| lsm_l_mesh {landscapemetrics} | R Documentation |
MESH (landscape level)
Description
Effective Mesh Size (Aggregation metric)
Usage
lsm_l_mesh(landscape, directions = 8)
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). |
Details
MESH = \frac{\sum \limits_{i = 1}^{m} \sum \limits_{j = 1}^{n} a_{ij} ^ 2}{A} * \frac{1} {10000}
where a_{ij} is the patch area in square meters and A is the
total landscape area in square meters.
The effective mesh size is an 'Aggregation metric'. Because each patch is squared
before the sum is calculated and the sum is standardized by the
total landscape area, MESH is a relative measure of patch structure. MESH is
perfectly, negatively correlated to lsm_l_division.
Because the metric is based on distances or areas please make sure your data
is valid using check_landscape.
Units
Hectares
Range
cell size / total area <= MESH <= total area
Behaviour
Equals cellsize/total area if class covers only one cell and equals total area if only one patch is present.
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
Jaeger, J. A. 2000. Landscape division, splitting index, and effective mesh size: new measures of landscape fragmentation. Landscape ecology, 15(2), 115-130.
See Also
lsm_p_area,
lsm_l_ta,
lsm_c_mesh
Examples
landscape <- terra::rast(landscapemetrics::landscape)
lsm_l_mesh(landscape)