[talk-au] Monitoring admin boundaries Was: Re: Mapping tree cover

[Warin]

On 11/10/21 8:16 pm, Andrew Davidson wrote:
> On 9/10/21 10:54 pm, Andrew Harvey wrote:
>>
>> Andrew Davidson has been keeping an eye on changes and doing some 
>> updates. I've updated a few I noticed changed in NSW.
>
> I checked the existing boundaries in NSW/SA/ACT/TAS last year before 
> the other states were imported.
>
> Geoscape (aka PSMA) put out new versions of their admin boundary 
> product every quarter, along with a report that lists the diffs from 
> the previous release. I've been using these to update the boundaries 
> when they change (at least the ones that other mappers haven't already 
> done).
>
>> I'm not aware of something up and running spitting out differences, 
>> but we could code something up with some tolerance to ignore 
>> boundaries out by a little bit.
>
> The boundaries aren't exactly the same as the official versions as 
> they have been modified slightly to match up at state borders (and 
> some mappers have used coastlines, rivers, roads when they imported 
> the boundaries).
>
> It might be worth having a service that reports on when and how much 
> an admin boundary changes in OSM to let other mappers have a chance to 
> check if this is a real change or an oops.
>
>

Some of the "opps' are due to the use of roads, water ways as boundaries 
.. where someone changes the road/water which then opens the boundaries. 
Where I have come across this in the past I have simply repaired it 
using the road/water as the base. Lately I have been using the PSMA and 
thus separating the boundary from the road/water, usually this 
simplifies things as you don't need a short way through the middle of 
roundabouts etc.