NAME
r.li.edgedensity - Calculates edge density index on a raster map, using a 4 neighbour algorithm
KEYWORDS
raster,
landscape structure analysis,
patch index
SYNOPSIS
r.li.edgedensity
r.li.edgedensity --help
r.li.edgedensity [-b] input=name config=name output=name [patch_type=string] [--overwrite] [--help] [--verbose] [--quiet] [--ui]
Flags:
- -b
- Exclude border edges
- --overwrite
- Allow output files to overwrite existing files
- --help
- Print usage summary
- --verbose
- Verbose module output
- --quiet
- Quiet module output
- --ui
- Force launching GUI dialog
Parameters:
- input=name [required]
- Name of input raster map
- config=name [required]
- Configuration file
- output=name [required]
- Name for output raster map
- patch_type=string
- The value of the patch type
- It can be integer, double or float; it will be changed in function of map type
r.li.edgedensity calculates:
- the density of all edges of patch type k
, or
- the density of all edges in the sampling area if k is
not specified,
with:
- k: patch type
- m: number of patch types
- n: number of edge segments of patch type k
- eik :total edge length in
the landscape involving patch type k
- Area: total landscape area
The unit is meters per hectare.
Do not use absolute path names for the
config and
output
file/map parameters.
If the "moving window" method was selected in
g.gui.rlisetup, then the
output will be a raster map, otherwise an ASCII file will be generated in
the folder
C:\Users\userxy\AppData\Roaming\GRASS8\r.li\output\
(MS-Windows) or
$HOME/.grass8/r.li/output/ (GNU/Linux).
If the input raster map contains only NULL values then r.li.edgedensity
consider to have 0 patches.
If area is 0 r.li.edgedensity returns NULL; this is only possible if input
raster is masked.
To calculate the edge density index on map
my_map, using
my_conf configuration file (previously defined with
g.gui.rlisetup) and saving results in
my_out, run:
r.li.edgedensity input=my_map conf=my_conf output=my_out
To calculate edge density index of patch_type 34, using
"my_conf" configuration file and on map "my_map", saving results in "my_out"
file run:
r.li.edgedensity input=my_map conf=my_conf output=my_out patch_type=34
Forest map (Spearfish sample dataset) example:
g.region raster=landcover.30m -p
r.mapcalc "forests = if(landcover.30m >= 41 && landcover.30m <= 43,1,null())"
r.li.edgedensity input=forests conf=movwindow7 out=forests_edgedens_mov7
r.univar forests_edgedens_mov7
Forest map (North Carolina sample dataset) example:
g.region raster=landclass96 -p
r.mapcalc "forests = if(landclass96 == 5, 1, null() )"
r.li.edgedensity input=forests conf=movwindow7 out=forests_edgedensity_mov7
# verify
r.univar forests_edgedensity_mov7
r.to.vect input=forests output=forests type=area
d.mon wx0
d.rast forests_edgedensity_mov7
d.vect forests type=boundary
r.li - package overview,
g.gui.rlisetup
McGarigal, K., and B. J. Marks. 1995. FRAGSTATS: spatial pattern
analysis program for quantifying landscape structure. USDA For. Serv.
Gen. Tech. Rep. PNW-351. (
PDF)
Serena Pallecchi student of Computer Science University of Pisa (Italy).
Commission from Faunalia Pontedera (PI), Italy (www.faunalia.it)
Markus Metz
SOURCE CODE
Available at:
r.li.edgedensity source code
(history)
Latest change: Friday Nov 29 00:12:28 2024 in commit: 89e8c2c4defdebca6f0d968ac72d98d6238a73d6
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GRASS Development Team,
GRASS GIS 8.4.1dev Reference Manual