Re: [talk-au] Why set coast line to nation park or, administrative boundaries?
On 1/4/23 09:50, Graeme Fitzpatrick wrote: Don't know if this helps. or makes it worse! More data = good. The fact that the data is confusing, to me, simply means that a simple assumptions of using the high tide as the boundary for all is a problem. Had a thought so looked at Gold Coast Council's online city plan, where I know that a National Park touches the shore: https://cityplan.goldcoast.qld.gov.au/eplan/property/41NPW429/0/184?_t=property compared to what we have https://www.openstreetmap.org/edit#map=18/-28.09018/153.45895 Darker green on Council map is NP, bright green is Council Public Open Space, patch of ocean is Council "ground", which we show as being within the Admin Boundary of Gold Coast City based on PSMA Admin Boundaries, but which is also "outside" the Australian "coastline"? Other spots on the GC show similar, in that there is a discrepancy, & often an overlap, between Council & State boundaries. Umm State seaward boundaries should be 3 nautical miles seaward from the 'coastline' (~5.5 km). I forget if that 'coastline' used is high or low tidal stuff. You should be able to see the OSM state boundary here https://www.openstreetmap.org/relation/13056696#map=13/-28.0814/153.5054 Council boundaries should be a lot closer to the coast(which ever one you chose)? On Fri, 31 Mar 2023 at 18:14, Warin <61sundow...@gmail.com> wrote: On 29/3/23 14:30, Andrew Harvey wrote: On Wed, 29 Mar 2023 at 14:05, OSM via Talk-au wrote: Since the coastline tag is also supposed to represent the high water mark then I would say that they should be snapped together (since they then represent the same feature - that is, the high water mark). This would mean that the boundary data already in OSM from the government basemaps would just be their own mapping of the high water mark, and probably be less up to date or refined as our own. Exactly. So if anything we should be actively snapping them. Are there any links to these boundaries linked to the high water mark??? I would have though that CAPAD data would be accurate as it should come from the National Parks people using the gazette. My trove searches only turned up low water mark stuff - but I only looked in NSW. ___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au ___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au
Re: [talk-au] Why set coast line to nation park or, administrative boundaries?
Don't know if this helps. or makes it worse! Had a thought so looked at Gold Coast Council's online city plan, where I know that a National Park touches the shore: https://cityplan.goldcoast.qld.gov.au/eplan/property/41NPW429/0/184?_t=property compared to what we have https://www.openstreetmap.org/edit#map=18/-28.09018/153.45895 Darker green on Council map is NP, bright green is Council Public Open Space, patch of ocean is Council "ground", which we show as being within the Admin Boundary of Gold Coast City based on PSMA Admin Boundaries, but which is also "outside" the Australian "coastline"? Other spots on the GC show similar, in that there is a discrepancy, & often an overlap, between Council & State boundaries. Thanks Graeme On Fri, 31 Mar 2023 at 18:14, Warin <61sundow...@gmail.com> wrote: > > On 29/3/23 14:30, Andrew Harvey wrote: > > > > On Wed, 29 Mar 2023 at 14:05, OSM via Talk-au > wrote: > >> Since the coastline tag is also supposed to represent the high water mark >> then I would say that they should be snapped together (since they then >> represent the same feature - that is, the high water mark). This would mean >> that the boundary data already in OSM from the government basemaps would >> just be their own mapping of the high water mark, and probably be less up >> to date or refined as our own. >> > Exactly. So if anything we should be actively snapping them. > > > Are there any links to these boundaries linked to the high water mark??? > > > I would have though that CAPAD data would be accurate as it should come > from the National Parks people using the gazette. > > > My trove searches only turned up low water mark stuff - but I only looked > in NSW. > ___ > Talk-au mailing list > Talk-au@openstreetmap.org > https://lists.openstreetmap.org/listinfo/talk-au > ___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au
Re: [talk-au] Why set coast line to nation park or, administrative boundaries?
On 29/3/23 14:30, Andrew Harvey wrote: On Wed, 29 Mar 2023 at 14:05, OSM via Talk-au wrote: Since the coastline tag is also supposed to represent the high water mark then I would say that they should be snapped together (since they then represent the same feature - that is, the high water mark). This would mean that the boundary data already in OSM from the government basemaps would just be their own mapping of the high water mark, and probably be less up to date or refined as our own. Exactly. So if anything we should be actively snapping them. Are there any links to these boundaries linked to the high water mark??? I would have though that CAPAD data would be accurate as it should come from the National Parks people using the gazette. My trove searches only turned up low water mark stuff - but I only looked in NSW. ___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au
Re: [talk-au] Why set coast line to nation park or administrative boundaries?
Apologies for a couple of errors in my previous posts:
1. DCS is acronym for Department of Customer Services (not Community Services)
2. reference to national park boundary was for Wadbilliga National Park (not
Wadbilla)
On Fri, 31 Mar 2023, at 12:14 PM, cleary wrote:
>> I'm not necessarily disputing this, but there are so many anecdotes and
>> opinions being expressed on this topic. Could I ask if we have any
>> source or citation for this? I mean the Department of Community
>> Services doesn't even exist any longer, and doesn't sound like it
>> should have been producing authoritative maps even when it did? I
>> don't even know what "as authoritative as can be obtained", even means.
>> Is there legislation, regulation, gazette?
>
> See https://six.nsw.gov.au/content/about which states:
>
> Spatial Services, on behalf of the Surveyor General, creates and
> maintains a spatial representation of the State and acts as a 'single
> source of truth' for foundation spatial information and survey
> infrastructure and services in NSW. It supports the legislative and
> statutory requirements for the NSW Surveying and Spatial Information
> Act 2002.
>
> Spatial Services provide leadership to NSW in the production and
> maintenance of foundation spatial datasets and services by capturing,
> sourcing, aggregating and quality-assuring information so that
> government, industry and the community can make informed decisions and
> create social and economic value.
>
> It also digitises and preserves NSW state records including historic
> aerial imagery, land titles, plans and state survey records.
>
> Spatial Services will be part of Government and Corporate Services within DCS.
>
>
>>And the government paying
>> a royalty to "surveyors", just sounds odd. Wouldn't a government
>> normally engage surveyors in the normal way, rather than paying
>> royalties?
>
> Some Government authorities do have their own surveying staff (but even
> Government projects such as roads and railways etc may be outsourced).
> A lot of Government data is taken from the work of private surveyors.
>
> see
> https://www.copyright.com.au/2019/07/surveyors-in-the-west-receive-first-payment-in-august/
>
> I understand that these plans are the source of data that are used to
> show lots etc. on government maps. Suburb, LGA and national park
> boundaries are then derived from this information.
>
> I found a some examples of statutes referring to national park boundaries :
>
> One example referred to expansion of Wadbilla National Park with the
> added area described as "An area of about 6 735 hectares, being the
> balance of Murrabrine State Forest No 947, dedicated 4 November 1955,
> and the balance of No 1 Extension thereto, dedicated 14 September 1979,
> and being the land shown by diagonal hatching on diagram catalogued
> Misc F 1289 in the Forestry Commission of New South Wales. Subject to
> any variations or exceptions noted on that diagram" (from Schedule 1 of
> National Park Estate (Land Transfers) Act 1998)
>
> One is ultimately referred to a diagram and to any variations or
> exceptions noted on the diagram.
>
> Another example referred to revocation of part of Kosciuszko National
> Park {Clause 27, Schedule 2 to the National Parks and Wildlife Act 1974
> No 80) which described the affected parts of the national park by lot
> numbers : (a) Lots 12–22, DP 1171834, (b) Lots 21–22, DP 1171835,
> (c) Lots 30–48, DP 1171836, (d) Lots 40–45, DP 1171838, (e) Lots
> 50–53, DP 1171839, (f) Lots 60–73, DP 1171841, (g) Lots
> 7–15, DP 1171844, (h) Lots 27–50, DP 1171846. Again one has to go to
> the government sources of this data to work out the boundary lines.
>
>
>> Clearly, if you change the location, you should update the source.
>> It's an issue, but OSM does track that changes have been made and by
>> who and why. Our licence allows us to do this - and I'd argue it's the
>> specific purpose for the existence of OSM - that is you can change the
>> data. Nothing is immutable. All you need is a source, or ground-truth.
>
> I agree. The problem is that there does not appear to be any other
> source for administrative boundaries - they are government data. If we
> had another source, then we could choose to use that other source.
>
>
>
>
>
>
> ___
> Talk-au mailing list
> Talk-au@openstreetmap.org
> https://lists.openstreetmap.org/listinfo/talk-au
___
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Re: [talk-au] Why set coast line to nation park or administrative boundaries?
Hi all, this thread has deviated lots from the initial question about high water marks but on a broader level, it’s important to note that statewide maps like the NSW Base Map are not the basis for legal questions. Individual property title plans are. The statewide maps just give a good (sometimes excellent) representation of relative patterns across broad areas. To quote from the NSW Six Maps FAQ: “It is important to note that cadastral data displayed within SIX Maps has no legal status and is intended for viewing purposes only. Only the registered deposited or strata plan of survey is recognised as the legal definition of the boundaries.” The NSW Base Map we use in OSM is the same as that shown at the Six Maps website. The reliance on property titles is shown in the two examples Cleary provided which refer to lot numbers. The property plans for the individual lots provide the legal basis for the boundaries of those lots. (Some of these might refer to natural features perhaps.). The schematic maps are indicative only. The NSW Base Map is compiled from layers, each of differing precision/accuracy. Roads, POIs, houses, etc are often very accurate. Streams are extremely coarse. Property boundaries are usually accurate in towns but often very imprecise in regional areas (inc National park boundaries etc). The “shape” of each allotment is broadly accurate, but there are a lot of offsets and imprecision in where the boundary actually is. As described in the six maps FAQ page, many of these boundaries were transcribed from old, broad-scale, paper plans. The process of increasing the accuracy of the statewide datasets is on an as-needs basis. Broadly, the bulk of attention is on newly subdivided lots in towns and cities, and remote properties, inc public lands, get little attention (unless there’s some legal appeal presumably). You can easily see these inaccuracies on the nsw base map by seeing how often road alignments deviate out of the road easements. The actual roads are geospatially accurate. On imagery and on the ground, the roads lie within fenced easements. On the base map, the easements are often offset, so roads appear to go through private paddocks. For public lands, the same issue arises. The statewide maps are the best we have usually, but they’re not the legal representation of boundaries. The Base Map is a fantastic resource, but actual boundaries often need to be moved to better align with fence lines. Where the boundaries follow creeks and the like, the boundaries are probably best treated as indicative and left untouched, as there’s no verifiable way of knowing where they should lie without chasing up individual property plans. Cheers Ian ___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au
Re: [talk-au] Why set coast line to nation park or administrative boundaries?
> I'm not necessarily disputing this, but there are so many anecdotes and
> opinions being expressed on this topic. Could I ask if we have any
> source or citation for this? I mean the Department of Community
> Services doesn't even exist any longer, and doesn't sound like it
> should have been producing authoritative maps even when it did? I
> don't even know what "as authoritative as can be obtained", even means.
> Is there legislation, regulation, gazette?
See https://six.nsw.gov.au/content/about which states:
Spatial Services, on behalf of the Surveyor General, creates and maintains a
spatial representation of the State and acts as a 'single source of truth' for
foundation spatial information and survey infrastructure and services in NSW.
It supports the legislative and statutory requirements for the NSW Surveying
and Spatial Information Act 2002.
Spatial Services provide leadership to NSW in the production and maintenance of
foundation spatial datasets and services by capturing, sourcing, aggregating
and quality-assuring information so that government, industry and the community
can make informed decisions and create social and economic value.
It also digitises and preserves NSW state records including historic aerial
imagery, land titles, plans and state survey records.
Spatial Services will be part of Government and Corporate Services within DCS.
>And the government paying
> a royalty to "surveyors", just sounds odd. Wouldn't a government
> normally engage surveyors in the normal way, rather than paying
> royalties?
Some Government authorities do have their own surveying staff (but even
Government projects such as roads and railways etc may be outsourced). A lot of
Government data is taken from the work of private surveyors.
see
https://www.copyright.com.au/2019/07/surveyors-in-the-west-receive-first-payment-in-august/
I understand that these plans are the source of data that are used to show lots
etc. on government maps. Suburb, LGA and national park boundaries are then
derived from this information.
I found a some examples of statutes referring to national park boundaries :
One example referred to expansion of Wadbilla National Park with the added area
described as "An area of about 6 735 hectares, being the balance of Murrabrine
State Forest No 947, dedicated 4 November 1955, and the balance of No 1
Extension thereto, dedicated 14 September 1979, and being the land shown by
diagonal hatching on diagram catalogued Misc F 1289 in the Forestry Commission
of New South Wales. Subject to any variations or exceptions noted on that
diagram" (from Schedule 1 of National Park Estate (Land Transfers) Act 1998)
One is ultimately referred to a diagram and to any variations or exceptions
noted on the diagram.
Another example referred to revocation of part of Kosciuszko National Park
{Clause 27, Schedule 2 to the National Parks and Wildlife Act 1974 No 80) which
described the affected parts of the national park by lot numbers : (a) Lots
12–22, DP 1171834, (b) Lots 21–22, DP 1171835, (c) Lots 30–48, DP 1171836,
(d) Lots 40–45, DP 1171838, (e) Lots 50–53, DP 1171839, (f) Lots
60–73, DP 1171841, (g) Lots 7–15, DP 1171844, (h) Lots 27–50, DP 1171846.
Again one has to go to the government sources of this data to work out the
boundary lines.
> Clearly, if you change the location, you should update the source.
> It's an issue, but OSM does track that changes have been made and by
> who and why. Our licence allows us to do this - and I'd argue it's the
> specific purpose for the existence of OSM - that is you can change the
> data. Nothing is immutable. All you need is a source, or ground-truth.
I agree. The problem is that there does not appear to be any other source for
administrative boundaries - they are government data. If we had another source,
then we could choose to use that other source.
___
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Re: [talk-au] Why set coast line to nation park or administrative boundaries?
On Thu, 30 Mar 2023 at 18:15, cleary wrote: > > My knowledge is limited to NSW as that is the state in which I have > previously made enquiries. Verbal descriptions of administrative boundaries > have not been used in recent years. Boundaries are now defined > geospatially, with the NSW Department of Community Services being > responsible for producing the official maps. It is my understanding that > the DCS NSW maps are as authoritative as can be obtained (except for the > surveyors' charts from which the DCS maps are derived). I think the > government pays a royalty to surveyors in order to be able to use the > surveyors' data in government maps and licence others to use these maps. > DCS NSW certainly does not snap the boundaries to nearby features. > > I'm not necessarily disputing this, but there are so many anecdotes and opinions being expressed on this topic. Could I ask if we have any source or citation for this? I mean the Department of Community Services doesn't even exist any longer, and doesn't sound like it should have been producing authoritative maps even when it did? I don't even know what "as authoritative as can be obtained", even means. Is there legislation, regulation, gazette? And the government paying a royalty to "surveyors", just sounds odd. Wouldn't a government normally engage surveyors in the normal way, rather than paying royalties? > I'm uncertain about the terms of use of the government data but, > generally, when reproducing another person or organisation's resources > (images, text etc) with permission, one is required not to distort that > resource so as to not embarrass the donor. Where a source such as the NSW > Government has given permission to use its data in OSM, I feel we have an > obligation to use it correctly. It would be wrong to show inaccurate > boundaries and attribute them to the Government source. As the person who > initiated obtaining access to the NSW data a few years ago, I feel > particularly embarrassed that we might mis-use it. > > Clearly, if you change the location, you should update the source. It's an issue, but OSM does track that changes have been made and by who and why. Our licence allows us to do this - and I'd argue it's the specific purpose for the existence of OSM - that is you can change the data. Nothing is immutable. All you need is a source, or ground-truth. The only reason I can see for snapping administrative boundaries to nearby natural features is for convenience - but I see it as convenience at the expense of accuracy. > > I don't agree. I think in many cases, for all practical purposes, the boundary is the feature. And the law has traditionally allowed for accretions and erosion. But if there is some legislative instrument that defines the boundary by a particular accurate geospatial set that we have access to, regardless of the feature, then I could be convinced to change my mind. And to my mind, if you committed an offence on national park land above the high water mark, and tried to argue you were outside the park, because of some geospatial alignment, I reckon you're cooked unless you could find a legislative instrument to support that being the hard and fast line. Ian. ___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au
Re: [talk-au] Why set coast line to nation park or administrative boundaries?
On Thu, 30 Mar 2023 at 17:15, cleary wrote: > > I'm uncertain about the terms of use of the government data but, > generally, when reproducing another person or organisation's resources > (images, text etc) with permission, one is required not to distort that > resource so as to not embarrass the donor. Where a source such as the NSW > Government has given permission to use its data in OSM, I feel we have an > obligation to use it correctly. It would be wrong to show inaccurate > boundaries and attribute them to the Government source. As the person who > initiated obtaining access to the NSW data a few years ago, I feel > particularly embarrassed that we might mis-use it. > > but I believe that if we are going to do something, we should do it > properly and, in OSM, that would mean as accurately as we can manage - > even if it is inconvenient and untidy. > I don't actually disagree with you, but being picky to the nth degree here :-), does that mean we should only map using DCS NSW Imagery, & treat the DCS Base & Topo maps as gospel? I think we're all agreed that while they're helpful, their Imagery is *wwwaaayyy* out of date, while the others should only be taken as an indication, not definitive. Thanks Graeme ___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au
Re: [talk-au] Why set coast line to nation park or administrative boundaries?
My knowledge is limited to NSW as that is the state in which I have previously made enquiries. Verbal descriptions of administrative boundaries have not been used in recent years. Boundaries are now defined geospatially, with the NSW Department of Community Services being responsible for producing the official maps. It is my understanding that the DCS NSW maps are as authoritative as can be obtained (except for the surveyors' charts from which the DCS maps are derived). I think the government pays a royalty to surveyors in order to be able to use the surveyors' data in government maps and licence others to use these maps. DCS NSW certainly does not snap the boundaries to nearby features. I'm uncertain about the terms of use of the government data but, generally, when reproducing another person or organisation's resources (images, text etc) with permission, one is required not to distort that resource so as to not embarrass the donor. Where a source such as the NSW Government has given permission to use its data in OSM, I feel we have an obligation to use it correctly. It would be wrong to show inaccurate boundaries and attribute them to the Government source. As the person who initiated obtaining access to the NSW data a few years ago, I feel particularly embarrassed that we might mis-use it. The only reason I can see for snapping administrative boundaries to nearby natural features is for convenience - but I see it as convenience at the expense of accuracy. I will abide by any collective decision of mapping colleagues but I believe that if we are going to do something, we should do it properly and, in OSM, that would mean as accurately as we can manage - even if it is inconvenient and untidy. On Tue, 28 Mar 2023, at 9:42 PM, Andrew Harvey wrote: > Personally I'd prefer to snap them, it makes it easier for us to > maintain, better for data consumers, and overall cleaner data. > > I speculate these departmental GIS teams are creating the boundaries > from their own coastline datasets anyway, so why not just have them > match OSM's coastline? > > I think it's unlikely these GIS representations are the absolute set in > stone authority, if they rebuild their GIS data with newer coastline > data their boundary geometry will change. > > I agree with Frederik here, if someone wants the boundaries exactly as > they appear in the government published dataset they should go there > and not expect OSM to be exactly the same. They shouldn't be > untouchable objects in OSM, we can hold a different representation of > the boundary to the department's GIS dataset that doesn't make OSM > wrong. > > I think you'll find exactly what Frederik says, that the moment you > step foot on the land out of the water you'll be deemed in the national > park for most purposes, except particular cases where the boundaries > does extend out in the water. > ___ > Talk-au mailing list > Talk-au@openstreetmap.org > https://lists.openstreetmap.org/listinfo/talk-au ___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au
Re: [talk-au] Why set coast line to nation park or, administrative boundaries?
On 29/3/23 14:30, Andrew Harvey wrote: On Wed, 29 Mar 2023 at 14:05, OSM via Talk-au wrote: Since the coastline tag is also supposed to represent the high water mark then I would say that they should be snapped together (since they then represent the same feature - that is, the high water mark). This would mean that the boundary data already in OSM from the government basemaps would just be their own mapping of the high water mark, and probably be less up to date or refined as our own. Exactly. So if anything we should be actively snapping them. In Victoria, from a very interesting document "THECOAST AND THECADASTRE" AReport for the Victorian Environmental Assessment Council August 2019" Unfortunately it is a PDF download only .. and I cannot get a direct link so search for the above "Victoria the Coast and the Cadastre" I quote from here on from the document, I do recommend reading all of it if your interested in these 'ambulatory boundaries'. - Detail of the plan defining Cape Conran Coastal Park2. The inland boundary follows geometrically well-defined lines, and is fixed in position. North of the inland boundary is freehold land. The seaward boundary of the Park is ‘Low Water Mark’ and hence is ambulatory. South of the seaward boundary (i.e.Bass Strait) is unreserved Crown land. Topographic features may move, and ambulatory boundaries may move in response under the common law doctrine of accretion. The doctrine is well established internationally, but has resulted in very little Australian case law, so we have come to accept Surveyor Generals’ rulings as beingde factoexpressions of the common law. TheLocal Government Act 1989, section 3(3A) states: “if a boundary of a municipal district is described by reference to the seacoast (regardless of whether it is referred to as the Sea shore or the waters of the sea or a bay or in any other way) that boundary is to be taken to be the line for the time being of the Low Water Mark on that sea coast”. the surveyed sea boundary is defined only at that date. The sea boundary is still subject to change due to gradual and imperceptible movement. The fundamental concepts (snip) 1The legal boundary between tidal waters and adjacent land is the High Water Mark (except where the sea boundary is otherwise defined). (snip) 6Land below high water mark (or other sea boundary) belongs to the Crown - There are statements about; the high water mark being used for both private and 'public' land the 'foreshore' being council land The report suggest that climate change will make things difficult and that the government should 'make changes'. My pessimism says that they will make no changes until things get much worse. ___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au
Re: [talk-au] Why set coast line to nation park or administrative boundaries?
On Wed, 29 Mar 2023 at 20:25, Warin <61sundow...@gmail.com> wrote: > > As for the administrative boundaries .. the present official view is > that local councils cannot now sell 'land' between the high tide and low > tide, however they have in the past. > > What the state of this 'land' between high and low tide is now I'm not > certain of. > Several years ago now, I was having this same conversation with a bloke from Sydney. His family have owned a private marina in Sydney (I'm not sure if the main or Middle Harbour?) since the mid-1800s. They have a car park on the shore, a jetty going out over the water, with their office built on it, & a pier going further out from that. Several years before I was speaking to him, they'd put in for planning approval to rebuild & extend the existing office on the existing jetty, where it's above the actual land / water boundary. Council had no issue with it, but they were still waiting State Govt approval, as the two departments involved (call them Lands vs Harbours & Marine) were arguing, *in court !*, over which Dept had the right to give them the OK to go ahead! NB neither Dept had any issue with the planned work, they were arguing over which of them had control of that bit of wet dirt, 2m below the jetty, which hasn't seen the light of day for 170 years!, & which wasn't going to be touched, or affected in any way, by the proposed work :-( Thanks Graeme ___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au
Re: [talk-au] Why set coast line to nation park or administrative boundaries?
On 28/3/23 20:46, Frederik Ramm wrote: Hi, I would advise caution with this. Government bodies will typically hold their own GIS data for park boundaries or administrative boundaries, and the GIS data they have will never fully align with the coastline. However, it is not our job to be an agent for publishing government data. We have to look further and ask for the actual situation. If the national park boundary is mostly along the coastline The problem arises that OSM uses the high tide mark for the coastline ... there is the possibility that National Parks use the low tide mark - so they cover anything washed up on the beach. The official government data looks to me to use the low tide mark. I have sent an inquiry to the National Parks people in the state of interest. As for the administrative boundaries .. the present official view is that local councils cannot now sell 'land' between the high tide and low tide, however they have in the past. What the state of this 'land' between high and low tide is now I'm not certain of. ___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au
Re: [talk-au] Why set coast line to nation park or administrative boundaries?
On 28/3/23 22:06, Little Maps wrote: Slightly different issue… but the accuracy of governmental admin boundaries can vary a lot depending where you are in Aus. In regional NSW, allotment boundaries (and associated park, state forest and local gov boundaries) as shown on the NSW gov base map (and as often used in OSM) are often inaccurate by 20-50 m and sometimes lots more. This inaccuracy is clearly stated on the Six Maps FAQ page (see Q 6&7). I too have found inaccuracies with respect to their own imagery. Where I have come across it I have used whatever data is present in OSM and offset the base map to match that. This could have been sourced from bing or any other imagery but at least the map will be consistent in what ever offset it has in that area. ___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au
Re: [talk-au] Why set coast line to nation park or, administrative boundaries?
On 29/3/23 14:30, Andrew Harvey wrote: On Wed, 29 Mar 2023 at 14:05, OSM via Talk-au wrote: Since the coastline tag is also supposed to represent the high water mark then I would say that they should be snapped together (since they then represent the same feature - that is, the high water mark). This would mean that the boundary data already in OSM from the government basemaps would just be their own mapping of the high water mark, and probably be less up to date or refined as our own. Exactly. So if anything we should be actively snapping them. I believe this is wrong. For example in NSW... From https://rg-guidelines.nswlrs.com.au/deposited_plans/natural_boundaries/consents_naturalboundaries "However Crown Lands is not the only owner of land below MHWM. Where Crown Lands is not the owner of land adjoining the foreshore, consent must be obtained from the appropriate authority. Some of these include: * National Parks and Wildlife Service (where tidal waters have been included in land resumed for state or national parks)" This is my first time responding on talk-au, lmk if I've messed up any formatting to link to the original question. Welcome! The content looks fine to me. ___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au
Re: [talk-au] Why set coast line to nation park or, administrative boundaries?
On Wed, 29 Mar 2023 at 14:05, OSM via Talk-au wrote: > Since the coastline tag is also supposed to represent the high water mark > then I would say that they should be snapped together (since they then > represent the same feature - that is, the high water mark). This would mean > that the boundary data already in OSM from the government basemaps would > just be their own mapping of the high water mark, and probably be less up > to date or refined as our own. > Exactly. So if anything we should be actively snapping them. > This is my first time responding on talk-au, lmk if I've messed up any > formatting to link to the original question. > It's come through but as a new thread, and for some reason from talk-au instead of from you and via talk-au. ___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au
Re: [talk-au] Why set coast line to nation park or, administrative boundaries?
I looked at the separation of park boundaries and coastlines down in Wilson's Prom a while ago and asked the #oceania discord at the time but never ended up changing anything. If you look at the legal definition of many national parks, their boundaries are defined by the high water mark. Since the coastline tag is also supposed to represent the high water mark then I would say that they should be snapped together (since they then represent the same feature - that is, the high water mark). This would mean that the boundary data already in OSM from the government basemaps would just be their own mapping of the high water mark, and probably be less up to date or refined as our own. The other issue I wasn't sure about was the copyright of the government maps that declare these national parks as following the high water mark. You could argue that its a legal fact and therefore can't be copyrighted but it is also hard to find that information outside of government run archives. (The parks are usually represented on maps of the area by the Surveyor General and make references to the high water mark, at least in Vic). This is my first time responding on talk-au, lmk if I've messed up any formatting to link to the original question. On Tue, 28 Mar 2023, at 10:58 AM, Warin wrote: Hi Looks like some are setting natural features to government boundaries. A recent case along the WA south coast has been going on for some years.. The coast line looks very confused and the National Park boundaries are being changed to the coast line in reverse of what is stated on the change sets... (bangs head on wall). I was altered to it by OSMInspector identifying the National Park boundary being broken by the 'adjustment' of the 'coastline' ... that broke the National Park boundary... The National Park boundary looks, in some places, to be the low tide mark and then in other places to be the hi tide mark, so it is not consistent. I do understand where the two (natural feature and government boundary) coincide that it is easier to use the same way. But every now and then someone moves it to conform to the latest imagery of the natural feature .. thus moving the government boundary .. unintended but there we go. My only solution si to have them as separate ways .. making it easier to divorce the new nodes added for the new nature feature addition from the old government boundary. Any other ideas??? ___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au
Re: [talk-au] Why set coast line to nation park or administrative boundaries?
Slightly different issue… but the accuracy of governmental admin boundaries can vary a lot depending where you are in Aus. In regional NSW, allotment boundaries (and associated park, state forest and local gov boundaries) as shown on the NSW gov base map (and as often used in OSM) are often inaccurate by 20-50 m and sometimes lots more. This inaccuracy is clearly stated on the Six Maps FAQ page (see Q 6&7). https://www.spatial.nsw.gov.au/__data/assets/pdf_file/0005/216383/SIXMapsFAQ.pdf Basically, this statewide dataset is not intended to be used at the high zoom levels that we can use in OSM. Personally, I’d echo Frederick and Andrew’s view that we may be seeking a false sense of exactitude by focusing on small apparent differences between statewide datasets and natural features. Cheers Ian___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au
Re: [talk-au] Why set coast line to nation park or administrative boundaries?
Personally I'd prefer to snap them, it makes it easier for us to maintain, better for data consumers, and overall cleaner data. I speculate these departmental GIS teams are creating the boundaries from their own coastline datasets anyway, so why not just have them match OSM's coastline? I think it's unlikely these GIS representations are the absolute set in stone authority, if they rebuild their GIS data with newer coastline data their boundary geometry will change. I agree with Frederik here, if someone wants the boundaries exactly as they appear in the government published dataset they should go there and not expect OSM to be exactly the same. They shouldn't be untouchable objects in OSM, we can hold a different representation of the boundary to the department's GIS dataset that doesn't make OSM wrong. I think you'll find exactly what Frederik says, that the moment you step foot on the land out of the water you'll be deemed in the national park for most purposes, except particular cases where the boundaries does extend out in the water. > ___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au
Re: [talk-au] Why set coast line to nation park or administrative boundaries?
Hi, I would advise caution with this. Government bodies will typically hold their own GIS data for park boundaries or administrative boundaries, and the GIS data they have will never fully align with the coastline. However, it is not our job to be an agent for publishing government data. We have to look further and ask for the actual situation. If the national park boundary is mostly along the coastline but there's a tiny patch of sand where the coastline has changed but the public data has not - does that really mean that this little patch is not part of the national park (and I could go there and, whatever, light a fire or something I'm not allowed to do in the national park)? OpenStreetMap becomes more complex the more different boundaries we track. Having a coastline with an administrative boundary that runs "almost" along the coast but is always a meter off, and then having in addition to that a national park boundary that is also "almost" the same but not quite - we should only do that if it is an important feature. "Hey, everyone knows that along the coast of XY there's this one meter wide stretch that is not officially part of the XY city so the city rule about nude bathing doesn't apply there" or whatever, that might be a reason to carefully map the difference - but if the difference is not "on purpose" but just an imprecision that the city and national park administration were likely to fix if they had the technical means then I would not try to map these boundaries separate from the coastline. Especially since they will certainly not be verifiable on the ground... Bye Frederik On 28.03.23 11:33, cleary wrote: Warin's proposal, that natural features be separated from administrative boundaries, is strongly supported. Boundaries are often near natural features but they rarely align precisely. Further, natural features such as coastline and waterways can change surprisingly quickly while administrative boundaries change much less often. On Tue, 28 Mar 2023, at 10:58 AM, Warin wrote: Hi Looks like some are setting natural features to government boundaries. A recent case along the WA south coast has been going on for some years.. The coast line looks very confused and the National Park boundaries are being changed to the coast line in reverse of what is stated on the change sets... (bangs head on wall). I was altered to it by OSMInspector identifying the National Park boundary being broken by the 'adjustment' of the 'coastline' ... that broke the National Park boundary... The National Park boundary looks, in some places, to be the low tide mark and then in other places to be the hi tide mark, so it is not consistent. I do understand where the two (natural feature and government boundary) coincide that it is easier to use the same way. But every now and then someone moves it to conform to the latest imagery of the natural feature .. thus moving the government boundary .. unintended but there we go. My only solution si to have them as separate ways .. making it easier to divorce the new nodes added for the new nature feature addition from the old government boundary. Any other ideas??? ___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au ___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au -- Frederik Ramm ## eMail frede...@remote.org ## N49°00'09" E008°23'33" ___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au
