[OSM-talk] Introducing "Fix waterway direction"

Malcolm Herring malcolm.herring at btinternet.com
Thu Aug 28 20:00:31 UTC 2014


On 28/08/2014 19:49, Peter Barth wrote:
> A more detailed description can also be found on my user diary here:
> http://www.openstreetmap.org/user/Peda/diary/23632

Your statement that canals may flow uphill is incorrect. Where canals 
pass over a summit, the water supply is fed into the topmost pound and 
then flows in both directions (i.e. downhill) from that feed. Therefore 
the water flow should always match a topological analysis. In the case 
of contour canals, no actual water flow may take place, therefore the 
direction of the way would be arbitrary.

Also, for navigational reasons, canal administrations [in Europe 
(CEVNI)] have to define a left & right bank to determine the colours of 
buoys & nomenclature of signage. These may conflict with the actual 
water flow, since the left/right choice is arbitrary. Likewise the 
direction of the way.




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