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

Andrew Davidson theswavu at gmail.com
Mon Oct 11 09:16:01 UTC 2021

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 

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.

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