r.li.edgedensity.1grass - Man Page
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
Description
- 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.
Notes
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.
Examples
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
See Also
r.li - package overview
g.gui.rlisetup
References
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)
Authors
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)
Accessed: Tuesday Mar 19 11:02:00 2024
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