Calculate elevation statistics — elevation • mapme.biodiversity

This function allows to efficiently calculate elevation statistics for polygons. For each polygon, the desired statistic/s (mean, median or sd) is/are returned. The required resources for this indicator are:

nasa_srtm

Format

A tibble with a column for elevation statistics (in meters)

Details

The following arguments can be set:

stats_elevation: 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

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

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

aoi <- system.file("extdata", "sierra_de_neiba_478140_2.gpkg",
  package = "mapme.biodiversity"
) %>%
  read_sf() %>%
  init_portfolio(
    years = 2000:2020,
    outdir = outdir,
    tmpdir = tempdir(),
    add_resources = FALSE,
    verbose = FALSE
  ) %>%
  get_resources("nasa_srtm") %>%
  calc_indicators("elevation",
    stats_elevation = c("mean", "median", "sd", "var"), engine = "extract"
  ) %>%
  tidyr::unnest(elevation)

aoi
#> Simple feature collection with 1 feature and 9 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: 1 × 10
#>   WDPAID NAME            DESIG_ENG ISO3  assetid elevation_mean elevation_median
#>    <dbl> <chr>           <chr>     <chr>   <int>          <dbl>            <dbl>
#> 1 478140 Sierra de Neiba National… DOM         1          1704.             1702
#> # ℹ 3 more variables: elevation_sd <dbl>, elevation_var <dbl>,
#> #   geom <POLYGON [°]>
# }