
MlulcUSGS(2M)     GRASS Reference Manual      MlulcUSGS(2M)


NAME

     MlulcUSGS - creates grid cell layers from a Composite Them Grid
     (CTG) file created by Mlulc.read.  Mlulc.read extracts the CTG
     data from an ASCII landuse/landcover (lulc) CTG format file 
     supplied by the USGS. 
     (Map Development Tool)

SYNOPSIS

     Mlulc.USGS INFILE 

DESCRIPTION

     Mlulc.USGS creates the following grid cell layers from the CTG file
     created by Mlulc.read and places them into the current Mapset:

         1. Land Use & Land Cover
         2. Political Units
         3. Census Units
         4. Hydrologic Units
         5. Federal Land Ownership
         6. State Land Ownership

     Since the CTG file may not contain all of the above layers, Mlulc.USGS
     will extract only the grid cell layers which have been supplied.

     The CTG file contains all of the window information necessary for
     creating the grid cell layers including: 

         1.  Grid Zone
         2.  Projection Type (UTM)
         3.  Cell Resolution (ew_res = nw_res)
         4.  Multi-bye data formation
         5.  window coordinates    

     Mlulc.USGS will use the window information supplied with the CTG file
     and NOT the window currently set for the user's mapset (Note that 
     this is different from many of the other Mapdev Commands).

     When Mlulc.USGS is executed, it will check the file for a specified
     layer and then ask you if you wish to extract the grid cell layer.
     You will then be prompted for the name of the cell file.  Mlulc.USGS
     will then create the cell file and all support files.

EXAMPLE:
  
     The following example extracts grid cell data from the CTG file lulc
     which contains only LAND USE/LAND COVER data:

       Mlulc.USGS lulc

       MAP TITLE: DODGE CITY, KS 1:250,000 LU, PB, CN, HU, FO
       The Composite Theme Grid file contains <1> overlays
       and has a map code type of <01>
 
       Do you Wish to Create <LAND USE/LAND COVER> Grid Cell(y/n) [y] y

       Enter File Name for LAND USE/LAND COVER Overlay
       Enter 'list' for a list of existing grid cell files
       Hit RETURN to cancel request
       > landuse

       Creating <landuse> from <LAND USE/LAND COVER> Overlay: 95%
       Number of Categories: 76  (UNLABELED)
       Writing Cell Header Information
       Writing Color Table Information

       Conversion is Complete


SEE ALSO

     Mlulc.read

BUGS

     Mlulc.USGS does not currently extract census unit data. Also, only
     the cataloging unit is extracted from the CTG file (see the Land
     Use and Land Cover Data Users Guide supplied by the USGS).  

AUTHOR

     Kenneth Shepardson, Spectrum Sciences & Software, Inc. (904) 862-3031


GRASS 3.1           Spectrum Sciences & Software, Inc.             1



