On 2017.08.13. 23:11, David Kewley wrote: > Development in Orange County, California pushes into areas currently > covered by polygons (often large multipolygons) tagged as natural=scrub, > landuse=meadow, or landuse=[farm|farmland]. These were part of the FMMP > import http://wiki.openstreetmap.org/wiki/California_Farms. > > Mostly I try to leave those large multipologons alone, because I don't > feel confident I can handle them properly, and because I'm using iD (due > to using a Chromebook), where relation handling is rudimentary. > > But I'd like to update the urban-wildland boundary, where new suburban > developments are pushing into former wildland, farmland, or > (historical?) "grazing land". See for example the new development (with > 2017 imagery recently added to Bing) at > http://www.openstreetmap.org/edit?editor=id#map=16/33.5352/-117.6034. > > Editing these huge multipolygons, and reviewing others' edits to them, > becomes very cumbersome, at least to me. It seems to me probably > sensible and reasonable at the urban edge to split off small parts of > these multipolygons, e.g. at roads, to make the smaller bits easier to > edit and review in the context of the expanding urban edge. > > > As one test / demonstration edit > (http://www.openstreetmap.org/changeset/51090963), I carved off a bit of > natural=scrub from a large outer role of a multipolygon, into its own > polygon. I manually added new boundary way segments, stitched them > together into the existing ways, copied tags, and made the split-off > piece its own polygon, independent of its original parent multipolygon. > I did the split at an existing highway=residential object (Golden Ridge > Lane). > > I know, I should find a way to use JOSM, which I expect makes this much > easier. :) > > Meanwhile, does this seem a reasonable approach to making the urban > interface a bit more manageable in the future? I.e. splitting off parts > of large multipolygons (so long as they don't have names or other unique > identifiers that matter, just generic tags things like natural=scrub), > to make future editing easier? > > I know for the above example of a new residential area, I could make a > landuse=residential island, and make it an inner role in the surrounding > landuse=meadow multipolygon. But at some point as the urban sprawl > expands, it seems to me it makes more sense to stop pretending the area > is dominated by the natural features, and make it clear it's dominated > by e.g. landuse=residential, with possibly interspersed natural features > like scrub. > > > What would the group suggest? > > Is my test edit reasonable, or should it be reverted?
looks very reasonable. you have added the split-off piece as a separate way, not multipolygon, which makes it easier to handle. nitpicking - i would disconnect it from the road here :) http://osm.org/go/TPVmeC512?m= > Thanks, > David > > > P.S. As an aside (not my main point today), the FMMP-based distinction > in this area between scrub and meadow seems awfully arbitrary. I could > be mistaken, but I don't believe the "meadow" is actually used today for > grazing nor feed harvesting, and in the aerial photography, it appears > indistinguishable from the adjacent "scrub". It appears (and I'm nearly > certain from driving by) that there's both substantial grass and > substantial woody plant cover, in similar ratios in both "meadow" and > "scrub". > > I don't believe there's any current agricultural use of that land, at > least not near where I'm giving examples today. There might be some > large-acreage, semi-wildland grazing or feed harvesting activity > remaining in Orange County, but I've not noticed any. > > As documented in the FMMP wiki > page http://wiki.openstreetmap.org/wiki/California_Farms, the FMMP > designation "Grazing Land" was mapped to landuse=meadow. > > But the FMMP designation of "Grazing Land" explicitly does not mean that > there *is* grazing activity there, just that it is "...land on which the > existing vegetation, whether grown naturally or through management, is > suitable for grazing or browsing of livestock." (See for example > http://www.conservation.ca.gov/dlrp/fmmp/Documents/soil_criteria.pdf.) > So wildlands that will never again see livestock, or harvesting for > livestock feed, can still be designated Grazing Land by FMMP. Those > areas map better to natural=grassland or natural=scrub, I think. > > So landuse=meadow seems less useful than natural=scrub or > natural=grassland for many of these areas. Even though this is a > secondary point today, I'd welcome comments on this as well.-- Rihards _______________________________________________ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us