The Working Group for Mountain Watershed Management of the European Forestry Commission, ever since its Tenth Session in Oslo, Norway, in 1972, has elicited a joint effort by its specialists for the preparation of a manual on torrent and avalanche control. Three parts were envisaged: management of torrent watersheds, control of torrents, and control of avalanches. Material provided by specialists, particularly on watershed management, has been included in the first four volumes of the "FAO Conservation Guides" series, but the first two parts of the manual have still to be completed. For the third part, the Group appointed as coordinator Mr. J.P. Graf, Federal Forestry Inspector in Switzerland and one of the most qualified experts in the field of avalanche control. Mr. Graf has edited the text of the manual from the contributions of numerous specialists among whom we should mention: Professor Benini (Padova University, Italy), Mr. de Crecy (CTGREF, France), Dr. Kronfellner-Kraus (Institute of Forestry Research, Austria), Dr. Kravogel (Forestry Service, Austria), Professor Poucet (CTGREF, France), Professor Seyberth (Ministry of the Interior, Bavaria), and numerous specialists whose contributions have been published in "Bundnerwald".
FAO, which provides the Secretariat of the Working Group, wishes to express its deep gratitude in the name of the Group to Federal Inspector Graf for the excellent team work which he so willingly coordinated and for this important technical contribution. The manual will be useful not only in European countries but also elsewhere in developed and developing countries where there are similar conditions and where the same problems have to be confronted. FAO hopes that this new contribution to the series "FAO Conservation Guides" will be widely diffused so that the arsenal of techniques which the expert can use in the management of mountainous regions will be enlarged.
Forest Resources Division
Volume 5 of the FAO Conservation Guides deals with the control of avalanches. Methods for determining the characteristics of the snow cover and for localizing avalanche risk are followed by descriptions of the various techniques for temporary defence, for deviating, braking and containing avalanches, for snow stabilization in the starting zone and for wind deflection. Finally, the manual contains some classic examples, a glossary, a list of symbols used and a bibliography.