TE (class level)

Total (class) edge (Area and Edge metric)

Usage

lsm_c_te(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: Include landscape boundary in edge length
directions: The number of directions in which patches should be connected: 4 (rook's case) or 8 (queen's case).

Value

tibble

Details

$$TE = \sum \limits_{k = 1}^{m} e_{ik}$$ where $e_{ik}$ is the edge lengths in meters. TE is an 'Area and edge metric'. Total (class) edge includes all edges between class i and all other classes k. It measures the configuration of the landscape because a highly fragmented landscape will have many edges. However, total edge is an absolute measure, making comparisons among landscapes with different total areas difficult. If count_boundary = TRUE also edges to the landscape boundary are included.

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

Units

Meters

Range

TE >= 0

Behaviour

Equals TE = 0 if all cells are edge cells. Increases, without limit, as landscape becomes more fragmented

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_te(landscape)
#> # A tibble: 3 × 6
#>   layer level class    id metric value
#>   <int> <chr> <int> <int> <chr>  <dbl>
#> 1     1 class     1    NA te       181
#> 2     1 class     2    NA te       203
#> 3     1 class     3    NA te       296