[talk-au] Victorian Coastline

[Ian Sergeant]

On 27 January 2011 21:06 <Pheasant.Coucal at gmail.com> wrote:

> * ABS2006 boundaries don't follow coastlines when coastlines change.

What about when coastlines haven't changed, but when the ABS2006
boundary drifts from the coastline?

The answer here, is we don't know whether they intended to follow the
coastline and the coastline data they had was just inaccurate, or
whether they intended to mark a different boundary, or whether they
had no intention, because they just didn't cast their minds to the
issue at all.

Our chances of getting an official position on this is close to zero, IMO.

>  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.

They are - the coastline is being constantly updated as better imagery
and surveys become available.

> The real problem is: How to explain this clearly and simply to people
> who don't read/understand/follow this argument?

This is because you are regarding the ABS2006 import as representative
of nothing but the boundary of the ABS2006 statistical zones.  Then
when we discuss admin boundaries and coastline, you say we are not
comparing like with like.

However, the ABS2006 import has been used all over Australia for
administrative boundaries.  It is these admin boundaries that we are
talking about here, directly derived from the statistical boundaries,
but not necessarily equivalent to them.  You may have an entirely
valid argument to say that ABS2006 should never have been imported to
represent anything but the ABS2006 statistical boundaries - but the
reality is that is not what has happened.

I don't care about statistical boundaries, I care about the suburb and
town administrative boundaries.  We should adjust these to the
coastline.  We should then remove the source for the admin boundary as
ABS2006, with the admin boundary then derived from the coastline.  An
accurate coastline survey/trace is at least as good as any other
source we have for the admin boundary in this case.

Ian.