Snow fence
From Wikipedia, the free encyclopedia
A snow fence is a structure used to force drifting of snow to occur in a predictable place, rather than in a more natural method. Snow fences are primarily employed to minimize the amount of snowdrift on roadways. In rural areas, farmers and ranchers may use temporary snow fences to create large drifts in basins for a ready supply of water in the spring.
Snow fences are also used in avalanche control.
A typical style of temporary snow fence seen in North America today is often one of two varieties: orange plastic attached to stakes at regular intervals or a cedar or other lightweight woodstrip and wire fence, also attached to metal stakes. A permanent snow fence is generally of larger wooden poles set deeply into the ground with large wooden planks running vertically across them. A permanent snow fence is built when a roadway is subject to predictable snow and wind patterns each winter, usually in mountain passes.
The drifting of snow behind a fence follows the laws of physics as the pressure on the downwind side is less than that on the windward side, allowing light materials such as snow or leaves to settle there.
[edit] References
- Campbell, E. (March 1975). Snowdrift Structures. Avalanche Protection in Switzerland (pp. 103-116). Fort Collins CO: General Technical Report RM-9, USDA-Forest Service.
- Mears, A.I. (1992). Avalanche Structural Protection in: Snow - Avalanche Hazard Analysis for Land - Use Planning and Engineering. Denver CO: Colorado Geological Survey, Department of Natural Resources, Bulletin 49.
