correcting elevations on digit. contours

GRASS GRASS user
1

Dear GRASS user,

I would like to ask for an help or good idea on such a problem:
  I am working on a project of computing DEM from digitized
contours. It is together about 120 maps with contours and elevations /DXF
format; 1:50 000/.
  And the problem is that some of contours have bad elevations. I would like
to check all maps to find a mistakes and afterthat cover a raster
DEM with contours to correct elevations in ArcView database.
  And afterthis operation compute whole model. Even there is a
smaller DEM /1 map sheet/ in GRASS, not every mistakes were easy to see.
  
  I would very appreciate any idea how to visualise
problem regions on map sheet in GRASS GIS?
  
Thank you at all
        
Rado

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Radoslav Bonk
Comenius University,Faculty of Natural Sciences
Department of Physical Geography and Geoecology
Mlynska Dolina 842 15,Bratislava SLOVAKIA
fax:07/65429064
e-mail: bonk@fns.uniba.sk
PRIVAT: Svinia 221, 082 32; tel:+421/91/958 187
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2

Radoslav Bonk wrote:

        And the problem is that some of contours have bad elevations. I would like
to check all maps to find a mistakes and afterthat cover a raster
DEM with contours to correct elevations in ArcView database.

The method we used (not with grass, but it must work with any GIS)
was to convert each contour map in a raster and then visualise it
in 3D where all mistakes introduce some strange aspects in the
topography, so you know where to correct the vector files... This
does not work for some little errors but eliminates the major ones.

Another thing to do is to draw the contour map with odd, even and
main contours in differents colors (ex: 10,30,70,90 in red, 20, 40,
60 and 80 in green and 0, 50, 100 in black) It's very easy to
detect misplaced values...

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