| Volumes and Issues Contents of Issue 1 |
www.nat-hazards-earth-syst-sci.net/9/197/2009/
doi:10.5194/nhess-9-197-2009
© Author(s) 2009. This work is distributed
under the Creative Commons Attribution 3.0 License.
Hazard index maps for woody material recruitment and transport in alpine catchments
1Department of Hydraulic Engineering, Autonomous Province of Bolzano/Bozen South Tyrol, Bolzano, Italy
2Institute of Mountain Risk Engineering, University of Natural Resources and Applied Life Sciences, Vienna, Austria
3Abenis AG, Chur, Switzerland
4Abenis Alpinexpert srl, Bolzano, Italy
Abstract. A robust and reliable risk assessment procedure for hydrologic hazards deserves particular attention to the role of transported woody material during flash floods or debris flows. At present, woody material transport phenomena are not systematically considered within the procedures for the elaboration of hazard maps. The consequence is a risk of losing prediction accuracy and of underestimating hazard impacts. Transported woody material frequently interferes with the sediment regulation capacity of open check dams and moreover, when obstruction phenomena at critical cross-sections of the stream occur, inundations can be triggered. The paper presents a procedure for the determination of the relative propensity of mountain streams to the entrainment and delivery of recruited woody material on the basis of empirical indicators. The procedure provided the basis for the elaboration of a hazard index map for all torrent catchments of the Autonomous Province of Bolzano/Bozen. The plausibility of the results has been thoroughly checked by a backward oriented analysis on natural hazard events, documented since 1998 at the Department of Hydraulic Engineering of the aforementioned Alpine Province. The procedure provides hints for the consideration of the effects, induced by woody material transport, during the elaboration of hazard zone maps.
Full Article (PDF, 4272 KB)
Citation: Mazzorana, B., Zischg, A., Largiader, A., and Hübl, J.: Hazard index maps for woody material recruitment and transport in alpine catchments, Nat. Hazards Earth Syst. Sci., 9, 197-209, doi:10.5194/nhess-9-197-2009, 2009. Bibtex EndNote Reference Manager XML
