r.li.edgedensity1grass
Calculates edge density index on a raster map, using a 4 neighbour algorithm
Usage
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]
Keywords
raster, landscape structure analysis, patch index
Overview
r.li.edgedensity calculates:
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the density of all edges of patch type k , or |
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the density of all edges in the sampling area if k is not specified, |
with:
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eik :total edge length in the landscape involving patch type k |
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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_outTo 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=34Forest map (Spearfish sample dataset) example:
g.region raster=landcover.30m -pr.mapcalc "forests = if(landcover.30m >= 41 && landcover.30m <= 43,1,null())"r.li.edgedensity input=forests conf=movwindow7 out=forests_edgedens_mov7r.univar forests_edgedens_mov7
Forest map (North Carolina sample dataset) example:
g.region raster=landclass96 -pr.mapcalc "forests = if(landclass96 == 5, 1, null() )"r.li.edgedensity input=forests conf=movwindow7 out=forests_edgedensity_mov7# verifyr.univar forests_edgedensity_mov7r.to.vect input=forests output=forests type=aread.mon wx0d.rast forests_edgedensity_mov7d.vect forests type=boundary
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)
Source code
Available at: r.li.edgedensity source code (history)
Accessed: Monday Feb 24 17:50:42 2025
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Releases
8 releases since Debian 6.0 (Squeeze); the text changed 7 times.