[GRASS-dev] vector dissolve problems

[Markus Neteler]

Hi,

I try to merge the 100km tiles of the CORINE vector
landcover maps which are delivered in SHAPE format.

Due to the tiling there are annoying boundaries now
when patching the tiles together. I then tried to
reclass and dissolve them based on the landuse
code to no avail.

Procedure:
for i in E43N26 E44N26 E45N26 E43N25 E44N25 E45N25
do
 unzip /cdrom/data/clc00/100km$i.zip
 v.in.ogr 100km$i.shp out=clc2000_$i
done

v.patch -e `g.mlist type=vect pat="clc2000_*" sep=,` out=clc2000_tn_bl

# break tile boundaries:
v.clean clc2000_tn_bl out=clc2000_tn_bl_clean tool=break

# reclass to landuse code:
v.reclass clc2000_tn_bl_clean out=clc2000_tn_bl_recl col=CODE_00

# dissolve 
v.extract -d clc2000_tn_bl_recl out=clc2000_tn_bl_dissolved

The resulting map remains essentially unchanged:
http://mpa.itc.it/markus/tmp/vect_dissolve_troubles.png

Manual removal in v.digit works. But since I have 700 tiles...

Any ideas?

Markus