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Pedaling Fool
09-01-2010, 15:53
Iíve noticed that when people sometimes talk about elevation gain during a hike what theyíre really talking about is elevation gain/loss. Maybe Iím misunderstanding it, but arenít these two completely different things.

An example:
If one walk 5 miles starting from sea level (SL) and itís broken down as such:

Mile 1 Ė Elevation 0 ft Ė 500ft Ė----- A gain of 500 ft (500ft above SL)
Mile 2 Ė Elevation 500 ft Ė 250ft ------ A loss of 250 ft (250ft above SL)
Mile 3 Ė Elevation 250 ft Ė 325 ft ----- A gain of 75 ft (325 ft above SL)
Mile 4 Ė Elevation 325 ft Ė 300 ft ----- A loss of 25 ft (300 ft above SL)
Mile 5 Ė Elevation 300 ft Ė 500 ft ----- A gain of 200 ft (500 ft above SL)

Now in the above schedule one would have a net gain of 500 feet after 5 miles of hiking, but he would have an elevation gain of 775 ft, with a total elevation gain/loss of 1,000 feet.

So in the above scenario you can not say you had a total elevation gain of 1,000 feet. Iíve heard people say that the total elevation gain on a thru-hike is over 91 miles, but itís not thatís the total elevation gain/loss.

I donít believe (some one correct me if Iím wrong) that no one has published how much elevation gain is done on a thru-hike, not to mention elevation gain broken down by section.

BTW, I know of Map Manís article on elevation gain / loss http://www.whiteblaze.net/forum/showthread.php?t=31293, but I've never seen anything on just elevation gain.

couscous
09-01-2010, 17:50
If someone tried to compute this, it seems the answer would vary dramatically based on the number of data points.
Using your example...
If the data points were every five miles the elevation gain is 500', 0' at start, 500' at end.
If the data points were every mile, the elevation gain is 775'.. total of the 3 climbs.
If the data points were every 1/2 mile, the elevation gain might be 1,000' as more climbs within each mile section are identified.
With 21791 data points (every 1/10 mile), you would still miss many of the climbs whenever elevation gain & loss occurred inside the 1/10 mile sections.

Many Walks
09-01-2010, 18:28
I believe some time ago AT Journeys included an interesting little note that the cumulative total elevation gain on the AT is like climbing Mt. Everest 16 times. Not sure what data they used, but it was a fun piece of trivia.

couscous
09-01-2010, 19:13
I'll start with this and see it's what you're looking for:
Elevation gains by section...
Springer Mtn - Hightower Gap - 1572
Hightower Gap - Woody Gap (GA 60) - 3605
Woody Gap (GA 60) - Neels Gap (US 19/129) - 3362
Neels Gap (US 19/129) - Tesnatee Gap (GA 348) - 1900

kayak karl
09-01-2010, 19:27
whats the vertical exaggerations of the map your using?

Reid
09-01-2010, 19:30
Nothing is truly flat out there either. When I lived at the beach I was running 8 miles a day 3 days a week but when I moved back to the mountains area (thank God!) It was hard just to crank out 4 miles. There's places in the piedmont area that I think is a harder terrain to negotiate than the mountains are.

couscous
09-01-2010, 19:44
whats the vertical exaggerations of the map your using?

Maptech - Terrain Navigator - Appalachian Trail Data Set (Got it in 2003)
Orientation is north-to-south, switched out climbing & descending for NOBO
http://www.twchikers.com/mta/neelsgap.jpg

LIhikers
09-01-2010, 20:48
It might make things a little more clear if we talked about elevation gain and altitude change as two seperat things, but I wouldn't hold my breath waiting for that to happen.

Pedaling Fool
09-02-2010, 07:42
I believe some time ago AT Journeys included an interesting little note that the cumulative total elevation gain on the AT is like climbing Mt. Everest 16 times. Not sure what data they used, but it was a fun piece of trivia.
Yes, but that includes elevation gain and loss during a thruhike.

Pedaling Fool
09-02-2010, 07:47
If someone tried to compute this, it seems the answer would vary dramatically based on the number of data points.
Using your example...
If the data points were every five miles the elevation gain is 500', 0' at start, 500' at end.
If the data points were every mile, the elevation gain is 775'.. total of the 3 climbs.
If the data points were every 1/2 mile, the elevation gain might be 1,000' as more climbs within each mile section are identified.
With 21791 data points (every 1/10 mile), you would still miss many of the climbs whenever elevation gain & loss occurred inside the 1/10 mile sections.
I understand, I was just using a simple example to see if I'm understanding this whole elevation gain/loss thing.

Pedaling Fool
09-02-2010, 07:50
It might make things a little more clear if we talked about elevation gain and altitude change as two seperat things, but I wouldn't hold my breath waiting for that to happen.
Standard terminology would help. When I said net elevation gain of 500 feet, I really meant altitude change from the start to finish.

sbhikes
09-02-2010, 09:22
What I never understood was if a trail on a map is actually rising in elevation on the earth isn't the distance measured on the map incorrect? Isn't the map losing some of the distance because the trail is actually the hypotenuse of a triangle?

garlic08
09-02-2010, 09:58
What I never understood was if a trail on a map is actually rising in elevation on the earth isn't the distance measured on the map incorrect? Isn't the map losing some of the distance because the trail is actually the hypotenuse of a triangle?

Yes, there is a tiny loss. A map is a horizontal projection of a three dimensional curve on a flat sheet of paper. I hiked the PCT with another engineer, and we tried to estimate that loss, and came up with a SWAG (silly, wild-assed guess) of probably less than 20 miles.

Here's a comparison of the climbing on three long trails in the US: http://www.nationalgeographic.com/adventure/0406/excerpt2.html

mister krabs
09-02-2010, 10:14
I view elevation gain as distinct and separate from elevation change. Gain is how much I had to go up, change is that minus how much I had to go down.

10-K
09-02-2010, 10:27
How does this related to vertical exaggeration on an elevation profile - I thought this addressed the changes in distance?

When you look at an elevation profile, flat terrain is a horizontal line between a known distance. Elevation gain and loss is represented by a line that isn't horizontal and therefore longer than a line representing flat terrain.

This is pretty interesting....

Pedaling Fool
09-02-2010, 10:48
Sbhikes,
Like garlic said the difference isn't that much, you can play with it on paper and see how little of a difference it is. The elevation profiles on maps (like illustrated in the map on Post #7) is not a true representation. It's something the map makers have to do to make it fit, it's call Vertical Exaggeration, so the scale of the profile is different from the scale of the map it's printed on.

4eyedbuzzard
09-02-2010, 10:52
Trail miles on the maps and guides are either wheel measured or an interpretation / estimate representing wheeled miles from a map. They aren't "as the crow flies miles". Elevation exaggeration is typically 7 to 1 (it can vary but maps should indicate this exaggeration in the legend) as this has been found to represent how the average person "experiences" the physical difficulties of slopes. Also see this old link.

http://www.whiteblaze.net/forum/archive/index.php/t-12539.html

Spogatz
09-02-2010, 10:53
No one told me there would be math....

I hike to get away from math....

Now my head hurts....

4eyedbuzzard
09-02-2010, 10:55
No one told me there would be math....

I hike to get away from math....

Now my head hurts....

Two hikers depart Harpers Ferry travelling in opposite directions. One hikes at 8 mpd, the other at 11 mpd . . . :banana

Shutterbug
09-02-2010, 13:22
Iíve noticed that when people sometimes talk about elevation gain during a hike what theyíre really talking about is elevation gain/loss. Maybe Iím misunderstanding it, but arenít these two completely different things.

An example:
If one walk 5 miles starting from sea level (SL) and itís broken down as such:

Mile 1 Ė Elevation 0 ft Ė 500ft Ė----- A gain of 500 ft (500ft above SL)
Mile 2 Ė Elevation 500 ft Ė 250ft ------ A loss of 250 ft (250ft above SL)
Mile 3 Ė Elevation 250 ft Ė 325 ft ----- A gain of 75 ft (325 ft above SL)
Mile 4 Ė Elevation 325 ft Ė 300 ft ----- A loss of 25 ft (300 ft above SL)
Mile 5 Ė Elevation 300 ft Ė 500 ft ----- A gain of 200 ft (500 ft above SL)

Now in the above schedule one would have a net gain of 500 feet after 5 miles of hiking, but he would have an elevation gain of 775 ft, with a total elevation gain/loss of 1,000 feet.

So in the above scenario you can not say you had a total elevation gain of 1,000 feet. Iíve heard people say that the total elevation gain on a thru-hike is over 91 miles, but itís not thatís the total elevation gain/loss.

I donít believe (some one correct me if Iím wrong) that no one has published how much elevation gain is done on a thru-hike, not to mention elevation gain broken down by section.

BTW, I know of Map Manís article on elevation gain / loss http://www.whiteblaze.net/forum/showthread.php?t=31293, but I've never seen anything on just elevation gain.

The Topo Map from Delorme has a feature that allows one to determine that information. It says that one who hikes the Appalachian Trail from Springer Mountain to Mt. Katahdin will walk 927.7 miles of climbing for a total elevation gain of 520,270.1 feet. Of course it could be off a bit because it shows the total distance of the trail to be less than 2,000 miles.

Shrkbit143
09-02-2010, 13:34
Elevation gain is the total ascended elevation you hiked. If you hiked 5 miles and you started at 1200ft and hike up for 500ft and then down for 200ft and then up for 500ft you would just add the two 500ft ascendings for a total of 1000ft of elevation gain. I also have been told for every 1000ft add a mile to your hike.
Elevation change is the difference from two points. Same 5 mile hike, you start at 1200ft and stopped 5 miles later at 1500ft. You have an elevation change of 300ft.
Springer Mountain is at 3,780 and Katahdin is at 5,268 for an elevation change of only 1488ft
Donít ask me what the elevation gain is for the trip between the two. Most will say to damm much!

Jonnycat
09-02-2010, 14:51
What I never understood was if a trail on a map is actually rising in elevation on the earth isn't the distance measured on the map incorrect? Isn't the map losing some of the distance because the trail is actually the hypotenuse of a triangle?

I guess it would depend upon whether or not the person making the measurement took into account the actual distance, which would include the hypotenuse as you mention. To me, it would make sense to do so.

Pedaling Fool
09-02-2010, 15:21
...from Springer Mountain to Mt. Katahdin will walk 927.7 miles of climbing...
You misplaced your decimal point, move it one place to the left and that'll be closer to the actual answer -- which no one really knows.

Kerosene
09-02-2010, 15:30
In my opinion, elevation gain/loss only refers to the difference in elevation above sea level between two points. Vertical gain/loss, or rise/fall, or ascent/descent, is a more appropriate label for the terrain covered.

I attempt to calculate average vertical change per mile for each of my section hikes, where vert change is [Gain - Loss], assuming Loss is always zero or negative. Most my hiking days south of Harpers Ferry seem to average 350-450 feet of vertical change per mile, whereas that number jumps to 600-700+ in the Whites and southern Maine.

Personally, I find extended, steep downhills to be much more difficult than long uphills.

Jonnycat
09-02-2010, 15:39
Personally, I find extended, steep downhills to be much more difficult than long uphills.

Indeed. Uphill is just more work on the muscles, while downhill is putting more weight on the feet, pounding them into the ground, and on the knees.

Pedaling Fool
09-02-2010, 15:40
The Topo Map from Delorme has a feature that allows one to determine that information. It says that one who hikes the Appalachian Trail from Springer Mountain to Mt. Katahdin will walk 927.7 miles of climbing for a total elevation gain of 520,270.1 feet. Of course it could be off a bit because it shows the total distance of the trail to be less than 2,000 miles.
BTW, they're wrong, it's not "total elevation gain" it's total elevation gain/loss.

In my opinion, elevation gain/loss only refers to the difference in elevation above sea level between two points. Vertical gain/loss, or rise/fall, or ascent/descent, is a more appropriate label for the terrain covered.

I attempt to calculate average vertical change per mile for each of my section hikes, where vert change is [Gain - Loss], assuming Loss is always zero or negative. Most my hiking days south of Harpers Ferry seem to average 350-450 feet of vertical change per mile, whereas that number jumps to 600-700+ in the Whites and southern Maine.

Personally, I find extended, steep downhills to be much more difficult than long uphills.
Yes there needs to be standard terminology. I guess the fact that there's not is because this issue seems to be treated as an issue of trivia...and in large part I guess it is.

4eyedbuzzard
09-02-2010, 16:40
Well, obviously the elevation ASL of Springer and Katahdin is pretty much negligible (1500 ft or so) in terms of the footage total of climbs and descents (maybe those are better terms). Disregarding this elevation difference, the cumulative elevation in climbs / ascents / whatever must be equal to that of descents. Depending upon the method used to estimate these gains and losses, it's around 500,000 to 600,000 feet of total gain / loss. You'll wind up ascending 500 - 600K and, of course, descending 500-600K feet total during a thru-hike.

The Old Fhart
09-02-2010, 17:35
John gault-“Now in the above schedule one would have a net gain of 500 feet after 5 miles of hiking, but he would have an elevation gain of 775 ft, with a total elevation gain/loss of 1,000 feet.

Scrooge would never let Bob Cratchit get away with bookkeeping like that. Whether it is money or feet you keep track of the pluses in one column and the minuses in another column. Every time you climb you add that elevation to the gain column and every time you go down you add that amount to the loss column. When you have done this for the ENTIRE trail you add each column individually and the figures you get will be the totals for gains and losses.

Those of you who have had integral calculus know that if you only take one measurement, one at Springer and another at Katahdin you will get zero elevation loss and about 1488 feet of gain. These figures are meaningless so you take more and more readings, successively dividing the total of about 2178 miles into smaller and smaller pieces to get better numbers for the gains and losses (as Couscous said). As your distance between readings approaches zero, and the number of samples approaches infinity, you get almost exact values for the elevation gained, and loss, for the length of the trail. There is some practicality to how many readings you’d want to take if you’re doing this in the field taking hand readings and there are some sections that are constantly up or down and you would only need to take a reading for gain or loss when the direction of the slope changed.

Although the trail is statistically almost level, I believe the figure I’ve seen on a tee-shirt was 509,000 feet of gain which seems to be a reasonable estimate, no matter which direction you hike the trail. This figure (I believe) was derived by someone with lots of time on their hands who laboriously checked the profile maps for the entire trail and got these figures. The ATC has a GPS track of the trail that was done several years ago and I’m sure there is software that can be used to get the necessary information from this data in a short time.