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General Category => Map Making Support => Topic started by: n2stitch on February 17, 2009, 10:12:27 AM

Title: Land Use Data - How to Assign MP_Types?
Post by: n2stitch on February 17, 2009, 10:12:27 AM
I have shape files for landcover downloaded from here:

http://www.webgis.com/terr_pages/lulcgeo_mo.html

I'd like to put them in the postgis database and run a query on them to add correct mp_types to them, and then export back out as shapefiles (same as the water and road data in the tutorial).

One, how do I find out what types to assign, and two how do I write the query?

Lalita
Title: Re: Land Use Data - How to Assign MP_Types?
Post by: maps4gps on February 17, 2009, 11:55:05 AM
If you get any metadata with these files, check to see what the source data is.  USGS had DLG files for the 250K scale (~1% 100K) LULC paper maps created in the 1970's.  The 1992 and 2001 raster data use a different classification scheme than is in the reference gave.  When the 2001 data was first released, USGS stated that the classification methods had changed enough that a comparison to the 1992 data would not be valid to determine land cover changes.

It would be great if someone has taken the 2001 raster data and made vector polygons.

I do not remember if you said what you wanted the data for, but you could use the free version of Globalmapper to overlay these vector files on recent photography to determine if they will meet you needs.
Title: Re: Land Use Data - How to Assign MP_Types?
Post by: -Oz- on February 17, 2009, 10:02:39 PM
If you're not doing custom types I use the cgpsmapper manual to decide what to make the MP_TYPE, I cut out and posted just the types section here: http://www.gpsfiledepot.com/cgpsmapper_types.pdf
Title: Re: Land Use Data - How to Assign MP_Types?
Post by: n2stitch on February 18, 2009, 11:39:31 AM
Thanks you guys.  I'll check it all out and see what I can come up with.

Lalita