[Qgis-user] to line or not to line

[Anita Graser]

Hi Gerhardus,

The common approach I saw most of the time is to have a polygon layer that
traces the form of the river banks and a line layer that contains the river
center line and can be used to calculate distances easily.

Best wishes,

Anita

On Sat, Oct 29, 2011 at 7:50 PM, Gerhardus Geldenhuis <
gerhardus.geldenhuis at gmail.com> wrote:

> Hi
> This question is not as much QGIS specific but more about generic GIS
> concepts.
>
> In all of the tutorials I have watched so far rivers is represented as
> lines. This makes sense and if you were to do later analysis I would imagine
> a line would make it easier to get information like the length of all rivers
> in an area. However rivers do not play nice and have varying widths. I could
> adjust the line width but that would only be accurate for a certain part of
> the river. My question is thus how do you represent a river of any feature
> for that matter, of varying width and substantial length. If the river is a
> polygon then I would loose the ability to extract length data or is that
> assumption wrong? Do I represent a river/feature as both a line and a
> polygon then?
>
> Regards
>
> --
> Gerhardus Geldenhuis
>
> _______________________________________________
> Qgis-user mailing list
> Qgis-user at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/qgis-user
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/qgis-user/attachments/20111029/5d2a8445/attachment.html>