[OSM-talk] Introducing "Fix waterway direction"

[Christoph Hormann]

On Thursday 28 August 2014, Peter Barth wrote:
> Hi all,
>
> I created a new challenge for MapRoulette: "Fix waterway direction".
>
> As the waterway's direction in OSM denotes the direction of the
> water's flow, I started to compare them to SRTM. This leads to more
> than 1 million wrong directions for Europe only. Many times SRTM is
> right, however, due to data errors, not every time. That's why I
> created this challenge.
>
> [...]

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?  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).

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.

-- 
Christoph Hormann
http://www.imagico.de/