[OSM-talk] call for brainstorm on "relations for rivers"

Tyler tyler.ritchie at gmail.com
Sat Jun 20 03:32:26 BST 2009


>
> Tagging the riverbank doesn't render very accurately as the river under
> normal flows
> looks way out of scale on the map (making them look like the Amazon, which
> they are not)
>

This is true for non-braided but similarly erratic rivers in the states.
There are often portions where the river may change its course drastically
seasonaly, as well as be taken up entirely during seasonal flood events
http://maps.google.com/?ie=UTF8&ll=47.94892,-123.557825&spn=0.017218,0.035319&t=h&z=15
(sattelite image of the Elwha river)
see also http://en.wikipedia.org/wiki/Elwha_River I have a hunch that the
Elwha and similar sized rivers will render too large in many such areas with
the bars.

I would suggest a tag eg: "river=braided" that would render the outside
> maximum extent (as can be seen in the wiki)
> a light grey filled *area* would be perfect as it would very closely
> represent how they actually look in the environment
>

A more general tag might be nice, but I'm not sure there is a more general
term. Braided may, indeed be the appropriate term, I'll check out my
hydrology text tonight.


It is worth noting however that the river channels are not fixed and
> constantly change their positions across the braided riverbed


This is the case for many younger rivers. I think that's where constant
mapping and improvement come in, and for older or well managed rivers the
banks are unlikely to change much and are probably the most useful
information (maybe combined with mean annual discharge?).

-Tyler
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/talk/attachments/20090619/d075c7e8/attachment.html>


More information about the talk mailing list