Talk:WikiProject Whitewater Maps
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Discuss WikiProject Whitewater Maps here:
Riverside observation. Grading system.
Hi, as I now live in a town with a river, i.e. Shrewsbury, I'm interested in how I can improve the data for the Whitewater maps. I've been canoeing once, about 5 years ago down a fairly quite stretch of the Severn just upstream of Shrewsbury, so I don't have much of an idea of terms used, nor the ability to map from on the river itself. Even so, I'd like to try and add something from riverside observation. I've seen a few slopes, some concreted and some not, footpaths leading down near the water and some ladders leading into the water. How do I tell which are put_in, egress, etc?
The stretch of the Severn I know best (where NCN81/my route to work runs alongside, i.e. the big loop around the town centre) is quite calm. Is that of interest or are you after, as the name suggests the rougher bits (like downstream of the weir).
All for now. Higgy 21:43, 22 April 2008 (UTC)
- The kind of information we're going for is something which could be used in conjuction with a kayaking guidebook for a river. In particular I'd like to help illustrate kayakwiki river guides with some maps of individual rivers. So you can imagine that these guidebooks will generally identify an interesting stretch of river, with some rapids/drops, say 10/15 kilometres long, and suggest a good place to "put in" and "take out". Generally kayakers prefer to have a nearby car park, and no need to walk across private land for these places. I guess there's no harm in labelling any spot where kayakers can easily get on and off the river, although that might clutter the map a bit if there are many potential places.
- Anyone can also help create kayaking maps by adding features like bridges and power lines which are always useful just for figuring out where you are on a river. Then there's things like wiers, and tree hazards, which might either be minor obstacles or severe hazards. If something looks like a severe hazard, it's probably most useful to tag it as such, and then have a kayaker downgrade it later if it turns out to be runnable.
- Whitewater gradings are a tricky thing. They are very subjective, and quite difficult to judge from the river bank actually. Even with photo illustrations of different river grades, there is often confusion caused by different eye-levels / distance from the rapid. UK rivers guidebook river gradings page is reasonably good, but notice how different grade 5 looks just because it is taken from a long way away. Same problem when looking first hand. You have to get down to kayakers eye-level to judge difficulty better. Anyway, that link shows how the gradings go.
- Should non-kayakers attempt to guess a grade just by looking at the river? Well I think it's enevitable that grade guesses will get whacked in, and these will need to be refined over time. So yes. But if you don't want to be responsible for any nasty accidents, you may want to err on the side of caution with your grading (tag it more difficult than it is). For individual rapids/drops you may prefer to use 'unknown' (thereby indicating that there is a rapid/drop, but you don't know what grade it should be). Alternatively if a rapid certainly looks like something wihch would take a kayaker by surprise and give them a pummelling, you could label it grade 6. That way a kayaker will certainly get out and take a look at it, and hopefully edit the map to set the grade correctly!
- (Are you starting to see why this needs a special disclaimer?!)
- -- Harry Wood 10:21, 23 April 2008 (UTC)
