pictures/imod_logo.png

iMOD User Manual version 5.2 (html)


9.14ASC-files

The format is relatively straight-forward: the first six lines indicate the reference of the grid, followed by the values listed in the order they would naturally appear (left-right, top-down). For example, consider a grid, shown to the left. This could be encoded into an ASCII grid file that would look like:

ESRI ASCII Format:

pictures/h1-h3/image60.png

Variable

Format

Description

#

-

Comments

Ncols

Integer

Numbers of columns

Nrows

Integer

Numbers of rows

Xllcorner

Real

The western (left) x-coordinate

Yllcorner

Real

The southern (bottom) y-coordinate

Cellsize

Real

The length of one side of a square cell

NODATA_
value

Real

The value that is regarded as “missing” or “not applicable”; this line is optional, but highly recommended as iMOD will expect this line to be declared

DataBlock

Integer
Real

Listing of the raster values for each cell, starting at the upper-left corner (north-west). These number are delimited using a single (or more) space(s) character(s).

Note: These ESRI ASCII rasters will be converted into IDF-files whenever they are read into iMOD. However, iMOD can export IDF-files into ESRI ASCII files again.