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Coefficient of variation of patch area (Area and edge metric)

Usage

lsm_c_area_cv(landscape, directions = 8)

Arguments

landscape

A categorical raster object: SpatRaster; Raster* Layer, Stack, Brick; stars or a list of SpatRasters

directions

The number of directions in which patches should be connected: 4 (rook's case) or 8 (queen's case).

Value

tibble

Details

$$AREA_{CV} = cv(AREA[patch_{ij}])$$ where \(AREA[patch_{ij}]\) is the area of each patch in hectares.

AREA_CV is an 'Area and Edge metric'. The metric summarises each class as the Coefficient of variation of all patch areas belonging to class i. The metric describes the differences among patches of the same class i in the landscape and is easily comparable because it is scaled to the mean.

Units

Hectares

Range

AREA_CV >= 0

Behaviour

Equals AREA_CV = 0 if all patches are identical in size. Increases, without limit, as the variation of patch areas increases.

References

McGarigal K., SA Cushman, and E Ene. 2023. FRAGSTATS v4: Spatial Pattern Analysis Program for Categorical Maps. Computer software program produced by the authors; available at the following web site: https://www.fragstats.org

Examples

landscape <- terra::rast(landscapemetrics::landscape)
lsm_c_area_cv(landscape)
#> # A tibble: 3 × 6
#>   layer level class    id metric  value
#>   <int> <chr> <int> <int> <chr>   <dbl>
#> 1     1 class     1    NA area_cv 156. 
#> 2     1 class     2    NA area_cv 130. 
#> 3     1 class     3    NA area_cv  84.6