Avalanche net

Avalanche nets (snow avalanche protection nets, snow nets) are flexible snow supporting structures for avalanche control, constructed of steel or nylon cables or straps held by steel poles, optionally supplied with compression anchors downhill. They are installed in the upper parts of potential avalanche paths to prevent snow from starting to slide into an avalanche, or to retard the slide. [ [http://geosurvey.state.co.us/Default.aspx?tabid=400 "Mitigation and Land Use - Avalanches"] , Colorado Geological Survey]

Snow avalanche nets have the following advantages compared to rigid supproting structures (snow fences, snow racks, snow bridges): [ [http://www.mountainmanagement.biz/snow.htm "Avalanche systems"] ]
*considerably lower costs
*better blending into the environment
*easier installation
*rigid structures are more prone to damage in unstable terrains (with earthquakes, landslides, rockfall, [Nets are less damaged by rocks because their flexible structure dissipates the kinetic energy of falling rocks, see [http://www.patentstorm.us/patents/6926471-description.html "Protective barrier, in particular for mountainous places"] , patent description] permafrost soil creep [ [http://www.wsl.ch/forschung/forschungsprojekte/lawinenverbauungen_permafrost/index_EN?redir=1& "Snow-supporting structures in permafrost"] ] ) and in conditions of heavy rainfall and mudflows.

Avalanche nets have some drawbacks:
*More difficult to anchor in loose ground.

ee also

*Avalanche dam
*Avalanche snow bridge

References

* [http://www.bafu.admin.ch/php/modules/shop/files/pdf/phpUiQM8a.pdf Defense structures in avalanche starting zones] , Federal Office for the Environment, Switzerland