Discussion: Too much detail on 1:10,000 maps?

Is it my failing eyesight, or are mappers taking advantage of the increasing use of 1:10,000 scale maps and stuffing more features onto the maps? Not to single out the Pine Hill map from last weekend's A-meet, but there seemed to be a lot of tiny rock detail.

Or maybe it just seems like a lot to me because I learned to orienteer in central NJ where a black dot on the map is more likely to be a tick than a boulder...

I have a lot of difficulty deciphering complex rock detail but attribute it to my inexperience in this type of terrain. I am so accustomed to reading the brown that having the contours obscured is a problem for me.
I appreciated the accuracy of the new Pine Hill and West Point maps with regard to the cliffs & boulders, despite any additional map clutter. In and all-around sense these maps seem part of a recent uptick in map quality which must be a combination of LIDAR basemaps and good mappers. Great work all. Thanks.

"...Don't use stones as a basis for your navigation in an area full of stones..."

One of many quotes from Thierry Gueorgiou's training tips which has been cited on A/P before.

On this link, opposite "Archives," check out the increased detail on the 2005 map, compared with the 1982 version. I too find it very difficult to read the simple land form details on the modern map.

Please don't assume that LIDAR basemaps beget higher quality orienteering maps. There have been high quality basemaps for years produced from basic photogrammetry. At best, LIDAR may make it easier for a mediocre mapper to produce a passable map. On the other hand, Vladimir, the producer of the Pine Hill map, has been making quality maps for years from basemaps of varying quality. The final product, however, is amazingly consistent and not highly dependent on the starting point.

Mostly there's a whole lot of stuff in the Pine Hill terrain.

Its urban proximity created the very dense trail network, not the mapper.
Geologic history created the detailed topo and rock features, not the mapper. A combination of these factors probably contributed to the detailed and slightly thick vegetation pattern.

The Pine Hill mapper also mapped the Batsto and Pakim Pond/Four Mile Circle maps in New Jersey, with the same scale and contour interval, maps with relatively few details, and essentially no rock features.

I spent about 6+(?) hours walking on the Pine Hill map over the weekend. The mapping standard (height of features) for rock features seemed typical for Hudson Valley-New England glaciated rocky terrain. The min ht for boulders seemed to be ~0.8m, and for cliffs ~1.5- 2.0m, or roughly twice the size applied on many DVOA maps :-). A couple boulders struck me as surprisingly small (but not problematic) in this context, but I saw nothing undersized with the cliffs. Even the small specks of tagless cliffs were quite serious in the terrain. The bare rock is the only feature that I thought was somewhat overmapped. On the other hand I thought dot knolls were undermapped to a similar degree.


I think it is fair to say that PIne Hill is one of the most detailed terrains in North America, and the mapping was simply thorough and complete, which is quite an accomplishment by itself. I think most of the competitors were in agreement, with only minor things to comment about.

I had a vague feeling (which the more regular mappers can correct me on) that 10,000 maps were still mapped as if they were to be 1:15,000 and just inflated. Ie. no difference in mapping detail if done properly.

That is the rule Tooms, but is it followed, I know of a couple of maps that I have run on, that are mapped at 15, printed at 10, but have 15 size symbols on them, so are they mapped as 15 or 10

Offset-printed or digital, Jim? It's pretty easy to get the 15-symbol-on-10 map effect with OCAD, you just rescale the bugger and don't replace the symbol set.

There have been previous AP threads on this topic - can't find them quickly though. Basically, symbols on 1:10k maps should be 150% bigger than those on 1:15k maps, so theoretically it should not be feasible to map more features.
There is a general tendency to overmap detail, especially rock. Decisions about generalisation and minimum dimensions for common features need to be taken before the mapping commences.
I know of one map where the mapper obtained the OA Mapping Committee's permission to use 1:15k size symbols on a 1:10k map, and it was not very successful. The map was used for the 3rd day of Easter 2006, and caused mayhem in the overall results, particularly in many of the eyesight-challenged classes. I hope if this area is being used at the Aust Champs carnival this year that it has been remapped.

Digital. The map in question is Mineral Springs, and it won't be used at Bushrangers O9. The reason the Club that owned the map wanted the 15 symbol size, was because it was a remap, and they didn't want to take of information that was on the old map

The ISOM guidelines specifically warn against the practice of using 1:10 to cram in more detail. That said, you can put in quite a bit of detail at the 1:15, it's just really hard to read. Enlarging to 1:10 makes it much more readable.

Using the 1:15 sized symbols on a 1:10 map is just about the most annoying practice going. Not only does it ruin the readability advantage of 1:10, but you also end up overrunning a lot of stuff because it looks like a 1:15 map.

I didn't mean to criticize the map quality or the mapmaker - I though both were very accurate. I think simmo answered my question - if the symbols on 1:10 are 150% bigger, then 1:10 should be just a readable as the 1:15: as EricW said - it was just a very complex area.

The Irishtown map (as discussed above) is like the Diamond Hill map near Bendigo. Both were mapped at 1:10,000 before ISOM. Late 80s and early 90s. I redrew Diamond Hill without field working it, and it was almost impossible to recreate some of the finer contour detail with ISOM standard lines. If some think there is too much detail on 1:10k maps, then its not new around here. If anything, I think the trend is going the other way. I have been quite disappointed with one or two maps at relatively recent carnivals where I would have preferred more detail on the map.