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AREA_SD (class level)

Source: R/lsm_c_area_sd.R
lsm_c_area_sd.Rd

Standard deviation of patch area (Area and edge metric)

Usage

lsm_c_area_sd(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

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

AREA_SD is an 'Area and Edge metric'. The metric summarises each class as the standard deviation of all patch areas belonging to class i. The metric describes the differences among patches of the same class i in the landscape.

Because the metric is based on distances or areas please make sure your data is valid using check_landscape.

Units

Hectares

Range

AREA_SD >= 0

Behaviour

Equals AREA_SD = 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

See also

lsm_p_area, sd
lsm_c_area_mn, lsm_c_area_cv,
lsm_l_area_mn, lsm_l_area_sd, lsm_l_area_cv

Examples

landscape <- terra::rast(landscapemetrics::landscape)
lsm_c_area_sd(landscape)
#> # A tibble: 3 × 6
#>   layer level class    id metric    value
#>   <int> <chr> <int> <int> <chr>     <dbl>
#> 1     1 class     1    NA area_sd 0.00319
#> 2     1 class     2    NA area_sd 0.00233
#> 3     1 class     3    NA area_sd 0.00679