Maps are an important part of our sport. This may be obvious but how
much thought do you give to the maps that you use when you are out on a
course? We tend to take them very much for granted and spend much more
time worrying about other items of orienteering kit.
Maps have come a long way from when the sport started.
In an article written by Robin Sloan of Roxbourgh Reivers about his
experiences orienteering in the sixties he illustrated how maps have
evolved. He wrote "For the entry fee, it has to be said, You didn't get
very much, just a black and white Xerox of the Ordanance Survey map,
….. the usual map scale was 1:25 000 so there was very little detail
compared to our present day 1: 10 000 maps and what detail there was
would often be obscured by little tree symbols". Robin goes on to
recount how a big advance was made in 1968 when the first three colour
map was produced of Wauchope Forest near Hawick. The colours used were
black, brown and blue, a far cry from today's maps with their wealth
of information about runnability and changes in vegetation density. Well
before you become too complaisant perhaps you should read on and look
at the following sections of map. They are from an Orienteering
Mapmaking Comparative Workshop that was held in 2000 in Czech. All of
the maps are for the same area but are drawn by different individuals.
All started with the same base map and had one day in which to carry
out their survey. Obviously some allowances have to be made for
individuals working at different speeds but it is still interesting to
view the results.
Even to the most casual observer it is obvious that
these maps look very different. The first thing that hits you is the
difference in the amount of detail. Look at maps 1 & 4. They have the
most contour detail. While map 3 gives a much more simplified view of
the shape of the land. Map 4 has the most information about the
runnability of the area.
The arrows drawn on the maps highlight areas where
there are distinct differences.
Vegetation changes.
Map 1 - area A. Note the rectangular area with the dotted line
indicating a distinct vegetation change. Compare this with the other
maps. Three of the maps agree with the distinct vegetation but none of
them agree about exactly what colours should be where within this small
area. This is perhaps shown even more dramatically in a different area:
Map 2 - area B. You will see a long band of mixed vegetation. While all
4 maps agree that there is a distinct vegetation change from the
white/runnable area around this area, each mapper has their own
interpretation of what is within the area.
Contours and the shape of the land.
Map 2 - area B - continue looking at this portion of the map but bring
your eyes to the southwest of the band of vegetation and on map 4 you
will see a large depression. Compare this to map 1 which shows two small
depressions in the same area.
Map 4 section D seems to indicate a complex and
navigationaly challenging terrain. At the other extreme is map 3 where
less complexity is present in the map - you you could be forgiven for
thinking that it was a completely different place.
Boulders and crags.
Boulders and crags should be relatively straight forward to map with
perhaps the main difficulty being ensuring the correct plotting on the
map. Well have a look at Map 3 - area C. This shows 5 boulders, 2 large
and 3 small, as does map 1, though the mappers disagree about the
relative sizes. However, maps 2 and 4 tell a different story.
This is not an isolated case: look back to map 1 area
A to the north east of the distinct block of vegetation for another
example. This mapper has identified 4 crags, 2 larger than the others
and 3 boulders of varying size. Now look at other maps of the same area.
Between the four maps the number of black features varies from 6 to 8
with different interpretations of whether the feature is a boulder or a
crag.
After looking at these maps you could be forgiven
for thinking it was futile to even attempt to navigate your way around
anything harder than a yellow - perhaps an orange if you were feeling
adventurous! Why this is not true is because orienteers routinely adapt
to and cope with these differences in style with differing levels of
ease. The requirement is that there is consistency in style in the
mapping and accuracy with the main features and contours. So be it a
black and white photocopied map, a contour only map or one that has not
been revised for some time orienteers need to decide what aspects of
the map they can trust and then favour those features when choosing
attack points and looking at the finer details close to a control site.
And when you hear orienteers saying that a map is really good they are
probably indicating that their translation of what is on the map to what
they see on the ground readily lines up with how the mapper interpreted
the ground features on the map.
Without actually visiting the area it is impossible
to judge which map is most accurate and which would give the most
enjoyable run but what we can see is that the individual mapping the
area has a dramatic effect on the what the resulting map looks like.
If this subject has interested you and you would like
to view the other 12 versions of this map you can find them on the web
at
http://peiza.kicks-ass.net/kartritare/
Robin Sloan's article appeared in Solus in Aug 2003