On Sat, Jun 20, 2020 at 8:33 PM Joseph Eisenberg <joseph.eisenb...@gmail.com> wrote: > > I was thinking just create separate polygons for inholdings, tagged with > > access=private and possibly ownership=private > > While many Americans like to put "no trespassing" signs on their private > property, a privately owned parcel is not access=private unless there are > signs on the roads and paths leading into it which say so. > > Many privately-owned parcels in the national forests are used for forestry > only, and there is no issue with crossing through on a road or trail in many > cases. > > Generally it is difficult to maintain land ownership data in OpenStreetMap. > Fortunately, in the USA there are publicly-available databases which contain > this cadastral information, so it is not necessary for us to duplicate it in > OpenStreetMap. Database users should expect to get land ownership information > directly from official sources, if they want accurate and up-to-data land > ownership info by parcel. > > For example in Oregon you can get data at > https://www.oregon.gov/geo/Pages/sdlibrary.aspx > > We should not try to map all land ownership data by parcel in OpenStreetMap.
In the particular case of these public lands, the land ownership, the land use, and the land's access constraints are inextricably bound together. Your contention tends to be interpreted by the 'hard liners' as an assertion that "public lands that are partly or wholly for recreation, such as National Forests, but also any of a entire menagerie of other land classes, ought not to be mapped." This assertion has effectively arisen whenever the subject of National Forests arises: much of the US public expects to see them on a map, but get met with the pernicious reply, "go to several dozen government agencies and get their cadastre, but don't map these oblects." (I'll accept that that';s not what you meant, but the slope here is indeed slippery.) In fact, OSM is the only good place that I have to aggregate this information. When I'm using these boundaries for planning, the parcels may be administered by multiple Federal, State and local government agencies, plus NGO's and land trusts. Each of these has its own database of what it manages. OSM is the best place that I have to see all of these public recreation lands at once. One of my favorite motivating examples is planning a trip to Roundtop Mountain https://www.openstreetmap.org/node/357583100#map=14/42.1726/-74.0598. The on-trail route from Palenville, far to the east, would have been quite arduous, beyond what I'd attempt on a day trip. Access from Twilight Park to the north would be out of the question - it's a gated community that does not welcome random visitors. The snowmobile trail access from Cortina Lane was closed at the time of year that I was planning the trip. I could have made the trip from the Platte Clove Bruderhof; the religious community there is welcoming, and the trail is open to the public, but I dislike imposing on their hospitality. With OSM, I was able to see that the Roundtop Mountain Unit (New York City Department of Environmental Protection, Bureau of Water Supply) was adjacent to the Kaaterskill Wild Forest, and with my NYC parking tag and access card in my pack, happily approached the mountain by a much shorter route from the west. I'd not have been able to do this with either agency's information alone. Now, on to the original question: I will concede that I've never mapped a National Forest - but I have helped with the mapping of some similarly-structured National Wildlife Refuges, and imported data about a great many state lands in New York, many of which have similarly diffuse boundaries. What I've done: 1. The outermost boundary of many of these lands consists simply of an an area in which the managing agency is authorized to acquire land, and sometimes to apply regulation to the use of property similar to what a zoning board might impose (and with similar requirements, such as compensating a landowner if the regulation significantly impairs the value of a parcel). Ordinarily it is unsigned and unobservable in the field. I ignore it for OSM; it's a regulatory designation for the government's operations, with little impact on protection, public access, land cover or land use. 2. The actual boundary - of ownership, regulation, protection, and likely land use - is what most map users expect to see. In many cases, these boundaries are quite diffuse. In all the cases that I've mapped, they're also observable in the field. The managing agency will post the boundaries at intervals. (In my area, many of the signs look like https://en.wikipedia.org/wiki/Forest_Preserve_(New_York)#/media/File:NYS_Forest_Preserve_sign.jpg, but there are numerous older-style markers. Where a road traverses a parcel, the signage will likely be fancier; one common form is https://hikingthetrailtoyesterday.files.wordpress.com/2017/01/1wolf-lakedsc046871.jpg. This boundary is, in all cases, what I put on the map. 3. Inholdings are mapped only by exclusion. If a given facility has multiple parcels, contains inholdings, or is otherwise topologically complex, it's mapped as a multipolygon, and whatever land is not part of the facility is not part of the multipolygon. There's no question about "how do I map an inholding"; the question is "how do I exclude an inholding from the surrounding facility", and the answer is, "by making a multipolygon with an inner ring." 4. Some facilities have protected areas within protected areas. That's actually a case that's foreseen by IUCN. A large area like a national park (or National Forest, or whatever!) may have some class of protection like 'sustainable use of resources' or 'national park' while enclosing a protected landscape or seascape, a wilderness area, an area intensively managed for the protection of endangered species, a recreation area, or whatever. I try to model this faithfully in the areas that I've mapped. So, for instance, the Adirondack https://www.openstreetmap.org/relation/1695394 and Catskill https://www.openstreetmap.org/relation/6265477 Parks in New York each contain a plethora of Wilderness, Wild Forrest, Intensive Use, Primitive, Canoe, and other areas, which are individually mapped. Each of these large parks is also a public-private partnership, and includes farms. mines, and villages as well as forests, with the land use intensively regulated by state agencies Many of the state facilities, particularly (for various reasons) the Wild Forest areas, are quite diffuse indeed, and need complex multipolygons like https://www.openstreetmap.org/relation/6360587 to represent them. These complex multipolygons surely make the map look messy, but the complexity on the map reflects a complex reality in the field. That complexity doesn't make mapping them useless, or mean that we should refer map users to the state agencies. I can look at OSM and the maps derived from it, and see where a hike might trespass, and where I'm safely on public-access land. -- 73 de ke9tv/2, Kevin _______________________________________________ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us
