[OSM-talk] open question about boundaries sharing nodes with ways or nodes

[Jóhannes Birgir Jensson]

It's not that simple. I work in an government agency and the issue of 
boundaries rises often, both for public and private issues.

Iceland is an advanced nation regarding technology adaption. However 
boundaries are not all clearly defined as GIS vectors and many of them 
are disputed.

There are many natural reserve areas, some small and some large - yet we 
do not have definite and GPS accurate definitions of them available yet. 
Most of them are based upon text descriptions of areas that were defined 
previously for another purpose. Travelling the country and documenting 
place names has proven to be an interesting experience - a survey was 
done earlier this century.

A common scenario is the definition of where two estates are adjacent to 
each other. The legal document defines the boundary as lying between 
place names #1 and #2, from where a direct line through to #3 and 
followed by the middle of a river. Not a single GPS point in that. Then 
we go to find where the place names are, it should be easy right? Not 
really, the new residents are unsure of where place name #1 is, it could 
possibly be that tiny hillock amongst many, or it could be the one 3 
hillocks over, next to the flat rock. So we already are unsure of our 
starting point, and each point has similar issues. Sometimes the place 
is defined as 50 paces from another place and then the measurement 
sticks used originally have been found and found wanting or being larger 
than they should...

A flash flood from a glacier melting changes the river regularly, 
shifting it faster around than in more stable geographical areas. And 
look at that, a volcano has just created a new lava field, which changed 
the course of a river by the virtue of completely closing off its 
previous path (Wikipedia: Nornahraun and Holuhraun and the river Jökulsá 
á Fjöllum).

There have been court battles and disputes all over the country and 
municipalities also have disputes, some based on these textual 
descriptions of places no one knows where are or where the features have 
shifted several times over since the original line was drawn in the 
unknown place.

So the government will tell you that the boundary is between these place 
names, and isn't always able to tell you if these place names are at the 
same spot as they originally were. There is work ongoing of converting 
these into GPS co-ordinates but that could have to go through courts in 
some cases.

So the government doesn't always have the definite answer via GPS 
points.



Þann 14.10.2015 11:43, Colin Smale reit:
> Well, although it is definitely not unknown, I think it probably is
> fair to call it rare in the grand scheme of things... The vast
> majority of administrative boundaries in the world are not disputed,
> and the ones that are, are more likely to be the national borders
> (admin_level=2) than internal provincial or municipal boundaries, of
> which there are many, many more.
> 
> On 2015-10-14 13:35, Martin Koppenhoefer wrote:
> 
>> sent from a phone
>> 
>>> Am 14.10.2015 um 12:27 schrieb Colin Smale
>>> <colin.smale at xs4all.nl>:
>>> 
>>> The boundary is where the government says it is...
>> 
>> yes, but the governments of adjoining states having different ideas
>> about this is also not rare.
>> 
>> Cheers
>> Martin
> 
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