The data source watercourse_100mseg is derived from the raw data source 'watercourses'. It 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 with two spatial layers: watercourse_100mseg_lines: the line segments; watercourse_100mseg_points: the corresponding downstream endpoints ('downstream' as defined in watercourses). The coordinate reference system is 'Belge 72 / Belgian Lambert 72' (EPSG-code 31370). Both layers have the same number of rows, and 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. This version was derived from version 'watercourses_20200807' (Zenodo DOI) 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). See R and GRASS code in the GitHub repository 'n2khab-preprocessing' at commit 6b1d8f7 for the creation from the watercourses data source. A reading function to return the data source in a standardized way into the R environment is provided by the R-package n2khab.