Landscape division index (Aggregation metric)
lsm_c_division(landscape, directions = 8)tibble
Raster* Layer, Stack, Brick, SpatRaster (terra), stars, or a list of rasterLayers.
The number of directions in which patches should be connected: 4 (rook's case) or 8 (queen's case).
$$DIVISON = (1 - \sum \limits_{j = 1}^{n} (\frac{a_{ij}} {A}) ^ 2)$$ where \(a_{ij}\) is the area in square meters and \(A\) is the total landscape area in square meters.
DIVISION is an 'Aggregation metric. It can be in as the probability that two
randomly selected cells are not located in the same patch of class i. The landscape
division index is negatively correlated with the effective mesh size (lsm_c_mesh).
Proportion
0 <= Division < 1
Equals DIVISION = 0 if only one patch is present. Approaches DIVISION = 1 if all patches of class i are single cells.
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: https://www.umass.edu/landeco/
Jaeger, J. A. 2000. Landscape division, splitting index, and effective mesh size: new measures of landscape fragmentation. Landscape ecology, 15(2), 115-130.
lsm_p_area,
lsm_l_ta,
lsm_l_division