ASSESSMENT OF GEOMORPHIC HAZARDS AND PRIORITIES FOR FOREST MANAGEMENT ON THE RIGI NORTH FACE, SWITZERLAND

The Rigi Mountain is situated about 15 km east of Lucerne, Switzerland. This general area, located on the northern border of the Swiss Alps, receives high annual precipitation totals. Therefore the Gotthard railroad, which carries very heavy traffic, is endangered by rockfalls and mountain torrents. In addition, the forest on the Rigi North Face above the railway line, although zoned as ''protection forest,'' is showing extensive damage believed due to air pollution. Thus, its effectiveness as protection against hazards must be examined. This paper describes very detailed field observations with a high degree of objectivity, that led to maps of the dangerous processes. These included the entire section of the railway track and all possible danger locations. A geographical information system, covering each forest plot and the potential damage, provides a basis for rapid information up-dating. From this, priorities and procedures for developing protective measures can be derived.