Written by 10:38 am Wilderness Navigation Masters

7) Understanding the elevations & slopes

Reading Time: 4 minutes(Last Updated On: June 7, 2021)

For the same hiking distance, going uphill will take you more time than going on a flat surface.

I think it’s common sense.

Because the walking speed going uphill is slower than the walking speed going on a flat surface.

For that, in order to estimate the walking time of our hike, (which have ascents parts, descents parts, and flat parts ) we need to sort all of our hike different sections into these 3 categories.

In order to do that, we need to define some technical terms like elevation gain/loss, cumulative elevation gain, cumulative elevation loss, and slope.

  

Hello and welcome to this video of the online course Wilderness Navigation Masters, where you will learn about some technical terms that will help you to sort your hike different sections, to understand well the difficulty of it or to just explain it well if you talk to another person.

Now, let’s see every term in detail.

Elevation gain/loss

Elevation gain/loss is the altitude difference between your starting point and your arrival point, if it’s a positive value, it’s again and if it’s a negative value, it’s a loss.

[Trip A -> B] Elevation = Altitude B – altitude A

For example, if our trip consists of a hike from point A at an altitude of 300 feet to the point B with an altitude of 380 feet, the elevation, in this case, is 80 feet of elevation gain.

And if it was the opposite, I mean we are starting from point B to point A, in this case, the elevation will be 80 feet of elevation loss.

But if our hike consists of something like that, knowing just the elevation gain/loss between the first and the last point will not represent the real difficulty of the hike.

Because, here, the elevation loss is only 200 feet, and if you tell someone that you hike with an elevation loss of 200 feet, I’m sure he will imagine something way different than that.

For that, we need something more accurate which is cumulative of all the elevation gains and the cumulative of all the elevation losses.

Cumulative elevation gain/loss

  • What is the cumulative elevation gain? (called also cumulative gain, elevation gain, total ascent, or just gain. But personally, I prefer cumulative elevation gain because it’s more descriptive)

Cumulative elevation gain is the sum of every gain throughout the entire trip, and in this example, it’s the sum of elevations from point A to B and C to D, which is 60 feet.

The same thing with the cumulative elevation losses.

  • The cumulative elevation loss (called also cumulative loss, elevation loss, total descent, or just loss. ) is the sum of the elevation losses.

In this case, the sum of the sections from B to C and D to E, which is 120 feet.

I think if you tell someone that you’ve hiked with a cumulative elevation gain of 60 feet and a cumulative elevation loss of 120 feet, it’s more descriptive than just with an elevation of 40 feet.

How to know altitudes from topo maps

Now, you may ask me how do I know the altitudes of the different points on my hike, I will tell you that this is simple with the help of the contour lines and the altitude values that we found on summits.

Slope

In outdoor activities, especially the ones when you are moving on your feet like hiking or running, knowing the parts that you will be going uphill or downhill is too much important. For that, you need to know how to measure a slope.

But first, what is a slope?

The Wikipedia definition of a slope is a surface on which one end or side is at a higher level than another; a rising or falling surface.

Slopes can be measured in percentage.

 

During your planning for your outdoor activity, you may hear that your trail has a slope of 2% for example. That means for every horizontal distance of 100 feet there is an elevation of 2 feet.

Now let’s see the exercises.

 

This is box title

What are the elevation, the cumulative elevation gain, and the cumulative elevation loss of this trip that start from point A to point B, knowing that the contour interval is 40 feet?

SHOW ANSWER

To answer this question, you have to measure first the elevations of these points using the contour lines.

Then, sort the ones when you gain elevation, then the ones when you lose elevation.

These are my approximate elevations for every point :

  • Point A: 8080 feet
  • Point B: 8600 feet
  • Point C: 7960 feet
  • Point D: 8600 feet
  • Point E: 8000 feet

*if you get elevations slightly more/less than mines by 40 feet, no problem.

After I sort them.

Ascents :

A -> B : +520 feet

C -> D : +640 feet

Descents :

B -> C : -640 feet

D -> E : -600 feet

————————-

– Cumulative elevation gain :

   520 + 640 = 1160 feet

– Cumulative elevation loss :

   (-520) + (-640) = – 1240 feet

– Elevation loss :

  E (8000) – A (8080) = -80 feet

That’s all for this video, don’t forget to let us know in the comments section below if you are already knowing about these terms, if yes, what are the terms that you were using.

Thank you for watching and see you in the next video.

Last modified: June 7, 2021

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