Slope Comfort Zone??

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gdurkee
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Slope Comfort Zone??

Post by gdurkee »

Campers:

I posted this elsewhere as well, but I think there's more map nerdlings here who might have other suggestions for an approach.

What degree slope are you comfortable traveling on? That is, what slope would you just walk/clamber on without too much thought? At what slope angle do you start getting a little more amped up, but still climb (still 3rd class). And about where does it become 4th/5th class? The last is probably more rock type dependent, but still looking for a slope degree.

What I'm trying to do is create a map layer that reflects terrain that has a high probability of being traveled on over a decade+ time span and slopes that have a lower probability.

This came up in the search for a couple of aircraft that have not been found in about 50 years. I have a semi-coherent theory that in, say, Sequoia Kings, someone has traveled on almost all of the terrain over that time. Certainly almost all easy terrain has been traveled on: flat meadows up to ?? degree slopes. Probably fewer on steeper terrain and then none on almost vertical places. This might be then used to draw high probability areas to search -- the areas that may not have seen much or any use.

I'm thinking of using just 3 slope classes to divide this up.

As a side note, the two aircraft are a T-33 jet that went down in 1957. The canopy was found on Langille/LeConte in 1977 but the aircraft has never been found. The other is a single engine plane that was last known over Merced in the 60s sometime, heading east. That was never found.

The Fawcett plane search is a good example. Even though in remote terrain, it was found within a year by a random hiker.

To me, this could well indicate that neither of the missing aircraft are in Sequoia Kings or at least point to areas where people never go -- are there such areas??

The T-33 is an especially grim story:
Short version:
http://www.aviation-history.com/lockheed/steeves.htm

Longer:
http://www.americanthinker.com/2007/12/ ... humil.html

As a side note, I don't think the plane is at the location described at the end of that article, but it's a very good summary. I plotted the coordinates given and there's roads all over the place there, also signs of running cattle in the area -- hard to believe a cowboy or tourist didn't stumble across it there... .

So, with huge search areas like that, how do you begin to narrow the probable area to search?

Thought & comments welcome!

g.
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oldranger
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Re: Slope Comfort Zone??

Post by oldranger »

George,

Neat idea! I have been puzzled for years trying to figure out where the 3rd P-40 went down near Roaring River in the 40s. One went down just upstream from the station. A second went down with the pilot in a branch of Cuningham Creek. The third has not been found to my knowledge. This is really strange since the area was still being grazed and there were cowboy trails all over the place. As a result I came up with a similar principal to yours the location of the crash is likely a place not accessible on horseback and is not in a location that is likely to be traveled by backpackers. Given the direction the flight was traveling high probability areas are the steep southern slopes of Sentinel Ridge and the e. facing slopes of lower Box Canyon and Ferguson Creek. These slopes are not steep enough to meet your criteria but there are cowboy trails that provide easy travel routes near the bottom of the canyons and there are no compelling destinations that would normally attract back packers on the sides of these ridges. Consequently they are likely to be ignored.

Similarly there are other locations in the park that are unlikely to experience much if any foot traffic yet do not have terrain that requires technical skills. As a result I expect there are several areas that for reasons other than steepness cannot be ruled out as having a high probability of having undiscovered wreckage.

Mike
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gdurkee
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Re: Slope Comfort Zone??

Post by gdurkee »

Mike:

Yes. Actually, I've written an outline which includes not only the terrain driven model (slope) but would add layers to represent cross country routes; popular peaks and approaches and cowboy trails (though for that I was mostly thinking of the areas down towards Kennedy Meadows & Monache -- but RR is obvious too). Vegetation is another one. There's brushy terrain near Ash Mt. that could probably hide an airplane. Bob Meadows thinks a Red Fir forest -- especially on steep terrain -- could hide an airplane. Finally, you can put a buffer around all the trails and routes to represent line-of-sight and, presumably, a cleared search area over time. So all this can be represented on a map and at least give a more narrowed search area.

I think I'll put a huge map out at training this spring and ask the b/c rangers to draw in xc routes and maybe even areas they think don't get any visitation.

Along the same lines, for missing people, it would be good to have a basic "terrain trap" map. Areas that hikers might get lost in because they get sucked into it -- Rock Creek & Roaring River, towards the falls, come to mind. It would just serve to remind incident planning staff that there's areas that might take priority if a lost party is anywhere near it... .

I remember those P-40s. I can't remember if there's any still missing. Two missing military aircraft is a lot... .

g.
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Re: Slope Comfort Zone??

Post by oldranger »

George,

Unless the 3rd P-40 was found in the last 19 years it still hasn't been found. In the mid 90's I was still getting calls on where I thought it was. My theory was near where w. fork ferguson meets ferguson. Saw reflections in that are while going up Moraine ridge trail in the early morning but it could have been water. Not sure 50 year old aluminum would flash that much. Never checked it out.

Mike
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jimqpublic
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Re: Slope Comfort Zone??

Post by jimqpublic »

Brilliant!

I can't help you, but brilliant. You can probably ignore everything that follows.

I haven't played around too much with the USGS DEMs, do they provide better or worse detail than the topo maps? As you guys know, it's the cliffs hiding between contour lines that can catch you. Photogrammetrically compiled contours tell a lot with tiny variations in spacing and other irregularities. Contours "generated" by DTM software often have no soul- unless extensive breaklines are included as part of the data set.

With traditional, manually compiled contours I look for variations in the interval to tell me more of the character. They often give clues to cliff bands.

Mention was made of presuming a corridor around trails would have been traveled many times. Sort of true. In harsh terrain I think people are more likely to stay on the trail. 1000 people walking up a trail will all follow a single route. 10 people walking cross-country from point A to point B will follow 10 different routes.

So there are probably some areas near trails- but in difficult terrain- that are highly unlikely to ever be traveled.

Another issue is whether people would report wreckage. If I were to run across obviously old wreckage I might not put any effort into finding out if it was "missing".
Jim
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BrianF
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Re: Slope Comfort Zone??

Post by BrianF »

I'll throw some numbers out. I don't carry an inclinometer but I have climbed with someone who did. As you indicated the comfort zone is going to be largely affected by terrain and exposure. We have all scrambled up a short steep slope or rock but not many would be willing if it was just above a cliff or if it continued "steep" for 100'. I think that above 45 degrees it becomes extremely terrain dependent -firm rock or snow vs. loose rock or talus or scree. On dicey terrain 45 degrees can be hairy. Above 60 degrees most people would call it technical climbing, depending on holds and exposure it may still be 3rd class but far fewer people would travel there on a limited number of routes.
Back in the day when I did alot ice and snow climbing I was surprised that my friends inclinometer readings seeming far less steep than my eyes and fear level told me. 55 degree ice feels far steeper!
The direction you are moving in is what matters, not the place you happen to be -Colin Fletcher
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gdurkee
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Re: Slope Comfort Zone??

Post by gdurkee »

Jim:

Good points. In random order:

I've thought about the trail corridor buffer. Over time, though, I think 300 feet is not a bad estimate -- maybe even larger, even in difficult terrain. I find garbage everywhere as sign of people being there. Some bugs in this though. It's definitely beta and open to comments! Time becomes an important component, though of unknown effect for the moment.

DEMs are useful (and Eric can jump in here anytime) to give you a 3 dimensional effect (though better with creating what's called "Hillshade" which adds "shadow" and more pronounced valleys and ridges). You then put that under, say, the USGS Quad, make the quad slightly transparent and "voila!" you have a sort of 3D map. You can also calculate contours and other fun stuff (calculate signal distance & paths of cell/radio signals; calculate 30 to 37 deg. for avalanche terrain etc.). Depending on the resolution, you can at least find 30 foot cliffs and estimate others.

Also unknown if people would report wreckage. Small bits -- not sure. But an entire airplane, I think so, which is shown from experience (or, maybe not!).

Another fantasy search strategy for these long-term missing things (people or aircraft) is to set up something like what DARPA did a few months ago. Offer a reward and bring in social networking to track "searchers" and clues. I'd vary it slightly. Small reward and online place to dump GPS tracklogs -- slowly build a database of where people go over several years. Get an exact idea of where people travel and extrapolate through continued time. Narrow search area that way.

Haven't checked (and maybe people here know) but you might then be able to use a drone to search the now smaller segments for a heat signature of an engine or something. This is all testable, though may not work:
A map is not the territory it represents, but if correct, it has a similar structure to the territory, which accounts for its usefulness.

Philosopher and scientist Alfred Korzybski, 1931
Somewhere in the 55 to 60 degrees is where I'm making a break for the moment. Extending marginal terrain to maybe 70??. See what comments are.

Incidentally, there was a study that found people overestimated the degree of slope if they were standing on top of a skateboard at the top of a steep hill vs. on top of a small box (though both overestimated over just standing on the hill well-anchored...).

Thanks,

g.
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Re: Slope Comfort Zone??

Post by BrianF »

George, I have to wonder at your premise that most negotiable terrain has been traveled. You certainly know better than me. I can see that near and above treeline all the way to the peaks that is probably the case and that is the territory I spend my time in and so most familiar with. In the more heavily forested areas (that could hide a plane easily) I would think that the vast majotity of travel is along the corridors -trails and creeks and rivers. I also bet that the degree of slope becomes a deterent at a much lower level in the forest, not so much because it is harder or more dangerous but because unless someone had a clear destination, they would be less likely to wander up a steep hill in the forest than in alpine areas. It becomes a matter of motivation rather than what is possible or scary. I know people do random things and there are ALOT of people, but I would bet there are many areas in deep forests that haven't seen people since the hunter gatherers and shepherds and their fires kept it clear, and of course at this stage you could probably walk 100' from an old plane crash in the forest and not see it.
I Know you are veteran of many searches and know how to prioritize the areas to look. In my local backcountry which is deep chapparal most travel (and objects of searches)is along trails and creeks, then comes ridges and last is the dense chapparal of any slope because people seldom have the desire to try to penetrate it, But we would also check out prominent rock outcrops as they sometimes attract people to do the bushwhack and "shortcuts" between trails and creeks. What I am trying to say is that I bet most people won't put in hard labor to wander randomly in a forest; to get to a lake or a climb or a prominence or a view, yes. But how do you map asthetics? It is a very interesting project and I hope you keep us posted.
Of course, planes crash with little regard to asthetics or priorities, which undoubtedly is why yours haven't come to light (but in my experience car-overs do have an affinity for HUGE patches of Poison Oak).
The direction you are moving in is what matters, not the place you happen to be -Colin Fletcher
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Re: Slope Comfort Zone??

Post by Wandering Daisy »

Check out geologic maps. The USGS has geologic quads. Many geologist do their thesis by mapping a quad. There is a state geologic library in Sacramento. These maps identify talus and moraines - two features that are less traveled. In the same manner, a vegetation map may help. Nasty brush is less traveled. I also find that Google maps are quite good with the combination of their terrain maps and air photos.

I would hesitate to identify difficult travel by slope alone. Above timber, vegetation is a good hint -grassy slope vs. talus. Some of my most difficult travel has been on relatively flat land - bushwhaking through manzanita.

You can separate bare land from grass from trees with LANDSAT photos. I have done this using ERDAS, a rastor GIS satallite image processor. I actually did a masters thesis on classifying hydrlogic units using LANDSAT data and map data. Be aware that when layering data, there are location problems - you get a lot of noise simply because there are several meter, even 100 meter+ errors in each data set's exact location.
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Re: Slope Comfort Zone??

Post by Shawn »

George - what a great idea.



Unless the 3rd P-40 was found in the last 19 years it still hasn't been found.
Back in 2004 I spoke with Don Jordan a couple of times on the phone. He was certain that the long lost P40 was up around the Sphinx crest somwhere.

http://www.donrjordan.com/sierra_p-40s.html" onclick="window.open(this.href);return false;
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