[OSM-talk] waterway - "routable network" and reservoirs/lakes

[Christoph Hormann]

On Tuesday 28 July 2015, Maarten Deen wrote:
>
> Do you think that hydrological analysis is a wider field of
> application than water navigation?
> I was of the opinion that the connection of waterways within OSM was
> primarily for navigation.

That certainly depends on your point of view and metric used but it is 
not unreasonable to think it is, especially considering that most of 
the waterbody data in OSM represents non-navigable waterbodies.

I have for quite some time now pointed out that in terms of 
visualization if you want to do more with the OSM water data than just 
draw everything in uniform color a full water flow network is the basis 
of almost everything you might want to do.  In particular any 
differentiated rendering depends on a consistent importance rating 
which can only be produced based on water flow analysis.

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