Re: [Talk-us] tagging a national forest boundary
This exact question is the reason why I haven't imported the Green Mountain National Forest in Vermont (well also the fact that I haven't figured out how to convert Shapefiles to OSM format yet, but anyhow….). My research leads me to believe the the National Forest Boundary is simply the area within which the USFS has a mandate to acquire land. In the southern part of the GMNF the USFS only owns about 50% of the land within this boundary, but they add more each year. Anyway I've been trying to decide how to map this situation. It seems to be the case with many national forests on the east coast since they were created in areas where much of the land was already privately owned. Seems we need a way to tag the official outer boundary of national forests (and parks?) as there is often a sign marking these boundaries on major roads even if you aren't yet entering USFS owned land. The best I can come up with is to use boundary=national_park for the outer boundary and then use landuse=forest on a multipolygon that excludes the inholdings. This would render on Mapnik with a green dashed line on the boundary, dark green for USFS land, and light green for inholdings. Zeke On Thu, Sep 30, 2010 at 10:50 PM, Nathan Edgars II nerou...@gmail.comwrote: On Thu, Sep 30, 2010 at 9:52 PM, Greg Troxel g...@ir.bbn.com wrote: I think you two might be talking past each other. I am slightly fuzzy on multipolygons, but I think the notion is that a multipolygon has a number of outer rings, and a number of inner rings, and it defines the area that consists of points within an outer ring and not within an inner ring. So in the national forest/inholdings case, I think you have a polygon (closed way) that is the boundary (typically drawn strongly on a traditional topo), labeled as the forest boundary. Then you have a polygon for each inholding, with no particular tags required. And then a multipolygon with the forest boundary as outer and all the inholdings as inner. Bloody hell, I know this. The problem is that some of the inholdings touch the boundary, so they're actually outer ways (and the portion of the boundary there is nothing): http://www.openstreetmap.org/?lat=28.99352lon=-81.64891zoom=15layers=Mrelation=1202373 Yet the boundary is still something official. ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] tagging a national forest boundary
On Fri, Oct 1, 2010 at 7:37 AM, Greg Troxel g...@ir.bbn.com wrote: Are you happy with the rendering now? It looks like it matches what you've described. Well, the boundary=protected_area doesn't display at all, but that's a rendering problem. ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] tagging a national forest boundary
On Thu, Sep 30, 2010 at 2:47 PM, Ian Dees ian.d...@gmail.com wrote: On Thu, Sep 30, 2010 at 1:41 PM, Nathan Edgars II nerou...@gmail.com wrote: I'm importing the USFS data for the Ocala National Forest boundary. There's the actual forest boundary, and there are private inholdings inside the boundary that are not owned by the USFS. For flexibility, I'm making a multipolygon for each. But which one is the real boundary? What tags go on each? You're creating separate multipolygons for each of the private inholdings? You should be creating one multipolygon with several internal ring ways as inner members of the multipolygon relation. The whole multipolygon relation should have whatever tags you've decided on and the member ways should not have any tags. That's what I'm doing. But I then have two multipolygons: one for the forest boundary and one for this boundary minus the inholdings. The difference is nontrivial, since some of the inholdings go right up to the forest boundary, implying that the forest actually in some way includes these inholdings. ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] tagging a national forest boundary
On Thu, Sep 30, 2010 at 2:25 PM, Nathan Edgars II nerou...@gmail.comwrote: On Thu, Sep 30, 2010 at 2:47 PM, Ian Dees ian.d...@gmail.com wrote: On Thu, Sep 30, 2010 at 1:41 PM, Nathan Edgars II nerou...@gmail.com wrote: I'm importing the USFS data for the Ocala National Forest boundary. There's the actual forest boundary, and there are private inholdings inside the boundary that are not owned by the USFS. For flexibility, I'm making a multipolygon for each. But which one is the real boundary? What tags go on each? You're creating separate multipolygons for each of the private inholdings? You should be creating one multipolygon with several internal ring ways as inner members of the multipolygon relation. The whole multipolygon relation should have whatever tags you've decided on and the member ways should not have any tags. That's what I'm doing. But I then have two multipolygons: one for the forest boundary and one for this boundary minus the inholdings. The difference is nontrivial, since some of the inholdings go right up to the forest boundary, implying that the forest actually in some way includes these inholdings. Are you manufacturing the forest boundary outer ring or is it coming from the shapefile? I don't think you should imply that there is a natural=forest boundary logically separate from the National Forest's boundary. Assuming you're using USFS's shapefiles, there should be one thing in there: the boundary of the national forest. If there are holes in the forest anywhere (including directly on the external border), then they should be inner polygons of a multipolygon. ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] tagging a national forest boundary
On Thu, Sep 30, 2010 at 3:29 PM, Ian Dees ian.d...@gmail.com wrote: I don't think you should imply that there is a natural=forest boundary logically separate from the National Forest's boundary. Assuming you're using USFS's shapefiles, there should be one thing in there: the boundary of the national forest. If there are holes in the forest anywhere (including directly on the external border), then they should be inner polygons of a multipolygon. There are two separate definitions of what the national forest is. On http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5192654.pdf there's the dark green line (national forest boundary), but not everything inside it is light green fill (national forest land). Both are in the shapefiles. ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] tagging a national forest boundary
On Thu, Sep 30, 2010 at 2:34 PM, Nathan Edgars II nerou...@gmail.comwrote: On Thu, Sep 30, 2010 at 3:29 PM, Ian Dees ian.d...@gmail.com wrote: I don't think you should imply that there is a natural=forest boundary logically separate from the National Forest's boundary. Assuming you're using USFS's shapefiles, there should be one thing in there: the boundary of the national forest. If there are holes in the forest anywhere (including directly on the external border), then they should be inner polygons of a multipolygon. There are two separate definitions of what the national forest is. On http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5192654.pdf there's the dark green line (national forest boundary), but not everything inside it is light green fill (national forest land). Both are in the shapefiles. Thanks for the example. I would suggest using a border/boundary tag for the national forest boundary area and a landuse tag for the national forest land. I don't think there are any globally accepted values for this particular usecase, though. The national park/forest situation in the US is pretty unique. ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] tagging a national forest boundary
On Thu, Sep 30, 2010 at 3:38 PM, Ian Dees ian.d...@gmail.com wrote: Thanks for the example. I would suggest using a border/boundary tag for the national forest boundary area and a landuse tag for the national forest land. Yes, that's what I was thinking: boundary=protected_area for the outer boundary (not going to try to figure out which subtags) and landuse=forest for the inner. The inner should probably have a bit more though to say that it's a national forest. ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] tagging a national forest boundary
Nathan Edgars II nerou...@gmail.com writes: On Thu, Sep 30, 2010 at 2:47 PM, Ian Dees ian.d...@gmail.com wrote: On Thu, Sep 30, 2010 at 1:41 PM, Nathan Edgars II nerou...@gmail.com wrote: I'm importing the USFS data for the Ocala National Forest boundary. There's the actual forest boundary, and there are private inholdings inside the boundary that are not owned by the USFS. For flexibility, I'm making a multipolygon for each. But which one is the real boundary? What tags go on each? You're creating separate multipolygons for each of the private inholdings? You should be creating one multipolygon with several internal ring ways as inner members of the multipolygon relation. The whole multipolygon relation should have whatever tags you've decided on and the member ways should not have any tags. That's what I'm doing. But I then have two multipolygons: one for the forest boundary and one for this boundary minus the inholdings. The difference is nontrivial, since some of the inholdings go right up to the forest boundary, implying that the forest actually in some way includes these inholdings. I think you two might be talking past each other. I am slightly fuzzy on multipolygons, but I think the notion is that a multipolygon has a number of outer rings, and a number of inner rings, and it defines the area that consists of points within an outer ring and not within an inner ring. So in the national forest/inholdings case, I think you have a polygon (closed way) that is the boundary (typically drawn strongly on a traditional topo), labeled as the forest boundary. Then you have a polygon for each inholding, with no particular tags required. And then a multipolygon with the forest boundary as outer and all the inholdings as inner. Sort of related, landuse= tags and landcover tags (which we don't seem to have) should be separate. I haven't had time to dig into this, but I think it would be really useful if someone figured out what the taxonomies were in the various professional disciplines that deal with these issues, and just adopted one of them. OSM seems to insist on reinventing everything, and for replacing proprietary software and proprietary data that's great, but when entire research fields have argued about the right way to divide up land cover, it seems a shame to start over. pgpV9S3xK1UDf.pgp Description: PGP signature ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] tagging a national forest boundary
On Thu, Sep 30, 2010 at 9:52 PM, Greg Troxel g...@ir.bbn.com wrote: I think you two might be talking past each other. I am slightly fuzzy on multipolygons, but I think the notion is that a multipolygon has a number of outer rings, and a number of inner rings, and it defines the area that consists of points within an outer ring and not within an inner ring. So in the national forest/inholdings case, I think you have a polygon (closed way) that is the boundary (typically drawn strongly on a traditional topo), labeled as the forest boundary. Then you have a polygon for each inholding, with no particular tags required. And then a multipolygon with the forest boundary as outer and all the inholdings as inner. Bloody hell, I know this. The problem is that some of the inholdings touch the boundary, so they're actually outer ways (and the portion of the boundary there is nothing): http://www.openstreetmap.org/?lat=28.99352lon=-81.64891zoom=15layers=Mrelation=1202373 Yet the boundary is still something official. ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
