Difference between revisions of "Hazard rating definition table"
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|class="Header"|Danger Level | |class="Header"|Danger Level | ||
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|class="Header"|Likelihood of Avalanches | |class="Header"|Likelihood of Avalanches | ||
|class="Header"|Avalanche Size and Distribution | |class="Header"|Avalanche Size and Distribution | ||
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− | |class="Class" style="background-color:#231F20; color:#ffffff;"|5 | + | |class="Class" style="background-color:#231F20; color:#ffffff;"|5 |
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|Natural and human triggered avalanche certain. | |Natural and human triggered avalanche certain. | ||
|Large and very large avalanches in many areas. | |Large and very large avalanches in many areas. | ||
|- | |- | ||
− | |class="Class" style="background-color:#ED1C24;"|4 | + | |class="Class" style="background-color:#ED1C24;"|4 |
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|Natural avalanches likely; human-triggered avalanches very likely. | |Natural avalanches likely; human-triggered avalanches very likely. | ||
|Large avalanches in many areas; or very large avalanches in specific areas. | |Large avalanches in many areas; or very large avalanches in specific areas. | ||
|- | |- | ||
− | |class="Class" style="background-color:#F7941E;"|3 | + | |class="Class" style="background-color:#F7941E;"|3 |
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|Natural avalanche possible; human-triggered avalanches likely | |Natural avalanche possible; human-triggered avalanches likely | ||
|Small avalanches in many areas; or large avalanche in specific areas; or very large avalanches in isolated areas. | |Small avalanches in many areas; or large avalanche in specific areas; or very large avalanches in isolated areas. | ||
|- | |- | ||
− | |class="Class" style="background-color:#FFF200;"|2 | + | |class="Class" style="background-color:#FFF200;"|2 |
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|Natural avalanche unlikely; human-triggered avalanches possible | |Natural avalanche unlikely; human-triggered avalanches possible | ||
|Small avalanches in specific areas; or large avalanches in isolated areas | |Small avalanches in specific areas; or large avalanches in isolated areas | ||
|- | |- | ||
− | |class="Class" style="background-color:#50B848;"|1 | + | |class="Class" style="background-color:#50B848;"|1 |
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|Natural and human-triggered avalanche unlikely. | |Natural and human-triggered avalanche unlikely. | ||
|Small avalanches in isolated areas or extreme terrain. | |Small avalanches in isolated areas or extreme terrain. |
Revision as of 12:29, 25 January 2017
Definition
Avalanche hazard; avalanche danger is the potential for an avalanche(s) to cause damage to something of value. It is a function of the likelihood of triggering and the destructive size of the avalanche(s). It implies the potential to affect people, facilities or things of value, but does not incorporate vulnerability or exposure to avalanches. Avalanche hazard is commonly expressed using relative terms such as high, moderate and low.
North American Public Avalanche Danger Scale
Avalanche danger is determined by the likelihood, size and distribution of avalanches.
Danger Level | Likelihood of Avalanches | Avalanche Size and Distribution |
5 | Natural and human triggered avalanche certain. | Large and very large avalanches in many areas. |
4 | Natural avalanches likely; human-triggered avalanches very likely. | Large avalanches in many areas; or very large avalanches in specific areas. |
3 | Natural avalanche possible; human-triggered avalanches likely | Small avalanches in many areas; or large avalanche in specific areas; or very large avalanches in isolated areas. |
2 | Natural avalanche unlikely; human-triggered avalanches possible | Small avalanches in specific areas; or large avalanches in isolated areas |
1 | Natural and human-triggered avalanche unlikely. | Small avalanches in isolated areas or extreme terrain. |
Source:
Statham, G., Haegeli, P., Birkeland, K. W., Greene, E., Israelson, C., Tremper, B., et al. (2010). The North American public avalanche danger scale. Paper presented at the International Snow Science Workshop, Lake Tahoe, CA.
See also http://www.avalanche.ca/cac/bulletins/danger-scale.