# lsm_c_cohesion: COHESION (class level) In landscapemetrics: Landscape Metrics for Categorical Map Patterns

## Description

Patch Cohesion Index (Aggregation metric)

## Usage

 1 lsm_c_cohesion(landscape, directions = 8) 

## Arguments

 landscape Raster* Layer, Stack, Brick, SpatRaster (terra), stars, or a list of rasterLayers. directions The number of directions in which patches should be connected: 4 (rook's case) or 8 (queen's case).

## Details

COHESION = 1 - (\frac{∑ \limits_{j = 1}^{n} p_{ij}} {∑ \limits_{j = 1}^{n} p_{ij} √{a_{ij}}}) * (1 - \frac{1} {√{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'. It characterises the connectedness of patches belonging to class i. It can be used to asses if patches of the same class are located aggregated or rather isolated and thereby COHESION gives information about the configuration of the landscape.

Percent

#### Ranges

0 < COHESION < 100

#### Behaviour

Approaches COHESION = 0 if patches of class i become more isolated. Increases if patches of class i become more aggregated.

tibble

## References

McGarigal, K., SA Cushman, and E Ene. 2012. FRAGSTATS v4: Spatial Pattern Analysis Program for Categorical and Continuous Maps. Computer software program produced by the authors at the University of Massachusetts, Amherst. Available at the following web site: http://www.umass.edu/landeco/research/fragstats/fragstats.html

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

lsm_p_perim, lsm_p_area,
lsm_l_cohesion
 1 lsm_c_cohesion(landscape)