Return the data source watersurfaces_hab as a list of two objects

Source: R/read_habitatdata.R

read_watersurfaces_hab returns the data source watersurfaces_hab as a list of two objects:

  • watersurfaces_polygons: an sf object in the Belgian Lambert 72 CRS (EPSG-code 31370) with all polygons that contain standing water types (habitat or RIB).

  • watersurfaces_types: a tibble with information on the standing water types (HAB1, HAB2,..., HAB5) that occur within each polygon of watersurfaces_polygons.

read_watersurfaces_hab(
  file = file.path(locate_n2khab_data(),
    "20_processed/watersurfaces_hab/watersurfaces_hab.gpkg"),
  collapse = TRUE,
  version = c("watersurfaces_hab_v7", "watersurfaces_hab_v6", "watersurfaces_hab_v5",
    "watersurfaces_hab_v4", "watersurfaces_hab_v3", "watersurfaces_hab_v2",
    "watersurfaces_hab_v1", "watersurfaces_hab_v6.1_interim")
)

Arguments

file

The absolute or relative file path of the data source. The default follows the data management advice in the vignette on data storage (run vignette("v020_datastorage")). It uses the first n2khab_data folder that is found when sequentially climbing up 0 to 10 levels in the file system hierarchy, starting from the working directory.
collapse

Logical. Ignored since watersurfaces_hab_v7. From that version on, the 'collapse' step is part of the workflow to create the data source. The argument answers: should the resulting watersurfaces_types list element have a single row for each combination of polygon_id and type? This causes collapsing:

  • as a single string of different values of code_orig that led to the same type;

  • of values of certain, using the any summary function.
version

Version ID of the data source. Defaults to the latest available version defined by the package. Versions with the 'interim' suffix are designed to be used within the Research Institute for Nature and Forest (INBO) only.

Value

A list of two objects:

  • watersurfaces_polygons: an sf object of standing water polygons with four attribute variables:

    • polygon_id

    • polygon_id_ws: id for the polygon in the watersurfaces data source

    • polygon_id_habitatmap: id's of all overlapping polygons of habitatmap_stdized that contain standing water habitat. The different id's are separated by '+'.

    • description_orig: descriptions of all overlapping polygons of habitatmap_stdized that contain standing water habitat. The different descriptions are separated by '+'.

    • year_assessment: the year when the types in the polygon have been assessed. This column only appears since data source version watersurfaces_hab_v7.

    • method_assessment: the method used to assess the types in the polygon. This column only appears since data source version watersurfaces_hab_v7.

  • watersurfaces_types: a tibble with following variables:

    • polygon_id

    • type: habitat or RIB type listed in types.

    • certain: TRUE when the type is certain and FALSE when the type is uncertain.

    • code_orig: original type code in raw habitatmap.

Details

The data source watersurfaces_hab is a combination of habitatmap_stdized (see read_habitatmap_stdized) and the watersurface map of Flanders. It contains all standing water types in Flanders.

The data source watersurfaces_hab is a GeoPackage, available at Zenodo, that contains:

  • watersurfaces_hab_polygons: a spatial layer with all polygons that contain standing water types listed in types.

  • watersurfaces_hab_types: a table in which every row corresponds with a combination of polygon and type.

The polygons with 2190_a habitat (dune slack ponds) are generated by selecting all watersurface polygons that overlap with dune habitat polygons (21xx) of the standardized habitat map.

For each of the other considered habitat types (31xx and rbbah) we select the watersurface polygons that overlap with the selected habitat type polygons of the standardized habitat map. We also select polygons of the standardized habitat map that contain standing water types but do not overlap with any watersurface polygon of the watersurface map.

The R-code for creating the watersurfaces_hab data source can be found in the n2khab-preprocessing repository.

References

  • Leyssen A., Scheers K., Packet J., Van Hecke F., Wils C. (2024). Watervlakken 2024: Polygonenkaart van stilstaand water in Vlaanderen. Uitgave 2024. Rapporten van het Instituut voor Natuur- en Bosonderzoek 2024 (52). Instituut voor Natuur en Bosonderzoek, Brussel. doi:10.21436/inbor.114075267 .

  • De Saeger S., De Bruyn A., Dhaluin P., Erens R., Guelinckx G., Hennebel D., Jacobs I., Kumpen M., Van Oost F., Cool R., Spanhove T., Leyssen A., Oosterlynck P., Van Dam G. & Wils C. (red.) (2025). Biologische Waarderingskaart en Natura 2000 Habitatkaart, uitgave 2025. Rapporten van het Instituut voor Natuur- en Bosonderzoek 2025 (38). Instituut voor Natuur- en Bosonderzoek, Brussel. doi:10.21436/inbor.129502912 .

See also

Other functions involved in processing the 'habitatmap' data source: read_habitatmap(), read_habitatmap_stdized(), read_habitatmap_terr(), read_watersurfaces_refpoints()

Other functions involved in processing the 'watersurfaces' data source: read_watersurfaces(), read_watersurfaces_refpoints()

Examples

if (FALSE) {
# This example supposes that your working directory or a directory up to 10
# levels above has the 'n2khab_data' folder AND that the latest version of
# the 'watersurfaces_hab'
# data source is present in the default subdirectory.
# In all other cases, this example won't work but at least you can
# consider what to do.

wsh <- read_watersurfaces_hab()
wsh_polygons <- wsh$watersurfaces_polygons
wsh_types <- wsh$watersurfaces_types
wsh_polygons
wsh_types
}