The word map comes from mappa mundi (Latin for “sheet of the world”) and it can best described as a flat diagram of a pre-determined area. There are many kinds of maps and they are almost always drawn from above, but essentially they all require basic features:
1. Scale – the ratio between an object on the map to an object in real life. For example: a 1:25000 topographic map means that every 1 cm (or inch) on the map represents 25000 cm (or inches) in real life.
2. Reference point – most maps use the geographic north (more about this later) to allow you to align your map in real life. For example: an arrow pointing north on the map (usually to the top of the map).
3. Symbols – these will have a legend to explain what they are. For example: blue almost always represents water in maps (but even that can vary!)
4. Grid lines – Maps use square grids to express a location using a Cartesian coordinate system (an X/Y axis system that represents location). For example: The UTM grid, which is what gives us longitude and latitude, is used by maps to allow the user to find an exact location on a grid anywhere in the world.
Using this set of features, a map can create an accurate representation of the specified area.
When it comes to being outdoors, we focus on one kind of maps: topographic maps (“topo” maps).
Topographic maps
Topo maps have another feature that makes them so unique for the outdoor adventurer, and also gives them their name: Contour lines.
Contour lines represent changes in elevation on the ground and in doing so, they create a three dimensional view on a flat map. By creating the three dimensional effect they allow us to read the arrangement of natural objects (topography) so we can visualize the terrain.
What can we use topo maps for?
1. Navigation
2. Calculate distances
3. Determine the location of natural and artificial objects
4. Plan routes
A map allows us to get familiar with a place prior to visiting it and it is a tool (with a compass) to navigate while in the area. The map is a vital tool for the outdoor enthusiast and learning how to properly utilize it is vital.
In the coming weeks I will go over all the parts of a map, from symbols to contour lines, to grids and the different Norths (yes, there is more than one). We will go over the different uses such as route planning, finding natural features and understanding the terrain.
Finally, we will go over how to use a map in conjuncture with a compass to successfully navigate while outdoors.
How does that sound to you? Is there anything else you would like to know as part of this series?