Hiking - How to use an IGN map when hiking?
IGN maps, like treasure maps, remain a mystery to most hikers. We walk you through the key steps to reading an IGN map and making the most of your hiking trip.
Step 1 - Understanding scale and legend
On IGN maps, produced by the Institut National de l'Information Géographique et Forestière, the cover page provides a first level of information. The title, subject, scale, and GPS compatibility (for some editions) are all indicated. Depending on the scale, the level of detail shown on the map will vary.
For hiking maps, the scale is most commonly 1:25,000. This level of detail allows the map to show the nature and features of the terrain, paths, waterways, roads and tracks, and relief.
On the institute's website, scale is defined as follows: "it is the reduction ratio between the cartographic representation and the terrain." This concept allows the length measured on the map to be related to the actual length on the ground. For a concrete example, refer to the video with mountain guide Florian Olivier, who also provides further explanations on:
- contour lines,
- spot heights,
- legend symbols, etc.
Step 2 - Knowing how to locate yourself on your map
Next, when out on a hiking trip with an IGN map, it is important to know your position on your topographic map.
To position yourself accurately, you will need to draw on your powers of observation and rely on the features around you: waterways, summits, tracks or footpaths, buildings and other man-made structures.
See more detailed examples in the video below.
Step 3 - Orienting your IGN map correctly
Finally, to make proper use of your map in the field, learn how to orient it — it is not a complicated exercise. Especially since on an IGN map, the North indicated corresponds to the right or left edges of the map.
Two options are then available to hikers:
- if you have a compass: align a meridian (black line on the map) with your compass needle.
- if you know your position: find a clearly identifiable landmark on the map, such as a church steeple, a building, or a mountain. Then rotate your map while aiming at that chosen point. For added reliability, you can check the orientation by sighting a second landmark.
Watch more explanations in the video. Also find out how to prepare for hiking in the rain.
Photos ©Cyrille Quintard ©Focus-Outdoor
