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COHESION (landscape level)

Source: R/lsm_l_cohesion.R
lsm_l_cohesion.Rd

Patch Cohesion Index (Aggregation metric)

Usage

lsm_l_cohesion(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

$$COHESION = 1 - (\frac{\sum \limits_{i = 1}^{m} \sum \limits_{j = 1}^{n} p_{ij}} {\sum \limits_{i = 1}^{m} \sum \limits_{j = 1}^{n} p_{ij} \sqrt{a_{ij}}}) * (1 - \frac{1} {\sqrt{Z}}) ^ {-1} * 100$$ where \(p_{ij}\) is the perimeter in meters, \(a_{ij}\) is the area in square meters and \(Z\) is the number of cells.

COHESION is an 'Aggregation metric'.

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

Units

Percent

Ranges

Unknown

Behaviour

Unknown

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

Schumaker, N. H. 1996. Using landscape indices to predict habitat connectivity. Ecology, 77(4), 1210-1225.

See also

lsm_p_perim, lsm_p_area,
lsm_l_cohesion

Examples

landscape <- terra::rast(landscapemetrics::landscape)
lsm_l_cohesion(landscape)
#> # A tibble: 1 × 6
#>   layer level     class    id metric   value
#>   <int> <chr>     <int> <int> <chr>    <dbl>
#> 1     1 landscape    NA    NA cohesion  90.6