| When I ask most people if they can read a map, | | | | is actually an indicator of which way the land is |
| I get a yes response. But when I ask them | | | | rising and allowing you to imagine as if you were |
| where on the map we are now, I mostly get a | | | | reading the number while looking up a hill. This is |
| blank expression or a few guesses here and | | | | very helpful in planning your routes. |
| there. | | | | Contour lines are probably the most important |
| The hardest challenge people find in reading a map | | | | part of locating where you are on the map. They |
| is how to visualise the 2D image of the map in a | | | | show you ridges, saddles, peaks of mountains and |
| 3D image. In other words, how to make those | | | | open fields, all which you can use to determine |
| lines and "green sections" look like the side of a hill | | | | where you are located. However, when you are in |
| with light scrub. | | | | dense scrub or are located in amongst multiple |
| As with any skill, it all begins with the basics. | | | | ridges with similar features you may need to |
| There is no use investing in the latest and | | | | refer to further parts of the map to assist, such |
| greatest technology such as a handheld GPS unit | | | | as the legend. |
| if the basics of map reading are not learned. I | | | | The legend, also known as the key, is a list of |
| can't tell you the amount of times I have been | | | | images representing corresponding items on the |
| out in the field to hear "the batteries are dead", | | | | map (i.e. a long-dashed lined would represent a |
| and "I don't know where we are, the way-point | | | | vehicle track). The legend covers natural items |
| was in the GPS". | | | | such as rivers, creeks, dams, rapids in rivers, |
| Before anything, there are a few rules about | | | | swamp, cliffs, plus many more and also covers |
| maps: | | | | man-made items such as power-lines, roads, |
| 1. Don't draw on them with permanent markers | | | | tracks, mine-shafts, jetties and much more. This |
| or pens (you may need to use them again and | | | | section of the map is very handy in helping you |
| need to be able to see features and points), | | | | position yourself on a map and gives you visual |
| 2. Try not to fold the map (this reduces the | | | | references to refer to. |
| longevity of the map, causing rips and tears) | | | | You will also find magnetic declination, Datum |
| 3. Waterproof your map (A wet map with running | | | | information & the age of the map, all which come |
| ink is about as good as a tanning salon in the | | | | in handy when using a magnetic compass, but we |
| desert) | | | | will get to that once we've conquered map |
| There are ways of working with the above points | | | | reading first! |
| but I won't be covering this today. | | | | Across the map you will find parallel lines running |
| Once you have your map spread out nice and | | | | both North-South & East-West. These are called |
| flat, it's time to familiarise yourself with the | | | | grid-lines and when four of these lines intersect to |
| different parts of the map. | | | | form a box, they create what we call a |
| In this example I would like to use a 1:25,000 | | | | grid-square. On a 1:25,000 map each grid-square is |
| map. 1:25,000 basically means that for every one | | | | 4cm x 4cm, which equates to 1km x 1km in |
| centimetre on the map this represents 250 | | | | distance on the ground. The lines which run |
| metres on the ground, therefore a ratio of | | | | North-South are called Eastings as the numbers |
| 1:25,000 is used. This is called the scale and is | | | | running across the top of the map increase as |
| present on either the side or the rear of the map | | | | they move towards to East. The lines running |
| in linear (straight-line) format. You can use the | | | | East-West are called Northings and the same |
| linear scale with a ruler for speedy calculations of | | | | principle applies, they increase as they go |
| distances on the map. | | | | northward. |
| There will also be a section stating the contour | | | | Once we locate ourselves on the map using visual |
| interval. Contours are the imaginary lines which | | | | referencing we can then convert this in to a grid |
| are drawn on the map to represent certain | | | | reference. There are a few different ways we |
| heights at different locations. These so-called lines | | | | can take grid references and we really are |
| are used to determine the height of the terrain in | | | | starting to get a little ahead of ourselves so I will |
| the area and assist in determining rises and | | | | leave this for another time. |
| depressions in the land. On a 1:25,000 map the | | | | The goal here is to be able to pick up a map, |
| distance between contour lines represents a | | | | have a look at it in 2D view and picture it in 3D |
| distance of 10 metres on the ground. You will | | | | view. Likewise you will get to the point where you |
| notice with the numbers on the contour lines that | | | | will visualise your surroundings in 3D and convert it |
| some may appear to be written upside-down, this | | | | in to 2D to read easily and confidently on a map. |