[GRASS-user] Help needed in creating a thematic map

GRASS GRASS user
1

List:

I need to create a map in GRASS like the attached map. This needs to be done on a daily basis, and it needs to be created by those who have little GIS or GRASS knowledge or experience. The critical aspect is to manually draw/digitize the critical "likely" or "possible" areas. And I am struggling with v.digit doing this, but it's not the main problem. The key issue is attaching attribute data to the polygonal regions that define the period over which the "likely" or "possible" areas apply, as the graphic shows. ALSO, the boundary data and the attributes (the valid Date period) need to be exported to an ascii text file which is then ftp'ed to a central location — the end users use their own software to combine other such files to create a graphic (actually the one I am showing). Now, combining the exported data into the format needed by the end user is not an issue, it's really a matter of how to most efficiently (easily) get the Starting and Ending dates into the attributes of the polygons. Also, should I try to use a separate vector map for each polygon of the same type ("likely" or "possible") or should they be in different layers?

I'll have to write detailed instructions covering how to do this, but I need to know how to do this first!

I'm very open to suggestions…

Regards,
Tom

--
Thomas E Adams
National Weather Service
Ohio River Forecast Center
1901 South State Route 134
Wilmington, OH 45177

EMAIL: thomas.adams@noaa.gov

VOICE: 937-383-0528
FAX: 937-383-0033

(attachments)

finalfop.gif

2

Thomas,

On Sun, Mar 8, 2009 at 4:03 AM, Thomas Adams <Thomas.Adams@noaa.gov> wrote:

List:

I need to create a map in GRASS like the attached map. This needs to be done
on a daily basis, and it needs to be created by those who have little GIS or
GRASS knowledge or experience. The critical aspect is to manually
draw/digitize the critical "likely" or "possible" areas. And I am struggling
with v.digit doing this, but it's not the main problem.

(which v.digit do you use?)
Perhaps Featureserver would be a good idea here:
http://featureserver.org/
http://www.paolocorti.net/2008/02/21/a-day-with-featureserver-1/

(random demo: http://dev.riverchange.org/featureserver/
use the + at top right to activate WMS
SHIFT-left-mouse-button to zoom in via box
)

Or the new digitizer in GRAS 6.4:
http://grass.osgeo.org/screenshots/vector.php
-> New vector digitizer tool with advanced editing features

The key issue is
attaching attribute data to the polygonal regions that define the period
over which the "likely" or "possible" areas apply, as the graphic shows.

Both Featureserver and GRASS digitizer support this.

ALSO, the boundary data and the attributes (the valid Date period) need to
be exported to an ascii text file which is then ftp'ed to a central location

(new) v.out.ascii export attributes in point mode. You could export
the ASCII data in "standard" format, then convert centroids to points
and in a second run of v.out.ascii export attributes.

— the end users use their own software to combine other such files to create
a graphic (actually the one I am showing). Now, combining the exported data
into the format needed by the end user is not an issue,

At this point I would export SHAPE format which includes the attributes
in the DBF table.

it's really a matter
of how to most efficiently (easily) get the Starting and Ending dates into
the attributes of the polygons.

I would just use two columns in the attribute table.

Also, should I try to use a separate vector
map for each polygon of the same type ("likely" or "possible") or should
they be in different layers?

IMHO yes.

I'll have to write detailed instructions covering how to do this, but I need
to know how to do this first!

I'm very open to suggestions…

Hope this helps,
Markus

3

Hi,
have you tried Qgis, which also comes with built in GRASS features.
Digitisation and attribution is quite easy in Qgis.
Ravi Kumar

--- On Sun, 3/22/09, Markus Neteler <neteler@osgeo.org> wrote:

From: Markus Neteler <neteler@osgeo.org>
Subject: Re: [GRASS-user] Help needed in creating a thematic map
To: "Thomas Adams" <Thomas.Adams@noaa.gov>
Cc: "grass-user" <grass-user@lists.osgeo.org>
Date: Sunday, March 22, 2009, 1:38 AM
Thomas,

On Sun, Mar 8, 2009 at 4:03 AM, Thomas Adams
<Thomas.Adams@noaa.gov> wrote:
> List:
>
> I need to create a map in GRASS like the attached map.
This needs to be done
> on a daily basis, and it needs to be created by those
who have little GIS or
> GRASS knowledge or experience. The critical aspect is
to manually
> draw/digitize the critical "likely" or
"possible" areas. And I am struggling
> with v.digit doing this, but it's not the main
problem.

(which v.digit do you use?)
Perhaps Featureserver would be a good idea here:
http://featureserver.org/
http://www.paolocorti.net/2008/02/21/a-day-with-featureserver-1/

(random demo: http://dev.riverchange.org/featureserver/
use the + at top right to activate WMS
SHIFT-left-mouse-button to zoom in via box
)

Or the new digitizer in GRAS 6.4:
http://grass.osgeo.org/screenshots/vector.php
-> New vector digitizer tool with advanced editing
features

> The key issue is
> attaching attribute data to the polygonal regions that
define the period
> over which the "likely" or
"possible" areas apply, as the graphic shows.

Both Featureserver and GRASS digitizer support this.

> ALSO, the boundary data and the attributes (the valid
Date period) need to
> be exported to an ascii text file which is then
ftp'ed to a central location

(new) v.out.ascii export attributes in point mode. You
could export
the ASCII data in "standard" format, then convert
centroids to points
and in a second run of v.out.ascii export attributes.

> — the end users use their own software to combine
other such files to create
> a graphic (actually the one I am showing). Now,
combining the exported data
> into the format needed by the end user is not an
issue,

At this point I would export SHAPE format which includes
the attributes
in the DBF table.

> it's really a matter
> of how to most efficiently (easily) get the Starting
and Ending dates into
> the attributes of the polygons.

I would just use two columns in the attribute table.

> Also, should I try to use a separate vector
> map for each polygon of the same type
("likely" or "possible") or should
> they be in different layers?

IMHO yes.

> I'll have to write detailed instructions covering
how to do this, but I need
> to know how to do this first!
>
> I'm very open to suggestions…

Hope this helps,
Markus
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