[GRASS-user] Creating a ground water from a vector files of contours?

[Dylan Beaudette]

On 2/5/07, Hamish <hamish_nospam at yahoo.com> wrote:
> Bob wrote:
> >
> > Like the subject line says, I need help creating a ground water map
> > using a vector file of contours.  The ground water file came from a
> > E00 file that was read into Grass using v.in.e00.  I am currently
> > running v.surf.rst which is taking a long time to run.  Are there
> > other ways to do this problem?
>
> g.region res=
> v.to.rast
> r.surf.contour
>
>
> "r.surf.contour - Surface generation program from rasterized contours."
>
>
> It works pretty well, but do read the help page for some hints.
>
> Also from the man page:
> "BUGS
>
> r.surf.contour has not been fully updated for NULL support and still
> considers a value of "0" to be NULL. Thus any contour lines at 0
> elevation (e.g. the coastline) will be ignored. In such cases converting
> any 0 values in the input map to -1 with r.mapcalc may be a suitable
> work-around.
>
> Currently r.surf.contour will only produce CELL (integer) map output.
> If you would like a finer grade output map (i.e. floating point) it is
> recommended to multiply the input map by 100 (for example) using
> r.mapcalc, then divide the resultant r.surf.contour output map by 100.0,
> again with r.mapcalc.
>
> Volunteers are sought to remedy both these issues."
>
>
>
> Hamish
>
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>

not sure how well this would work, but ...

how about

v.to.points
transfer elevation from contour lines to point [z] coordinates
v.surf.rst or other interpolator...

???

cheers,

dylan