grainscape (version 1.0.0)

grainscape-maps: Test maps included with grainscape

Description

Simple, artificial land cover maps intended for users to explore the functionality of the package. Each map has discrete integer land cover classes representing distinct land cover types. Typical analyses begin by reclassifying these to reflect resistance to movement (see the examples below and the package vignette).

Format

Three ESRI ArcASCII (.asc) raster grids stored in extdata and read with terra::rast(): patchy.asc and fragmented.asc are 400 x 400 cells, tiny.asc is 100 x 100 cells. Cell values are integer land cover classes (1-5 for patchy.asc, 1-4 for fragmented.asc and tiny.asc), with no associated coordinate reference system.

Details

The maps are distributed as ESRI ArcASCII (.asc) grids in the package's extdata directory and are read with terra::rast(). They use an arbitrary unprojected coordinate system (no CRS) with a unit cell size.

patchy.asc

A caricatured map of five land cover classes (integer values 1-5), where patches are large, easy to identify polygonal regions for heuristic purposes. This unrealistic map can be used to illustrate the method and understand how it works. The map also serves a similar heuristic purpose in a review of graph-based connectivity methods (Galpern et al., 2011). (400 x 400 raster cells.)

fragmented.asc

A simulated land cover map with four land cover classes (integer values 1-4), produced using an algorithm that generates fragmentation. (400 x 400 raster cells.)

tiny.asc

Similar to fragmented.asc (four land cover classes, integer values 1-4) but smaller in extent for lightning-fast computation and experimental use. (100 x 100 raster cells.)

Examples

## load a bundled map and reclassify it into a resistance surface
patchy <- terra::rast(
  system.file("extdata", "patchy.asc", package = "grainscape", mustWork = TRUE)
)
patchyCost <- terra::classify(patchy, rcl = cbind(1:5, c(1, 10, 8, 3, 6)))
terra::plot(patchyCost)