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SPLIT (landscape level)

Source: R/lsm_l_split.R
lsm_l_split.Rd

Splitting index (Aggregation metric)

Usage

lsm_l_split(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

$$SSPLIT = \frac{A^2} {\sum \limits_{i = 1}^{m} \sum \limits_{j = 1}^{n} a_{ij}^2}$$ where \(a_{ij}\) is the patch area in square meters and \(A\) is the total landscape area.

SPLIT is an 'Aggregation metric'. It describes the number of patches if all patches the landscape would be divided into equally sized patches.

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

Units

None

Range

1 <= SPLIT <= Number of cells squared

Behaviour

Equals SPLIT = 1 if only one patch is present. Increases as the number of patches increases and is limited if all cells are a patch

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

Jaeger, J. A. 2000. Landscape division, splitting index, and effective mesh size: new measures of landscape fragmentation. Landscape ecology, 15(2), 115-130.

See also

lsm_p_area, lsm_l_ta,
lsm_c_split

Examples

landscape <- terra::rast(landscapemetrics::landscape)
lsm_l_split(landscape)
#> # A tibble: 1 × 6
#>   layer level     class    id metric value
#>   <int> <chr>     <int> <int> <chr>  <dbl>
#> 1     1 landscape    NA    NA split   9.59