Re: [OSM-talk-ie] Estimate of number of building=* in Ireland
May 15, 2020, 00:04 by davecor...@gmail.com: > The fact that so many buildings are being mapped as building=yes when more > accurate tagging is plainly obvious makes this an utterly frustrating > project. > > Saying that others can come along after and correct it is a totally > avoidable requirement by using more appropriate tagging in the first place. > Its also unlike to ever get corrected as evidenced by the volume of data in > Ireland that was created and never improved upon. > If there is not enough mappers then likely mapping more building as building=yes is more efficient than using specific building value anyway. And anyone may map whatever (s)he wants, it is perfectly fine to map roads without mapping buildings, map trees instead of mapping roads, map buildings as building=yes, map bicycle parkings and map no shops at all... Note also that for example StreetComplete allows newbies and beginners to build on build on initial not finished data and for example specify more exact building types. > The logical approach should be to map it as house/garage/shed etc and ONLY > use building=yes if you cannot make an educated guess. > > Doing otherwise puts this data on the level of the tiger import. > No. TIGER import had plenty of outright invalid, incorrect and insane data. This is merely missing not very important part of info. https://wiki.openstreetmap.org/wiki/File:TIGER_fixup_example_before.jpg https://wiki.openstreetmap.org/wiki/File:Braided-streets-example.jpg https://wiki.openstreetmap.org/wiki/TIGER_fixup ___ Talk-ie mailing list Talk-ie@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-ie
Re: [OSM-talk-ie] Estimate of number of building=* in Ireland
The fact that so many buildings are being mapped as building=yes when more accurate tagging is plainly obvious makes this an utterly frustrating project. Saying that others can come along after and correct it is a totally avoidable requirement by using more appropriate tagging in the first place. Its also unlike to ever get corrected as evidenced by the volume of data in Ireland that was created and never improved upon. The logical approach should be to map it as house/garage/shed etc and ONLY use building=yes if you cannot make an educated guess. Doing otherwise puts this data on the level of the tiger import. On Thu, May 14, 2020 at 1:04 PM Colm Moore wrote: > Hi, > > Apologies, there was something else I meant to mention. > > Some locations have a very low number of building polygons per capita > (i.e. implying high number of people per building). This may be > **suggestive** of locations that are under-mapped. This bears out in some > of suburbs on the Kilkenny side of Waterford city, where there are lots of > unmappable (tree cover and fuzzy images) garden sheds, etc. There are other > reasons for this, like apartment buildings, terraced houses mapped as > building=terrace, etc. > > On Wed, 13 May 2020 at 14:38, Donie Kelly wrote: > > > Don’t buildings have tags? Did I see a residential tag? Is it used in all > > cases? > > Yes, buildings can be given detailed descriptions, e.g. building=house, > building=apartments. However, about half of the buildings on the island > just use building=yes. Only saying building=yes gets the building on the > map quickly, makes them readily findable and lets other mappers fill in > details later. Not all buildings are readily identifiable from aerial > images and details like number of storeys can be even harder to determine. > > Note that building=residential can be used for buildings that > are residential, but the type isn't readily identifiable, e.g. I saw some > semi-detached houses in Kilkenny that were attached back-to-back instead of > side-to-side. > > Interpreting the total number of buildings on the island from the total > number of, say houses, would be more complicated than comparing number of > buildings in Kilkenny to the number of buildings on the island. > > On Thu, 14 May 2020 11:47:29 Tadeusz Cantwell wrote: > > > The residential tag should be used for an area not a house. > > Yes, landuse=residential should be used for residential sites / estates / > neighbourhoods. The iD editor now supports additional sub-tags, > e.g. residential=rural, residential=apartments and residential=halting_site > You can also add name=* to the likes of housing estates, which can help > detail the hierarchy of a town. > > Colm > > > > --- > > > ___ > Talk-ie mailing list > Talk-ie@openstreetmap.org > https://lists.openstreetmap.org/listinfo/talk-ie > ___ Talk-ie mailing list Talk-ie@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-ie
[OSM-talk-ie] Estimate of number of building=* in Ireland
Hi, Apologies, there was something else I meant to mention. Some locations have a very low number of building polygons per capita (i.e. implying high number of people per building). This may be **suggestive** of locations that are under-mapped. This bears out in some of suburbs on the Kilkenny side of Waterford city, where there are lots of unmappable (tree cover and fuzzy images) garden sheds, etc. There are other reasons for this, like apartment buildings, terraced houses mapped as building=terrace, etc. On Wed, 13 May 2020 at 14:38, Donie Kelly wrote: > Don’t buildings have tags? Did I see a residential tag? Is it used in all > cases? Yes, buildings can be given detailed descriptions, e.g. building=house, building=apartments. However, about half of the buildings on the island just use building=yes. Only saying building=yes gets the building on the map quickly, makes them readily findable and lets other mappers fill in details later. Not all buildings are readily identifiable from aerial images and details like number of storeys can be even harder to determine. Note that building=residential can be used for buildings that are residential, but the type isn't readily identifiable, e.g. I saw some semi-detached houses in Kilkenny that were attached back-to-back instead of side-to-side. Interpreting the total number of buildings on the island from the total number of, say houses, would be more complicated than comparing number of buildings in Kilkenny to the number of buildings on the island. On Thu, 14 May 2020 11:47:29 Tadeusz Cantwell wrote: > The residential tag should be used for an area not a house. Yes, landuse=residential should be used for residential sites / estates / neighbourhoods. The iD editor now supports additional sub-tags, e.g. residential=rural, residential=apartments and residential=halting_site You can also add name=* to the likes of housing estates, which can help detail the hierarchy of a town. Colm --- ___ Talk-ie mailing list Talk-ie@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-ie
Re: [OSM-talk-ie] Estimate of number of building=* in Ireland
both building=residential and landuse=residential are valid tagging (though, if possible then building=house or other more specific value is preferable) May 14, 2020, 12:47 by t4d...@gmail.com: > The residential tag should be used for an area not a house. > > On Wed, 13 May 2020 at 14:38, Donie Kelly wrote: > >> Don’t buildings have tags? Did I see a residential tag? Is it used in all >> cases? >> >> > On 13 May 2020, at 13:24, Colm Moore wrote: >> > >> > Hi, >> > >> > Inspired by seeing the estimate in the Microgrant application of 5.5 >> million buildings on the island of Ireland, I did some number crunching. >> > >> > I downloaded the populations of Kilkenny townlands (1,500+) from the CSO >> and analysed the population against the number of buildings per civil >> parish (100+) for County Kilkenny. This is assuming Kilkenny has all or >> nearly all buildings mapped. Based on my inspections, this is largely true. >> > >> > The CSO data is somewhat distorted for the Kilkenny city area (100+ >> townlands), due to the way the CSO have arranged the townlands and civil >> parishes. I could look at this in more detail, but there would be a few >> hours of effort (unless someone has a simple way of calculating number of >> buildings per area, for a large number of areas). >> > >> > I calculated the 'number of buildings per civil parish' using the >> Overpass Turbo query [building=* in "civilparishname, Kilkenny"]. Overpass >> Turbo gives a summary of the data in the bottom right corner of the screen, >> e.g. >> > >> > Loaded – nodes: 4261, ways: 867, relations: 2 >> > Displayed – pois: 0, lines: 0, polygons: 866 >> > >> > I took the number of polygons to mean the number of buildings (this >> might not be perfect - I don't know how those numbers add up). >> Additionally, some polygons, e.g. building=terrace represent several >> buildings, while in other cases buildings may have been crudely split or >> joined-up. >> > >> > Depending on the civil parish, we're looking at 0.32-2.29 polygons per >> capita (0.44-3.15 people per building). Rural areas ten to have more >> polygons per capita, especially due to farm outbuildings, while urban areas >> have fewer polygons per capita, due to apartments buildings and >> semi-detached buildings (e.g. two square houses joined together might have >> only six nodes). >> > >> > I also calculated 4.40-5.83 nodes per polygon. This means some civil >> parishes have predominantly rectangular polygons / buildings, whereas >> others have many L-shaped or other-shaped polygons / buildings. >> > >> > As I wasn't able to immediately get some 'number of buildings per civil >> parish' numbers (Overpass Turbo had problems returning them, possibly due >> to duplicate names and variations in name spellings), I had to calculate >> them from their component townlands, using the Overpass Turbo query >> [building=* in "townlandname, civilparishname, Kilkenny"]. >> > >> > Depending on the townland, we're looking at 0.23-8.00 polygons per >> capita (0.13-4.37 people per building) and 3.91-6.45 nodes per polygon >> (i.e. some townlands have large numbers of semi-detached or terraced >> buildings, whereas others have a high number of complicated-shape polygons >> / buildings or buildings with too many mapped nodes). It is usual to see >> more extreme spreads when looking at smaller areas. >> > >> > I'm coming up with about 5.4 million (close enough!) buildings for the >> whole island, assuming the pattern is the same everywhere. However, as >> shown by analysing the smaller areas, there is variation and the 'final' >> number will vary from that. Of course, given that OSM is an ongoing >> project, there will never be a final number. >> > >> > Colm >> > VictorIE >> > ___ >> > Talk-ie mailing list >> > Talk-ie@openstreetmap.org >> > https://lists.openstreetmap.org/listinfo/talk-ie >> >> ___ >> Talk-ie mailing list >> Talk-ie@openstreetmap.org >> https://lists.openstreetmap.org/listinfo/talk-ie >> > ___ > Talk-ie mailing list > Talk-ie@openstreetmap.org > https://lists.openstreetmap.org/listinfo/talk-ie > ___ Talk-ie mailing list Talk-ie@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-ie
Re: [OSM-talk-ie] Estimate of number of building=* in Ireland
The residential tag should be used for an area not a house. On Wed, 13 May 2020 at 14:38, Donie Kelly wrote: > Don’t buildings have tags? Did I see a residential tag? Is it used in all > cases? > > > On 13 May 2020, at 13:24, Colm Moore wrote: > > > > Hi, > > > > Inspired by seeing the estimate in the Microgrant application of 5.5 > million buildings on the island of Ireland, I did some number crunching. > > > > I downloaded the populations of Kilkenny townlands (1,500+) from the CSO > and analysed the population against the number of buildings per civil > parish (100+) for County Kilkenny. This is assuming Kilkenny has all or > nearly all buildings mapped. Based on my inspections, this is largely true. > > > > The CSO data is somewhat distorted for the Kilkenny city area (100+ > townlands), due to the way the CSO have arranged the townlands and civil > parishes. I could look at this in more detail, but there would be a few > hours of effort (unless someone has a simple way of calculating number of > buildings per area, for a large number of areas). > > > > I calculated the 'number of buildings per civil parish' using the > Overpass Turbo query [building=* in "civilparishname, Kilkenny"]. Overpass > Turbo gives a summary of the data in the bottom right corner of the screen, > e.g. > > > > Loaded – nodes: 4261, ways: 867, relations: 2 > > Displayed – pois: 0, lines: 0, polygons: 866 > > > > I took the number of polygons to mean the number of buildings (this > might not be perfect - I don't know how those numbers add up). > Additionally, some polygons, e.g. building=terrace represent several > buildings, while in other cases buildings may have been crudely split or > joined-up. > > > > Depending on the civil parish, we're looking at 0.32-2.29 polygons per > capita (0.44-3.15 people per building). Rural areas ten to have more > polygons per capita, especially due to farm outbuildings, while urban areas > have fewer polygons per capita, due to apartments buildings and > semi-detached buildings (e.g. two square houses joined together might have > only six nodes). > > > > I also calculated 4.40-5.83 nodes per polygon. This means some civil > parishes have predominantly rectangular polygons / buildings, whereas > others have many L-shaped or other-shaped polygons / buildings. > > > > As I wasn't able to immediately get some 'number of buildings per civil > parish' numbers (Overpass Turbo had problems returning them, possibly due > to duplicate names and variations in name spellings), I had to calculate > them from their component townlands, using the Overpass Turbo query > [building=* in "townlandname, civilparishname, Kilkenny"]. > > > > Depending on the townland, we're looking at 0.23-8.00 polygons per > capita (0.13-4.37 people per building) and 3.91-6.45 nodes per polygon > (i.e. some townlands have large numbers of semi-detached or terraced > buildings, whereas others have a high number of complicated-shape polygons > / buildings or buildings with too many mapped nodes). It is usual to see > more extreme spreads when looking at smaller areas. > > > > I'm coming up with about 5.4 million (close enough!) buildings for the > whole island, assuming the pattern is the same everywhere. However, as > shown by analysing the smaller areas, there is variation and the 'final' > number will vary from that. Of course, given that OSM is an ongoing > project, there will never be a final number. > > > > Colm > > VictorIE > > ___ > > Talk-ie mailing list > > Talk-ie@openstreetmap.org > > https://lists.openstreetmap.org/listinfo/talk-ie > > ___ > Talk-ie mailing list > Talk-ie@openstreetmap.org > https://lists.openstreetmap.org/listinfo/talk-ie > ___ Talk-ie mailing list Talk-ie@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-ie
