landscapemetrics (version 1.4.4)

lsm_l_ai: AI (landscape level)

Description

Aggregation index (Aggregation metric)

Usage

lsm_l_ai(landscape)
# S3 method for RasterLayer
lsm_l_ai(landscape)
# S3 method for RasterStack
lsm_l_ai(landscape)
# S3 method for RasterBrick
lsm_l_ai(landscape)
# S3 method for stars
lsm_l_ai(landscape)
# S3 method for list
lsm_l_ai(landscape)

Arguments

landscape

Raster* Layer, Stack, Brick or a list of rasterLayers

Value

tibble

Details

$$AI = \Bigg[\sum\limits_{i=1}^m \Big( \frac{g_{ii}}{max-g_{ii}} \Big) P_{i} \Bigg](100) $$

where \(g_{ii}\) is the number of like adjacencies based on the single-count method and \(max-g_{ii}\) is the classwise maximum number of like adjacencies of class i and \(P_{i}\) the proportion of landscape compromised of class i.

AI is an 'Aggregation metric'. It equals the number of like adjacencies divided by the theoretical maximum possible number of like adjacencies for that class summed over each class for the entire landscape. The metric is based on he adjacency matrix and the the single-count method.

Units

Percent

Range

0 <= AI <= 100

Behaviour

Equals 0 for maximally disaggregated and 100 for maximally aggregated classes.

References

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: http://www.umass.edu/landeco/research/fragstats/fragstats.html

He, H. S., DeZonia, B. E., & Mladenoff, D. J. 2000. An aggregation index (AI) to quantify spatial patterns of landscapes. Landscape ecology, 15(7), 591-601.

See Also

lsm_c_ai

Examples

# NOT RUN {
lsm_l_ai(landscape)

# }