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Reading And Understanding Topo Maps


Thrak

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I've considered getting TOPO for my 76CS but every time I look at a topographical map I end up boggling at the thing. I know that the lines are elevation changes and such but I simply don't assimilate what I'm seeing. It never "means" much to me. I went down to Barnes and Noble and checked out the DeLorme maps. GAH!

 

Am I the only one here who has this problem? It makes me feel like an idiot. B)

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I would highly recommend going to this link, which is a free online booklet that explains topo maps and how to read and understand them.

 

Use the links on the left side of the page to navigate around the booklet, and look especially at Section 2, pertaining to land navigation.

 

Topo maps are a lot of fun, and I hope you learn to enjoy them. Once you get a feel for picturing a landscape with them, they become very enjoyable to look at.

 

Good luck!

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Well I don't have a problems with thempersonally... Go find a full quad and look at that. Once you are comfortable looking at the map as a giant sheet of paper, then you will be able to use it on the small screen... Until then the zoomed in view will show too little to understand and zoomed out will show so much it will confuse.

 

Good Luck,

Ben

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Topo is your friend.

 

24K topo maps are very detailed. The elevation changes are the lines on the map. On 24K maps, they are generally showing an elevation change of 20 feet. If you think of a topo map as if someone took all the land features and cut them into horizontal planes, each plane 20 feet thick. Now they traced those lines on paper, and that gives the way the topographical features lie.

 

The above poster is correct, close lines mean a steep slope, lines further apart mean a more gentle slope.

 

As far as the topo maps in GPSr software, I believe they are based on 1:100,000 scale, which means that each line will show a larger elevation change (I believe it is 100 feet, but not a hundred percent sure on that number).

 

You can order a custom topo from Offroute.com for virtually anywhere in the USA. These are what are called 24K or 1:24,000 scale maps. Get one for an area you are familiar with and go out and experiment with it. You will be very pleased with your results.

 

BTW, I find that using a regular compass that is adjustable for Magnetic North/True North declination is invaluable for map use and also caching.

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If I may add a couple more links, this one gives an excellent demonstration of how contour lines work, as well as other aspects of topo maps.

 

If you want to get into topo maps, compasses, etc. a little more then read on....

 

mytopo.com is a tremendous resource. Maps can be ordered covering any area, and they're printed on waterproof, tear-resistant paper.

 

If you really want to get a lot of extra functionality from your gps (especially for hunting, hiking, etc.), then get the UTM grids printed on the mytopo maps, and then get UTM grid tools from maptools.com. This will enable you easily to plot your exact location on a map in the field, using the information from your gps (be sure, if you do this, that your gps datum is set to match the map's datum, and the coordinate system for your gps is set to UTM). These, combined with a decent compass, will enable you to navigate your way out of difficulty, should your gps fail.

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I have to second Sputnik's recommendation for Be Expert with Map and Compass. That book has been around for quite a while and is useful for both Orienteering and Geocaching. It really gives you a feel for how the map relates to the real world. I used it back when I actually did use map and compass exclusively. It taught me how to find my position on the map using the compass to triangulate my location, and how to take bearings on a course. You'll learn about magnetic declination and topographic contours, etc.. Great book.

 

Parsa

Edited by Parsa
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There is another advantage to having paper topo maps and a seperate compass. GPSr units are, after all, electronic devices. And, as we all know, these devices can on occasion cease working.

 

Now, if you're in a local area doing your caching, this isn't too big a problem. However if you've decided to combine caching with camping, just to use an example, then having a topo map and compass can mean the difference between getting back to camp or wandering around lost for hours or days.

 

Learning how to read and use topo maps isn't difficult, once you get the idea in your brain about relating what you see on the map to what you see on the land. Then it's just a great way to keep track of caches, backup your ability to find your way home, and just enjoy the whole thing a lot more.

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GeoPup is on the right track. A better idea might be to model a hill out of clay. Now just cut the model horizontally at specific intervals, say 1 inch. Now lay those cut pieces of the model on a piece of paper, oriented correctly, and trace their outline. Do this with each section of cut off clay. Now look at what is on the paper. A topographic map of the hill model.

 

Granted, that is simplifying things a lot, but that's the general idea. Each contour line is a horizontal slice of the terrain.

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geopup reminded me of doing that very thing in a geography class many years ago. We would trace the contour lines of a hill or mountain (preferably one including a stream) shown on a topo map onto a sheet of paper, then---one by one---use a pin to transfer the shape of each contour line onto a separate sheet of corrugated cardboard (i.e., poke along the contour line onto a piece of cardboard for the first line, then a separate piece of cardboard for the second line, and so on). Then we cut along the pin pricks on each sheet of cardboard and took the resulting pieces and stacked them sequentially. Instantly the mountain was created in 3D and from that time onward topo maps became "alive".

 

This is a great project to do with kids, whether they're your own, your neighbors, a scout troop, etc. and the lesson will last a lifetime.

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You could always learn how to read a topographical map the way I did.....join the Army. If there are enough terrain features on the map (not barren and flat like a dessert or the plains) I can pin-point my location just by looking at the map and my surroundings. So learning how to read topography is a very worthwhile thing to do. Even though my GPSr has mapping, I always carry a topo map of the area I am in. I real map is still more accurate and includes many significant objects and features that a top of the line GPSr with mapping will not.

 

NEO GEO, speaking of terrain and the Army.....I clicked on your link and was shocked to see someplace I have actually been and seen for myself. I am willing to guess you've done some training here as well.

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You could always learn how to read a topographical map the way I did.....join the Army.

Another option, with less of a long-term commitment, is to try the sport of Orienteering.

See: http://www.us.orienteering.org/

The goal is to find a series of 'Control Points' that are scattered around a typically wooded area using only a detailed topo map. The courses are graded in difficulty so you can start on an easy course where the Control Points are placed on a fairly small course and at obvious places (trail junctions, near river crossings, etc.) and progress up to more difficult challenges where you really need to be able to interpret all the details on the topo map.

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