Accessibility is the ease with which larger cities can be reached from a certain location. This function allows to efficiently calculate accessibility statistics (i.e. travel time to nearby major cities) for polygons. For each polygon, the desired statistic/s (mean, median or sd) is/are returned. The required resources for this indicator are:
Details
The following arguments can be set:
- stats_accessibility
Function to be applied to compute statistics for polygons either one or multiple inputs as character. Supported statistics are: "mean", "median", "sd", "min", "max", "sum" "var".
- engine
The preferred processing functions from either one of "zonal", "extract" or "exactextract" as character.
Examples
library(sf)
library(mapme.biodiversity)
temp_loc <- file.path(tempdir(), "mapme.biodiversity")
if (!file.exists(temp_loc)) {
dir.create(temp_loc)
resource_dir <- system.file("res", package = "mapme.biodiversity")
file.copy(resource_dir, temp_loc, recursive = TRUE)
}
(try(aoi <- system.file("extdata", "sierra_de_neiba_478140_2.gpkg",
package = "mapme.biodiversity"
) %>%
read_sf() %>%
init_portfolio(
years = 2022,
outdir = file.path(temp_loc, "res"),
tmpdir = tempdir(),
add_resources = FALSE,
verbose = FALSE
) %>%
get_resources("nelson_et_al",
range_traveltime = c("5k_10k", "100k_200k", "500k_1mio", "1mio_5mio")
) %>%
calc_indicators("traveltime", stats_accessibility = c("min", "max"), engine = "extract") %>%
tidyr::unnest(traveltime)))
#> Simple feature collection with 4 features and 8 fields
#> Geometry type: POLYGON
#> Dimension: XY
#> Bounding box: xmin: -71.80933 ymin: 18.57668 xmax: -71.33201 ymax: 18.69931
#> Geodetic CRS: WGS 84
#> # A tibble: 4 × 9
#> WDPAID NAME DESIG_ENG ISO3 assetid minutes_min minutes_max distance
#> <dbl> <chr> <chr> <chr> <int> <dbl> <dbl> <chr>
#> 1 478140 Sierra de Nei… National… DOM 1 35 348 5k_10k
#> 2 478140 Sierra de Nei… National… DOM 1 162 528 100k_20…
#> 3 478140 Sierra de Nei… National… DOM 1 239 553 500k_1m…
#> 4 478140 Sierra de Nei… National… DOM 1 106 464 1mio_5m…
#> # ℹ 1 more variable: geom <POLYGON [°]>