I am assessing about sixty maps in an effort to prioritize mapping efforts, and I'm struggling coming up with an objective measure of map quality. How do you assess the quality of a map, and given a large number of maps, how can a prioritization be devised? The number of maps makes the problem harder, because it's not practical to assemble a committee and visit all the maps systematically.
The eight broad criteria I'm currently using are:
- Existing map quality
- Terrain quality
- Difficulty obtaining permission from landowners
- Parking accessibility
- Size of accessible area
- Distance from population centers
- Intended use
Landowner permission, parking, size, distance, and intended use can be quantified somewhat objectively, but existing map quality, terrain quality, and vegetation are tricky. I would further decompose map quality into accuracy of contours, accuracy of mapped point features, trail network completeness, and the completeness of the map overall.
Comparison with "truth" is an attractive sentiment; LIDAR data is typically much more accurate than base maps made from
aerial stereophotos twenty years ago, and an objective comparison can be made. In the absence of LIDAR, it's a harder problem.