Calculate habitat connectivity — sf_habitat

Performs complete habitat connectivity analysis using vector-based spatial operations. Buffers habitat, fragments it along barriers, and calculates areas of connected patches.

Usage

sf_habitat_connectivity(
  habitat,
  barrier,
  species,
  interpatch_distance = NULL,
  buffer_radius = NULL
)

Arguments

habitat: SF object. Original habitat spatial data.
barrier: SF object. Barrier spatial data (e.g., roads, waterways).
species: character. Species name.
interpatch_distance: Numeric. The distance (in meters) where habitat patches are considered connected. E.g., if set to 500, patches 498m apart are connected, those 501m apart are not connected. This is passed internally to a spatial operation known as "buffering", where this distance is used as a radius from the edge of the habitat zone. This means the specified interpatch_distance is halved exactly. So an interpatch distance of 500 will be converted to 250. Note that interpatch_distance is mutually exclusive to habitat_buffer, so you can only specify either interpatch_distance or habitat_buffer, and never both.
buffer_radius: Numeric. The radius in metres around the habitat. Since patches of habitat will be connected when their edge-to-edge gap is <= 2 * buffer radius, we recommend you specify buffer_radius to be half the "interpatch distance". This is the distance past which habitat patches are no longer considered connected. For example, if your interpatch distance is 500m, set buffer_radius = 250. Note that interpatch_distance is mutually exclusive to habitat_buffer, so you can only specify either interpatch_distance or habitat_buffer, and never both.

Value

Data frame with connectivity metrics for each connected patch, including patch_id, area, and area_squared.

Examples

lizard_barrier_shp <- example_barrier_shp()
#> Reading layer `lizard_barrier' from data source 
#>   `/home/runner/work/_temp/Library/urbioconnect/ex/lizard_barrier.shp' 
#>   using driver `ESRI Shapefile'
#> Simple feature collection with 1 feature and 1 field
#> Geometry type: MULTIPOLYGON
#> Dimension:     XY
#> Bounding box:  xmin: 326089.6 ymin: 5820342 xmax: 327662.5 ymax: 5821909
#> Projected CRS: GDA94 / MGA zone 55
lizard_habitat_sf <- terra::as.polygons(
  example_habitat(),
  dissolve = TRUE
  ) |>
  sf::st_as_sf()
result <- sf_habitat_connectivity(
  habitat = lizard_habitat_sf,
  barrier = lizard_barrier_shp,
  species = "Blue-tongued lizard",
  interpatch_distance = 10
  )
#> Warning: attribute variables are assumed to be spatially constant throughout all geometries
#> Warning: repeating attributes for all sub-geometries for which they may not be constant
result
#> # patch_connectivity:  data.frame
#> # Species:             Blue-tongued lizard
#> # Patches:             479
#> # Resolution:          NA
#> # Interpatch Distance: 10 m
#>   patch_id  area
#>      <dbl> <dbl>
#> 1        1 1536.
#> 2        2  287.
#> 3        3  292.
#> 4        4  851.
#> 5        5    8 
#> # ℹ 474 more rows