landscapemetrics (version 1.4.4)

lsm_c_cohesion: COHESION (class level)

Description

Patch Cohesion Index (Aggregation metric)

Usage

lsm_c_cohesion(landscape, directions)
# S3 method for RasterLayer
lsm_c_cohesion(landscape, directions = 8)
# S3 method for RasterStack
lsm_c_cohesion(landscape, directions = 8)
# S3 method for RasterBrick
lsm_c_cohesion(landscape, directions = 8)
# S3 method for stars
lsm_c_cohesion(landscape, directions = 8)
# S3 method for list
lsm_c_cohesion(landscape, directions = 8)

Arguments

landscape

Raster* Layer, Stack, Brick 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).

Value

tibble

Details

$$COHESION = 1 - (\frac{\sum \limits_{j = 1}^{n} p_{ij}} {\sum \limits_{j = 1}^{n} p_{ij} \sqrt{a_{ij}}}) * (1 - \frac{1} {\sqrt{Z}}) ^ {-1} * 100$$ 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'. 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.

Units

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.

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.

See Also

lsm_p_perim, lsm_p_area, lsm_l_cohesion

Examples

# NOT RUN {
lsm_c_cohesion(landscape)

# }