watercourse_100mseg
R/read_watercourses.R
read_watercourse_100mseg.Rd
Returns the data source watercourse_100mseg
as a list of two sf
objects:
lines
(LINESTRING
geometry): represents
line segments of length 100 m derived from the raw watercourses
data source;
points
(POINT
geometry):
represents the downstream
endpoints of all segments ('downstream' as defined in watercourses
).
Optionally, only one of these objects is returned. The coordinate reference system is 'BD72 / Belgian Lambert 72' (EPSG-code 31370).
read_watercourse_100mseg( file = file.path(locate_n2khab_data(), "20_processed/watercourse_100mseg/watercourse_100mseg.gpkg"), element = NULL, version = "watercourse_100mseg_20200807v1" )
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 |
---|---|
element | Optional string.
The string must be one of two possible values: |
version | Version ID of the data source. Defaults to the latest available version defined by the package. |
By default, a list of two sf
objects (see 'Description').
The lines
and the points
objects have the same number of
rows.
They share the same attributes:
rank
A unique, incremental number for each segment/endpoint. It just reflects the downstream-to-upstream order of segments within each original line.
vhag_code
The VHAG code from the raw watercourses
data
source.
It distinguishes the different watercourses, so it is common to all
segments/points that belong to the same watercourse.
Optionally, only one of these sf
objects is returned.
The data source watercourse_100mseg
represents all officially known
watercourses
of the Flemish Region as line segments of 100 m (or < 100 m, for the most
upstream segment of a watercourse).
The data source can be used as a base layer of statistical
population units (line segments) and corresponding anchor points,
in the design of monitoring and research of watercourses.
The data source is a GeoPackage, available at Zenodo, and contains two spatial layers:
watercourse_100mseg_lines
: the line segments;
watercourse_100mseg_points
: the corresponding downstream
endpoints.
Both layers have the same number of rows and share the same attributes.
The data source was derived from the raw
watercourses
data
source as follows:
each line ('watercourse') of watercourses
is split into
segments of 100 m, where
the remaining segment of < 100 m (per original line) is situated most
upstream.
For this step, the direction of the lines has been reverted (in
watercourses
the direction is from upstream to downstream).
A unique rank number is assigned to each segment, as well as the
VHAG code from the corresponding line in watercourses
.
the downstream endpoint of each segment is located, and assigned the
same attributes (rank
and vhag_code
).
The R and GRASS code for creating the watercourse_100mseg
data source
can be found in the
n2khab-preprocessing
repository.
Other functions returning environmental data sets:
read_shallowgroundwater()
,
read_soilmap()
,
read_watersurfaces()
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 # 'watercourse_100mseg' 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. (lines <- read_watercourse_100mseg(element = "lines")) (points <- read_watercourse_100mseg(element = "points")) str(read_watercourse_100mseg(), give.attr = FALSE) }