Topographic maps are a key part of exploring and a valuable asset to any outdoorsman. However, just looking at one of these maps can be intimidating. “Ahh! Squiggly Lines!!!” This guide should give you a very basic idea of what on earth you’re looking at and how to understand it.
- Getting your hands on a topographic map: So you want to get yourself a map. Well, you can buy a fancy pants DeLorme Atlas, or you can zoom in on your location and print a custom map at http://www.digital-topo-maps.com for free!
The Map At A Glance
This is your basic topographic map. From this first image, it just looks like a bunch of oddball shapes drawn by a toddler. However, if you look closely, you can see that the lines note changes in the curvature of the earth. The space between each line is a 20 foot rise or decline of altitude. That means that each line basically represents a twenty foot layer of dirt, rock, and earth.
You can see that these lines almost give a 3D effect, and show how steep, how high, and how wide a hill or mountain is. Lines closer together indicate a decline in a shorter distance, therefore steeper. Lines further apart indicate a more gradual decline of the slope. Notice the ripple or crease in the South West side of this hill. The lines scrunch tightly together, showing a steeper slope. If you go to this location, you will find a gutter carved into the hill by erosion. It’s significantly steeper here, and tends to act like a funnel, causing flash floods.
Notice that some lines are thicker and darker than others and have a number on them. I’ll explain the importance of this later.
Also take note of landmarks, such as the gravesite in the lower left corner and the well in the center left. The color changes between white and green are important too, and illustrate differences in plant density. Green portions note ample vegetation, such as forests and thick brush.
How To Find Your Position
Go ahead and find North on the map, and reposition your map to be parallel to actual North (in these images, North is up for simplicity sake). Finding your position becomes much easier with a map like this one, and is based off of looking at your surroundings. Essentially, what you are trying to do is find a significant feature in eyesight, and find it on the map. This cliff face (spreading across top of picture) for example, is an obvious feature, and would be pretty hard to miss in the real world. Now estimate where in relation to that feature you are. Pick a point on the map by educated guess and then look for another prominent feature. Determine where you are in relation to that object, and you have a pretty good idea of where you are at. An even more precise way of determining location is walking to a land mark, such as the very peak of a hill, the base of a valley, or a graveyard. Yes, it’s spooky in the graveyard, but at least you know your location.
Remember those big, bold, beautiful, lines I pointed out earlier? The ones with the numbers? Those numbers are the feet above sea level of that line! You can figure out how high or low other lines are by taking the nearest numbered line, and counting by twenty up or down, every time you pass another line. Take the first hill I showed you. Start with the bold line marked 1600. Now count the lines to the top of the hill. There’s 8. Now multiply by 20 feet to get a 160 foot increase in altitude.
Studying The Map
Exploring your map without even moving your physical position can be very rewarding. There’s a lot of amazing things you can see if you know where to go.
Just looking at this small portion of the map, you can see several wells, which offer drinking water and civilization, the pipeline, a burial ground, and small springs and tributaries to the river. You can also find the highest near elevation, providing astounding views.
Finding Water & Other Resources
You see that blue squiggle on the page? That’s water. Sweet, sweet water, the thing you need in order to not die of thirst. Walk to it for refreshment, or find a narrow spot in the line for easier crossing.
Determining Your Path
One of the biggest benefits of topographic maps when hiking, is showing the path of least resistance when moving off trail. Look for a flat area, not noted for forests or jagged terrain. Another easy way to travel, is moving alongside or in a river. The air is noticeably cooler, and you can’t really get lost. I admit it’s possible, but pretty hard. Careful, though. Riversides will have more vegetation, animals (e.g. water moccasins), and insects than anywhere else.
So now you know how to read a topographic map! If you have any questions (or objections to my methods), let me know in the comments. I’ll be glad to give more info where it’s needed.
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