Re: [Tagging] Any support for a flow tag?
On 01/04/2011 16:47, j...@jfeldredge.com wrote: One example of a waterway with reversing flow would be the estuary of a river. While the tide is rising, the flow in the estuary may slow, come to a standstill, or even temporarily reverse directions (called a tidal bore). ---Original Email--- Subject :Re: [Tagging] Any support for a flow tag? From :mailto:dieterdre...@gmail.com Date :Fri Apr 01 09:38:31 America/Chicago 2011 Estuaries are generally mapped as coastlines, so river flows are not applicable. Tidal flows, being dynamic, cannot have a direction. Within the river domain, the nominal flow is always towards the sea, even if temporarily reversed by incoming tides. A tidal bore is a wave, not a current. It travels upstream, but the river continues to flow downstream. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Any support for a flow tag?
We have some in Australia. Of course, the usual flow state in these
areas is none (or very little).
It's very flat ground, often hundreds (or thousands) of km from the
sea. River channels wander through, carrying water that comes from
wherever the floods are. If it rained to the south, the water flows
north, and vice versa. If there's no rain anywhere for a while, it
dries up into isolated pools.
Stephen
On 2 April 2011 00:38, M∡rtin Koppenhoefer dieterdre...@gmail.com wrote:
I have never come across a waterway with changing flow
direction, but I don't exclude that this does exist, so the suggested
directional / flow tag could have a benefit for these. Another solution
would be to not consider these cases part of {river, stream, canal, drain,
ditch}, but rather invent another tag for them.
___
Tagging mailing list
Tagging@openstreetmap.org
http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Any support for a flow tag?
2011/3/31 Lennard l...@xs4all.nl If the direction of the way is drawn in the same flow of the water, it should always be drawn with an arrow. What if it's drawn the other way? mapping error. What if a coastline is drawn the other way? Rendering the flow of waterways in mapnik would help to fix those errors, because more people would become aware. cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Any support for a flow tag?
On 4/1/2011 9:53 AM, M∡rtin Koppenhoefer wrote: 2011/3/31 Lennard l...@xs4all.nl mailto:l...@xs4all.nl If the direction of the way is drawn in the same flow of the water, it should always be drawn with an arrow. What if it's drawn the other way? mapping error. What if a coastline is drawn the other way? Rendering the flow of waterways in mapnik would help to fix those errors, because more people would become aware. Still doesn't deal with unknown or abnormal flow. For a coastline, it's obvious which side is land, but it's not always obvious which way a waterway flows (if it even has a constant flow). ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Any support for a flow tag?
2011/4/1 Nathan Edgars II nerou...@gmail.com
On 4/1/2011 9:53 AM, M∡rtin Koppenhoefer wrote:
flow of waterways in mapnik would help to fix those errors, because more
people would become aware.
mapping error. What if a coastline is drawn the other way? Rendering the
Still doesn't deal with unknown or abnormal flow. For a coastline, it's
obvious which side is land, but it's not always obvious which way a waterway
flows (if it even has a constant flow).
Yes of course. I set FIXME=please check flow direction if I am unsure
(usually you can deduct the flow direction but there is rare cases where it
is not possible). I have never come across a waterway with changing flow
direction, but I don't exclude that this does exist, so the suggested
directional / flow tag could have a benefit for these. Another solution
would be to not consider these cases part of {river, stream, canal, drain,
ditch}, but rather invent another tag for them.
cheers,
Martin
___
Tagging mailing list
Tagging@openstreetmap.org
http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Any support for a flow tag?
On 4/1/2011 10:38 AM, M∡rtin Koppenhoefer wrote: Yes of course. I set FIXME=please check flow direction if I am unsure (usually you can deduct the flow direction but there is rare cases where it is not possible). With manmade channels it's far from rare. Example: http://www.openstreetmap.org/?way=73765043 I have never come across a waterway with changing flow direction, http://my.sfwmd.gov/portal/page/portal/xrepository/sfwmd_repository_pdf/lake_management_area_descriptions.pdf The smaller S-58 water control structure located at the north end of Trout Lake generally acts as the drainage divide for flows through the KCOL. This is the case except under very high water conditions when water can be released northward through the C-32C Canal into the Lake Preston, Myrtle, and Joel LMA. There's also http://en.wikipedia.org/wiki/Reversing_Falls (which in a general sense is oneway into the sea but on a large scale reverses daily). ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Any support for a flow tag?
2011/4/1 Nathan Edgars II nerou...@gmail.com On 4/1/2011 10:38 AM, M∡rtin Koppenhoefer wrote: Yes of course. I set FIXME=please check flow direction if I am unsure (usually you can deduct the flow direction but there is rare cases where it is not possible). With manmade channels it's far from rare. Example: http://www.openstreetmap.org/?way=73765043 I have never come across a waterway with changing flow direction, http://my.sfwmd.gov/portal/page/portal/xrepository/sfwmd_repository_pdf/lake_management_area_descriptions.pdf The smaller S-58 water control structure located at the north end of Trout Lake generally acts as the drainage divide for flows through the KCOL. This is the case except under very high water conditions when water can be released northward through the C-32C Canal into the Lake Preston, Myrtle, and Joel LMA. not sure if this is a case for common waterways (or if it is another type), but sounds as if it were and if you needed 2 waterways to model this (one for the standard, and one for the high water conditions when water is released into another direction, if I get this right (sounds like an overfall). There's also http://en.wikipedia.org/wiki/Reversing_Falls (which in a general sense is oneway into the sea but on a large scale reverses daily). If I get this right it is seawater, so IMHO the listed waterways are not suitable. cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Any support for a flow tag?
2011/4/1 Nathan Edgars II nerou...@gmail.com On 4/1/2011 11:24 AM, M∡rtin Koppenhoefer wrote: like an overfall). if I get this right (sounds No, it's the same canal, with water flowing the other direction. This is the S-58 structure: http://www.openstreetmap.org/?node=944499871 There is normally no flow through S-58, so what little water enters the C-32C Canal south of it flows into Trout Lake. But during high water conditions, water flows north out of Trout Lake, through S-58. OK, interesting case, what do you propose for the conditional tagging? Do you have specifics how much is high water? I guess this would be needed to describe the system adequately. If you wanted to make it simple, you could describe the situation in the description tag and ignore complex tags, but I guess that's too easy ;-) and I agree that it would be nice to map this situation in high detail. cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Any support for a flow tag?
On 4/1/2011 11:40 AM, M∡rtin Koppenhoefer wrote: OK, interesting case, what do you propose for the conditional tagging? Do you have specifics how much is high water? Most likely the water management district decides on a case-by-case basis. I would guess that there are also waterways with no normal direction at all. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Any support for a flow tag?
One example of a waterway with reversing flow would be the estuary of a river. While the tide is rising, the flow in the estuary may slow, come to a standstill, or even temporarily reverse directions (called a tidal bore). ---Original Email--- Subject :Re: [Tagging] Any support for a flow tag? From :mailto:dieterdre...@gmail.com Date :Fri Apr 01 09:38:31 America/Chicago 2011 -- John F. Eldredge -- j...@jfeldredge.com Reserve your right to think, for even to think wrongly is better than not to think at all. -- Hypatia of Alexandria ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Any support for a flow tag?
On 01/04/2011 17:47, j...@jfeldredge.com wrote: One example of a waterway with reversing flow would be the estuary of a river. While the tide is rising, the flow in the estuary may slow, come to a standstill, or even temporarily reverse directions (called a tidal bore). Surely most estuaries reverse direction with an incoming tide, especially close to the sea? A tidal bore is a specific phenomenon (a step change in the water depth, moving upstream), and is not simply a reversal of direction:http://en.wikipedia.org/wiki/Tidal_bore ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Any support for a flow tag?
Well, what I was thinking (but didn't express clearly) was that whether you see a reversal, or merely a slowing, would depend upon where in the estuary you measured the flow. Thanks for the clarification on the tidal bore terminology.. ---Original Email--- Subject :Re: [Tagging] Any support for a flow tag? From :mailto:colin.sm...@xs4all.nl Date :Fri Apr 01 12:14:01 America/Chicago 2011 -- John F. Eldredge -- j...@jfeldredge.com Reserve your right to think, for even to think wrongly is better than not to think at all. -- Hypatia of Alexandria ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
[Tagging] Any support for a flow tag?
I'm wondering if there would be any support for a flow=forward/backward/etc. tag for waterways. This would make the flow direction explicit, and would provide a machine-readable way to tag unknown or abnormal flow. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Any support for a flow tag?
Hi, Nope it's actually just a rendering rule that can be created. If the direction of the way is drawn in the same flow of the water, it should always be drawn with an arrow. this rendering rule could be immediatly applied on mapnik, then you would see water pointing everywhere ... this just needs to be manually fixed. Perhaps a recreation map like cyclemap and/or hikebikemap.de could impliment this? (i complained on the talk-ca) and this is the solution. It's on my list to impliment it for CommonMapnik rendering, so the geobase NHN will all look great, since the geometry is correct with the flow (canvec rivers are not). cheers, sam On 3/31/11, Nathan Edgars II nerou...@gmail.com wrote: I'm wondering if there would be any support for a flow=forward/backward/etc. tag for waterways. This would make the flow direction explicit, and would provide a machine-readable way to tag unknown or abnormal flow. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging -- --- Across Canada Trails - Beyond 2017 - The National Trails Network Victoria, BC Canada Twitter: @Acrosscanada Blog: http://acrosscanadatrails.posterous.com/ Facebook: http://www.facebook.com/sam.vekemans Skype: 'Sam Vekemans' Member, CommonMap Inc. http://commonmap.org/ IRC: irc://irc.oftc.net #CommonMap Also find us on Facebook, Twitter and LinkedIn ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Any support for a flow tag?
On 31-3-2011 19:25, Sam Vekemans wrote: Nope it's actually just a rendering rule that can be created. Technically, yes. That would also be the wrong approach. If the direction of the way is drawn in the same flow of the water, it should always be drawn with an arrow. What if it's drawn the other way? this rendering rule could be immediatly applied on mapnik, then you would see water pointing everywhere ... this just needs to be manually fixed. Which we're not going to do. It's on my list to impliment it for CommonMapnik rendering, so the geobase NHN will all look great, since the geometry is correct with the flow (canvec rivers are not). Thanks for already listing a major objection against rendering implicit flow direction only based on way direction. That saves me from having to explain that part to you. Cheers. -- Lennard ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Any support for a flow tag?
On 3/31/2011 1:25 PM, Sam Vekemans wrote: On 3/31/11, Nathan Edgars IInerou...@gmail.com wrote: I'm wondering if there would be any support for a flow=forward/backward/etc. tag for waterways. This would make the flow direction explicit, and would provide a machine-readable way to tag unknown or abnormal flow. Nope it's actually just a rendering rule that can be created. If the direction of the way is drawn in the same flow of the water, it should always be drawn with an arrow. That's a big if. Probably about half the waterways I've come across where I knew the flow direction were mapped the other way. As I mention, there's also the case where the mapper doesn't know the direction of flow, or where flow is stagnant, reversing, or otherwise abnormal. As a similar example, see motorways and motorway_links. Even though oneway=yes is implied, many mappers, myself included, will still add that tag. There's also oneway=no to override the default. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
