Edge Density (Area and Edge metric)
Usage
lsm_c_ed(landscape, count_boundary = FALSE, directions = 8)
Arguments
- landscape
A categorical raster object: SpatRaster; Raster* Layer, Stack, Brick; stars or a list of SpatRasters.
- count_boundary
Count landscape boundary as edge.
- directions
The number of directions in which patches should be connected: 4 (rook's case) or 8 (queen's case).
Details
$$ED = \frac{\sum \limits_{k = 1}^{m} e_{ik}} {A} * 10000$$
where \(e_{ik}\) is the total edge length in meters and \(A\) is the total
landscape area in square meters.
ED is an 'Area and Edge metric'. The edge density equals the sum of all edges of class i
in relation to the landscape area. The boundary of the landscape is only included in the
corresponding total class edge length if count_boundary = TRUE.
The metric describes the configuration of the landscape, e.g. because an aggregation
of the same class will result in a low edge density. The metric is standardized to the
total landscape area, and therefore comparisons among landscapes with different total
areas are possible.
Because the metric is based on distances or areas please make sure your data
is valid using check_landscape.
Behaviour
Equals ED = 0 if only one patch is present (and the landscape
boundary is not included) and increases, without limit, as the landscapes becomes more
patchy
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
Examples
landscape <- terra::rast(landscapemetrics::landscape)
lsm_c_ed(landscape)
#> # A tibble: 3 × 6
#> layer level class id metric value
#> <int> <chr> <int> <int> <chr> <dbl>
#> 1 1 class 1 NA ed 2011.
#> 2 1 class 2 NA ed 2256.
#> 3 1 class 3 NA ed 3289.
