[GRASS-user] Help needed with interactive selection of vectors

Maris Nartiss maris.gis at gmail.com
Thu Nov 8 14:46:04 EST 2007


Hi,
I was not able to fully understand Your needs. Please clarify following aspects:
1) How input data looks like;
2) What do You mean by "manually select smaller subbasins"?
3) And what is "*direct* link"? Uniq ID or model result parser?

I assume You have following workflow:
1) run some closed modeling program, that outputs some (ASCII?) results;
2) operator adds some colors to existing shapes based on 1st step output;
3) result is uploaded to server.
If I'm correct, You could create parser for 1st step result file,
upload parsed results to database (PostGIS with basins or dbf for
joining with GRASS vectors) and generate image with areas colored by
attribute in GRASS/MapServer/GMT/et.al.

Sorry, if I was thinking in other direction,
Maris.


2007/11/8, Thomas Adams <Thomas.Adams at noaa.gov>:
> List:
>
> I work for the US National Weather Service at the Ohio River Forecast
> Center. We generate, on a daily basis, a graphic that looks like this:
> http://www.erh.noaa.gov/er/ohrfc/fop.html
>
> The linked graphic would be pretty trivial to create in GRASS using
> ps.map. However, during times where there is a reasonable risk for
> significant flooding, the map must be altered to designate the smaller
> subbasins (or areas) that are at risk and to annotate the period over
> which the threat exists. I'm sorry I can not link an example to show,
> since there is no current flooding in the US or risk thereof.
>
> Currently, the process is carried out interactively using ArcGIS. I am
> trying to offer up an open source alternative with GRASS. I am sure a
> more sensible, non-interactive way of generating the map explicitly
> through a modeling approach would be best (and we do, of course, base
> designating the basins at risk on hydrologic modeling), but there is no
> *direct* link. Currently human interaction is used and some will insist
> on this.
>
> So, I am left wondering how to best approach this is GRASS, namely, either:
>
> (1) have the ability to manually select smaller subbasins and group them
> together to designate the area at risk, or
>
> (2) hand draw/digitize the area
>
> Any suggestions are appreciated!
>
> Regards,
> Tom
>
> --
> Thomas E Adams
> National Weather Service
> Ohio River Forecast Center
> 1901 South State Route 134
> Wilmington, OH 45177
>
> EMAIL:	thomas.adams at noaa.gov
>
> VOICE:	937-383-0528
> FAX:	937-383-0033
>
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