Re: [Talk-us] Waterway directionality in drainage canals
On 04/28/2012 09:23 PM, Paul Norman wrote: From: Nathan Edgars II [mailto:nerou...@gmail.com] Sent: Saturday, April 28, 2012 2:24 AM To: Tag discussion, strategy and related tools; OpenStreetMap talk-us list Subject: [Talk-us] Waterway directionality in drainage canals It's the standard to draw a waterway in the direction of flow. I've questioned this several times, but it's an ingrained default. My question is more specific: what happens to a drainage canal that reverses direction? I offer the Everglades and surrounding agricultural land as an example. There are huge "water conservation areas" that store water. When it rains, gates are closed and opened to direct water into these. During a drought, gates send water back out into the canals for local use. When there's a big storm, water will instead go directly out to sea. So there are a lot of major canals that have no fixed direction. How should these be mapped? Is there any existing scheme that can show how water flows under different conditions? The same issue came up with minor drainage ditches and cranberry fields here. They're used to drain sometimes and sometimes to flood the field for harvest. I came up with the proposal http://wiki.openstreetmap.org/wiki/Proposed_features/directional for directional=* but it's abandoned. One weakness with the proposal is that unknown values are a special case of directional=no, not directional=yes How about the oneway property? That is already often used on rivers (not so often on streams), but an explicit "oneway=no" would specify that water may flow in both directions... Just an idea. -- Cheers, Alex ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Waterway directionality in drainage canals
It's the standard to draw a waterway in the direction of flow. I've questioned this several times, but it's an ingrained default. My question is more specific: what happens to a drainage canal that reverses direction? I offer the Everglades and surrounding agricultural land as an example. There are huge "water conservation areas" that store water. When it rains, gates are closed and opened to direct water into these. During a drought, gates send water back out into the canals for local use. When there's a big storm, water will instead go directly out to sea. So there are a lot of major canals that have no fixed direction. How should these be mapped? Is there any existing scheme that can show how water flows under different conditions? Calling all real technical-consulting planet-oriented hydrologists: join in this conversation, please! (You never know). NE2, you might invent, then propose a "newer, meant to be better because we discussed it first" standard after asking that question the way you did. One way you seem to do so (NE2, though others, too) is with tags containing colons, as that has emerged in much structured tagging in a somewhat orderly way. Without deriving a dialect of it off the top of my head, that might even be a specific instance of what is known as a regular language. (We use network=US:I for Interstates, for example). Inventing a stub language like tidal=yes and barrier=marine_gate and semantics for the actual direction of the way that represents something ABOUT its flow (like seasonal or active or whatever) is real work that can be sketched on a whiteboard as an idea development methodology. It's more difficult via a channel like this digested list, but difficulties can be overcome. But after some fits and starts and people double-checking and looking over each other's shoulders and finding things that work...we have something. Considering how sane, smart growth of tags and processes whereby these evolve with real intent seems a fundamental topic. Positing something like the quick stub of brain-spew above shows how some of us are good at posing questions, some of us are good at longer-term vision or middle-building, many of us are great at mapping, and all of us can recognize these differences are strengths when our numbers speak together. (Even when it is seen that there is some spew that happens, it is the process of getting better of which I type). There really is a "middle" of OSM which feels quite under-built to me, at least from the perspective of California. Maybe that is just me having an early-feeling, though confident and articulate voice, or lack of finding specific more-local OSM community. I have collaborated over networked wires for many decades in many ways. This newer "middle of OSM" overlaps in my mind with "conversation places" where listening and structured whiteboard-like collaboration takes place. Let's build OSM's better middle with this in mind. I look for these conversation places myself, so I reach out a bit. I do not say how (right now), it's complex, everybody seems to have ideas and want to be listening and sorting that out is hard work and would take too long (right here). But "listening areas" and "working groups" and such are the neighborhood of what I mean. Am I unplugged-in from these? Or does "our national scene" (OSM in the US) largely get hashed out right here in talk-us? We seem to be lacking in coordination: there are terrific skill-sets here, and much gets done, but new focus for those laser-bolts of "good methods we figured out work really well for us" that can synergy and feedback-loop and leap us ahead, well, as they say, could "use improvement." I do put myself out here, and yes, it feels a little bold to say this. I listen, I look for structured listening. I look for better coordination and yes, maybe even towards leadership. Leadership doesn't have to be vested in an individual, it can consist of a core of "ideas that work, only" as a beginning. Yes, this is hard work. SteveA California ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Waterway directionality in drainage canals
> From: Nathan Edgars II [mailto:nerou...@gmail.com] > Sent: Saturday, April 28, 2012 2:24 AM > To: Tag discussion, strategy and related tools; OpenStreetMap talk-us > list > Subject: [Talk-us] Waterway directionality in drainage canals > > It's the standard to draw a waterway in the direction of flow. I've > questioned this several times, but it's an ingrained default. > > My question is more specific: what happens to a drainage canal that > reverses direction? I offer the Everglades and surrounding agricultural > land as an example. There are huge "water conservation areas" that store > water. When it rains, gates are closed and opened to direct water into > these. During a drought, gates send water back out into the canals for > local use. When there's a big storm, water will instead go directly out > to sea. > > So there are a lot of major canals that have no fixed direction. How > should these be mapped? Is there any existing scheme that can show how > water flows under different conditions? The same issue came up with minor drainage ditches and cranberry fields here. They're used to drain sometimes and sometimes to flood the field for harvest. I came up with the proposal http://wiki.openstreetmap.org/wiki/Proposed_features/directional for directional=* but it's abandoned. One weakness with the proposal is that unknown values are a special case of directional=no, not directional=yes ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Waterway directionality in drainage canals
In many European canals, the convention is for the waterway authorities to arbitrarily define a direction so that a 'left' and 'right' bank can be defined and the appropriate navigational marks installed. So in those cases, where you see red on one side and green on the other, the nominated 'direction' can be deduced. If you face in the direction that places the red marks on your right & green marks on your left, then you are facing downstream. Of course, that does not help you in the case of non-navigable or unmarked waterways. ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
[Talk-us] Waterway directionality in drainage canals
It's the standard to draw a waterway in the direction of flow. I've questioned this several times, but it's an ingrained default. My question is more specific: what happens to a drainage canal that reverses direction? I offer the Everglades and surrounding agricultural land as an example. There are huge "water conservation areas" that store water. When it rains, gates are closed and opened to direct water into these. During a drought, gates send water back out into the canals for local use. When there's a big storm, water will instead go directly out to sea. So there are a lot of major canals that have no fixed direction. How should these be mapped? Is there any existing scheme that can show how water flows under different conditions? ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us