[talk-au] Victorian Coastline

4x4falcon info at 4x4falcon.com
Thu Jan 27 11:01:46 GMT 2011


On 27/01/11 18:06, {withheld} wrote:
> On 27/01/11 20:21, 4x4falcon wrote:
>> On 27/01/11 14:12, Steve Bennett wrote:
>>> On Thu, Jan 27, 2011 at 3:10 PM, 4x4falcon<info at 4x4falcon.com>   wrote:
>>>> Physical things can change (eg road or railway realignment), non
>>>> physical
>>>> don't necessarily change.  In the case of boundaries do we definitely
>>>> know
>>>> that when a road is realigned does the boundary change with it.  This
>>>> has
>>>> been discussed many times since the import of the ABS boundary data.
>>>
>>> My guess would be that the boundaries generally do change, but I could
>>> be totally wrong. And I think high quality traces are likely to be
>>> more accurate than the ABS's data.
>>
>> That's the problem it's your guess.  There has been no definitive answer
>> since the original import.
>>
>    I really don't know why this knotty problem keeps cropping up. I can
> readily find examples locally for each of these cases:
>
> * ABS2006 boundaries don't follow roads when road alignment changes.
> * ABS2006 boundaries don't follow rivers when river channels change.
> * ABS2006 boundaries don't follow coastlines when coastlines change.
> * ABS2006 boundaries do not always correspond to suburb boundaries.
> * ABS2006 boundaries do not always correspond to postcode boundaries.
> * ABS2006 boundaries do not always correspond to shire boundaries.
> * ABS2006 boundaries do not always correspond to parish boundaries.
>
>    I couldn't find an example rail line easily; but I think the pattern
> ought to be clear. (Simple logic says a single exception disproves the
> rule.)

What was the source of this if you don't mind me asking as I'm sure 
Steve will.

>    As I've stated elsewhere in this very thread, just because the
> boundaries *look* like something we want; does not necessarily *mean*
> they represent that thing. And bending them to fit a fiction just
> damages what worth they originally had... statistical boundaries for a
> past census? This is the one immutable fact about them. Their casual
> correspondence to a feature we would like to map helps locate and
> identify that feature (even if the drawing happens to be co-linear with
> the ABS boundary), and they should be applauded for providing those few
> hints, especially in areas with few other mapped features.

Agree totally.

>    However, if somebody has an accurate survey of (to drag the
> conversation back to it's Subject), say the Victorian Coastline, why
> aren't they drawing/updating the thing they have surveyed. Who cares if
> it happens to follow another line on the map? This is not a comparison
> of like with like.
>
>    The real problem is: How to explain this clearly and simply to people
> who don't read/understand/follow this argument?


Cheers
Ross



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