- Avalanche control
Avalanche control or avalanche defense activities aim at the elimination and reduction of hazard and damage resulting from
avalanche s. [http://geosurvey.state.co.us/Default.aspx?tabid=400 "Mitigation and Land Use - Avalanches"] , Colorado Geological Survey]There are two major groups of techniques for avalanche defense: active techniques and passive techniques, sometimes more narrowly defined as "explosive" and "structural", according to the prevalent techniques used.
Active techniques
Active techniques involve the artificial triggering of smaller avalanches which are expected to be less harmful. Small avalanches may be triggered manually by disturbing snow up the possible avalanche path. However the most common method is the use of
explosive s. Explosives may be delivered manually, bybombing , or byshelling . Each method has its drawbacks and advantages.Explosive control has proved to be effective in areas with easy access to avalanche starting areas and where minor avalanches can be tolerated. It is mostly unacceptable, however, in areas with human residence and where even a small probability of a larger avalanche is unacceptable.
Passive techniques
Passive techniques amount to slowing down, stopping, and diverting the moving snow and preventing it from moving, either completely or from moving in big masses. Passive techniques involve building various
structure s and some other approaches.Avalanche dam s,ditch es,earth mound s, terraces, etc. may serve for deflection, retardation, and catchment.Other passive methods include:
*reforestation , up the naturaltree line — forests serve all the functions of artificial avalanche defenses: retention, redistribution, retardation and catchment
*snow compaction — done inski resort areas by mechanical equipment, such assnow groomer s.ee also
*
Landslide mitigation , control of a similar disaster typeReferences
*Jaedicke, Christian; Naaim-Bouvet, Florence; Granig, Matthias (2004) "Wind-tunnel study of snow-drift around avalanche defense structures", "
Annals of Glaciology , vol. 38, p.325-330External links
* [http://www.avalanche.org National Avalanche Center] of the
United States Forest Service
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