The Atacama desert has many areas of bare sand and rock, but also some places with mixed stoney soil:
https://www.flickr.com/photos/chrishunkeler/32097822997 https://www.flickr.com/photos/chrishunkeler/46125841885/in/photostream/ On Mon, Jul 13, 2020 at 12:31 AM Michael Montani <michael.mont...@un.org> wrote: > Doing some wrap up: > > > *> Barren sounds to me to imply nothing can grow there.Bare sounds more * > > *neutral and factual to me, it just says there is nothing but bare soil to > * > *mark the area with.Please correct if I am wrong!* > > For the 'barren vs bare' discussion, I would go for natural=bare_soil, not > only for the meaning but also for a matter of consistency with the already > existing natural=bare_rock. > > > *>Even those photos show that there is some vegetation there, even though * > *it's sparse.* > > *At what level of plant growth, does it stop being "bare ground"? One * > *"plant" (tree / shrub / patch of grass etc) per sq km / 100 / 10 / 1 sq > m?* > > *Maybe, instead of saying it's bare ground, we need some way of describing > * > *the level of ground cover eg vegetation=sparse or similar?* > > To me, I'm ok in considering bare_soil with some vegetation. But obviously > not too much, otherwise I would switch to natural=scrub. Also, a > natural=bare_soil + vegetation=sparse to me would be natural=scrub or > natural=grassland. A (little) tree/shrub/patch every (approximately) 10 sq > m or more seems good to me to state it's bare_soil. The photos I posted, > have some scrub polygon surrounding the groundy area for sure. > > Also, I would go for bare_soil targeting silt or clay soil, loam and > mixture humus and mineral soil. To me, all these areas don't have a current > OSM tag correctly defining all of them, apart when inserted in an > environmental or geological context as wetlands. > Indeed, I wouldn't use bare_soil when a wetland can reasonably describe in > a correct way the area, as well as a thin layer of grass (e.g. lichens in > tundra) is covering the ground (in that case natural=grassland). > Furthermore to me is not meaningful to specify whether a soil is mostly > humus as, if the organic matter percentage is high, most probably > vegetation will grow there in a while. As you may have imagined, this tag > proposal was born mostly to map arid areas rather than general soil, but > soil seems to be a huge gap in OSM landcover tagging. > > Unfortunately is very hard to retrieve on-the-ground photos in Africa, but > I think these areas are very common in places outside the European context. > Feel free to add photos (if you have any) at > https://wiki.openstreetmap.org/wiki/Talk:Proposed_features/Ground#Examples > > > Thanks, > > -- > *Michael Montani* > GIS Consultant, *Client Solutions Delivery Section* > *Service for Geospatial Information and Telecommunications Technologies* > United Nations Global Service Centre > United Nations Department of Operational Support > > Brindisi | Phone: +39 0831 056985 | Mobile: +39 3297193455 | Intermission: > 158 6985 > E-mail: michael.mont...@un.org <m...@un.org> | www.ungsc.org > > ------------------------------ > *Da:* Joseph Eisenberg <joseph.eisenb...@gmail.com> > *Inviato:* domenica 12 luglio 2020 21:15 > *A:* Tag discussion, strategy and related tools <tagging@openstreetmap.org > > > *Oggetto:* Re: [Tagging] Feature Proposal - RFC - (Ground) > > The link [2] to https://www.hq.nasa.gov/iwgsdi/Barren_Land.html has these > categories: > > *1.2.2.2.1 Bare Exposed Rock*: Those ecosystems characterized by areas of > bedrock exposure, desert pavement, scarps, talus, slides, volcanic > material, rock glaciers, and other accumulations of rock without vegetative > cover. > > This is mostly covered by natural=bare_rock or natural=scree (or > natural=shingle) currently. > > *1.2.2.2.2 Beaches*: Those ecosystems along shorelines characterized by > smooth sloping accumulations of sand and gravel. The surface is stable > inland, but the shoreward part is subject to erosion by wind and water and > to deposition in protected areas. > > This is natural=beach, or natural=wetland + wetland=tidalflat, or > natural=shingle, possibly overlapping with water (if below the high tide > line or high water line). > > *1.2.2.2.3 Dry Salt Flats*: Those ecosystems occurring on the > flat-floored bottoms of interior desert basins that do not qualify as > wetlands. > > We don't have a good tag for this, as Christoph mentioned previously, > probably because these features are rare in Europe. > > *1.2.2.2.4 Mixed Barren Land*: Those regions in which a mixture of barren > land features occurs and the dominant land use occupies less than > two-thirds of the area. This includes, for example, a desert region where > combinations of salt flats, sandy areas, bare rock, surface extraction, and > transitional activities could occur in close proximity. > > We should map these areas based on the most specific area: natural=sand, > natural=bare_rock, landuse=quarry, etc. > > *1.2.2.2.5 Sandy Areas Other Than Beaches*: Those ecosystems composed > primarily of dunes -- accumulations of sand transported by wind. ... > > This is usually mapped as natural=sand > > *1.2.2.2.6 Strip Mines, Quaries, and Gravel Pits*: Those regions where > vegetative cover and overburden are removed to expose such deposits as > coal, iron ore, limestone, and copper. This includes inactive, unreclaimed, > and active strip mines, quarries, borrow pits, and gravel pits until other > cover or use has been established. > > Mapped as landuse=quarry > > *1.2.2.2.7 Transitional Areas*: Those regions that are in transition from > one land use activity to another. This transitional phase occurs when, for > example, forest lands are cleared for agriculture, wetlands are drained for > development, or when any type of land use ceases as areas become > temporarily bare as con- struction is planned for such future uses as > residences, shopping centers, industrial sites, or subur- ban and rural > residential subdivisions. This also includes land being altered by filling, > such as occurs in spoil dumps or sanitary landfills. (Definition Source: A > Land Use and Land Cover Classification System for Use with Remote Sensing > Data) > > This might be landuse=landfill, landuse=construction, or > landuse=brownfield in many cases. Areas where trees have been recently > cleared are somewhat debatable, if it's not certain what the area is > transitioning into, but there is landuse=meadow + meadow=transitional for > areas of grass that are transitioning into scrub or early woodland again. > > So we certainly need a new tag for salt flats, and I agree that there are > some places like badlands and deserts with clay soils where we don't have > well established tags for unvegetated areas, but many types of "barren" > land can already be mapped with existing tags. That's why it's important > that new tags are precisely defined. > > – Joseph Eisenberg > > On Sun, Jul 12, 2020 at 10:37 AM mbranco2 <mbran...@gmail.com> wrote: > > I hope that this discussion and the related proposal wiki page will lead > to a solution, because I found several times, mapping in Africa with HOT > projects, "desertic lands" and I didn't find a tag for this. > > If we search the Internet for "barren soil", we can find a lot of > ground-level related images. > > And I think that we could map such characteristic even with only imagery > (without direct survey), because it's a "macro" feature, as is a wood or a > scrub. > > Maybe images was shot in a particular season, and the soil condition is > not always the same? > Well, if I check several imageries and in all of them I see a "desertic > land", I'm confident I can map that area with the tag we're talking about. > And I think it doesn't matter if for few days a year (or few days in > several years...) it will rain and there will be - for few days - a bit of > vegetation: it's not an OSM mapping rule, to map the "main" characteristic > of an item? > > Surely it could be useful if botanists and/or geologists could better > specify (with more specific tags) the cause: no rain? pollution? specific > ground-conditions such as presence of salt or sulfur? > > For the main tag, I think that "natural" is the right key (being already > natural=sand/bare_rock/shingle/scree...). > About the value, I'd prefer a botanic or geologist suggest us the best > word. > > Some references: > - "Barren vegetation" [1] (..."Regions on the earth’s surface where soils > are dominating the ecosystems with little to no plant cover are often > referred to as “Barren”. ) > - "Barren land" [2] (an old web page from NASA: "...ecosystems in which > less than one third of the area has vegetation or other cover. In general, > Barren Land has thin soil, sand, or rocks."). This web page cites "A Land > Use and Land Cover Classification System for Use with Remote Sensor Data", > a free paper you can find in Google Books too. > - "Barren soil is starving Africans" [3] > > Other examples of "desertic" lands: > - Bonneville (USA) [4] (maybe some of you saw World's Fastest Indian, the > lovely movie with Anthony Hopkins :-) ) > - La Leona (Patagonia) [5] > > Ciao! > Marco (mbranco2 / UNGSC-mbranco2) > > [1] https://en.wikipedia.org/wiki/Barren_vegetation > [2] https://www.hq.nasa.gov/iwgsdi/Barren_Land.html > [3] https://www.nature.com/news/2006/060327/full/060327-15.html > [4] https://en.wikipedia.org/wiki/Bonneville_Salt_Flats > [5] https://visitpatagonia.com.ar/en/activities/petrified-forest-la-leona/ > > > > > > <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> > Mail > priva di virus. www.avast.com > <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> > <#m_-5644143951967344045_x_m_-7039561711865801855_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> > _______________________________________________ > Tagging mailing list > Tagging@openstreetmap.org > https://lists.openstreetmap.org/listinfo/tagging > > _______________________________________________ > Tagging mailing list > Tagging@openstreetmap.org > https://lists.openstreetmap.org/listinfo/tagging >
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