## NAME

m.lulc.USGS - Creates raster map layers from a Composite Theme Grid (CTG) file created by m.lulc.read . m.lulc.read extracts the CTG data from an ASCII landuse/landcover (lulc) CTG format file supplied by the USGS.
(GRASS Data Import/Processing Program)

## SYNOPSIS

m.lulc.USGS input_file

## DESCRIPTION

m.lulc.USGS creates the following raster map layers from the CTG file created by m.lulc.read , and places them into the user's 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 layers listed above, m.lulc.USGS will extract only the raster map layers which exist in the CTG file.

The CTG file contains all of the geographic region definition information necessary for creating the raster map layers, including:

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

m.lulc.USGS will use the geographic region information definition supplied with the CTG file and NOT the geographic region definition currently set for the user's mapset; (note that this is different than is the case with many of the other GRASS map development commands).

When m.lulc.USGS is executed, it will check the file for a specified layer and then ask the user if he wishes to extract the associated raster map layer. The user is then prompted for the name of a new raster file in which output is to be placed. m.lulc.USGS will then create this raster file and all supporting (e.g., category, cell header, color table, etc.) files.

## EXAMPLE

In the example below, raster data is extracted from a CTG file (named lulc) that contains only LAND USE/LAND COVER data:

m.lulc.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> Raster File (y/n) [y] y

    	Enter File Name for LAND USE/LAND COVER Overlay
    	Enter 'list' for a list of existing raster 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

## BUGS

m.lulc.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 User's Guide supplied by the USGS).

## SEE ALSO

USGS Land Use and Land Cover Data User's Guide

g.region
m.lulc.read

## AUTHOR

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

Last changed: $Date: 2002/01/25 05:45:33 $