[OSM-talk] Introducing "Fix waterway direction"

[Peter Wendorff]

Am 28.08.2014 um 21:48 schrieb Peter Barth:
> Hi,
> 
> Christoph Hormann schrieb:
>> Great to see the waterways are getting some attention. Does this only 
>> analyze SRTM elevations at start and end point or are the surrounding 
>> waterways considered?  
> 
> currently start and end point only. I have code to do more, but for the
> easy tasks that was not necessary as I have a fairly high number of true
> positives.
> 
>> If a waterway meets another waterway at one side 
>> but is unconnected at the other for example this is usually a strong 
>> indicator for the direction independent of the elevations data (which 
>> is only helpful usually in mountain areas).
> 
> Actually I found many streams where start and end point are not
> connected to anything at all. However, for those cases (not mountain
> areas) the aerials didn't help neither in most cases ;) But as I'd like
> to get a mostly complete waternetwork for another project, I'm planning
> on extending the challenge at some point.
> 
>> In terms of usability it would of course be good if you could see the 
>> direction in MapRoulette so you can verify the data without actually 
>> loading it in the editor.
> 
> Serge suggested this, too. But I did never understand what the direction
> would tell the user? Does it denote the current way's direction or the
> supposed correct direction? How would the user know? And my biggest
> concern is, that in many cases you need aerial anyway to be really sure.
> 
> Anyways, would be happy to add this, once I got, how this should be done
> :)
You may add arrows in both directions, color-coded for "assumed" and
"current" (and explained in the challenge description on the top right)

regards
Peter