mapme.biodiversity (version 0.9.3)

gsw_occurrence: Calculate Global Surface Water (GSW) Occurrence

Description

GSW occurrence raw data comes in raster files with integer cell values between [0, 100]. This value gives the percentage of the time that a given pixel was classified as water during the entire observation period. So a 0 denotes a pixel that was never classified as water, 100 denotes a pixel with permanent water.

Usage

calc_gsw_occurrence(engine = "extract", min_occurrence = NULL)

Value

A function that returns an indicator tibble with occurrence as variable and the corresponding area (in ha) as value.

Arguments

engine

The preferred processing functions from either one of "zonal", "extract" or "exactextract". Default: "extract".

min_occurrence

Threshold to define which pixels count towards the GSW occurrence area [0, 100].

Details

The raw data values are aggregated based on a provided threshold parameter min_occurrence, the function returns the area covered by values greater or equal than this threshold.

The required resources for this indicator are:

• global_surface_water_occurrence

Examples

# \dontshow{
mapme.biodiversity:::.copy_resource_dir(file.path(tempdir(), "mapme-data"))
# }
if (FALSE) {
library(sf)
library(mapme.biodiversity)

outdir <- file.path(tempdir(), "mapme-data")
dir.create(outdir, showWarnings = FALSE)

mapme_options(
  outdir = outdir,
  verbose = FALSE
)

aoi <- system.file("extdata", "shell_beach_protected_area_41057_B.gpkg",
  package = "mapme.biodiversity"
) %>%
  read_sf() %>%
  get_resources(get_global_surface_water_occurrence()) %>%
  calc_indicators(
    calc_gsw_occurrence(engine = "extract", min_occurrence = 10)
  ) %>%
  portfolio_long()

aoi
}