Are there any recent data that separately shows frequency of skier/boarder accidental triggering by...
-slope angle
-slope aspect
...where that data has been normalized for slope use in each instance?
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Are there any recent data that separately shows frequency of skier/boarder accidental triggering by...
-slope angle
-slope aspect
...where that data has been normalized for slope use in each instance?
According to The Avalanche Handbook, citing work by McClung/Grimsdottir, aspect by itself is a poor predictor when slope use it taken into account. This isn't relevant to your question, but their data set and analysis may be relevant. You'll want to start here:Quote:
Originally Posted by Hohes
http://www.geog.ubc.ca/avalanche/pub...ing_NatHaz.pdf
Thanks CookieMonster for the link. That looks like some reading.
At your prompt, looking now at my copy of The Avalanche Handbook, 3rd edition, page 224, figure 8.6. There is a chart that uses normalized data for likelihood of triggering by aspect, and references the paper you linked to. I think that is what I am after.
Regarding slope steepness and normalized data I found this at Wikipedia:
It gives the following source: Pascal Hageli, http://www.avisualanche.ca/publications.htmlQuote:
But when the incidence of human triggered avalanches are normalized by the rates of recreational use hazard increases uniformly with slope angle, and no significant difference in hazard for a given exposure direction can be found.
I am slowly scanning his papers for the relevant research.
Happy to help! The link at avisualanche contains lots of good material, although I can't remember which of his work contains the info you need. Try his thesis?
Sent from my Paranoid Android using TGR forums.
Read it - interesting.Quote:
Originally Posted by Hohes
Lucky that CMH built that valuable database over the years. Unrealistic and hypothetical: it would be nice to investigate trigger probability by slope aspect where the only difference between aspects was solar radiation. No ski-quality slope-use bias, no wind loading bias etc. I don't know why I am thinking about this, just as a trivial summer hobby I guess - prompted possibly by recent exhortations that "the north sector is more dangerous because that is where most avalanches happen" during a rather casual presentation I saw on contemporary European reduction methods ["Munter (2003) recognises that the lack of usage data is a serious problem for his risk analysis" - I wish I had known that during the presentation!] I do not personally need the data to satisfy myself as my experience and intuition tells me the answer - and the answer changes with time-since-storm and time-of-day and time-of-season. I am glad that the CAC Slope Evaluation Card left slope aspect off the Terrain Character checklist.
I kind of gave up. Few external links lead to actual papers, just the website of the journal that published them. Searching that website was fruitless.Quote:
Originally Posted by CookieMonster
You want his thesis: http://www.avisualanche.ca/downloads...EbookColor.pdf ( It's a big read, but worth it if you're feeling patient. )Quote:
Originally Posted by Hohes
Laura Adams' MSc thesis is astoundingly brilliant - if you haven't read it. I'd go as far as saying that -overall- it's the best thing I've ever read on the subject, and I learned a lot from the references too.
http://www.fsavalanche.com/NAC/techP...eses/adams.pdf