AREA (patch level)

Patch area (Area and edge metric)

Usage

vm_p_area(landscape, class_col = NULL, patch_col = NULL)

Arguments

landscape

sf* object.

class_col

the name of the class column of the input landscape

patch_col

the name of the id column of the input landscape

Value

the function returns tibble with the calculated values in column "value", this function returns also some important information such as level, class, patch id and metric name.

Details

$$AREA = a_{ij} * (\frac{1} {10000})$$ where \(a_{ij}\) is the area in square meters.

AREA is an 'Area and edge metric' and equals the area of each patch in hectares. The lower limit of AREA is limited by the resolution of the input raster, i.e. AREA can't be smaller than the resolution squared (in hectares). It is one of the most basic, but also most important metrics, to characterise a landscape. The metric is the simplest measure of composition.

Units

Hectares

Range

AREA > 0

Behaviour

Increases, without limit, as the patch size increases.

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

Examples

vm_p_area(vector_patches, "class", "patch")
#> # A tibble: 40 × 5
#>    level class id    metric  value
#>    <chr> <chr> <chr> <chr>   <dbl>
#>  1 patch 1     11    area   0.0026
#>  2 patch 1     12    area   0.0038
#>  3 patch 1     13    area   0.002 
#>  4 patch 1     14    area   0.0004
#>  5 patch 1     15    area   0.0001
#>  6 patch 1     16    area   0.0001
#>  7 patch 1     17    area   0.0001
#>  8 patch 1     18    area   0.0006
#>  9 patch 1     19    area   0.0001
#> 10 patch 1     20    area   0.0001
#> # ℹ 30 more rows