[Tagging] trees and waterways

[Pierre-Alain Dorange]

John F. Eldredge <john at jfeldredge.com> wrote:

> I am using my phone at the moment, not my PC, so I can't test this.  What
> happens if the way, or section of a way, that you have selected has a
> portion mapped in one direction, and another portion mapped in the
> opposite direction (which could easily happen if different parts of the
> way had been mapped by different people)?  Do you get an error message,
> or do JOSM and Potlatch go by the majority direction?

Don't know for Potlach but JOSM revert all ways selected. In the context
you expose, you must select only the portion in the wrong way then
revert or you can merge wrong way section with a right way section (JOSM
ask you the direction).

If the river (multiple sections) has been include in the waterway
relation (1), you can easily check sections with JOSM by opening the
relation window and sort the way, it qwill display the continuity (with
small icons on the right) so you can see if the whole river is correctly
ordered (all ways in the same direction).

note :
In France we began using widely this relation tag and it's also very
good tool to check river mapping advancement and to use efficiently
waterway (2).


(1) http://wiki.openstreetmap.org/wiki/Relations/Proposed/Waterway

(2) http://beta.letuffe.org/cron/etat-cours-eau/suivi-cours-eau.php
     http://beta.letuffe.org/ressources/cartes/hydrographie-france.png

-- 
Pierre-Alain Dorange
OSM experiences : <http://www.leretourdelautruche.com/map/>