Wednesday, February 13, 2008

The scale of the mapping problem

Last autumn, CLOK staged a district event on one of our traditional areas - Eston Nab. The post event comments on the club bulletin board included some rather scathing comments about the map.

Now having remapped/redrawn the map for one day of the October Odyssey back in the 1980's, where I was required to use the scale of 1:15,000 (because it was a badge event), when most people thought 1:10,000 was more appropriate, I have personally been on the receiving end of rather sharp critiscm of the map.

Nowadays, unless there is something major being held, it is usual for the event planner and controller to make small changes to the map, so no one person puts their name down as responsible. Instead, the 'club' gets the flack, or rather, the mapping committee.

The thing about this area is that the minor paths and gorse patches are prone to frequent change - it only takes half a dozen youths on scramble bikes to create a new path, or some youths with matches to clear some gorse bushes! The major features - contours, tracks, water features - they stay the same year in year out. And to be honest, I could have done my 2007 brown course using my 1980's map.

However, some people find the minor inaccuracies very difficult to cope with when participating. The question then becomes, shall we throw several £1,000's of the clubs' money at a professional mapper, so that the map is accurate for the day of the event (but then have to do the same thing again the following year) or do we accept the constantly changing nature of the area, update for changes found in the planning process, advise competitors accordingly, and move on?

Which brings us to the problem of dealing with competitor expectations!

I do think that the 'detail' problem is very much linked to the 'old people's eyesight' problem currently being debated on Nopesport with respect to this year's British Championships at Culbin in Scotland. And as a controller, there is the 'fainess/bingo control' issue to be considered also!

Maps for 'normal' events (I realise that sprint racing maps are a different animal) are being created at increasing levels of detail, and the clamour has now become one of maps of 1:10,000 for the youngsters and 1:7500 for the oldies, in order that the mapped detail can be read on the run.

I would counter this by saying that perhaps we ought to be going the other way - what if maps were surveyed for 1:20,000 and then enlarged to 1:15,000 for the youngsters and 1:10,000 for the oldies? That way, only the features which are large enough and distinctive enough to be mapped at 1:20,000 would be shown. Minor paths and individual gorse bushes just wouldn't be shown! It would also help to solve the eyesight problem - if the feature is big enough to be mapped it will show up as such on a 1:15,000 or 1:10,000 map - and it will be visible on the ground!

Which brings me nicely to my own personal moan (as a result of a reasonable run at the Robin Hood Trophy being spoilt) - we do seem to be making orienteering a search for a 'needle in a haystack' - the features being used are often no bigger than the kite itself! Looking at Routegadget for the RHT, there did seem to be an awful lot of mistakes being made not just in the circle, but within 10/15m of the flag.

If you cannot even see the feature from 10/15m away, then surely it becomes a total lottery in finding the flag - the old 'bingo' control scenario!

So how about it - lets move away from such detailed mapping. Surely it would solve the map 'shelf life' problem, the 'eyesight' problem, and the 'fairness/bingo' control problem at one fell swoop!

1 comment:

Anonymous said...

Competitors need realistic expectations or they will burn off organisers, setters and mappers. As an aside, rogainers complain that orienteering maps are too detailed and take the challenge out of navigation.?