[FEATURE] Display waterway flow direction (arrows)

[AKorolyov]

Hello!

  It would be good to see waterway flow direction.

  Useful for boating, for terrain orientation, etc.

  For natural watercourses (rivers, streams, ...) as well as for man made waterways (canals).

  T&R,

  Andrey

[Aceman444]

+1
This would be great. Even Mapnik does not show the direction so the raw OSM data contains many errors.

Dňa sobota, 21. februára 2015 19:38:59 UTC+1 AKorolyov napísal(-a):

[AKorolyov]

- it's one more reason why I'm asking for the feature, it will really help OSM contributors to find and fix such errors in source maps.

@K

[Aceman444]

And it would even allow users to guess the direction of the slope, even if they don't have the countour lines or hillshade maps downloaded.

Can you report the request at : https://code.google.com/p/osmand/issues/

Dňa nedeľa, 22. februára 2015 11:09:53 UTC+1 AKorolyov napísal(-a):

[P Wat]

Nice Idea.  I'd vote for it.  I am a frequent inland water-way user.
I also navigate estuaries and other tidal waterways - In these locations the flow (generally) changes direction twice a day.
Have you considered how you would identify the location at which one-way flow ends and tidal flow begins?
PW
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[xmd5a]

I am afraid that it will be done only for new OpenGL engine. It can't be done in old engine.

суббота, 21 февраля 2015 г., 21:38:59 UTC+3 пользователь AKorolyov написал:

[Aceman444]

Why? A simple arrow can be drawn on roads, in which way are waterways different?

Dňa piatok, 27. februára 2015 20:31:16 UTC+1 xmd5a napísal(-a):

[Aceman444]

That location is probably very hard to find (may take weeks of trial and error to locate it). Also I think there is no tag for that in the wiki yet, so we do not need to consider it until there is a specification.

Dňa piatok, 27. februára 2015 20:30:36 UTC+1 P Wat napísal(-a):

[P Wat]

Location of tidal limit - This should help eliminate weeks of observation!

According to UK Ordnance Survey (Probably the best maps in the world), "The Normal Tidal Limit is the point at which the level of a river or stream ceases to be affected by the tidal flow”.
This is annotated on OS (Ordnance Survey) maps as "NTL".
You can see this on Bing Maps if you select "Ordnance Survey Map"- Here are two examples:-
On the River Thames west of (inland from) London, at Teddington Lock 51.429300, -0.318129.
On the River Itchen at Swaythling (east of Southampton) 50.936196, -1.372121.
Attached pic shows NTL at Teddington.

UK Hydrographic (nautical) charts (which cover many navigable rivers outside UK) indicate by colour code.
The nautical charts of other countries may have alternative systems.

FWIW - The River Thames flows approximately west to east overall but, due to meandering, in the pictured example it flows southeast to northwest as far as the NTL  Downstream of the NTL and through London to the Thames Estuary on the East Coast it is tidal, ie flows both ways, though obviously predominantly eastward.

PW
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[xmd5a]

Because it is hardcoded and we have tasks which are more important for next release.

суббота, 28 февраля 2015 г., 0:40:08 UTC+3 пользователь Aceman444 написал:

[Aceman444]

This assumes OS maps are legal to use for OSM.
Second, this is UK only. Maybe other countries did not publish such good maps.
See http://wiki.openstreetmap.org/wiki/Proposed_features/Tidal_Rivers . It seems this topic is also unclear among mappers yet and there is no agreement how to map the tides. So until that is solved OsmAnd is free to not care about tidal parts of rivers.

Dňa sobota, 28. februára 2015 0:12:09 UTC+1 P Wat napísal(-a):

[P Wat]

Your link to Proposed_features/Tidal_Rivers makes interesting reading, with relevant points to various arguments - Thanks.
I could inject from my 10 years of commercial operation on the Thames, and current ongoing leisure use, tidal and non-tidal.
PW