Data Structure and Schema

GRAIN Attributes

The GRAIN Dataset is distributed as country-scale files in two formats, a lightweight GeoParquet format and as ESRI Shapefiles, to ensure compatibility with legacy GIS software. All files are projected to EPSG:4326 based on the WGS-84 datum as per standard geospatial data convention. The attribute scheme for each GRAIN canal is given in the table below.

Field	Type	Unit	Description
grain_id	String	–	Unique identifier – format: ISO3_PfafstetterL6ID_seq.numbering.
osm_id	String	–	OpenStreetMap feature ID.
country	String	–	Country where the canal segment is located.
continent	String	–	Continent in which the canal lies.
country_iso	String	–	ISO-3 country code.
length_KM	Float	km	Canal path length.
slope_mkm	Float	m km⁻¹	Longitudinal slope derived from SRTM DEM.
elev_diff_M	Float	m	Elevation difference between start and end points.
predicted_class	String	–	ML-classified label ("canal" or "river").
confidence	Float	–	Prediction confidence of ML classifier (0–1).
osm_label	String	–	Original OSM waterway label.
osm_name	String	–	Canal name from OSM (if available).
alt_name	String	–	Alternate canal name detected from OSM tags.
tags	String	–	Raw OSM tags (JSON string).
canal_use	String	–	Canal use class (e.g., Agricultural, Urban, Navigation).
koppen_class_code	String	–	Köppen–Geiger climate-zone code.
update_date	String	–	Date of dataset creation or latest update.
version	String	–	GRAIN dataset release version number.