Raster refers to a type of spatial data used by a GIS that consists of rows and columns of rectangular cells. Each cell contains values or attributes for that particular theme or layer. For example, if the theme is elevation, then the attributes will contain elevations in meters or feet. FARSITE uses raster data as inputs for all spatial data on topography, fuels, and crown structure. FARSITE can also export fire behavior information as raster themes for use in a GIS.
FARSITE can import GRASS ASCII or ARC/GRID ASCII format raster GIS files. All raster files must be of identical resolution, must overlap exactly, and all be the same type (e.g. GRASS or GRID and not mixed for a given Landscape (.LCP) File).
Be sure that the values in each raster map have the correct units or correspond to the requirements for each theme.
All GIS raster files must have a header to be imported into FARSITE. If you are unsure, examine the first 6 lines of one of your raster files. You should see one of the following formats. ARC/GRID ASCII and GRASS ASCII raster files have different headers:
|
ARC |
GRASS |
|
NCOLS |
north: |
|
NROWS |
south: |
|
XLLCORNER |
east: |
|
YLLCORNER |
west: |
|
CELLSIZE |
rows: |
|
NODATA_VALUE |
cols: |
All of the raster files FARSITE exports are ASCII format, not binary.