lsm_c_tca: TCA (class level)

In r-spatialecology/landscapemetrics: Landscape Metrics for Categorical Map Patterns

TCA (class level)

Description

Total core area (Core area metric)

Usage

lsm_c_tca(landscape, directions = 8, consider_boundary = FALSE, edge_depth = 1)

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).
consider_boundary	Logical if cells that only neighbour the landscape boundary should be considered as core
edge_depth	Distance (in cells) a cell has the be away from the patch edge to be considered as core cell

Details

TCA = \sum_{j = 1}^{n} a_{ij}^{core} * (\frac{1} {10000})

where here a_{ij}^{core} is the core area in square meters.

TCA is a 'Core area metric' and equals the sum of core areas of all patches belonging to class i. A cell is defined as core area if the cell has no neighbour with a different value than itself (rook's case). In other words, the core area of a patch is all area that is not an edge. It characterises patch areas and shapes of patches belonging to class i simultaneously (more core area when the patch is large and the shape is rather compact, i.e. a square). Additionally, TCA is a measure for the configuration of the landscape, because the sum of edges increase as patches are less aggregated.

Units

Hectares

Range

TCA >= 0

Behaviour

Increases, without limit, as patch areas increase and patch shapes simplify. TCA = 0 when every cell in every patch of class i is an edge.

Value

tibble

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

See Also

lsm_p_core, lsm_l_tca

Examples

landscape <- terra::rast(landscapemetrics::landscape)
lsm_c_tca(landscape)

r-spatialecology/landscapemetrics documentation built on April 3, 2024, 2:21 a.m.