested slope length, were not considered for the determination of the target profile. In order to incorporate all of these important factors, an Internet-based form has been developed which calculates the target profile. This article firstly gives a short overview of the most important aspects of rockfall in protection forests and secondly presents the approach used for the calculation of the new target profile. Although the German word “Steinschlag” only refers to small rock particles, forests also have a protective effect against large blocks (e.g. >5 m3), however, a long forested transit zone with a sufficient number of trees with larger stem diameters is required for a relevant energy and risk reduction. The new target profile offers possibilities to account for such situations as well.